Effect of including alcohol and cannabis content in a sexual risk-reduction intervention on the incidence of sexually transmitted infections in adolescents: A cluster randomized clinical trial

IMPORTANCE: Adolescents in the juvenile justice system are at high risk for sexually transmitted infections (STIs). Concurrent use of alcohol and cannabis increase this risk. OBJECTIVE: To determine whether a theory-based sexual risk-reduction intervention that included alcohol- and cannabis-focused content resulted in greater reductions in STIs than an intervention that included alcohol-related content only and an intervention that did not include substance use content. DESIGN, SETTING, AND PARTICIPANTS: Cluster randomized clinical trial with 3 conditions. Between July 1, 2010, and December 10, 2014, adolescents living at a juvenile detention facility in the southwestern United States were tested and treated for STI before randomization and again 12 months after the intervention. Data analyses were conducted in July and August 2017. Eligibility criteria included (1) being aged 14 to 18 years, (2) able to speak English, (3) having a remaining detention term of less than 1 month, and (4) signing a release granting access to STI results if tested at intake. Six hundred ninety-three adolescents were assessed for eligibility. Of these, 460 completed baseline assessments and were randomized to 1 of 3 intervention conditions. Data analysis was by intent-to-treat. INTERVENTIONS: There were 3 intervention conditions: sexual risk reduction intervention (SRRI); SRRI plus alcohol content (SRRI + ETOH); and SRRI + ETOH plus cannabis content (SRRI + ETOH + THC). Interventions were conducted in same-sex groups by trained clinicians and included video presentations with discussion, group activities, and active feedback by participants, consistent with the principles of motivational enhancement therapy. MAIN OUTCOMESAND MEASURES: Although not the outcomeonwhich the study was originally powered, the main outcome variable presented herein is STI incidence (Chlamydia trachomatis and/or Neisseria gonorrhoeae) 12 months after the intervention. RESULTS Of the 460 participants randomized, mean (SD) age was 15.8 (1.1) years, 347 participants (75.4%) were male, and 57.0% were of Hispanic ethnicity. Among the participants, 143 were randomized toSSRI, 155 to SRRI + ETOH, and 162 to SRRI + ETOH + THC. Attrition at 12-month follow-up was 99 (21.5%) for the STI outcome variable. Participants in the SRRI + ETOH + THC intervention had lower incidence of STI at follow-up (3.9%) than those in either the SRRI (12.4%; odds ratio, 0.29; 95% CI, 0.10-0.84) or the SRRI + ETOH (10.2%; odds ratio, 0.36; 95% CI, 0.12-1.05) interventions. CONCLUSIONS AND RELEVANCE: An intervention delivered in a motivational enhancement therapy format that includes theory-based sexual risk reduction combined with alcohol- and cannabis-focused elements is effective at reducing STI incidence among justice-involved adolescents. This 1-session manualized intervention can be delivered in the context of short-term detention and is easily disseminated to juvenile justice agencies.