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

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.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.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.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.