Effectiveness of bedaquiline containing all oral longer regimens in treating multidrug/rifampicin resistant tuberculosis in Pakistan

Background

Despite the introduction of bedaquiline (Bdq) containing all-oral regimens for treating patients with rifampicin resistant/multidrug resistant tuberculosis (MDR/RR-TB) in 2019, data on its effectiveness in Pakistan, which has the fifth highest MDR-TB burden, is lacking. This study evaluates treatment outcomes and identifies factors associated with unsuccessful outcomes among MDR/RR-TB patients treated with an all-oral longer treatment regimen (LTR).

Methods

This retrospective record review included all microbiologically confirmed pulmonary MDR/RR-TB patients treated with an all-oral LTR between August 2019 and February 2021 across nine PMDT centres in Pakistan. Sociodemographic and clinical data were retrieved from the Electronic Nominal Recording and Reporting System. Treatment outcomes, defined by WHO criteria, were analysed using SPSS and multivariate binary logistic regression to identify factors associated with unsuccessful outcomes. A p-value < 0.05 was considered statistically significant.

Results

The final analysis included 644 MDR/RR-TB patients (mean age 37.9 ± 17.6 years), mostly male (53.0 %), underweight (68.0 %), with TB treatment history (66.1 %), MDR-TB (84.9 %), lung cavitation (71.0 %), and no comorbidities (86.4 %). Fluoroquinolone resistance was found in 41.9 %, 16 % had used second-line drugs, and 9.8 % had previous MDR-TB treatment. A total of 400 (62.1 %) patients were declared cured, 53 (8.2 %) treatment completed, 117 (18.2 %) died, 37 (5.7 %) lost to follow-up (LTFU), and 37 (5.7 %) treatment failures. Overall treatment success rate was 70.3 % (n = 453). In multivariate analysis, history of TB treatment (OR:1.63, 95 %CI:1.09–2.64, p = 0.023), previous SLD use (OR:2.09, 95 %CI: 1.20–3.37, p = 0.012), resistance to Z (OR:0.43, 95 %CI: 0.20–0.81, p = 0.023), and resistance to > 5 drugs (OR:3.12, 95 %CI:1.36–11.64, p = 0.013) were significantly associated with death and treatment failure. Whereas, lung cavitation had statistically significant association with LTFU (OR:2.66, 95 %CI:1.10–7.32, p = 0.045).

Conclusion

Treatment success rate (70.3 %) in this study fell below the WHO recommended target success rate (>90 %). Enhanced clinical management, coupled with special attention to patients exhibiting identified risk factors could improve treatment outcomes.