Long-term Mortality Trends Among Individuals With Tuberculosis: A Retrospective Cohort Study of Individuals Diagnosed With Tuberculosis in Brazil.

BACKGROUND

Even after successful treatment, individuals surviving tuberculosis (TB) disease experience elevated mortality rates. However, there is limited evidence on how these risks vary over time and by individual characteristics.

METHODS

We conducted a retrospective cohort study of individuals diagnosed with TB in Brazil, using national TB notifications and linked mortality records for 2007-2016. We estimated mortality rate ratios (MRRs) and cumulative mortality by year since TB diagnosis, compared to general population mortality matched on age, sex, year, and state. We identified clinical and sociodemographic factors associated with elevated post-TB mortality, and compared the distribution of causes of death to the general population.

RESULTS

The study sample included 834 594 individuals, with 4.1 million person-years of follow-up (average, 4.9 years). The TB cohort had elevated mortality compared to the general population, particularly in the first year postdiagnosis (MRR, 11.28 [95% confidence interval {CI}, 11.18-11.37]). Post-TB MRRs declined from 3.59 (95% CI, 3.53-3.64) in year 2 to 1.46 (95% CI, 1.34-1.59) in year 10. Cumulative excess mortality was 6.12% (95% CI, 6.07%-6.17%) after 1 year and 9.90% (95% CI, 9.58%-10.24%) after 10 years. MRRs were highest for individuals 30-44 years old at diagnosis. Relapse, loss to follow-up, and co-prevalent conditions like human immunodeficiency virus (HIV) and alcohol use disorder were strongly associated with higher MRRs. Over time, major causes of death in the TB cohort shifted from TB and HIV to cardiovascular disease, cancer, and non-TB respiratory diseases.

CONCLUSIONS

Individuals developing TB disease face elevated mortality up to 10 years after diagnosis. These excess risks vary across demographic and clinical characteristics.