Willingness to Use Pre-Exposure Prophylaxis (PrEP): An Empirical Test of the Information-Motivation-Behavioral Skills (IMB) Model among High-Risk Drug Users in Treatment

Abstract

Evidence from recent pre-exposure prophylaxis (PrEP) trials has demonstrated its safety and efficacy in significantly reducing the risk of HIV acquisition for those who are at considerable risk of acquiring HIV infection. With a rapid increase in the amount of research on the efficacy of PrEP for HIV prevention, complementary research on the willingness to use PrEP has grown, especially among MSM, but limited research has been focused among people who use drugs (PWUD). As part of the formative process, we utilized the Information-Motivation-Behavioral Skills (IMB) model of health behavior change to characterize and guide intervention development for promoting willingness to use PrEP among high-risk PWUD. The analysis included 400 HIV-negative high-risk PWUD enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed support for the IMB model as PrEP-related behavioral skills were found to mediate the influence of PrEP-related information and motivation on willingness to use PrEP. The results provide evidence as to the utility of the IMB model to increase willingness to use PrEP among high-risk PWUD. It therefore makes an important contribution to our understanding of the applicability of theoretically-grounded models of willingness to use PrEP among high-risk PWUD, who are one of the key risk populations who could benefit from the use of PrEP.

Limited Knowledge and Mixed Interest in Pre-Exposure Prophylaxis for HIV Prevention Among People Who Inject Drugs

“…With increasing levels of opioid use and injection in many areas of the United States, 31,32 the introduction of even one case of HIV into PWID networks has the potential to rapidly spread HIV, 5 threatening the large strides made toward HIV prevention. Although there is a vast and growing literature on PrEP knowledge and interest among MSM, 33,34 few studies [10][11][12][13][14][15] and no in-depth qualitative examinations-have explored PrEP knowledge and interest among PWID. In our qualitative study among PWID in the US Northeast, where HIV transmission attributed to injection drug use appears to be increasing, 20 we found that knowledge of PrEP was extremely low, and interest in using PrEP was mixed and depended on prior PrEP knowledge and HIV risk perceptions that were complex and suboptimal.…”

“…Among patients engaged in methadone treatment for opioid use disorder, an intervention based on an Information-Motivation-Behavioral skills model of PrEP uptake resulted in increased willingness to use PrEP. 15,57 This model emphasized the need for at-risk individuals to have information (accurate, factual knowledge of HIV transmission and PrEP efficacy, safety, and dosage), motivation (perceived HIV risk and positive healthcare attitudes and personal intentions), and behavioral skills (self-efficacy for obtaining and using PrEP, action planning for PrEP consultations, screening appointments, and adherence). 58 However, the appropriateness of this model for out-of-treatment individuals with current injection drug use should be assessed in future studies.…”

“…9 A small number of surveys have identified low knowledge of the existence of PrEP among PWID in North America (ranging from 3% to 31% of samples surveyed). [10][11][12][13][14][15] Low knowledge of PrEP may result, in part, from physicians' reluctance to discuss or prescribe it to people who use and inject drugs, 16,17 possibly due, in part, to concerns or assumptions about medication adherence. 18 However, several studies have identified moderately high ''willingness'' to use PrEP among PWID, which was associated with engaging in known HIV risk behaviors.…”

“…18 However, several studies have identified moderately high ''willingness'' to use PrEP among PWID, which was associated with engaging in known HIV risk behaviors. [11][12][13][14][15] Nevertheless, in-depth research on PrEP knowledge, interest, and related intervention needs is lacking. We thus undertook a qualitative study to help inform efforts to increase PrEP uptake in this socially marginalized population.…”

Uptake and willingness to use PrEP among Chinese gay, bisexual and other men who have sex with men with experience of sexualized drug use in the past year

“…In order to develop effective intervention to promote PrEP, it is important to understand factors associated with willingness to use PrEP among GBMSM with experience of SDU. At least three quantitative studies investigated factors associated with willingness to use PrEP among high-risk drug users [30][31][32]. These studies had found a number of factors to be associated with willingness to use PrEP, including age, types and frequency of drug use, perceptions of HIV risk and PrEP (e.g., perceived effectiveness, would be less worried if on PrEP, concerns related to side effects, and confident to use/adhere to PrEP) [30][31][32].…”