Do patients with intersectional disadvantage have poorer outcomes from osteoarthritis management programmes? A tapered-balancing study of patient outcomes from the Good Life with osteoArthritis in Denmark (GLA:D®) programme

Objective: To investigate whether adults with potential multiple social disadvantage have poorer outcomes following attendance in an osteoarthritis (OA) management program (OAMP), and if so, what might determine this result. Methods: Among consecutive knee OA attendees of the Good Life With Osteoarthritis in Denmark (GLA:D) OAMP in Denmark we defined a group with potential “intersectional disadvantage” based on self-reported educational attainment, country of birth, and citizenship. Outcomes of this group were compared with GLA:D participants who were native Danish citizens with higher educational attainment. Outcomes were pain intensity, Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life subscale score, and the EuroQol 5-domain instrument in 5 levels (EQ-5D-5L) score at 3 and 12 months. After data preprocessing, we used entropy balancing to sequentially control for differences between the groups in baseline covariates. Mean between-group differences in outcomes were estimated by weighted linear regression. Results: Of 18,448 eligible participants, 250 (1.4%) were nonnative/foreign citizens with lower education. After balancing for differences in baseline score and in administrative and demographic characteristics, they had poorer outcomes than higher-educated native Danish citizens on pain intensity and EQ-5D-5L score at both follow-up points (e.g., between-group mean differences in pain visual analog scale [0–100] at 3 and 12 months: 3.4 [95% confidence interval (95% CI) –0.5, 7.3] and 6.2 [95% CI 1.7, 10.7], respectively). Differences in KOOS quality of life subscale score, were smaller or absent. Balancing for differences on baseline score, comorbidity, self-efficacy, and depression had the greatest effect on reducing observed outcome inequalities. Conclusion: Outcome inequalities widened following OAMP attendance, particularly at longer-term follow-up, but the magnitude of differences was generally modest and inconsistent across outcome measures. Tailoring content to reduce outcome inequalities may be indicated, but improving access appears the greater priority.