Disparities in the access to and use of biologic and targeted synthetic treatments in patients with inflammatory rheumatic and musculoskeletal diseases: a scoping review

Objectives To identify disparities in the access to and use of biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in inflammatory rheumatic and musculoskeletal diseases (iRMDs). Methods A systematic search of literature was conducted in Embase, Medline (to 30 May 2023), and relevant congress databases (to June 2023). Interventional and observational studies reporting measures of disparity in access to, receipt of, or utilisation of b/tsDMARDs in iRMDs were eligible. Outcomes included access to b/tsDMARDs, likelihood to receive treatment, time to first initiation, treatment adherence, and treatment persistence. Disparities across these outcomes are reported. Reporting follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews guidance. Results Of 4218 publications identified, 104 were included in this scoping review. All studies were observational; 70% reported data from patients with rheumatoid arthritis, and 65% were from North America or Europe. Gender (58%) and age (54%) were commonly investigated factors. Lower gross domestic product/capita ( n = 7 publications) was associated with reduced access to b/tsDMARDs, whereas older age ( n = 20 publications) and receiving government-funded health insurance (eg, Medicare/Medicaid) ( n = 6 publications) were negatively associated with the likelihood of receiving b/tsDMARDs. No clear association was identified for any disparity factors and time to the initiation of b/tsDMARDs. Conclusions Disparities in access to and use of b/tsDMARDs are reported in the literature along with the role of commonly studied social determinants of health (SDoH). More research is needed to identify the full spectrum of existing disparities and to reveal the role of SDoH, including the lesser-studied ones.