Under-Reporting of Known HIV-Positive Status Among People Living with HIV: A Systematic Review and Meta-Analysis

Background: Monitoring progress towards the UNAIDS ‘first 90’ target requires accurate estimates of levels of diagnosis among people living with HIV (PLHIV). Knowledge of HIV-positive status is often estimated using self-report, potentially leading to information bias. We aimed to systematically review the evidence and quantify levels of under-reporting of knowledge of HIV-positive status among PLHIV using objective proxies of knowledge of status. Methods: Databases were searched for studies providing self-reported and biological/clinical markers of prior knowledge of HIV-positive status among laboratory-confirmed PLHIV. PLHIV with antiretroviral drugs detected, viral load suppression, or prior diagnosis in medical records, but not reporting being HIV-positive, were classified as under-reporting known HIV-positive status. Random-effects models were used to derive pooled estimates of the proportion under-reporting known HIV-positive status. Possible sources of heterogeneity were investigated using sub-group analyses. Findings: Thirty-two independent estimates from 26 studies including 41,465 PLHIV were included. Most studies were conducted in North America (number of estimates [Ne]=12) or Africa [Ne=14], in the general population [Ne=10] or among men who have sex with men [MSM; Ne=10]). The pooled proportion under-reporting known HIV-positive status among all PLHIV was 20% (95% confidence interval: 13%–26%, I2=99%). In sub-group analysis, under-reporting was higher among MSM (32%, Ne=10) compared to the general population (9%, Ne=10). In the subset of North American studies with data stratified by race, under-reporting was higher among Black (18%, Ne=5) than non-Black (3%, Ne=3; p=0.026) individuals. Interestingly, the absolute magnitude of under-reporting was not associated with the level of self-reporting (slope 0.12, p=0.168). Interpretation: Substantial under-reporting of knowledge of HIV-positive status was found, particularly among MSM, and among Black PLHIV in North America. Supplementing self-reported data with biological/clinical proxies where possible may improve the validity of the ‘first 90’ estimates.  Funding Statement: NS, KMM, MCB and DD are supported by the HPTN Modelling Centre which is funded by the US National Institutes of Health (www.nih.gov/; grant number UM1AI068617) through the HPTN Statistical and Data Management Center. NS, KMM and MCB acknowledge the MRC Centre for Global Infectious Disease Analysis which is jointly funded by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement and is also part of the EDCTP2 programme supported by the European Union (grant number MR/R015600/1). KG was supported by a Postdoctoral Fellowship from the Fonds de recherche du Quebec – Sante. SHE was supported by the HPTN Laboratory Center (grant number UM1AI068613). Declaration of Interests: KMM has received an honorarium from Gilead for speaking. All remaining authors have no competing interests to declare.