Determinants of Implementation for HIV Pre-exposure Prophylaxis Based on an Updated Consolidated Framework for Implementation Research: A Systematic Review

Background: Delivery and use of HIV pre-exposure prophylaxis (PrEP) are suboptimal in the United States. Previous reviews of barriers and facilitators have not used an implementation science lens, limiting comprehensiveness and the link to implementation strategies. To summarize the state of the science, we systematically reviewed determinants of PrEP implementation using the updated Consolidated Framework for Implementation Research (CFIR 2.0). Setting: PrEP-eligible communities and delivery settings in the United States. Methods: In January 2021, we searched Ovid MEDLINE, PsycINFO, and Web of Science for peer-reviewed articles related to HIV/AIDS, interventions, implementation, and determinants or strategies. We identified 286 primary research articles published after 1999 about US-based PrEP implementation. Team members extracted discrete "mentioned" and "measured" determinants, coding each by setting, population, valence, measurement, and CFIR 2.0 construct. Results: We identified 1776 mentioned and 1952 measured determinants from 254 to 239 articles, respectively. Two-thirds of measured determinants were of PrEP use by patients as opposed to delivery by providers. Articles contained few determinants in the inner setting or process domains (ie, related to the delivery context), even among studies of specific settings. Determinants across priority populations also focused on individual patients and providers rather than structural or logistical factors. Conclusion: Our findings suggest substantial knowledge in the literature about general patient-level barriers to PrEP use and thus limited need for additional universal studies. Instead, future research should prioritize identifying determinants, especially facilitators, unique to understudied populations and focus on structural and logistical features within current and promising settings (eg, pharmacies) that support integration of PrEP into clinical practice.