Cohort study on association between catastrophic costs and unfavorable tuberculosis treatment outcomes among TB-HIV and TB-diabetes comorbid patients in India

India grapples with an alarming burden of tuberculosis (TB), reporting 2.6 million incident cases in 2023, necessitating intensified efforts toward TB elimination. The prevalence of catastrophic costs, defined as expenses exceeding 20% of annual household income, varies widely. Our objective was to determine the association between catastrophic costs from TB-HIV and TB-diabetes care and unfavorable TB treatment outcomes.

We conducted a cohort study in Bhavnagar, India, from July 2019 to January 2021, involving 234 TB-HIV and 304 TB-diabetes patients. Catastrophic costs were assessed using the World Health Organization’s tool. Unfavorable TB treatment outcomes included positive results from sputum smear, nucleic acid amplification, or culture tests at treatment completion, death during treatment, or treatment cessation for a month (for drug-sensitive TB) or two months (for drug-resistant TB). Firth regression was employed to address quasi-separation issues and identify predictors.

Among TB-HIV patients, 12% faced catastrophic costs, with 20% experiencing unfavorable TB outcomes. In this group, significant predictors included weight (OR: 0.93, 95% CI: 0.89–0.98), family type (OR: 2.5, 95% CI: 1.2–5.5), and initial hospitalization (OR: 2.6, 95% CI: 1.1–6.3). For TB-diabetes patients, 5% faced catastrophic costs, and 14% had unfavorable outcomes, with significant predictors being below the poverty line (BPL) (OR: 2.9, 95% CI: 1.5–5.9) and initial hospitalization (OR: 3.4, 95% CI: 1.1–11.1). Catastrophic cost incidence was higher in TB-HIV (12% vs. 4% in TB only) and TB-diabetes (5% vs. 4% in TB only) patients. However, catastrophic costs did not show a direct association with unfavorable outcomes in either group.

Our study found no direct association between catastrophic costs and unfavorable TB outcomes among TB-HIV/TB-diabetes patients. Instead, factors such as weight, family type, BPL status, and initial hospitalization were significant predictors. These findings underscore the importance of socio-economic conditions and initial hospitalization, advocate for enhanced support mechanisms including nutritional and financial aid, especially for BPL families.