标题：Use of a Social and Character Development Program to Prevent Substance Use, Violent Behaviors, and Sexual Activity Among Elementary-School Students in Hawaii
摘要：Objectives. We assessed the effectiveness of a 5-year trial of a comprehensive school-based program designed to prevent substance use, violent behaviors, and sexual activity among elementary-school students. Methods. We used a matched-pair, cluster-randomized, controlled design, with 10 intervention schools and 10 control schools. Fifth-graders (N = 1714) self-reported on lifetime substance use, violence, and voluntary sexual activity. Teachers of participant students reported on student (N = 1225) substance use and violence. Results. Two-level random-effects count models (with students nested within schools) indicated that student-reported substance use (rate ratio [RR] = 0.41; 90% confidence interval [CI] = 0.25, 0.66) and violence (RR = 0.42; 90% CI = 0.24, 0.73) were significantly lower for students attending intervention schools. A 2-level random-effects binary model indicated that sexual activity was lower (odds ratio = 0.24; 90% CI = 0.08, 0.66) for intervention students. Teacher reports substantiated the effects seen for student-reported data. Dose-response analyses indicated that students exposed to the program for at least 3 years had significantly lower rates of all negative behaviors. Conclusions. Risk-related behaviors were substantially reduced for students who participated in the program, providing evidence that a comprehensive school-based program can have a strong beneficial effect on student behavior. Substance use, violent behaviors, and early initiation of sexual activity occur at problematic levels among American youths. 1 – 4 Early initiation of substance use and engaging in violent behaviors during childhood place children at a greater risk of psychopathology, aggressive behaviors, and continuation of substance use during adolescence and into adulthood. 5 – 10 National estimates have indicated that approximately 43.3% of high school students had consumed alcohol, 35.9% had been in a physical fight, and 46.8% had engaged in sexual intercourse over the previous 12 months. 5 Thus, prevention programs that can reduce the incidence of such behaviors should provide clear public health benefits. Appropriately designed and implemented school-based prevention programs can prevent or reduce negative behaviors, 2 , 11 , 12 but some programs have not been evaluated for efficacy and effectiveness, 9 , 13 criteria deemed crucial in determining whether a program is ready for widespread adoption by schools. 14 , 15 Although studies indicate positive treatment effects for school-based prevention programs, the magnitude of effects is often modest. 16 , 17 The average effect size for such programs is 0.20 18 (comparable to a success rate of 9.5%), suggesting that there is considerable room for improvement in the effectiveness of prevention programs in reducing negative behaviors. In addition, accumulating evidence indicates that negative behaviors do not exist in isolation from one another, 2 , 19 so programs that address multiple co-occurring negative behaviors are likely to be of greater overall benefit. 20 , 21 Our goal was to evaluate the preventive benefits of the Positive Action program, a comprehensive schoolwide social and character development program. We hypothesized that the Positive Action program would result in lower rates of student substance use, violence, and voluntary sexual activity, as measured by student self-reports and teacher reports. Previous quasi-experimental studies of the Positive Action program 22 , 23 reported beneficial school-level effects on student achievement and serious problem behaviors (e.g., suspensions and violence). We build on previous research by reporting on a matched-pair, cluster-randomized controlled study. 14 These features of a study are important when examining the scientific credibility of intervention findings.
