Objective: Dissemination of preexposure prophylaxis (PrEP) is a priority for reducing new HIV infections, especially among vulnerable populations. However, there are limited data available on PrEP discontinuation following initiation, an important component of the PrEP cascade.
Design: Patients receiving PrEP within the San Francisco Department of Public Health Primary Care Clinics (SFPCC) are included in a PrEP registry if they received a PrEP prescription, were not receiving postexposure prophylaxis, and not known to be HIV-positive.
Methods: We calculated PrEP discontinuation for patients initiating PrEP at any time from January 2012 to July 2017 and evaluated their association with demographic and risk variables using Cox regression analysis.
Results: Overall, 348 patients received PrEP over the evaluation period. The majority (84%) were men, and the cohort was racially/ethnically diverse. The median duration of PrEP use was 8.3 months. In adjusted analysis, PrEP discontinuation was lower among older patients (aHR 0.89; 95% CI 0.80-0.99; P = 0.03); but higher among black patients (compared with white patients; aHR 1.87; 95% CI 1.27-2.74; P = 0.001), patients who inject drugs (aHR 4.80; 95% CI 2.66-8.67; P < 0.001), and transgender women who have sex with men (compared with MSM; aHR 1.94; 95% CI 1.36-2.77; P < 0.001).
Conclusion: Age, racial/ethnic, and risk category disparities in PrEP discontinuation were identified among patients in a public health-funded primary care setting. Further efforts are needed to understand and address PrEP discontinuation among priority populations to maximize the preventive impact of PrEP, and reverse HIV-related disparities at a population level.