Development of the Rheumatoid Arthritis Distress Scale (RADS): a new tool to identify disease-specific distress in patients with Rheumatoid Arthritis

BACKGROUND: Patients with Rheumatoid Arthritis (RA) may experience psychological distress (depression, anxiety) in addition to their physical symptoms. People with RA may also experience disease-specific distress (DSD), related to the specific burden of living with their life-long condition. DSD is a patient reported outcome in several long-term conditions, including type 1 and 2 diabetes. The aims of this study were to determine whether DSD is experienced by people with RA, and if so, develop a Patient Reported Outcome Measure (PROM) to assess for DSD in people with RA. METHODS: A five-phased qualitative study was conducted which consisted of a secondary data analysis of 61 interviews of people with rheumatological disease (Phase 1), validation of findings via a Patient and Public Involvement (PPI) group of people with RA (n = 4) (Phase 2), item generation for a PROM (Phase 3) and establishing face and content validity of the PROM via PPI group (n = 4) and individual cognitive interviews (n = 9) of people with RA respectively (Phase 4 and 5). The final PROM was presented at a Patient Education Evening for patients with long-term rheumatological conditions, including RA, and carers. RESULTS: Five themes of rheumatological disease distress emerged from Phase 1, which were validated in the Phase 2 PPI group. After Phases 3–5, the Rheumatoid Arthritis Distress Scale (RADS) was formed of 39 items and 3 supplementary questions. Overall participants reported the content of the RADS to be clear and relevant, and that DSD is a valid concept in RA, distinct from other entities like clinical depression or anxiety. CONCLUSIONS: DSD appears to be an important concept in RA. The 39-item RADS demonstrates acceptable face and content validity in this patient group. Further psychometric testing is needed. The RADS may be a useful tool for healthcare professionals to identify RA distress.