Abstract
Background Tuberculosis (TB) outcomes are strongly influenced by age-related factors and coexisting chronic illnesses. With a rapidly aging population and a rising non-communicable disease burden in India, understanding how comorbidities affect clinical presentation and treatment outcomes among geriatric TB patients is essential for optimizing programmatic care under the National Tuberculosis Elimination Programme (NTEP). Methods This retrospective comparative cohort study was conducted at a tertiary care hospital in New Delhi and included 951 adult TB patients enrolled under NTEP between March and August 2025. A retrospective cohort design was adopted, as exposure (age group and comorbidity status) and outcomes (treatment outcomes) had already occurred and were assessed using existing programmatic records. Patients were categorized into geriatric (≥60 years) and non-geriatric (18-60 years) groups. Demographic characteristics, comorbidities, clinical profiles, diagnostic modalities, and treatment outcomes were extracted from DOTS (Directly Observed Treatment, Short-course) records and the NIKSHAY platform. Associations between age group and categorical variables were assessed using the Chi-square and Fisher's exact tests, while continuous variables were compared using independent-sample t-tests. A multinomial logistic regression model, with death as the reference category, was used to identify independent predictors of treatment outcome across three groups: treatment success, treatment failure/loss to follow-up, and death. Results Of the 951 patients analyzed, 433 were geriatric and 518 were non-geriatric. Geriatric patients were more frequently male (68.8% vs. 56.9%; p < 0.001) and had a significantly higher burden of comorbidities (67.4% vs. 22.8%; p < 0.001), particularly diabetes mellitus (DM) (35.1% vs. 16.2%; p < 0.001). Pulmonary TB predominated in the geriatric group (84.3%), while extrapulmonary TB was more common among non-geriatric patients (43.8%; p < 0.001). Microbiological confirmation was higher in geriatric patients (72.5% vs. 46.1%; p < 0.001). Treatment success was significantly lower among geriatric patients (62.0% vs. 87.8%), while mortality (17.3% vs. 3.3%) and loss to follow-up/treatment failure (20.8% vs. 8.9%) were markedly higher (p < 0.001). On multinomial logistic regression, geriatric age was the strongest independent predictor of treatment failure, with geriatric patients having approximately 85% lower odds of achieving treatment success, compared to death, relative to non-geriatric patients (aOR = 0.148; 95% CI: 0.076-0.289; p < 0.001). Non-reactive human immunodeficiency virus (HIV) status was independently associated with significantly higher odds of treatment success (aOR = 4.644; 95% CI: 2.459-8.772; p < 0.001). Conclusion Geriatric TB patients exhibit a significantly higher comorbidity burden, greater pulmonary involvement, and markedly poorer treatment outcomes than younger adults. Geriatric age is an independent predictor of mortality, underscoring the urgent need for age-specific treatment strategies, intensified monitoring, and targeted comorbidity management within NTEP to improve outcomes in this vulnerable population.