Determinants of favorable treatment outcomes in multidrug-resistant tuberculosis in Zambia: A retrospective cross sectional study, 2018-2022.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is a persistent public health challenge in Zambia, with favorable treatment outcomes remaining below the World Health Organization target of 90%. However, limited national evidence on treatment outcomes and their determinants hinders the development of effective programmatic responses. This study aimed to estimate the proportion of MDR-TB patients achieving favorable treatment outcomes and to identify factors independently associated with these outcomes in Zambia from 2018 to 2022. METHODS: A retrospective cross-sectional study was conducted using secondary data from the National Tuberculosis and Leprosy Programme Yathu database. All confirmed MDR-TB cases initiated on treatment across Zambia's ten provinces from January 2018 to December 2022 were included. Demographic and clinical variables were extracted. Multivariable logistic regression was used to identify with factors independently associated with favorable treatment outcomes, reported as adjusted odds ratios (aORs) with 95% confidence intervals. RESULTS: A total of 1,258 participants were included; the median age was 36 years (IQR: 28-44). Of these, 67.2% (n = 843) were male, while 53.0% (n = 662) were living with HIV. Overall, 68.1% (n = 857) achieved favorable treatment outcomes, while 31.9% (n = 401) had unfavorable outcomes. Normal body weight was positively associated with favorable outcomes (aOR 2.07; 95% CI: 1.02-4.21), while residing in Muchinga (aOR 0.12; 95% CI: 0.03-0.45; p = 0.002), and Western (aOR 0.17; 95% CI: 0.04-0.80; p = 0.024), was negatively associated with favorable outcomes. CONCLUSION: Favourable MDR-TB treatment outcomes in Zambia is shaped by nutritional status and marked geographic disparities. Strengthening nutritional support and targeting provincial inequities are essential to improving treatment outcomes.