Evolving drivers of preexposure prophylaxis discontinuation among US MSM, 2018-2024.

OBJECTIVE: To examine temporal trends in reasons for stopping preexposure prophylaxis (PrEP) among MSM from 2018 to 2024, including how reasons co-occur and vary by demographics. DESIGN: Pooled repeated cross-sectional analysis of seven annual waves of the American Men's Internet Survey (AMIS), a national behavioral survey of US cisgender MSM (N = 54 612). METHODS: Among 3074 noncurrent PrEP users who reported reasons for stopping, we collapsed checklist items into six thematic categories and estimated adjusted prevalence by survey year using multivariable logistic regression with g-computation. Latent class analysis (LCA) identified subgroups with distinct discontinuation profiles. RESULTS: The most common reason was Altered Sexual Activity (55%), followed by Side Effects (31.6%) and Financial/Access (29.4%). After demographic adjustment, Altered Sexual Activity rose from 46.2% in 2018 to 61.2% in 2024 [adjusted odds ratio (aOR) 1.93], and Privacy/Discrimination roughly doubled from 5.6 to 11.3%, the only reason with a significant linear trend (aOR 1.14 per year; P = 0.003). Financial/Access remained stable at approximately 29% across all 7 years. LCA identified three classes: Changed Circumstances (35.1%), Structural Barriers (23.8%), and Clinical/Multi-Barrier (41.1%). Being uninsured was the strongest predictor of financial discontinuation (aOR 4.31). CONCLUSIONS: Over 7 years of PrEP scale-up, circumstance-driven discontinuation grew increasingly dominant while stigma-related discontinuation doubled and cost barriers persisted. Three distinct discontinuation profiles argue for tailored approaches: re-engagement pathways for those whose circumstances change, financial navigation for structural barriers, and comprehensive clinical support for those experiencing multiple challenges.