Comparative Economic Burden of Tuberculosis Patients with and Without Diabetes Mellitus in Kupang City, Indonesia: A Comparative Cross-Sectional Study

Abstract : Background: Tuberculosis and diabetes mellitus are major public health problems with a well-recognized bidirectional relationship. Diabetes mellitus increases the risk of active tuberculosis, while tuberculosis may worsen glycemic control. This comorbidity may also increase household economic burden through higher non-medical expenses, productivity loss, and catastrophic health expenditure. Evidence comparing the economic burden of tuberculosis patients with and without diabetes mellitus in Kupang City remains limited. Objective: To compare the economic burden between tuberculosis patients without diabetes mellitus and tuberculosis patients with diabetes mellitus in Kupang City, Indonesia, in 2025. Methods: This comparative cross-sectional study included 86 respondents, consisting of 43 tuberculosis patients without diabetes mellitus and 43 tuberculosis patients with diabetes mellitus who were receiving outpatient treatment at 10 primary health centers in Kupang City. Results: A significant difference in economic burden was observed between the two groups. The median total cost among tuberculosis patients without diabetes mellitus was IDR 255,000, whereas the median total cost among tuberculosis patients with diabetes mellitus was IDR 850,000. Direct non-medical costs and indirect costs were also higher in the tuberculosis-diabetes mellitus group. Catastrophic costs were significantly more frequent in the TB-DM group than in the TB non-DM group (44.2% vs. 20.9%; p = 0.021). Conclusion: Diabetes mellitus significantly increases the economic burden among tuberculosis patients. Compared with tuberculosis patients without diabetes mellitus, those with tuberculosis and diabetes mellitus incur higher total costs, greater non-medical expenditures, and higher indirect costs. These findings support the need for integrated tuberculosis-diabetes services and stronger financial protection strategies for vulnerable patients.