Systematic review and meta-analysis of the reproducibility of patient self-reported joint counts in rheumatoid arthritis

Objective. To assess the reproducibility of patient-reported tender (TJCs) and swollen joint counts (SJCs) of patients with rheumatoid arthritis (RA) compared to trained clinicians. Methods. We conducted a systematic literature review and metaanalysis of studies comparing patient-reported TJCs and/or SJCs to clinician counts in patients with RA. We calculated pooled summary estimates for correlation. Agreement was compared using a Bland-Altman approach. Results. Fourteen studies were included in the metaanalysis. There were strong correlations between clinician and patient TJCs (0.78, 95% CI 0.76-0.80), and clinician and patient SJCs (0.59, 95% CI 0.54-0.63). TJCs had good reliability, ranging from 0.51 to 0.85. SJCs had moderate reliability, ranging from 0.28 to 0.77. Agreement for TJCs reduced for higher TJC values, suggesting a positive bias for self-reported TJCs, which was not observed for SJCs. Conclusion. Our metaanalysis has identified a strong correlation between patient- and clinician-reported TJCs, and a moderate correlation for SJCs. Patient-reported joint counts may be suitable for use in annual review for patients in remission and in monitoring treatment response for patients with RA. However, they are likely not appropriate for decisions on commencement of biologics. Further research is needed to identify patient groups in which patient-reported joint counts are unsuitable.