Stanford
Prevention Policy Modeling Lab

Adolescent and School Health

Research Area

Adolescent and School Health

Click on a project title to learn more about PPML's work in Adolescent and School Health.

Past Projects

Estimating the size of sexual minority adolescent populations — at national, state, and local levels— is critical for recognizing and responding to disparities in health risks and outcomes. This project uses state Youth Risk Behavior Survey (YRBS) data to estimate the number of adolescents who identify as lesbian, gay, or bisexual (LGB). PPML predicts estimates in states where YRBS does not measure these responses directly using machine learning methods. Further expansion of this project used 2021 YRBS data aims to understand the proportions of high school students identifying as LGB by state, and further stratified by grade, year of age, and race/ethnicity.

 Associated Publications

Estimating the size of sexually active adolescent populations at a sub-national level, such as county, can improve local understanding of the disease burden of sexually transmitted infections. These estimates would also facilitate comparisons of disease rates, such as HIV and syphilis, between men who have sex with men and other populations. This project combined data from several different sources, including the National Survey on Family Growth, American Community Survey, and Youth Risk Behavior Survey, to develop state and county-level estimates for the proportion of the high-school-age population that is sexually active.

In addition, these estimates have been leveraged to calculate and disseminate disease rates for this population, computing rates of gonorrhea, chlamydia, primary & secondary syphilis, and HIV among sexually active adolescents.

Adolescent birth rates in the United States are declining, yet regional and racial disparities in teen birth rates and sexually transmitted infections persist. This study examined trends in adolescent sexual behaviors and contraceptive use, using national and state-level YRBS data from 2007 to 2023. We analyzed changes in sexual activity, condom use, and pregnancy prevention methods among sexually active female high school students, stratifying by region, race and ethnicity, and age.

In 2006, CDC recommended routine HIV testing for adolescents and adults, ages 13 to 64, in the United States. These recommendations were based on several factors and studies, including the overall and undiagnosed prevalence of HIV in the United States, the availability, accuracy, rapidity, and low cost of the HIV test, and the availability of highly effective and life-saving therapies for HIV. Model-based analyses suggested that routine HIV testing would be very cost-effective, although these analyses did not include adolescents specifically.

The current CDC recommendations are based on a model using case surveillance among those aged 13 and over. While the recommendations imply that it is worthwhile to get tested at least once in a lifetime, this recommendation is difficult to interpret early in the life course. National data highlight that HIV prevalence varies across age groups and is much lower in teens than in young and older adults. For these reasons, there is an important need to further refine the lower end of the age range for HIV testing guidelines.

This project examined the yield, cost, and cost-effectiveness of routine HIV testing in school-aged adolescents and young adults in the United States.

Associated Publication

Chlamydia diagnosis rates are highest among people under the age of 25. A significant percentage of this population is school-aged, enrolled in educational facilities. Schools offer a structured setting for targeted interventions intended to reduce chlamydia prevalence, such as screening. 

This project evaluated the impact and cost-effectiveness of school-based screening for chlamydia within a variety of community settings. The analysis explored the impact of screening programs by modeling a range of intervention strategies in urban settings, characterized by varying profiles and pre-existing levels of chlamydia screening in public high schools. Three urban school-based chlamydia screening programs provided a strong empirical basis for modeling specific programs and associated outcomes. The model incorporated the data and profile of each participating site, accommodating replication of existing programs as well as a generalization to enable exploration of potential outcomes under a wide range of different circumstances reflecting variation in epidemiology and existing health services coverage.

Associated Publication