Association Between Socioeconomic Conditions and Biologic Prescriptions for Inflammatory Bowel Diseases in the...

Inflammatory bowel diseases (IBD) are chronic conditions affecting millions of people globally. Brazil's public healthcare system provides free access to IBD medications. However, socioeconomic conditions may affect prescribing patterns. This study examined associations between income inequality, human development, and biologic prescription rates for IBD in the Brazilian public health system (SUS).

Data from the SUS Outpatient Information System (2008-2022) were analyzed. The biologic prescription rate (percentage of biologic prescriptions among all IBD prescriptions) was the outcome of interest. Random-effects negative binomial regression for panel data evaluated associations between the Gini Index, Municipal Human Development Index (MHDI), and biologic prescriptions while controlling for demographic, social, and healthcare variables.

Biologic prescription rates for IBD in Brazil increased from 3.03% to 16.69%. Municipalities with higher income inequality had 6% lower prescription rates than those with higher income equality (RR 0.94; 95% CI 0.92-0.96). Using low MHDI as the reference, municipalities with medium (RR 0.79; 95% CI 0.70-0.91), high (RR 0.68; 95% CI 0.60-0.78), and very high MHDI (RR 0.66; 95% CI 0.58-0.76) had progressively lower rates.

Income inequality and human development are associated with biologic prescription rates for IBD within the SUS. The paradoxical MHDI pattern probably reflects differential engagement of private health insurance across development levels, whereby biologic-eligible patients in wealthier municipalities access therapy outside the SUS and are not captured by SIA. These findings underscore the need for policies addressing structural disparities in IBD care and for future research integrating public and private sector prescription data.