Background: Tuberculosis (TB) remains an unresolved public health problem and is the leading cause of death attributable to a single infectious pathogen. The first step in developing strategies to reduce TB mortality is to identify the direct causes of death in patients with TB and the risk factors for each cause.

Methods: Data on TB patients systemically collected by the National Surveillance System of South Korea from January 2019 to December 2020 were included in this analysis. We analyzed the clinical characteristics of TB- and non-TB-related deaths, including TB-related symptoms, comorbidities, and radiographic and microbiological findings.

Results: A total of 12,340 TB patients (males, 61.1%; mean age, 61.3 years) were included. During the follow-up period, the overall mortality rate was 10.6% (1317 cases), with TB-related deaths accounting for 21.3% (280 cases) of all TB deaths. The median survival time in the TB-related death group was 22 days. TB-related death was associated with older age, lower body mass index (BMI), dyspnea, fever and general weakness, and bilateral radiographic patterns and AFB-positive smears. Non-TB-related deaths were associated with older age, male sex, lower BMI, comorbidities of heart, liver, kidney, and central nervous system (CNS) diseases, CNS TB involvement, the presence of dyspnea, general weakness, and bilateral radiographic patterns.

Conclusions: Patients with high-risk TB must be identified through cause-specific mortality analysis, and the mortality rate must be reduced through intensive monitoring of patients with a high TB burden and comorbidities.