RT Journal Article
SR Electronic
T1 Measuring outcomes in psoriatic arthritis: comparing Routine Assessment of Patient Index Data (RAPID3) and Psoriatic Arthritis Impact of Disease (PSAID)
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.190219
DO 10.3899/jrheum.190219
A1 Jessica A.  Walsh
A1 Marilyn T.  Wan
A1 Christine Willinger
A1 M. Elaine  Husni
A1 Jose U.  Scher
A1 Soumya M.  Reddy
A1 Alexis Ogdie
YR 2019
UL http://www.jrheum.org/content/early/2019/09/25/jrheum.190219.abstract
AB Objective To examine the construct validity of Routine Assessment of Patient Index Data (RAPID3) and Psoriatic Arthritis Impact of Disease (PSAID) in patients with psoriatic arthritis (PsA). In examining construct validity, we also addressed scores among subgroups with severe psoriasis, polyarticular disease, enthesitis and dactylitis and evaluated influences of sociodemographic factors and comorbidities (contextual factors) on these patient-reported outcomes (PROs). Methods Patients with PsA were enrolled in the Psoriatic Arthritis Research Consortium (PARC) between 2014-2016. PARC is a longitudinal observational cohort study conducted at four United States institutions. In this cross-sectional study, construct validity was assessed by examining Spearman’s correlation coefficients for RAPID3 and PSAID with physician-reported disease activity measures and other PROs (e.g., Short Form 12 (SF12-PCS/-MCS), Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue). Contextual factors and disease subgroups were assessed in multivariable linear regression models with RAPID3 or PSAID12 as outcomes of interest and the hypothesized contextual factors as covariates. Results Among 401 patients enrolled in PARC, 347 completed RAPID3 or PSAID12. Of these, most were Caucasian females with a mean age of 51.74 (SD 14.02). RAPID3 and PSAID were highly correlated (r=0.90). These measures were also correlated with the SF12-PCS (r=-0.67) and FACIT-Fatigue (r=-0.77). Important contextual factors and disease subgroups included enthesitis, joint counts, education, insurance type, and depression. Conclusion RAPID3 and PSAID12 have excellent construct validity in PsA and are strongly correlated despite differing items. Contextual factors (i.e., the presence of depression and obesity) should be considered when interpreting raw scores of the RAPID3 and PSAID12.