Understanding Typology of Preexposure Prophylaxis (PrEP) Persistence Trajectories Among Male PrEP Users in the United States

Abstract

Introduction Understanding longitudinal patterns of PrEP use among men who have sex with men (MSM) could offer insights for developing efficient and timely interventions to promote PrEP persistence. Setting We extracted two years of pharmacy fill records for 4,000 males who initiated PrEP in 2017 at a national chain pharmacy in the US. Methods Group-based trajectory models were used to develop PrEP trajectory clusters, with periods of use defined based on optimal PrEP seroprotection probabilities (i.e., PrEP use frequency ≥ 4 doses/week). Multinomial logistic regressions were used to evaluate the associations between sociodemographic covariates and identified trajectory group membership. Results We identified four distinct groups of PrEP persistence trajectories: 1) persistent use of PrEP throughout the period (persistent user), 2) brief use followed by sustained cessation of PrEP use (brief user), 3) PrEP use up to the mid-term followed by sustained cessation of PrEP use (mid-term user), and 4) PrEP use, followed by cessation and subsequent re-initiation (PrEP re-initiator). Persistent users and brief users accounted for 40.1% and 22.9% of the population, respectively, while mid-term users and re-initiators accounted for 18.9% and 18.2%, respectively. Older age at PrEP initiation, commercial insurance as the primary payer of PrEP, and use of specialty pharmacy were found to be associated with persistent PrEP use over the other patterns of non-persistence. Conclusions Subgroups of PrEP users could benefit from PrEP persistence interventions that target specific timings of likely PrEP cessation or considerations of re-initiation.