A randomized controlled trial was conducted from 2010 to 2012 in 11 high schools in two school districts in the southwestern United States. Personnel from the two districts selected the 11 schools, which were randomly assigned to receive either COPE or the attention control intervention, Healthy Teens. Schools were not matched on any characteristic. Program participants were freshman and sophomore students aged 1416 years enrolled in required health education classes. The 779 study participants had a mean age of 14 years, and 51.6% were female. The sample was 68.3% Hispanic/Latino, 14.1% White, 9.9% Black, 4.0% Asian, and 3.5% American Indian.
Research team members introduced the study to all students in the 11 high schools and gave assent/consent packets to those who expressed interest in the study. Students who returned a signed assent and parent consent were enrolled in the study. All students in the health classes received either COPE or Healthy Teens, but outcome measures were only obtained from study participants. The primary aim of the study was to assess the efficacy of COPE compared with Healthy Teens (which addresses various health issues that are not the focus of COPE) on healthy lifestyle behaviors measured by changes in physical activity and body mass index (BMI). Secondary outcomes were depressive and anxiety symptoms, social skills, substance use, and academic performance (i.e., grade in the health class).
High school health teachers received a full-day training on COPE to help them integrate the program into their health course for 15 weeks. Health teachers in the attention control schools received a full-day training on the Healthy Teens program. Healthy Teens was administered to mimic the delivery of COPE, but there was no overlap in content between the two programs. The Healthy Teens content focused on teen safety, dental care, infectious diseases, immunizations, and skin care. Students receiving Healthy Teens were provided with a manual and homework assignments each week, and the students were encouraged to review four parent newsletters with their parents. Notably, Healthy Teens students were only provided with pedometers during the first week and first post-intervention week to determine their average weekly step counts for assessment purposes. Fidelity to program implementation was monitored for both COPE and Healthy Teens programs. Health teachers in both groups were observed during program implementation by research staff for four announced sessions. The observers completed a standardized fidelity observation form during these sessions.
Because the study sample included a large number of Hispanic/Latino students, acculturation was measured with the Acculturation, Habits, and Interests Multicultural Scale for Adolescents. Acculturation, race/ethnicity, weight, and hours of television watched daily were included as control variables in the analyses. Outcome measures were assessed during the study period at baseline, post-intervention, 6-month follow-up, and 12-month follow-up.
Measures obtained at baseline and post-intervention were the following:
-- Step counts measured with a pedometer (Yamex SW-200).
-- Self-reported health behaviors measured using the 15-item Healthy Lifestyle Behaviors Scale. For each item (e.g., I exercise regularly), respondents answered using a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree).
Measures obtained only at post-intervention were the following:
-- Academic performance measured using the students health course grade obtained from school records.
-- Social skills measured with the Social Skills Rating System, completed by teachers.
Measures obtained at baseline, post-intervention, and 6-month follow-up were the following:
-- Self-reported anxiety symptoms measured with the anxiety subscale of the Beck Youth Inventory II (BYI-II).
-- Self-reported substance use measured with the Youth Risk Behavior Survey.
Measures obtained at baseline, post-intervention, and 6- and 12-month follow-up were the following:
-- Weight measured with a scale (Tanita).
-- BMI calculated from the weight measurement and height measured with a stadiometer.
-- Self-reported depressive symptoms measured with the depression subscale of the BYI-II. The subscale includes 20 items (e.g., I think that my life is bad). The sum of the items is standardized to a T score, with a mean of 50 and higher representing greater depression (i.e., <55 is the average norm, 5559 suggests mildly elevated depressive symptoms, 6069 suggests moderately elevated symptoms, 70+ suggests extremely elevated symptoms).