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.