Prescribing pattern of disease-modifying antirheumatic drugs in Scotland (2019-2023): a population-based retrospective cohort study.

Background: The increasing complexity of biologic and targeted therapies for inflammatory rheumatic diseases necessitates robust, real-world evidence to guide clinical decision-making. Scotland's newly established Homecare dataset, capturing ~ 90% of secondary care disease-modifying antirheumatic drugs (DMARDs) prescribing, offers a unique national resource to evaluate treatment patterns.

Research design and methods: We conducted a retrospective cohort study using Public Health Scotland's Homecare dataset (2019-2023), including 17,695 patients treated for rheumatoid arthritis, psoriatic arthritis, spondyloarthritis (SpA), juvenile idiopathic arthritis (JIA), and related conditions. We analysed DMARD utilisation, treatment sequencing, and persistence using descriptive statistics and pathway mapping.

Results: A total of 260,054 prescriptions were analysed, with biologic DMARDs comprising 90% of homecare supplies. Adalimumab and etanercept were the predominant agents. TNF inhibitors dominated first-line use, with high persistence rates (78.6%-97.1%), particularly in JIA and SpA. Among switchers, median time on initial therapy was 10.7 months (IQR: 4.2-23.3), decreasing with each subsequent treatment, highlighting the challenges in managing multi-refractory patients.

Conclusion: This is the first national study to characterise real-world DMARD prescribing in Scotland using comprehensive Homecare data. Findings provide critical benchmarks for therapeutic optimisation, inform guideline development, and support sustainable planning for high-cost medicines delivery in rheumatology.