Time until tuberculosis recurrence and associated factors in Brazil: a populationbased retrospective cohort study using a linked database.

Objective: To calculate the rate of tuberculosis recurrence, estimate its average time until recurrence, and identify factors associated with recurrence in Brazil.

Methods: Retrospective cohort study with a linked database from the Notifiable Diseases Information System. The study included individuals diagnosed with tuberculosis in 2015, focusing on those who experienced their first recurrence within 6.5 years. We estimated the relative risk (RR) and its 95% confidence interval (95%CI), as well as the population attributable fraction (PAF) or the population preventable fraction (PPF) of associated factors.

Results: Within a 6.5-year period, 3,253 individuals (6.5%) experienced tuberculosis recurrence, with a median time of 2.2 years. Positively associated factors included: male sex (RR: 1.4; 95%CI 1.3-1.5; PAF: 22.9%), age 30 to 59 years (RR: 3.0; 95%CI 1.6-5.7; PAF: 36.0%), black race (RR: 1.3; 95%CI 1.2-1.5; PAF: 3.5%), mixed race (RR: 1.3; 95%CI 1.2-1.4; PAF: 10.6%), deprivation of liberty (RR: 1.9; 95%CI 1.7-2.1; PAF: 9.1%), pulmonary/mixed clinical form (RR: 1.7; 95%CI 1.4-1.9; PAF: 37.1%), acquired immunodeficiency syndrome diagnosis (RR: 1.8; 95%CI 1.5-1.9; PAF: 4.3%), and alcohol use (RR: 1.2; 95%CI 1.1-1.3; PAF: 2.9%). Negatively associated factors were: 12 or more years of schooling (RR: 0.5; 95%CI 0.4-0.6; PPF: 3.3%) and supervised treatment (RR: 0.9; 95%CI 0.8-0.9; PPF: 4.4%).

Conclusion: This study revealed high tuberculosis recurrence rates in Brazil, influenced by sociodemographic, compartmental, and social factors, both positively and negatively impacting disease recurrence.