Validation studies of rheumatoid arthritis patient-reported outcome measures in populations at risk for inequity: a systematic review and analysis using the OMERACT summary of measurement properties equity table

Background: Existing patient-reported outcome measures (PROMs) in rheumatoid arthritis (RA) may be limited in their applicability to populations that are at risk for inequities. We conducted a systematic review to identify and rate evidence in the validation studies for PROMs in populations at risk for inequity. Methods: A systematic review of MEDLINE and EMBASE was completed. The search strategy was developed to identify measurement property studies for PROMs of interest (selected pain, disease activity, global evaluation and quality of life scales) in patients with RA. We identified experimental, observational, and qualitative studies reporting analysis of feasibility, construct validity and discriminant ability metrics for populations at risk for inequity by various factors including race, ethnicity, culture or language; employment status; sex and gender identity; education level; socioeconomic status; social support; age; health literacy and disability. These were rated based on the OMERACT Summary of Measurement Properties Equity table. Results: From 19,786 titles and abstracts screened, we identified 14 unique studies reporting validation metrics for pain (n = 3), DAS28-ESR or DAS28-CRP (n = 2), ACR20 (n = 1), patient global assessment (n = 2), EQ5D (n = 4), and PROMIS® (n = 3) by race (n = 10 studies), age (n = 6 studies), sex (n = 5 studies), education level (n = 2 studies), and disability, literacy, employment status, social support level and socioeconomic status (n = 1 study each). Five studies reported on feasibility, 12 reported construct validity metrics, and 4 studies reported on discriminant validity metrics. All studies by culture or language were rated as having good measurement property metrics. There was limited assessment of measurement property metrics for other populations at risk for inequity. Conclusion: Our study highlights important gaps in patient representation in rheumatology research for accepted outcome measures. New outcome measures being developed for research purposes and clinical practice should ensure and report representation of patients from populations at risk for inequities in the testing of metrics of feasibility, construct validity and discriminant ability metrics.