Background: Pre-exposure prophylaxis (PrEP) is only effective in preventing new HIV infections when taken consistently. In clinical practice, asking a patient about their adherence (self-report) is the predominant method of assessing adherence to PrEP. Although inexpensive and noninvasive, self-report is subject to social desirability and recall biases. Several clinical trials demonstrate a discrepancy between self-reported adherence and biomarker-based recent adherence. Less is known about the accuracy of self-report in real-world clinical settings. This brief report addresses this knowledge gap and describes the concordance between self-reported adherence and biomarker-based adherence in real-world clinical settings. Methods: A liquid chromatography–mass spectrometry urine test for tenofovir was developed and used clinically to detect recent nonadherence (no dose in at least 48 hours) for each individual. Two clinics' standard operating procedures recommend utilization of the urine-based adherence test for patients who self-report that they are not struggling with adherence. Those who self-report struggling with adherence receive enhanced adherence support without the need for additional testing. The number of results indicating recent nonadherence from these 2 clinics were analyzed to assess the concordance between self-reported adherence and biomarker-based adherence. Results: Across 2 clinics, 3987 tests were conducted from patients self-reporting as “adherent,” and 564 [14.1%; 95% confidence interval (CI): 13.1% to 15.2%] demonstrated recent nonadherence with the liquid chromatography–mass spectrometry test. At clinic #1 in Florida, 3200 tests were conducted, and 465 (14.5%; 95% CI: 13.3% to 15.8%) demonstrated recent nonadherence. At clinic #2 in Texas, 787 tests were conducted, and 99 (12.6%; 95% CI: 10.4% to 14.9%) demonstrated recent nonadherence. Conclusions: Utilization of biomarker-based adherence monitoring at these 2 clinics resulted in 564 additional patients receiving enhanced adherence support who otherwise would not have been identified as nonadherent to their prescribed PrEP regimen. These findings suggest that objective adherence monitoring can be used clinically to enable providers to identify nonadherent patients and allocate support services accordingly.

Background Viral rebound during antiretroviral treatment (ART) is most often driven by suboptimal adherence in the absence of drug resistance. We assessed the diagnostic performance of point-of-care (POC) tenofovir (TFV) detection in urine for the prediction of viral rebound and drug resistance during ART. Methods We performed a nested case-control study within the ADVANCE randomized clinical trial (NCT03122262) in Johannesburg, South Africa. Adult outpatients living with HIV and newly initiating ART were randomized to receive either dolutegravir or efavirenz, tenofovir disoproxil fumarate or alafenamide, and emtricitabine. All participants with rebound ≥200 copies/mL between 24 and 96 weeks of follow-up were selected as cases and matched to controls with virological suppression <50 copies/mL. Rapid POC urine-TFV detection was performed retrospectively. Results We included 281 samples from 198 participants. Urine-TFV was detectable in 30.7% (70/228) of cases and in 100% (53/53) of controls. Undetectable urine-TFV predicted rebound with a sensitivity of 69% [95%CI 63-75] and specificity of 100% [93-100]. In cases with virological failure and sequencing data (n = 42), NRTI drug resistance was detected in 50% (10/20) of cases with detectable urine-TFV versus in 8.3% (2/24) of cases with undetectable urine-TFV. Detectable urine-TFV predicted NRTI resistance (OR 10.4 [1.8-114.4] p = 0.005) with a sensitivity of 83% [52-98] and specificity of 69% [50-84]. Conclusions Point-of-care objective adherence testing using a urine-TFV test predicted viral rebound with high specificity. In participants with rebound, urine-TFV testing predicted the selection of drug resistance. Objective adherence testing may be used to rapidly provide insight into adherence, suppression, and drug resistance during ART.

Monitoring adherence to pre-exposure prophylaxis is a critical component of reaching ending the human immunodeficiency virus infection (HIV) epidemic goals in the US. Currently, providers still depend on “self-report” pre-exposure prophylaxis (PrEP) adherence, whereby providers ask their patients about their recent pill taking habits. There appears to be growing consensus across the HIV prevention community that “self-report” is an inadequate method of identifying that is in-need of additional adherence support services. In a recent survey, 97% of providers report utilizing self-reported adherence because it is convenient, but only 10% of these providers believe it is accurate. While “self-report” is convenient, evidence and testimonials from diverse stakeholders across the HIV prevention landscape indicate that there is a desire for more accurate, effective adherence monitoring methods. In this mini-review, we will briefly synthesize the emerging evidence and propose a solution to ensure all patients receive the support needed to protect them from HIV acquisition.

Background HIV pre-exposure prophylaxis (PrEP) is 99% effective at preventing new HIV infections if taken daily. To be successful, PrEP requires concurrent efforts to optimize uptake, persistence, and adherence. In 2018, cisgender (cis) women accounted for 19% of new HIV infections in the US but comprised only 7% of all PrEP users. Studies show poor PrEP adherence amongst cis women, but there is a paucity of real-world clinical data describing PrEP adherence among cis women and gender minority people. Methods An adherence test that measures the concentration of tenofovir in urine samples using a liquid chromatography mass spectrometry (LC-MS/MS) was used to assess recent PrEP adherence at 8 clinics. Urine samples were collected during routine visits and analyzed using the LC-MS/MS assay. Test results were retrospectively paired with gender data, when available, and sex assigned at birth (SAAB) data. Adherence data were aggregated and analyzed to assess non-adherence proportions by sub-population. Results Gender data were available from 1,461 patients at 5 clinics, 1,344 (92%) of whom were cis males (Figure 1). From the 5 clinics where gender and SAAB data were available, 3,835 tests were conducted and 517 (13.5%) indicated non-adherence (Figure 2). 3 additional clinics conduct routine adherence testing and collect SAAB data (gender data not available). At these 8 clinics, SAAB data were available for 2,773 PrEP patients, totaling 5,602 urine tests (Figure 3). Among these 5,602 adherence tests, 813 (14.5%) indicated non-adherence (Figure 4). SAAB females demonstrated significantly higher non-adherence than SAAB males (22% vs 14%, p< 0.001). Across clinics, 89%-98% of PrEP patients are SAAB male (Figure 5). Within these 8 clinics, SAAB female demonstrated consistently higher non-adherence (17%-44%, vs 12%-17% for SAAB males) (Figure 6). Figures 1 and 2 Figures 3 and 4 Figures 5 and 6 Conclusion Real-world data align with nationwide trends in PrEP utilization and show that the majority of PrEP patients are cis men. When initiated on PrEP, cis women exhibit higher rates of non-adherence than cis men. These data underscore the need to collect gender-identity data to monitor PrEP disparities and suggest that greater efforts are needed to target PrEP access, utilization, and accompanying support services to cis women and gender minority groups. Disclosures All Authors: No reported disclosures