Undernutrition increases the risk of unsuccessful treatment outcomes of patients with tuberculosis in Ethiopia: a multicenter retrospective cohort study

Background While undernutrition has been identified as a common risk factor for tuberculosis (TB), its impact on treatment outcomes has yet to be investigated in high TB burden and low-income countries such as Ethiopia. Therefore, this study aimed to investigate the effect of undernutrition on treatment outcomes among patients with TB in northwest Ethiopia. Methods A retrospective cohort study was conducted using data from different hospitals in northwest Ethiopia, for the period from July 2017 to August 2023. A Cox proportional hazard model was performed to determine the effect of undernutrition on TB treatment outcomes, which were defined as a composite of death, treatment failure, or loss to follow-up. Results A total of 602 patients with TB were included in the analysis. Of these, 367 (60.9%) were male, and 344 (57.1%) were undernourished. Upon completion of the follow-up period, 65 (10.8%) adults with TB had unsuccessful treatment outcomes. After adjusting for potential confounders, patients with undernutrition had a two times higher risk of experiencing unsuccessful treatment outcomes compared to well-nourished patients (AHR: 2.0, 95% CI: 1.2, 3.6). In addition, patients residing in rural areas (AHR: 3.1, 95% CI: 1.7, 5.4), having a history of prior TB treatment (AHR: 2.2, 95%CI: 1.1, 4.1), and the presence of diabetes comorbidity (AHR: 2.4, 95% CI: 1.1, 5.2) were at higher risk of unsuccessful treatment outcomes. Conclusions Undernutrition increases the risk of unsuccessful treatment outcomes in Ethiopia. This finding suggests that nutritional support during TB treatment can improve successful treatment outcomes in high TB burden and low-income countries such as Ethiopia.