ABSTRACT:
Universal health systems must ensure not only access but equitable distribution of high-cost medicines. Multiple sclerosis, a chronic disabling condition, challenges pharmaceutical equity. We evaluated socioeconomic and territorial inequalities in access to first-line disease-modifying therapies (DMTs) for relapsing-remitting multiple sclerosis (RRMS) within Brazil’s Unified Health System (SUS) in 2024. We conducted an observational ecological study using nationwide administrative data from the SUS Outpatient Procedure Authorization system (Apac). For each state, we estimated DMT consumption in Defined Daily Doses (DDD) and per-capita expenditure. Epidemiological prevalence and eligible populations were derived from official estimates. Socioeconomic position was proxied by the state-level Human Development Index (HDI). Inequality was measured using the Slope Index of Inequality (SII) and Relative Index of Inequality (RII), capturing absolute and relative gradients in treatment coverage, DDD consumption, and spending per eligible patient. Coverage varied markedly by region, ranging from 50.9% in the Center-West to 34.3% in the Northeast. Strong socioeconomic disparities were observed in patient coverage (SII = 0.2082; RII = 2.58), indicating substantially higher coverage in states with higher HDI. DDD consumption showed a similar gradient (SII = 61.65; RII = 2.50), suggesting greater treatment intensity in more advantaged states. In contrast, no consistent inequality pattern emerged for per-capita spending (SII = −99.18; RII = 0.96), pointing to misalignment between financial allocation and therapeutic need. Despite universal coverage principles, substantial inequalities persist in RRMS treatment access across Brazil. Incorporating SII and RII into routine pharmaceutical monitoring would provide actionable, comparable metrics to support distributive justice. Embedding these indicators within health technology assessment (HTA) and reimbursement processes could improve policy responsiveness, strengthen equity-sensitive governance, and reinforce HTA’s system-shaping role in middle-income settings.