Crush: A Randomized Trial to Evaluate the Impact of a Mobile Health App on Adolescent Sexual Health.

Purpose: Mobile technology allows delivery of sexual and reproductive health (SRH) information directly to youth. We tested the efficacy of Crush, a mobile application aimed at improving sexual health by promoting the use of SRH services and contraception among female adolescents.

Methods: We recruited 1,210 women aged 14-18 years through social media advertising and randomized them into a Crush intervention group and a control group that received a wellness app. At 3 and 6 months post randomization, we compared changes from baseline in behaviors, attitudes, self-efficacy, perceived social norms, birth control knowledge, perceived control and use intentions, and SRH service utilization. Odds ratios were estimated with multivariable logistic regression and adjusted for baseline outcome, age, race/ethnicity, mother's education, and sexual experience.

Results: There was no difference in accessing SRH services according to study group. Three months post baseline, Crush users had higher odds (p < .05) than control participants of reporting confidence in accessing SRH services (adjusted odds ratio [aOR] = 1.6, 95% confidence interval [CI]: 1.1-2.3) and of believing that it is a good thing to use birth control consistently (aOR = 2.3, 95% CI: 1.4-3.8). Six months after baseline, Crush users had higher odds than control participants of reporting they can control whether birth control is used every time they have sex (aOR = 1.8, 95% CI: 1.2-2.6) and perceiving they would get pregnant if they did not use birth control (aOR: 1.5, 95% CI: 1.1-2.2). Impacts on other behavioral constructs were also found.

Discussion: Crush was associated with improvements in knowledge, attitudes, and self-efficacy related to key SRH behaviors and may be a strategy to deliver SRH education to adolescent women. Studies including larger numbers of sexually active adolescents are needed to demonstrate behavioral impacts.