Determinants of unfavourable treatment outcomes of drug-resistant tuberculosis cases in Malaysia: a case–control study

Abstract

Objectives The emergence of drug-resistant tuberculosis (DR-TB) complicates TB management and poses significant challenges to achieve favourable treatment outcomes. Treating DR-TB is more complex and costly, requiring extended treatment durations and consideration of drug toxicity and side effects. This study aims to identify the determinants of unfavourable treatment outcomes among DR-TB patients in Malaysia. Design Retrospective case–control study. Setting Secondary data from the National Tuberculosis Registry (NTBR) across two states in Malaysia. Participants All reported DR-TB cases in the NTBR between 2016 and 2020 from Selangor and Wilayah Persekutuan Kuala Lumpur, Malaysia. Cases still undergoing treatment at the time of analysis were excluded. A total of 403 cases were analysed, with 181 (44.9%) experiencing unfavourable treatment outcomes and 222 (55.1%) having favourable treatment outcomes. The case group consists of individuals with DR-TB who experienced unfavourable treatment outcomes, while the control group comprises individuals with DR-TB who achieved favourable treatment outcomes. Outcome measures Unfavourable treatment outcomes, defined as death, treatment failure or loss to followup, were assessed. Predictors of these outcomes were identified through multiple logistic regression analysis. Results Significant determinants of unfavourable treatment outcomes included being male (adjusted OR (aOR) 2.38, 95% CI 1.44 to 3.94), being single or divorced (aOR 1.61, 95% CI 1.03 to 2.49), having no formal education (aOR 3.09, 95% CI 1.49 to 6.41), people living with HIV (aOR 2.87, 95% CI 1.40 to 5.87) and having DR-TB categorised as rifampicin-resistant tuberculosis (aOR 3.34, 95% CI 1.90 to 5.86) or multidrug-resistant/preextensively drug-resistant/extensively drug-resistant-TB (aOR 2.57, 95% CI 1.52 to 4.33). Conclusion The findings reveal a high proportion of DR-TB cases with unfavourable treatment outcomes and identify their key determinants. Targeted interventions addressing these factors are essential to improve treatment outcomes.