PrEP Adherence Lower in Cisgender Women Compared to Cisgender Men

debunking the patient zero theory of AIDS
Investigators sought to determine PrEP adherence in cisgender women compared to cisgender men, transgender women, transgender men, and non-binary patient populations.

Cisgender women have a higher rate of non-adherence to pre-exposure prophylaxis (PrEP) for HIV, according to a study presented at IDWeek, held virtually from October 21 to 25.

Although PrEP is 99% effective at preventing HIV infections, it requires concurrent efforts to optimize uptake, persistence, and adherence to be successful. Previous studies have shown that there is poor PrEP adherence among cisgender women. There is a lack of real-world data describing adherence among this population; therefore, this study assessed PrEP adherence among cisgender women compared to cisgender men, transgender women, transgender men, and non-binary patient populations.

A liquid chromatography mass spectrometry (LC-MS/MS) test was used to assess recent adherence at 8 clinics by measuring the concentration to tenofovir (TFV) in the urine. Test results were retrospectively paired with gender data, when available, and sex assigned at birth (SAAB) data. Adherence data was aggregated and analyzed to determine non-adherence proportions across sub-populations.

Results demonstrated that cisgender women exhibit higher rates of non-adherence compared to cisgender men when initiated on PrEP. Gender data was collected in 1461 unique patients, with 92% (n=1344) being cisgender men. Five clinics collected 3835 tests and revealed that 517 patients (13.5%) indicated non-adherence. Of 226 [CF1] cisgender women, 54 (24%) indicated non-adherence; of 3557 cisgender men, 462 (13%) indicated non-adherences (P <.001).

SAAB data was collected in 2773 unique patients and totaled 5602 adherence tests. At each of the 8 clinics, 89% to 98% of patients were SAAB men. SAAB women consistently demonstrated higher non-adherence (range, 17-44%) compared to SAAB men (range, 12%-17%).

Overall, the study authors conclude that the “data underscores the need to collect gender-identity data to monitor PrEP disparities and suggests that greater efforts are needed to target PrEP access, utilization, and accompanying support services to cisgender women and gender minority groups.”


Hebel S, Kahn-Woods E, Enghuus C, et al. Disparities in PrEP uptake and adherence among cisgender women using a pharmacologic measure. Presented at: IDWeek 2020; October 21-25, 2020. Poster 979.