Differences in Clinical Profiles and Biologic Treatment Approaches for Autoimmune Rheumatic Diseases Across Regions in Mexico: An Analysis of the BIOBADAMEX Cohort.

Objective: Being Mexico a very diverse developing country, the access to health care varies among geographical regions. We aimed to assess the differences in clinical features and treatment prescription in 3 regions of Mexico using data from the Mexican Adverse Events Registry (BIOBADAMEX).

Methods: We included all BIOBADAMEX patients from 2016 to 2023, compared the prescription patterns, the sociodemographic, clinical, and treatment characteristics between the northern (NR), central (CR), and southern regions (SR), and addressed the treatment survival by calculating hazards ratios (HRs).

Results: A total of 1084 patients were included: 389 (35.9%) from the NR, 569 (52.5%) from the CR, and 126 (11.6%) from the SR. The most common diagnosis was rheumatoid arthritis (61.0%). Patients from NR had longer disease duration (p = 0.03); those from SR had higher BMI (p < 0.001), DAS28 (p < 0.001), BASDAI scores (p = 0.02), and used more frequently glucocorticoids (p < 0.001). Patients from CR had more comorbidities (p = 0.001) and more regularly used conventional DMARDs (p = 0.007). Among patients with at least 2 assessments (n = 441), treatment with bDMARDs and tsDMARDs was discontinued in 247 (56%), 53% due to lack of efficacy. There was no association between the country region and treatment survival, but the main factors related to treatment discontinuation were disease duration (HR, 0.9; 95% confidence interval, 0.6-0.9) and lack of response (HR, 1.4; 95% confidence interval, 1.2-1.7).

Conclusions: In Mexico, patients with rheumatic diseases show regional differences in their clinical features and prescription patterns, which may be related to regional disparities in health care access and sociodemographic characteristics.