Participation in a digital self-management intervention for osteoarthritis and socioeconomic inequalities in patient-related outcomes.

Objective: To investigate changes in socioeconomic inequalities in patient-related outcomes and pain medication use, following participation in a digital self-management intervention for osteoarthritis (OA) in Sweden.

Method: Participants with hip/knee OA enrolled in the digital intervention were included. Self-reported outcomes collected were the numerical rating scale (NRS) pain, activity impairment, general health, Knee/Hip injury and Osteoarthritis Outcome Score (KOOS-12, HOOS-12) Pain, Function, and Quality of Life subscales, 5-level EuroQol 5 Dimensions (EQ-5D-5L), Patient Acceptable Symptom State (PASS) for function, walking difficulties, fear of movement, wish for surgery, pain medication use, physical function measured by the 30s chair-stand test, and level of physical activity. Educational attainment was used as a socioeconomic measure and the concentration index was used to assess the magnitude of inequalities at baseline and 3 month follow-up.

Results: The study included 21,688 participants (mean ± sd age 64.1 ± 9.1 years, 74.4% females). All outcomes except for PASS demonstrated inequalities in favour of highly educated participants at both time-points, with highly educated participants reporting better outcomes. At 3 month follow-up, the magnitude of inequality widened for activity impairment, but narrowed for NRS pain, EQ-5D-5L, KOOS-12/HOOS-12 Pain and Function, physical function, and wish for surgery. There were no statistically conclusive changes in the magnitude of inequalities for the remaining outcomes.

Conclusions: There were inequalities in patient-related outcomes in favour of those with higher education among participants of a digital self-management intervention for OA, although the magnitude of these pre-existing inequalities generally narrowed after the 3 month intervention.