Youth Risk Behavioral Surveillance System

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Introduction

This summary data portal presents an analysis of trends for selected indicators in youth risk behaviors in Lancaster County, as measured by the Youth Risk Behavior Surveillance System (YRBSS) administered every odd year from 2001-2015. The research data it is based on was facilitated by the existence of a national Youth Risk Behavior Surveillance System (YRBSS). The national YRBSS was first implemented in 1990 to measure prevalence among young people of behaviors that put their health at risk. The YRBSS is a coordinated system using a standardized survey tool and sampling methods reproduced in the majority of states and many localities across the United States.

Before the establishment of the YRBSS, there was little information on the prevalence of these important risk behaviors among youth in the United States. The YRBSS focuses on areas of risky behaviors that are arguably the major precursors to death, illness and disability among Americans; not only in their teen years, but also later in adult life. Unintentional injuries alone account for the majority of Lancaster County deaths among youth and young adults aged 14 to 24. Motor vehicle crashes, other unintentional injuries, assault and suicide accounted for 80 percent of all year 2013 deaths to those 14 to 24 years of age (Vital Statistics 2013). Although cardiovascular disease and cancer are the major killers of adults, the majority of risk behaviors for these diseases are initiated during adolescence. Unintended teen pregnancy and sexually transmitted disease infection acquired in the teen years cause additional illness and death among youth, young adults, and their children.

The Youth Risk Behavior Survey is an important surveillance, policy, and program management tool for communities, states, and the nation. YRBSS data provide quantifiable evidence of serious risks to health among youth which demand public attention and public health action. As such, the data are useful in raising public awareness of the extent of youth risk behaviors. YRBSS data are tools for policy, helping to identify public health issues among youth that support the need for health education and other prevention efforts for children and youth. The YRBSS is also a tool for prevention and intervention programs -- the data is instrumental in setting program goals and objectives, monitoring the progress and outcomes of public health and other community action, and implementing or modifying public health programs to address the behaviors of young people in priority issue areas.

Data Collection, Analysis:

Local data collection was made possible by the cooperation of the Nebraska Department of Health and Human Services and Department of Education officials coordinating the state YRBSS, as well as the Nebraska YRBSS contractor.The Lincoln-Lancaster County Health Department separately contracted with the YRBSS contractor over a number of years to obtain an “over-sample” of the Lancaster County portion of the state survey. This provides the additional sample size needed to obtain valid county-level statistics.

The Youth Risk Behavior Survey measures the prevalence of health-risk behaviors among adolescents through representative national, state, and local surveys conducted biennially. The national and state surveys use multi-stage cluster sampling to obtain samples of students in grades 9-12 reflecting the geographic, urban-rural, racial, gender, and grade make-up of the population in those grade levels. While the national YRBSS survey is done biennially in odd years (e.g. 2003, 2005, 2007, etc.) the CDC has given Nebraska permission to ask the 2013 and 2015 YRBSS surveys in the fall of 2012 and 2014 (2012-2013 and 2014-2015 school years respectively) in conjunction with other surveys. Therefore we show 2015 results even though the national data will not be available until later in 2015 since the survey elsewhere is being conducted in the spring of 2015. In Lancaster County, the great majority of public schools (urban and rural schools) have participated every survey year, with a high number of schools participating in most years. The survey is conducted in randomly selected classrooms of a required period (second or English period). Active parental consent has been enforced since 1997 in Lincoln’s public schools.

All YRBS data analysis about Lancaster County youth risk behaviors, whether changes over time or differences between groups, were based on review of statistically significant differences or changes (at a 95% confidence level) and a critical evaluation of consistent data trends. Our goal is to avoid misleading or invalid data comparisons while presenting public health data to meet the wide variety of citizen information needs. Some data analyses (data prior to 2011) are “grade-adjusted” numbers (with the exception of data by grade). This was necessary because of large variations from year to year in the proportion of students in each grade that were surveyed. Because there are often substantial behavioral differences between students in younger and older grades, these differences in grade composition of the sample from year to year interfered with valid comparison of behaviors between years or demographic groups. Data were therefore “grade-adjusted” to a common weighted grade distribution (1999 National Public Schools enrolment), so that we are comparing “apples to apples”, as it were.

Since 2011 we have had a sufficient sample size to have met the sampling methodology rules set forth by the CDC to establish weights for the YRBSS survey results. The weighting is done by CDC and is based on gender, grade and racial make-up of the student population. The “grade adjustment” or “weighted data” did not significantly affect trend directions, comparisons of males to females or of grades, or overall conclusions from the data. These procedures are used to remove any bias due to this particular sampling problem, and often helped to smooth out unstable data trends over time.

Acknowledgements

Nebraska Department of Health and Human Services