Variation in preferences for long-acting injectable PrEP among US men who have sex with men: a latent class analysis

BACKGROUND: Cabotegravir long-acting injectable HIV pre-exposure prophylaxis (LAI-PrEP) is shown to be safe and efficacious. Understanding variations in potential user preferences for LAI-PrEP may be useful to inform segmented implementation strategies, and subsequently improve uptake and thus community-level effectiveness.
METHODS: HIV-negative, sexually active men who have sex with men (MSM) aged >15 living in the US were recruited online for the 2019 American Men's Internet Survey. They completed a discrete-choice experiment with nine paired profiles with hypothetical LAI-PrEP attributes: out-of-pocket cost, perceived side effects, injection frequency, perceived stigma, and service location. Latent class analysis was used to segment respondents into groups based on their preferences for the hypothetical attributes presented, and relative importance of preference weights and willingness-to-pay were calculated. Finally, associations with group membership based on sociodemographic characteristics and sexual risk behavior were tested using logistic regression.
RESULTS: Two latent classes emerged from 2,206 respondents. 'Value-conscious' respondents (30%) exhibited strong dislike for higher out-of-pocket cost. Cost was 2.5 times more important than frequency and perceived side effects. 'Outcomes-conscious' respondents (70%) exhibited a strong dislike for perceived severe side effects. Their dislike for severe side effects was 3.2 times more important than cost. Neither group ascribed importance to service location nor stigma. Value-conscious respondents were significantly younger (mean [IQR]: 29.1 [21-33] vs. 31.3 [22-37] years, chi-2 p<0.000), more likely to be racial/ethnic minorities, less educated, live in rural areas, and have public or no insurance. Outcome-conscious respondents were marginally more likely to have ever used oral PrEP and were significantly less likely to have had condomless anal sex with an HIV-serodiscordant partner in the past year or to have only casual partners. Willingness-to-pay analysis demonstrated that the outcomes-conscious class would pay $354 to avoid side effects (vs. $32 in the value-conscious class).
CONCLUSIONS: Perceived side effects emerged as an important barrier for uptake of hypothetical LAI-PrEP for a large proportion of potential MSM users. Minimizing out-of-pocket costs is likely to increase uptake, especially among younger racial minority groups, and is important to equitable access. Tailored communication strategies are recommended for the two different groups of potential LAI-PrEP users.