Association between maintenance dialysis and tuberculosis treatment outcomes in Amazonas, Brazil: a population-based record-linkage cohort study (2001–2023)

Background Although maintenance dialysis (MD) affects only a small proportion of patients with tuberculosis (TB), individuals receiving dialysis are at increased risk of TB and may be more likely to experience unfavourable treatment outcomes. Evidence on this association remains limited in Brazil, particularly in high-burden settings characterized by geographic barriers and challenges in access to specialized healthcare services. We assessed the association between MD and unfavourable TB treatment outcomes in Amazonas, Brazil. Methods We conducted a retrospective population-based cohort study including all new TB cases reported in Amazonas, Brazil, between 2001 and 2023. Probabilistic record linkage was performed between the state TB surveillance system (SINAN-TB) and a dialysis registry to identify patients receiving MD before TB diagnosis. The primary exposure was MD prior to TB diagnosis. Unfavourable outcomes comprised death from any cause, loss to follow-up, or treatment failure. Multivariable logistic regression was used to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results Among 58,611 TB cases included in the analysis, 112 (0.2%) had evidence of MD before TB diagnosis. MD was strongly associated with higher odds of unfavourable outcomes (aOR 5.45; 95% CI 3.60–8.24). Illicit drug use (aOR 2.18; 95% CI 1.97–2.40), HIV/AIDS (aOR 2.06; 95% CI 1.94–2.19), mental illness (aOR 1.53; 95% CI 1.27–1.83), alcohol use (aOR 1.38; 95% CI 1.29–1.48), and smoking (aOR 1.30; 95% CI 1.20–1.42) were also associated with increased odds of unfavourable outcomes. In contrast, directly observed therapy (DOT) (aOR 0.67; 95% CI 0.63–0.71), female sex (aOR 0.82; 95% CI 0.79–0.85), and diabetes mellitus (aOR 0.84; 95% CI 0.78–0.91) were associated with reduced odds. Conclusions Within a large population-based TB cohort, MD was a rare but clinically important exposure that was strongly associated with unfavourable treatment outcomes. The protective effect of DOT highlights a feasible intervention pathway. These findings support the integration of TB care into dialysis services and reinforce the need to prioritize this population for targeted TB screening and preventive strategies in high-burden settings. Clinical trial number Not applicable.