Tuberculosis treatment outcome and determinants factors in resource-limited settings: Systematic Review and Meta-analysis
Authors and Affiliations:
Melees Yeshambaw Teferi, correspondent author, Armauer Hansen Research Institute
Hawult Taye Adane, Armauer Hansen Research Institute
Mekonnen Teferi Mekonnen, Armauer Hansen Research Institute

Abstract:
Background: Tuberculosis (TB) is one of the top 10 causes of death, and the leading cause from a single infectious agent (Mycobacterium tuberculosis), ranking above HIV/AIDS. Knowledge of TB treatment outcomes is substantially needed to assess the performance of TB controls programs. Therefore, this Meta-Analysis was conducted to produce pooled estimates of TB treatment outcome in resource limited-settings and analyze the predictive factors of successful TB treatment.

Methods: Potentially relevant studies were retrieved from PubMed, Google Scholar and Science Direct databases. Searching was limited to the studies that had been conducted in resource limited-settings and published in the English language. In this review, observational studies, including cohort, cross-sectional, and case-control studies, were included. The Joanna Briggs Institute (JBI) quality appraisal criteria were used for quality assessment of the studies. Heterogeneity across studies was assessed using Cochran’s Q test and I2 statistic. Publication bias was also checked with the funnel plot and Egger’s regression test. The outcome measures were successful and unsuccessful treatment outcomes. Pooled estimates of TB treatment success rate and pooled odds ratio (OR) were computed using the random-effects model with 95% CI using Stata V.14 software.
This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) in July 2019 under number CRD42019136986.

Result: A total of 32 studies fulfilled the criteria for inclusion in this review to estimate the successful treatment outcome. The overall pooled estimate of successful treatment outcome was 80.0% (95% CI: 78 -83). Nigeria identified with the lowest rate of successful treatment outcome, 64% (95% CI: 52%-77%), and Ethiopia had the highest, 84% (95% CI: 81-86). In patients with HIV co-infection the successful treatment outcome was 72% (95% CI: 64-79). Moreover, this study found that old age, HIV co-infection, retreatment cases and rural residence were the most frequently identified factors associated with poor TB treatment outcome. HIV-negative patients were one and half times more likely to have successful treatment outcome with an odds' ratio of 1.5 (95% CI: 1.45–1.52), compared to HIV-positive patients.
Conclusion: This meta-analysis revealed that the rate of successful treatment among TB patients in resource limited settings was good, but was still below the defined threshold of 85%. There were significant variations in treatment outcomes across the country. Old age, HIV-confection, history of previous TB treatment and patients residing in rural area were found to be strongly associated factors of poor treatment outcome. Special consideration should be given to TB patients with old ages, HIV co-infected, retreated cases and rural residents and countries that had a lower TB treatment success.

Keywords: Tuberculosis, Treatment outcomes, Systematic review, Meta-analysis

Melese Yeshambaw Teferi MSc

Armauer Hansen Research Institute (AHRI)

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