TY - JOUR T1 - Proposal for Levels of Evidence Schema for Validation of a Soluble Biomarker Reflecting Damage Endpoints in Rheumatoid Arthritis, Psoriatic Arthritis, and Ankylosing Spondylitis, and Recommendations for Study Design JF - The Journal of Rheumatology JO - J Rheumatol SP - 1792 LP - 1799 DO - 10.3899/jrheum090347 VL - 36 IS - 8 AU - WALTER P. MAKSYMOWYCH AU - OLIVER FITZGERALD AU - GEORGE A. WELLS AU - DAFNA D. GLADMAN AU - ROBERT LANDEWÉ AU - MIKKEL ØSTERGAARD AU - WILLIAM J. TAYLOR AU - ROBIN CHRISTENSEN AU - PAUL-PETER TAK AU - MAARTEN BOERS AU - SILJE W. SYVERSEN AU - JOAN M. BATHON AU - CHRISTOPHER J. RITCHLIN AU - PHILIP J. MEASE AU - VIVIEN P. BYKERK AU - PATRICK GARNERO AU - PIET GEUSENS AU - HANI EL-GABALAWY AU - DANIEL ALETAHA AU - ROBERT D. INMAN AU - VIRGINIA BYERS KRAUS AU - TORE K. KVIEN AU - DÉSIRÉE van der HEIJDE Y1 - 2009/08/01 UR - http://www.jrheum.org/content/36/8/1792.abstract N2 - Objective. At OMERACT 8 a framework for levels of evidence was proposed for the validation of biomarkers as surrogate outcome measures. We aimed to adapt this scheme in order to apply it in the setting of soluble biomarkers proposed to replace the measurement of damage endpoints in rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). We also aimed to generate consensus on minimum standards for the design of longitudinal studies aimed at validating biomarkers. Methods. Before the meeting, the Soluble Biomarker Working Group prepared a preliminary framework and discussed various models for association and prediction related to the statistical strength domain. In addition, 3 Delphi exercises addressing longitudinal study design for RA, PsA, and AS were conducted within the working group and members of the Assessments in SpondyloArthritis International Society (ASAS) and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). This formed the basis for discussions among OMERACT 9 participants. Results. The proposed framework was accepted by consensus. In the study design domain a requirement for both prospective observational studies and randomized controlled trials (RCT) in different drug classes was noted. A template for determining the level of statistical strength was proposed. The addition of a new domain on biomarker assay performance was considered essential, and participants suggested that for any biomarker this domain should be addressed first, i.e., before starting clinical validation studies. Participants agreed on most elements of a longitudinal study design template. Where consensus was lacking the working group has drafted solutions that constitute a basis for prospective validation studies. Conclusion. The OMERACT 9 Soluble Biomarker Group has successfully formulated a levels of evidence scheme and a study design template that will provide guidance to conduct validation studies in the setting of soluble biomarkers proposed to replace the measurement of damage endpoints in RA, PsA, and AS. ER -