Prevalence of Multidrug-Resistant Tuberculosis and Its Association With Previous Treatment History in Adults.

Background Multidrug-resistant tuberculosis (MDR-TB) poses a growing threat to global tuberculosis (TB) control efforts, particularly in high-burden countries like Pakistan. This study aimed to determine the prevalence of MDR-TB among adult pulmonary TB patients and evaluate its association with previous treatment history and other potential risk factors. Methods A cross-sectional analytical study was conducted at a tertiary care hospital in Lahore, Pakistan, from January to June 2024. A total of 250 adult patients with microbiologically confirmed pulmonary TB were enrolled using a non-probability consecutive sampling technique. Sociodemographic and clinical data were collected using a structured questionnaire. Sputum samples were tested using the GeneXpert MTB/RIF assay, and rifampicin-resistant samples were further analyzed by culture-based drug susceptibility testing to confirm MDR-TB. Data were analyzed using SPSS Version 26. Logistic regression was used to identify independent predictors of MDR-TB. Results The overall prevalence of MDR-TB was 18.8% (47/250). MDR-TB was significantly more prevalent in previously treated patients (40.0%) compared to newly diagnosed cases (6.9%) (p < 0.001). On multivariate analysis, previous TB treatment (adjusted odds ratio [AOR] = 7.85; 95% CI: 3.85-16.00), smoking history (AOR = 2.13; 95% CI: 1.02-4.45), and diabetes mellitus (AOR = 2.75; 95% CI: 1.33-5.68) were independently associated with MDR-TB. Age and gender were not significantly associated with MDR-TB. Conclusion The study revealed a high prevalence of MDR-TB, especially among previously treated patients. Previous TB treatment, smoking, and diabetes mellitus were key risk factors. These findings emphasize the importance of comprehensive drug resistance screening and the integration of non-communicable disease management and tobacco control into TB care strategies.