Missed Visits Associated With Future Preexposure Prophylaxis (PrEP) Discontinuation Among PrEP Users in a Municipal Primary Care Health Network

Background. Maintaining retention in preexposure prophylaxis (PrEP) care among diverse patient populations will be needed to support PrEP's efficacy. We characterized patterns of PrEP care retention in a US municipal primary care health network and examined whether missed visits, a metric of care retention that is easy to evaluate in clinic, are associated with subsequent discontinuation. Methods. We included individuals on PrEP from July 2012 until August 2017 in the San Francisco Primary Care Clinics, a 15-clinic municipal health network. We categorized PrEP usage patterns as follows: early discontinuation (<90 days), later discontinuation (after >= 90 days), and continuing use at the end of follow-up. We first examined early discontinuation using adjusted Poisson regression. In patients who continued PrEP for >= 90 days, we examined factors associated with late discontinuation. Results. Of the 364 individuals who started PrEP, 16% discontinued PrEP before 90 days, 46% discontinued later, and 38% were retained in care over a median 12 months of observation. Transgender women were more likely to discontinue PrEP early (adjusted risk ratio; 2.16; 95% confidence interval, 1.36-3.49), and younger users were more likely to discontinue late (0.82 per 10-year increase in age;.70-. 96), as were persons who use illicit drugs (1.59; 1.02-2.47). Missed visits during use of PrEP were associated with future discontinuation (adjusted risk ratio, 1.52; 95% confidence interval, 1.14-2.03). Later year of current PrEP use was associated with both early and late discontinuation. Conclusion. Diverse populations may require differentiated care to continue PrEP. Missed visits should trigger tailored interventions to maximize the impact of PrEP.