Patient-reported 28 swollen and tender joint counts accurately represent RA disease activity and can be used to assess therapy responses at the group level.

Objective: Formal joint assessments are critically important to improve rheumatological care of patients with RA. The aim of this study was to determine the usefulness of patient-recorded 28 tender joint counts (TJCs) and swollen joint counts (SJCs) using a tablet personal computer and to explore the possibility of using patient-recorded data to calculate 28-joint DAS (DAS-28) and EULAR response.
Methods: Forty-seven patients were included before initiation of adalimumab therapy and assessed at baseline and after 3 months. SJC and TJC were registered by the patients and thereafter by an experienced rheumatology specialist. Changes were correlated using Spearman's rank correlation test.
Results: The correlations between SJC and TJC derived by the physician and the patient at baseline were excellent (r = 0.78 and 0.87, respectively P < 0.01 for both). After 3 months, the correlations were less strong (0.645 and 0.745, respectively, P < 0.001 for both). When using the patient-derived SJC/TJC for calculation of the DAS-28 (patDAS-28), similar values were obtained, and correlations between DAS-28 and patDAS-28 were excellent (r = 0.91 at baseline, r = 0.90 at 3 months). According to the EULAR response criteria, the percentage of responders at the group level was nearly identical, although there was some disagreement at the individual level when DAS-28 and patDAS-28 were used to determine response to therapy.
Conclusion: Patient-reported SJC and TJC can in research settings be used instead of physician-reported ones. Patient-derived SJC and TJC may also make it possible for rheumatologists to obtain quantitative joint count recordings much more frequently than is feasible for traditional joint counts.