Prior exposure to antiretroviral therapy among adult patients presenting for HIV treatment initiation or re-initiation in sub- Saharan Africa: a systematic review

BackgroundAs countries in sub-Saharan Africa have scaled up access to antiretroviral therapy (ART) for HIV, patient attrition rates of up to 30% per year have created a large pool of individuals who initiate treatment with prior ART experience (non-naive re-initiators). Little is known about the proportion of non-naive re-initiators within the population presenting for treatment initiation. MethodsWe conducted a comprehensive, rapid review of recent peer-reviewed reports that presented data on proportions of adult patients initiating ART who were treatment naive and non-naive in sub-Saharan Africa. Searching PubMed, EMBASE, Web of Science, and international conference abstracts, we sought studies published after 1 January 2018 with data collected after January 2016, when universal HIV treatment access became the norm. We included clinical trials and observational studies and accepted self-report, laboratory discernment of antiretroviral metabolites, or viral suppression at initiation or previously reported in the medical record as evidence of prior exposure. We report results of each eligible study and identify gaps in the literature. ResultsOf 1,782 articles returned in our initial search, we found nine, describing ten cohorts, that contained sufficient information for the review, of which half were from South Africa. The proportion of the study samples with evidence of prior ART use ranged from 5% (self-report only) to 53% (presence of ART metabolites in hair or blood sample among self-reported naive patients). The vast majority of studies that were screened did not report proportions of initiators who were non-naive, and among the few that did, the metrics used to determine and report non-naive proportions were inconsistent and difficult to interpret. ConclusionThe proportion of patients initiating HIV treatment who are truly ART-naive is not well documented in the literature. From the studies identified, it seems likely that 20% to 50%--and likely at least 30%--of ART patients who present for ART are re-initiators. Standard reporting metrics and diligence in reporting this characteristic of ART initiation cohorts are needed, as is research to understand the reluctance of patients to report prior ART exposure.