Measuring Acceptability and Preferences for Implementation of Pre-Exposure Prophylaxis (PrEP) Using Conjoint Analysis: An Application to Primary HIV Prevention Among High Risk Drug Users

Abstract

Although people who use drugs (PWUD) are one of the key risk populations who could benefit from the use of pre-exposure prophylaxis (PrEP), to date, little attention has been given to incorporating PrEP into HIV prevention approaches targeting this underserved group. This study investigated the acceptability of PrEP based on a number of known PrEP attributes among high-risk PWUD in a drug treatment setting. A total of 400 HIV-negative PWUD, who reported drug- and/or sex-related risk behaviors were recruited from a methadone clinic to complete a stated preference (full-profile conjoint) survey. Participants ranked the eight hypothetical PrEP program scenarios with varied combinations of six attributes related to PrEP (cost, dosing, efficacy, side-effects, treatment setting, and frequency of HIV testing). SPSS conjoint procedure was used to estimate the relative importance of each attribute and preferences across eight possible PrEP delivery programs. PrEP acceptability ranged from 30.6 to 86.3% with a mean acceptability of 56.2% across the eight hypothetical PrEP program scenarios. The PrEP program scenario with the highest acceptability had the following attribute levels: insurance covered, daily dosing, 95% effective, no side-effects, treatment at HIV clinic, and HIV testing needed every 6 months. The cost associated with PrEP was the most important attribute (relative importance score: RIS = 38.8), followed by efficacy (RIS = 20.5) and side effects (RIS = 11.9); other attributes had no significant effect. Our findings reported a high acceptability of PrEP in response to different PrEP program scenarios with different attribute profiles. As the result of having this information, researchers and policymakers will be better equipped for evidence informed targeting and dissemination efforts to optimize PrEP uptake among this underserved population.

Keywords: Conjoint analysis; HIV prevention; Implementation science; Patient preferences; People who use drugs (PWUD); Pre-exposure prophylaxis (PrEP).

Figures

Figure 1

Example of full-profile conjoint task (hypothetical PrEP program scenarios)

Figure 2

Marginal utilities of pre-exposure prophylaxis (PrEP) attributes’ levels among participants (N = 400) PrEP: pre-exposure prophylaxis * Constant: 4.467 (0.110) Pearson’s R: 0.998 Kendall’s tau: 1.000