Appraisal of candidate instruments for assessment of the physical function domain in patients with psoriatic arthritis

Objective. Numerous patient-reported outcome measures (PROM) exist for the measurement of physical function for psoriatic arthritis (PsA), but only a few are validated comprehensively. The objective of this project was to prioritize PROM for measuring physical function for potential incorporation into a standardized outcome measurement set for PsA. Methods. A working group of 13 members including 2 patient research partners was formed. PROM measuring physical function in PsA were identified through a systematic literature review and recommendations by the working group. The rationale for inclusion and exclusion from the original list of existing PROM was thoroughly discussed and 2 rounds of Delphi exercises were conducted to achieve consensus. Results. Twelve PROM were reviewed and discussed. Six PROM were prioritized: Health Assessment Questionnaire (HAQ) and 4 modifications (HAQ-Disability Index, HAQ-Spondyloarthritis, modified HAQ, multidimensional HAQ), Medical Outcomes Study 36-item Short Form survey physical functioning domain, and the Patient-Reported Outcomes Measurement Information System (PROMIS) physical functioning module. Conclusion. Through discussion and Delphi exercises, we achieved consensus to prioritize 6 physical function PROM for PsA. These 6 PROM will undergo further appraisal using the Outcome Measures in Rheumatology (OMERACT) Filter 2.1.