HIV risk, risk perception, and PrEP interest among adolescent girls and young women in Lilongwe, Malawi: operationalizing the PrEP cascade

Introduction: As a user-controlled HIV prevention method, oral pre-exposure prophylaxis (PrEP) holds particular promise for adolescent girls and young women (AGYW). HIV prevention cascades, critical frameworks for the design and evaluation of PrEP programmes, outline the priorities of identifying individuals at greatest HIV risk and motivating them to initiate PrEP through perceived HIV risk. To inform future iterations of these cascades and PrEP delivery for AGYW, the objective of this study was to understand the level of interest in PrEP among AGYW at highest HIV risk, and the potential role of perceived risk in motivating PrEP interest. Methods: Using data from a cohort study of HIV-negative AGYW in Lilongwe, Malawi (February 2016 to August 2017), we assessed the relationship between epidemiologic HIV risk (risk index developed in a previous analysis) and PrEP interest, and the extent to which perceived risk explains the relationship between HIV risk and PrEP interest. We further aimed to operationalize the pre-initiation steps of the HIV prevention cascade in the study population. Results: In total, 825 AGYW were included in analyses, of which 43% met the criterion for high epidemiologic HIV risk. While epidemiologic risk scores were positively associated with PrEP interest, high numbers of AGYW both above and below the high-risk cutoff were very interested in PrEP (68% vs. 63%). Perceived risk partially explained the relationship between HIV risk and PrEP interest; greater epidemiologic HIV risk was associated with high perceived risk, which was in turn associated with PrEP interest. Many more high-risk AGYW were interested in PrEP (68%) than expressed a high level of perceived HIV risk (26%). Conclusions: These results highlight key relationships between epidemiologic HIV risk, risk perception and interest in PrEP. While risk perception did partially explain the relationship between epidemiologic risk and PrEP interest, there may be other important motivational mechanisms that are not captured in many HIV prevention cascades. The high number of participants with risk scores below the high-risk cutoff who both expressed high perceived risk and interest in PrEP suggests that demand for PrEP among AGYW may not be well aligned with epidemiologic risk.