Use and detailed metric properties of patient-reported outcome measures for rheumatoid arthritis: a systematic review covering two decades

Introduction The importance of patient-reported outcome measures (PROMs) for rheumatoid arthritis (RA) clinical studies has been recognised for many years. The current study aims to describe the RA PROMs used over the past 20 years, and their performance metrics, to underpin appropriate tool selection.

Methods The study included a systematic search for PROMs that have been in use over the period 2000–2019, with detailed documentation of their psychometric properties, and a user-friendly presentation of the extensive evidence base.

Results 125 PROMs were identified with psychometric evidence available. The domains of pain, fatigue, emotional functions, mobility, physical functioning and work dominated, with self-efficacy and coping as personal factors. Domains such as stiffness and sleep were poorly served. The most frequently used PROMs included the Health Assessment Questionnaire Disability Index (HAQ), the Short Form 36 (SF-36), the EuroQoL and the Modified HAQ which, between them, appeared in more than 3500 papers. Strong psychometric evidence was found for the HAQ, and the SF-36 Physical Functioning and Vitality (fatigue) domains. Otherwise, all domains except stiffness, sleep, education and health utility, had at least one PROM with moderate level of psychometric evidence.

Conclusion There is a broad range of PROMs for measuring RA outcomes, but the quality of psychometric evidence varies widely. This work identifies gaps in key RA domains according to the biopsychosocial model.