PURPOSE: Patient portal use may improve access to or use of sexual and reproductive health (SRH) services for adolescents. We examined the association between adolescent secure messaging on a portal and use of SRH services in one health system. METHODS: We conducted a retrospective cohort study using electronic health records of adolescents aged 13-17 at Kaiser Permanente Washington from 2019 to 2021. Using month of observation as our unit of analysis, we estimated unadjusted and adjusted odds ratios and 95% confidence intervals (CIs) for associations between secure messages sent and 3 outcomes: (1) sexually transmitted infection (STI) tests ordered in the observed month, and among pregnancy-capable individuals
(2) pregnancy tests
and (3) prescription contraceptive methods ordered. RESULTS: Thirty-seven thousand eight hundred eighteen unique individuals contributed 667,678 months of individual observation. Among observed months with STI testing, 6.1% sent secure messages compared to 1.1% in months with no STI testing. Observed months with secure messaging had significantly greater odds of STI tests ordered than months without messaging, after adjusting for covariates (adjusted odds ratio (aOR) 3.5, 95% CI 2.9-4.3). Among observed months with prescription contraceptive orders, 5.0% sent a portal message compared to 1.4% without prescription contraceptive orders. Observed months with secure messaging among pregnancy-capable individuals had significantly greater odds of pregnancy tests (aOR 2.6, 95% CI 2.2-3.1) and prescription contraceptive orders (aOR 1.9, 95% CI 1.7-2.2) than months without messaging. DISCUSSION: The use of secure messaging by adolescents was more common among those with concurrent SRH care needs.