Treatment Outcome and Adverse Events of Tenofovir Disoproxil Fumarate Based Regimens as Compared to Zidovudine Based Regimens Among People Living with HIV/AIDS: A Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND: Findings from different studies report inferior clinical and virologic efficacy with TDF/3TC/NVP. But, some studies show that, there was no statistically significant difference in mortality among ZDV and TDF based regimens. The objective of this review was to systematically identify, appraise and synthesize the best available evidence on efficacy and safety of TDF based regimen as compared to ZDV based regimens. METHODS: A three-step search strategy was used to locate published and unpublished studies. First, an initial limited search of google was undertaken followed by analysis of text words. A second extensive search was undertaken. We searched the PubMed, EMBASE, Google Scholar, Medline, and CINHAL. We did the initial search for articles on July 11-18, 2016, and updated the results on May 13, 2017.Third, the reference lists of all identified articles was searched for additional studies. RESULTS: ZDV based regimens had better outcome on prevention of mortality (OR=1.31, 95%CI (1.14, 1.50), I(2) = 0%, Chi(2) = 2.51), and lower virologic failure (OR = 1.44, 95% CI [1.18, 1.76], chi(2) = 5.91, P= 0.003, I(2) =83%) while, TDF based regimens were more tolerable (OR=0.15, 95%CI (0.08, 0.30), I(2) = 40%, Chi(2) = 3.31). The difference in incidence of opportunistic infection is not significant (OR = 0.83, 95% CI [0.52, 1.32], chi(2) = 0.11, P= 0.42, I(2) =0%). CONCLUSION: There is lower mortality and lower virologic failure in ZDV group, but better safety profile among TDF based regimens.