Drug resistance patterns, treatment outcomes and factors affecting unfavourable treatment outcomes among extensively drug resistant tuberculosis patients in Pakistan; a multicentre record review.

Background: Extensively drug resistant tuberculosis (XDR-TB) is considered as a major threat to global health. This study aimed to analyse the treatment outcomes and identify the factors significantly associated with unfavourable treatment outcomes among XDR-TB patients. Methods: We conducted a retrospective observational study at 10 Programmatic Management Units of the National Tuberculosis Control Program of Pakistan. The Electronic Nominal Recording Reporting System records were used to collect data of all eligible XDR-TB patients registered at the study sites between March 2012 and August 2018. Treatment outcomes were analysed as per the standard criteria. Factors associated with unfavourable treatment outcomes were analysed by using multivariate binary logistic regression analysis. Results: Out of the total 184 patients, 59 (32.1%) completed their treatment successfully. Whereby, 83 patients (45.1%) died, 24 (13%) had treatment failure, and 11 (6%) were lost to follow-up. Treatment outcomes were not evaluated in 7 (3.8%) patients. Factors significantly associated with unfavourable treatment outcomes included; conventional therapy with bedaquiline, unfavourable interim treatment outcomes and occurrence of adverse drug events (negative association). Conclusion: Treatment success rate in the study cohort was sub-optimal (i.e., <75%). The poor success rate and high mortality are concerning, and requires immediate attention of the program managers and clinicians.