OBJECTIVES : Adherence to HIV therapies is a primary determinant of treatment success. This systematic literature review aimed to estimate adherence among HIV-infected patients living in high-burden countries of Sub-Saharan Africa (SSA), with a special focus on South Africa (SA) and Botswana, to identify reasons for and predictors of poor adherence, and to evaluate consequences of non-adherence.

METHODS : Using the PICOS model, multiple databases were searched for papers published from 2014-July 2019 that addressed adherence to HIV treatment in SSA. Metanalyses were conducted including forest plots construction, calculation of pooled rates, and subgroup analysis when applicable.

RESULTS : 319 data sources met the inclusion criteria for review, including 50 studies from SA and 5 studies from Botswana. In SSA, 74% of HIV-infected patients on antiretroviral therapy (ART) are adherent. Lower adherence occurs in youth (67%) vs. adults (75%, p=0.04). Adherence is lowest in Central (54%) and highest in East (76%) Africa and higher in Botswana (71%) vs. South Africa (75%). In SA and Botswana, good adherence is lower among males (77%) vs. females (80%); those receiving NNRTI-based regimen ART (77%) and fixed-dose regimen ART (78%) vs. ART generally (75%); and when analysis is restricted to patients receiving EFV-based regimen (81%). Meta-analysis showed associations between non-adherence and virological failure and detectable viral load in SA and Botswana. In SSA, treatment failure, immunological failure, risk of low CD4 levels, and odds of opportunistic infections were associated with non-adherence. Sleeping through the dose was the most commonly reported reason for non-adherence. Alcohol use was the only statistically significant predictor of non-adherence. Limitations include varying data collection methods and definitions of adherence across studies, as well as limited data from certain areas and subgroups.

CONCLUSIONS : Rates of adherence to HIV therapy in SSA are suboptimal and nonadherence is associated with negative outcomes in patients.