Marijuana Use, Sexual Behaviors, and Prevalent Sexually Transmitted Infections among Sexually Experienced Males and Females in the United States: Findings from the National Health and Nutrition Examination Surveys

Background Several national guidelines consider illicit drug use as an indication for testing and/or counseling for some sexually transmitted infections (STIs). The legal and social landscape of marijuana use is changing, and its relevance with STI risk is unclear. Methods Sex-specific prevalence of T. vaginalis and/or C. trachomatis infection was examined by past-year marijuana use (no vs yes) among 2958 sexually experienced, 20- to 39-year-old participants of the 2013-2016 National Health and Nutrition Examination Surveys. Prevalence ratios (PRs) with 95% confidence intervals [CIs] were estimated by Poisson regression. Adjusted PRs (aPR) were estimated following propensity score covariate-adjustment accounting for sociodemographics, alcohol use, injection drug use, depression, and age at sexual debut. Results Past-year marijuana use was reported by 27.3% and 36.3% of females and males, respectively. Male and female past-year marijuana users were more likely to have new and multiple sexual partners in the past year (P < 0.05). Past-year marijuana use was associated with prevalent C. trachomatis and/or T. vaginalis infection among females (7.4% vs. 2.9%; PR, 2.57 [95% CI, 1.62-4.07]) and males (4.0% vs. 1.1%; PR, 3.59 [95% CI, 1.96-6.58]), but this association was attenuated after propensity score covariate adjustment among females (aPR, 1.15 [95% CI, 0.72-1.83]) and males (aPR, 2.10 [95% CI, 0.88-5.02]). Additional adjustment for new or multiple sexual partners further attenuated the associations (aPRs, 1.02 [95% CI, 0.65-1.51] and 1.91 [95% CI, 0.82-4.47] for females and males, respectively). Conclusions Sexually transmitted infection prevalence was higher among persons with a past-year history of marijuana use; however, this association was not significant after accounting for measured confounders. Additional work is needed to characterize STI prevalence by the mode, duration, and frequency of marijuana use.