The protective effect of isoniazid preventive therapy on tuberculosis incidence among HIV positive patients receiving ART in Ethiopian settings: a meta-analysis

BACKGROUND: Tuberculosis (TB) and HIV makeup a deadly synergy of infectious disease, and the combined effect is apparent in resource limited countries like Ethiopia. Previous studies have demonstrated inconsistent results about the protective effect of isoniazid preventive therapy (IPT) on active TB incidence among HIV positive patients receiving ART. Therefore, the aim of this meta-analysis was, first, to determine the protective effect of IPT on active tuberculosis incidence, and second, to assess the pooled incidence of active TB among HIV positive patients taking ART with and without IPT intervention in Ethiopia. METHODS: PubMed, Google scholar and Cochran library databases were searched from April 1 to 30, 2018. Two independent authors explored and assessed studies for eligibility, and extracted data based on predefined criteria. Studies that reported TB incidence among HIV positive patients taking ART in Ethiopia with and without IPT concomitant intervention, and with a clear stratified data on the incidence of TB based on the duration of IPT intervention were selected. A random effects model was used to estimate risk ratios and the pooled incident TB with the respective 95% confidence intervals. RESULTS: We identified 7 suitable studies in this analysis. Accordingly, IPT reduced the risk of TB incidence by 74%, risk ratio (RR) 0.26 (95% CI; 0.16–0.43%), compared to no IPT group. Moreover, IPT for 12 months reduced incident TB by 91% (RR: 0.09, 95% CI: 0.04 to 0.21), whereas 6 months IPT averted TB incidence by 63% (RR: 0.37, 95% CI: 0.26 to 0.52). The overall pooled incident TB among HIV infected patients receiving ART was 10.30% (95% CI; 7.57–13.02%). Specifically, incident TB among study cohorts with and without IPT was 3.79% (95% CI; 2.03–5.55%) and 16.32% (95% CI; 11.57–21.06%) respectively. CONCLUSION: IPT reduced the risk of incident TB among HIV positive patients receiving ART in Ethiopian settings. Moreover, the duration of IPT intervention has effect on its protective role. Thus, scaling up the isoniazid preventive therapy program and its strict compliance is necessary to avert HIV fueled tuberculosis. STUDY PROTOCOL REGISTRATION: CRD42018090804. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12879-019-4031-2) contains supplementary material, which is available to authorized users.