In the second stage of sampling, 180 schools with any of grades 9–12 were sampled with probability proportional to school enrollment size from within the 54 PSUs.
These behaviors frequently are interrelated and are established during childhood and adolescence and extend into adulthood.
To monitor priority health behaviors in each of these six categories, the prevalence of obesity, overweight, and asthma, and other priority health behaviors among youth and young adults, CDC developed the Youth Risk Behavior Surveillance System (YRBSS) ().
In the United States in 2014, 71% of all deaths among persons aged 10–24 years resulted from four causes: motor vehicle crashes (23%), other unintentional injuries (17%), homicide (14%), and suicide (17%) ().
These leading causes of mortality, morbidity, and social problems among youth and adults in the United States are related to six categories of priority health behaviors: 1) behaviors that contribute to unintentional injuries and violence; 2) tobacco use; 3) alcohol and other drug use; 4) sexual behaviors that related to unintended pregnancy and sexually transmitted infections (STIs), including HIV infection; 5) unhealthy dietary behaviors; and 6) physical inactivity.
Additional information about YRBSS is available at
This report summarizes results for 118 health behaviors plus obesity, overweight, and asthma from the 2015 national YRBS and overall trends in health behaviors during 1991–2015.
YRBSS includes school-based national, state, and large urban school district Youth Risk Behavior Surveys (YRBS) conducted among representative samples of students in grades 9–12.
Among those with weighted data for 2015, three state and one large urban school district surveys were conducted during fall 2014; the national survey, 29 state, and 16 large urban school district surveys were conducted during spring 2015; and five state and two large urban school district surveys were conducted during fall 2015. A three-stage cluster sample design produced a nationally representative sample of students in grades 9–12 who attend public and private schools.The first-stage sampling frame consisted of 1,259 primary sampling units (PSUs), consisting of counties, subareas of large counties, or groups of smaller, adjacent counties.Results from the 37 state and 19 large urban school district surveys with weighted data for the 2015 YRBSS cycle ( Figure) also are included in this report.Data from 10 state and two large urban school district surveys with unweighted data are not included.The 1,259 PSUs were categorized into 16 strata according to their metropolitan statistical area (MSA) status (e.g., urban city) and the percentages of black and Hispanic students in the PSUs.