Abstract and Introduction
Abstract
Background: Despite evidence supporting pre-exposure prophylaxis (PrEP) efficacy, there are concerns regarding the feasibility of widespread PrEP implementation among men who have sex with men (MSM). To inform the development of targeted PrEP delivery guidelines, sexual risk trajectories among HIV-negative MSM were characterized.
Methods: At semiannual visits from 2003 to 2011, HIV-negative MSM (N = 419) participating in the Multicenter AIDS Cohort Study provided data on sexual risk behaviors (SRBs) since their last visit. Based on their reported behaviors, participants were assigned a SRB score at each visit as follows: 0 = no insertive or receptive anal intercourse, 1 = no unprotected insertive or receptive anal intercourse, 2 = only unprotected insertive anal intercourse, 3 = unprotected receptive anal intercourse with 1 HIV-negative partner, 4 = condom serosorting, 5 = condom seropositioning, and 6 = no seroadaptive behaviors. Group-based trajectory modeling was used to examine SRB scores (<4 vs. ≥4) and identify groups with distinct sexual risk trajectories.
Results: Three sexual risk trajectory groups were identified: low-risk (n = 264; 63.0%), moderate-risk (n = 96; 22.9%; mean duration of consecutive high-risk intervals ~1 year), and high-risk (n = 59; 14.1%; mean duration of consecutive high-risk intervals ~2 years). Compared to low-risk group membership, high-risk group membership was associated with younger age (in years) [adjusted odds ratio (AOR) = 0.92, 95% confidence interval (CI): 0.88 to 0.96], being White (AOR = 3.67, 95% CI: 1.48 to 9.11), earning an income ≥$20,000 (AOR = 4.98, 95% CI: 2.13 to 11.64), distress/depression symptoms (Center for Epidemiologic Studies Depression Scale ≥ 16) (AOR = 2.36, 95% CI: 1.14 to 4.92), and substance use (AOR = 2.00, 95% CI: 1.01 to 3.97).
Conclusions: Screening for the sociodemographic and behavioral factors described above may facilitate targeted PrEP delivery during high-risk periods among MSM.
Introduction
Daily oral pre-exposure prophylaxis (PrEP), a biomedical intervention for HIV prevention, reduces the risk of HIV acquisition between 44% and 75% depending on the population. Although demonstration projects assessing the acceptability and feasibility of PrEP use are underway, potential barriers to widespread PrEP implementation have been identified and include: adherence, acceptability, behavioral disinhibition, cost, lack of existing infrastructure for monitoring side effects, and viral resistance among PrEP users who become HIV infected. Thus, many argue that PrEP should only be delivered to high-risk populations within comprehensive HIV prevention programs that consist of behavioral, biomedical, and structural interventions.
Given the robust data suggesting PrEP's efficacy among men who have sex with men (MSM) and the high rates of HIV infection within segments of this population, MSM will likely be a group prioritized for PrEP delivery in the United States. Interim recommendations from the Centers for Disease Control and Prevention state that PrEP should be offered to MSM "at substantial, ongoing, high-risk for acquiring HIV infection." However, little is known about the duration of risk among MSM. Thus, how MSM at ongoing high-risk should be identified for PrEP use and how long they will need to take PrEP remain unclear.
Although several repeated cross-sectional studies have examined population trends in sexual risk behaviors (SRBs) among MSM over time, to our knowledge, previous studies have not specifically investigated patterns of SRB within individual HIV-negative MSM over sustained periods. One study conducted among older HIV-positive and HIV-negative MSM identified sexual risk trajectories based on the number of sexual partners reported over time. However, the measure of risk used in that study did not consider sexual practices associated with the greatest risk of HIV acquisition, such as unprotected receptive anal intercourse (URAI), or the HIV status of reported partners. Thus, to better classify and understand longitudinal patterns of risk among MSM, a comprehensive measure of risk that accounts for multiple factors affecting the risk of HIV infection should be used.
To inform the development of more targeted PrEP delivery guidelines for MSM, we created a comprehensive SRB score and used data from the Multicenter AIDS Cohort Study (MACS) to characterize distinct sexual risk trajectories among HIV-negative MSM and identify sociodemographic and behavioral factors associated with longitudinal patterns of risk.