Long-term Survival of Treated Tuberculosis Patients in Comparison to a General Population In South India: A Matched Cohort Study

Abstract

ObjectivesThis study aimed to measure the mortality rate, potential years of life lost, and excess general mortality among individuals treated for pulmonary tuberculosis (TB) in a TB endemic country. MethodsA retrospective analysis was conducted on a population-based cohort study of 4022 TB patients and 12,243 gender-matched and age-matched controls from prevalence surveys conducted between 2000 and 2004 in the Thiruvallur district of Tamil Nadu, South India. ResultsThe mortality rate among TB patients was 59/1000 person-years. The excess standardized mortality ratio was 2.3 (95% CI: 1.7–3.1). The rate of potential years of life lost was 6.15/1000 (95% CI: 5.97–6.33) in the TB cohort compared to the general population of 1.52/1000 (95% CI: 1.46–1.60). Individuals aged >50 years, those underweight (<40 kg), with treatment failures, or lost to follow-up had higher mortality rates when compared with the rest of the TB cohort. The risk of death was significantly higher in the TB cohort until the end of the fourth year when compared with later years. ConclusionMortality in the TB cohort was 2.3 times higher than in the age-matched general population. Most deaths occurred in the first year after completing treatment. Post-treatment follow-ups and interventions for reducing comorbid conditions are necessary to prevent deaths.