A point-of-care tenofovir urine test improves accuracy of self-reported PrEP adherence and increases condomless sex reporting among young women.

Objectives: We evaluated a recently developed and validated point-of-care urine tenofovir (POC TFV) test to determine whether its use improves the accuracy of self-reported adherence to pre-exposure prophylaxis (PrEP) and sexual behavior.

Design: We enrolled sexually active HIV-negative women ages 16-25 years in Kampala, Uganda.

Methods: Women were followed quarterly for 24 months with HIV prevention counseling, PrEP dispensation, and adherence counseling. Midway through the study, the POC TFV test was introduced as part of routine study procedures. We examined changes in self-reported PrEP adherence, sexual behavior, and accuracy of self-reported PrEP adherence before and after the introduction of the POC TFV test.

Results: A total of 146 women receiving PrEP refills had ≥1 visit with a POC TFV test administered before the study exit. At baseline, the median age was 19 years (interquartile range [IQR]: 18-21) and the majority (76%) reported having condomless sex within the last three months. Participants more frequently self-reported low PrEP adherence (OR: 2.96, 95% confidence interval [CI]: 1.89-4.67, p = 0.001) and condomless sex (OR: 1.47, 95% CI: 1.04-2.06, p = 0.03) during visits using the test compared to visits without the test. The accuracy of self-reported PrEP adherence (determined by concordance with TFV-diphosphate levels) was greater when the test was used (61% versus 24%, OR: 4.86, 95% CI: 2.85-8.30, p < 0.001).

Conclusions: When the POC TFV test was used, we observed greater reporting of condomless sex, low PrEP adherence, and more accurate reports of PrEP adherence. The test could facilitate honest conversations between clients and providers and warrant further investigation.