Sociodemographic, behavioral, and life-course risk factors for tuberculosis in older Indian adults: evidence from a nationally representative survey.

While tuberculosis (TB) propagation is multifactorial, the intersection of biological vulnerability (undernutrition) and cumulative life-course adversities is increasingly recognized as a crucial modifiable determinant. This study aimed to identify the independent biological, socioeconomic, behavioral, and life-course determinants of self-reported TB prevalence among middle-aged and older adults in India. We conducted a cross-sectional analysis using Wave 1 of the Longitudinal Ageing Study in India (LASI, 2017-18). The analytical sample included 59,910 adults aged 45 years and above with non-missing data on TB status and body mass index. The outcome was a self-reported TB diagnosis within the preceding 2 years. Survey-weighted logistic regression was used to examine factors associated with self-reported TB. Firth bias-reduced logistic regression was performed as a sensitivity analysis because of the low prevalence of self-reported TB. Overall, 550 participants (0.92%) reported TB within the preceding two years. Undernutrition was more common among participants with self-reported TB than among those without TB. In adjusted survey-weighted models, undernutrition, history of being bedridden for 1 month or more during childhood, multimorbidity, and residence in the Western region were independently associated with higher odds of self-reported TB. The findings were broadly consistent in the Firth bias-reduced sensitivity analysis. TB prevalence in older Indian adults is independently driven by undernourishment and the cumulative impact of early-life disease/deprivation, alongside the burden of multimorbidity. These findings underscore the need for the National TB Elimination Program to strengthen nutritional support and integrate TB prevention with comprehensive geriatric care and robust pediatric health investments to reduce adult vulnerability.