Bedaquiline and delamanid result in low rates of unfavourable outcomes among TB patients in Eswatini

SETTING: Since 2015, Eswatini has been scaling up bedaquiline (BDQ) and delamanid (DLM) based drug-resistant TB treatment regimens under programmatic conditions. OBJECTIVE: Identification of factors associated with treatment outcomes in patients receiving BDQ and/or DLM either as a new treatment initiation or drug substitution. DESIGN: This is a retrospective cohort study of patients receiving BDQ and/or DLM in Eswatini between March 2015 and October 2018. We describe factors associated with unfavourable treatment outcomes (death, lost to follow-up, treatment failure and amplification of resistance) and culture conversion using multivariable flexible parametric survival and competing-risks regression analyses. RESULTS: Of 352 patients receiving BDQ and/or DLM, 7.8% and 21.2% had an unfavourable treatment outcome at 6 and 24 months, respectively. Predictors were age ≥ 60 years (adjusted hazard ratio [aHR] 4.49, 95%CI 1.61-12.57) vs. age 20-39 years, and a treatment regimen combining both drugs (aHR 4.49, 95%CI 1.61-12.57) vs. BDQ only. The probability of culture conversion was increased for two health facilities and patients with a poly resistance profile (adjusted sub-hazard ratio 2.01, 95%CI 1.13-3.59) vs. multidrug resistance. CONCLUSION: Single use of BDQ or DLM was associated with low rates of unfavourable outcomes, suggesting that these medications may be effectively adopted at scale under routine programmatic conditions. Combined use of BDQ and DLM was a risk factor for unfavourable outcomes and should prompt for collection of more data on the combined use of these medications.