Patient Reported Outcome Measures for Rheumatoid Arthritis Disease Activity: a systematic review following COSMIN guidelines

Background The current standard of care in rheumatoid arthritis (RA) requires regular assessment of disease activity (DA). All standard RA DA measurement instruments require joint counts to be undertaken by a healthcare professional with/without a blood test. Few healthcare providers have the capacity to assess patients as frequently as stipulated by guidelines. Patient Reported Outcome Measures (PROMs) could be an efficient and informative way to assess RA DA, which is highlighted by the SARS-COV-2 pandemic, as most consultations are remote rather than face-to-face. We aimed to assess all PROMs for RA DA against the internationally recognised COSMIN guidelines to provide evidence-based recommendations to select the most suitable PROMs. Methods Review registered on PROSPERO as CRD42020176176. The search strategy was based on a previous similar systematic review and expanded to include all articles up to January 2019. All identified articles were rated by two independent assessors following the COSMIN guidelines. Results 668 abstracts were identified, with 10 articles included. A further 21 were identified from a previous review. Ten PROMs were identified. There was insufficient evidence to place any of the identified PROMs into recommendation for use category A due to lack of evidence for content validity, as stipulated by the COSMIN guidelines. Conclusion Lack of evidence of content validity limits suitable PROM selection, therefore none can be recommended for use. It is acknowledged that all included PROMs were developed before the COSMIN guidelines were published. Future research on PROMs for RA DA must provide evidence of content validity.