Temporal and regional variation in the use of biologic and targeted synthetic DMARDs for rheumatoid arthritis: a nationwide cohort study.

OBJECTIVE

The objective of this study was to evaluate temporal and regional variation in biologic and targeted synthetic DMARD (b/tsDMARD) initiation for RA in England and Wales.

METHODS

An observational cohort study was conducted for people with RA enrolled in the National Early Inflammatory Arthritis Audit (NEIAA) between May 2018 and April 2022 who had 12-month follow-up data available. Temporal trends in escalation to b/tsDMARDs within 12 months of initial rheumatology assessment were explored, including comparisons before and after publication (July 2021) of national guidelines that lowered the threshold for b/tsDMARD initiation to include moderate-severity RA. Case-mix-adjusted, mixed-effects regression was used to evaluate regional and hospital-level variation in b/tsDMARD initiation.

RESULTS

Of 6098 RA patients with available follow-up, 508 (8.3%) initiated b/tsDMARDs within 12 months of initial assessment. b/tsDMARD escalation increased marginally towards the end of the study period (9.2% in May 2021/22); however, no significant differences were evident after guidelines were published permitting b/tsDMARD use for moderate-severity RA. The proportion of individuals escalated to b/tsDMARDs varied considerably between regions, ranging from 5.1% in Wales to 10.7% in North-West England. Following case-mix adjustment, the intraclass correlation (ICC) for hospitals within regions was 0.17, compared with a between-region ICC of 0.0, suggesting that the observable regional variation reflected hospital-level differences rather than systematic differences between regions themselves.

CONCLUSION

There is marked variation in escalation to b/tsDMARDs for people newly diagnosed with RA throughout England and Wales, despite a universal health-care system. These disparities must be addressed if we are to deliver equitable access to b/tsDMARDs, regardless of geography.