June 15, 2005
The YRBSS includes a national school-based survey conducted by CDC as well as state, territorial, and local school-based surveys conducted by education and health agencies. In these surveys, conducted biennially since 1991, representative samples of students in grades 9 through 12 are drawn. In 2003, a total of 15,214 students completed the national survey, and 32 states and 20 school districts also obtained data representative of their jurisdiction.
The national Youth Risk Behavior Survey is conducted from February through May of each odd-numbered year. All except a few states and cities also conduct their survey during this period. Separate samples are used in the national survey and state and local surveys. The national sample is not an aggregation of the state and local surveys, and state or local estimates cannot be obtained from the national survey.
Data-collection procedures are similar for national, state, and local surveys. Local procedures for obtaining parental permission are followed before administering a Youth Risk Behavior Survey in any school. We think it is worth noting that Federal law (the Protection of Pupil Rights Amendment 20 U.S.C. § 1232h) requires that parents be notified of the survey, be provided an opportunity to review the survey, and be provided an opportunity to opt their child out of participating in the survey.
For the national survey and the majority of state and local surveys, trained data collectors travel to each participating school to administer the questionnaire to students. These data collectors read a standardized script to participating students. The script includes an introduction to the survey and directions on how to complete the questionnaire.
Survey procedures for the national, state, and local surveys are designed to protect student privacy by allowing for anonymous and voluntary participation. In all surveys, students complete the self-administered questionnaire during one class period and record their responses directly in a computer-scannable booklet or on an answer sheet. To the extent possible, students' desks are spread throughout the classroom to minimize the chance that students will see each others' responses. Students also are encouraged to use an extra sheet of paper or an envelope, provided by the data collector, to cover their responses as they complete the questionnaire.
In the national survey, students who are absent on the day of data collection still can complete questionnaires if their privacy can be maintained. These make-up data-collection efforts sometimes are administered by the data collector; however, if the data collector cannot administer the questionnaire, school personnel can perform this task. Allowing students who were absent on the day of data collection to take the survey at a later date increases student response rates. In addition, because frequently absent students are more likely to engage in health-risk behaviors than students who are not frequently absent, these procedures help provide data that are representative of all high school students. In the 2003 national Youth Risk Behavior Survey, questionnaires from 664 students (5 percent of all participating students) were completed during a make-up data collection.
The national Youth Risk Behavior Survey uses a three-stage, cluster sample design to obtain a nationally representative sample of students in grades 9 through 12 in the United States. The target population comprises all public and private high school students in the 50 states and the District of Columbia. U.S. territories are excluded from the sampling frame. Sample sizes from the national Youth Risk Behavior Survey are designed to produce estimates that are accurate within ±5 percent at 95 percent confidence. For each national survey, the first-stage sampling frame includes primary sampling units (PSUs) consisting of large-sized counties or groups of smaller, adjacent counties. In the second stage of sampling, schools are selected from PSUs with probability proportional to size. To enable separate analyses, black and Hispanic students are over sampled. The final stage of sampling consists of randomly selecting, in each chosen school and in each of grades 9 through 12, one or two entire classes. Examples of classes include homerooms or classes of a required discipline (e.g., English and social studies). All students in sampled classes are eligible to participate. Sampled schools, classes, and students who refuse to participate in the survey are not replaced. Sampling without replacement maintains the integrity of the sample design and helps avoid the introduction of non-measurable bias into the sample.
Data on Steroid Use
Before each biennial survey, sites (states and districts) and CDC work together to revise the questionnaire so that it reflects site and national priorities. One question on illegal steroid use has been asked since 1991 – “During your life, how many times have you taken steroid pills or shots without a doctor’s prescription?” Since 1991, illegal steroid use has increased among high school students from 2.7 percent to 6.1 percent in 2003. Between 2001 and 2003, no change was noted in lifetime illegal steroid use. See the table below for more detailed 2003 national Youth Risk Behavior Survey results.
For more information on the methodology of the YRBSS see -- CDC. Methodology of the Youth Risk Behavior Surveillance System. MMWR. 53(RR-12):1-13, 2004. For the latest national, state, and local results see -- CDC. Youth Risk Behavior Surveillance – United States, 2003 MMWR. 53(SS-2):1-96, 2004.
Last Revised: June 16, 2005