Instruments Measuring Physical Function for Psoriatic Arthritis Endorsed at GRAPPA 2020 Annual Meeting: Updates of the GRAPPA-OMERACT Working Group

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.

As part of the supplement series GRAPPA 2020, this report was reviewed internally and approved by the Guest Editors for integrity, accuracy, and consistency with scientific and ethical standards. The authors are members of the Outcome Measures in Rheumatology (OMERACT), an organization that develops and validates outcome measures in rheumatology randomized controlled trials and longitudinal observational studies and receives arms-length funding from 36 sponsors. YYL is funded by the Clinician Scientist award of the National Medical Research Council, Singapore (NMRC/CSA-INV/0022/2017). The views expressed are those of the author(s) and not necessarily those of the NMRC. AMO is funded by the Jerome L. Greene Foundation Scholar Award, the Staurulakis Family Discovery Award, the Rheumatology Research Foundation, and the National Institutes of Health (NIH) through the Rheumatic Diseases Resource-based Core Center (P30-AR053503, Cores A and D; and P30-AR070254, Cores A and B). All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of the NIH, the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), or the Rheumatology Research Foundation (RRF). AO is funded by the Rheumatology Research Foundation and NIH/NIAMS K23 AR063764 and R01 AR072363. RC (the Parker Institute) is supported by a core grant from the Oak Foundation (OCAY-18-774-OFIL). AJM is funded by the National Psoriasis Foundation Psoriatic Disease Research Fellowship. LCC is funded by a National Institute of Health Research (NIHR) Research Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. Y.Y. Leung, MB ChB, MD, Associate Professor, Duke-NUS Medical School, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; A.M. Orbai, MD, MHS, Assistant Professor of Medicine, Director, Psoriatic Arthritis Program, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; W. Tillett, BSc, MB ChB, PhD, MRCP, Consultant Rheumatologist, Senior Lecturer, Royal National Hospital for Rheumatic Diseases, University of Bath, Bath, UK; A. Ogdie, MD, MSCE, Associate Professor of Medicine and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; L. Eder, MD, PhD, Women’s College Research Institute, Women’s College Hospital, Department of Medicine, University of Toronto, Toronto, Ontario, Canada; N. Goel, MD, Patient Research Partner, Consultant, Caduceus Biomedical Consulting, LLC, and Adjunct Assistant Professor, Duke University School of Medicine, Durham, North Carolina, USA; P. Hojgaard, MD, PhD, Department of Rheumatology, Holbaek Hospital, Holbaek, and the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; R. Holland, MBBS, Concord Repatriation General Hospital, Sydney, Australia; A.J. Mathew, MBBS, DNB, DM, Associate Professor in Rheumatology, Christian Medical College, Vellore, India and Clinical Research Fellow, Psoriatic Arthritis Program, University Health Network, University of Toronto, Toronto, Ontario, Canada; C.A. Lindsay, PharmD, Patient Research Partner, VP Professional and Advocacy Relations, Aurinia Pharma U.S., Inc., Rockville, Maryland, USA; A. Antony, MBBS, Monash University School of Clinical Sciences, Monash Medical Centre, Clayton, Melbourne, Australia; J. Chau, GRAPPA Patient Research Partner, Hong Kong; R. Christensen, BSc, MSc, PhD, Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, and Professor of Biostatistics and Clinical Epidemiology, Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark; L.C. Coates, MB ChB, PhD, Associate Professor, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK; P.J. Mease, MD, Rheumatology Research, Swedish Medical Center/Providence St. Joseph Health, and University of Washington School of Medicine, Seattle, Washington, USA; V. Strand, MD, Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA; O. FitzGerald, MD, FRCPI, FRCP(UK), Consultant Rheumatologist and Newman Clinical Research Professor, Conway Institute for Biomolecular Research, University College Dublin, Dublin, Ireland; M. de Wit, PhD, Patient Research Partner, Amsterdam, The Netherlands; K. Callis Duffin, MD, MS, Department of Dermatology, University of Utah, Salt Lake City, Utah, USA; D.D. Gladman, MD, FRCPC, Professor of Medicine, University of Toronto, Senior Scientist, Krembil Research Institute, and Director, Psoriatic Arthritis Program, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada. LE has been on advisory boards or received educational/research grants from Novartis, UCB, Eli Lily, Pfizer, and Janssen. There are no conflicts of interest from other co-authors. This paper does not require institutional review board approval. Address correspondence to Dr. Y.Y. Leung, Department of Rheumatology and Immunology, Singapore General Hospital, 20 College Road, The Academia, Singapore. Email: katyccc@hotmail.com.