Clear Links Between Starting Methamphetamine and Increasing Sexual Risk Behavior: A Cohort Study Among Men Who Have Sex With Men

Abstract

Background: It remains unclear if methamphetamine is merely associated with high-risk behavior or if methamphetamine use causes high-risk behavior. Determining this would require a randomized controlled trial, which is clearly not ethical. A possible surrogate would be to investigate individuals before and after starting the use of methamphetamine.

Methods: We performed a cohort study to analyze recent self-reported methamphetamine use and sexual risk behavior among 8905 men who have sex with men (MSM) receiving the "Early Test," a community-based HIV screening program in San Diego, CA, between April 2008 and July 2014 (total 17,272 testing encounters). Sexual risk behavior was evaluated using a previously published risk behavior score [San Diego Early Test (SDET) score] that predicts risk of HIV acquisition.

Results: Methamphetamine use during the last 12 months (hereafter, recent-meth) was reported by 754/8905 unique MSM (8.5%). SDET scores were significantly higher in the 754 MSM with recent-meth use compared with the 5922 MSM who reported that they have never used methamphetamine (P < 0.001). Eighty-two repeat testers initiated methamphetamine between testing encounter, with significantly higher SDET scores after starting methamphetamine [median 5 (interquartile range, 2-7) at recent-meth versus median 3 (interquartile range, 0-5) at never-meth; P < 0.001, respectively].

Conclusions: Given the ethical impossibility of conducting a randomized controlled trial, the results presented here provide the strongest evidence yet that initiation of methamphetamine use increases sexual risk behavior among HIV-uninfected MSM. Until more effective prevention or treatment interventions are available for methamphetamine users, HIV-uninfected MSM who use methamphetamine may represent ideal candidates for alternative effective prevention interventions (ie, preexposure prophylaxis).

Figure 1

Graphical illustration of temporal relationship between methamphetamine use and sexual risk behavior among repeat testing men who have sex with men (MSM) who started methamphetamine between their testing encounters.

Figure 2

SDET scores at first and most recent testing encounter in MSM repeat testers (n=1789; first and most recent test > 12 months apart): A) repeat testers that started using methamphetamine while in follow up, B) repeat testers that stopped using methamphetamine, C.) repeat testers that reported recent methamphetamine use at their first and most recent testing encounter, D) repeat testers that never used methamphetamine. P- values are displayed.