***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND No long-term impact has yet been observed with the use of the social-influences approach to school-based smoking prevention for youth . However , whether this lack of impact is due to method ologic problems with the studies or to the failure of the interventions is unclear . The Hutchinson Smoking Prevention Project ( HSPP ) , conducted from September 1984 through August 1999 , aim ed to attain the most rigorous r and omized trial possible to determine the long-term impact of a theory-based , social-influences , grade 3 - 12 intervention  on smoking prevalence among youth . METHODS Forty Washington school districts were r and omly assigned to the intervention or to the  control condition .  Study participants were children enrolled in two consecutive 3rd grade s in the 40 districts ( n = 8388 ) ; they were followed to 2 years after high school . The trial achieved high implementation fidelity and 94 % follow-up . Data were analyzed with the use of group-permutation methods , and all statistical tests were two-sided . RESULTS No significant difference in prevalence of daily smoking was found between students in the control and experimental districts , either at grade 12 ( difference [ Delta ] = 0.2 % , 95 % confidence interval [ CI ] = -4.6 % to 4.4 % , and P = .91 for girls ; Delta = 0.3 % , 95 % CI = -5.0 % to 5.5 % , and P = .89 for boys ) or at 2 years after high school ( Delta = -1.4 % , 95 % CI = -5.0 % to 1.6 % , and P = .38 for girls ; Delta = 2.6 % , 95 % CI = -2.5 % to 7.7 % , and P = .30 for boys ) . Moreover , no intervention impact was observed for other smoking outcomes , such as extent of current smoking or cumulative amount smoked , or in subgroups that differ in a priori specified variables , such as family risk for smoking . CONCLUSION The rigor of the HSPP trial suggests high credence for the intervention impact results . Consistent with previous trials , there is no evidence from this trial that a school-based social-influences approach is effective in the long-term deterrence of smoking among youth BACKGROUND Interventions design ed to prevent tobacco and alcohol use targeting high-risk adolescents are limited . In addition , few studies have attempted to improve parent-child communication skills as a way of improving and maintaining healthy youth decision-making . METHODS A total of 660 Hispanic migrant families participated in a r and omized pre-post control group study that was utilized to determine the impact of the intervention on parent-child communication . Both treatment and attention-control groups of youth were exposed to an eight-session culturally sensitive program presented by bilingual/bicultural college students . Parents jointly attended three of the eight sessions and participated in helping their child complete homework assignments supporting the content of each session . The content of the treatment intervention included ( 1 ) information about tobacco and alcohol effects , ( 2 ) social skills training ( i.e. , refusal skills ) , and ( 3 ) the specific development of parent-child communication skills to support healthy youth decisions . RESULTS Significant intervention by household size interactions for both parent and youth perceptions of communication were found indicating that the treatment was effective in increasing communication in families with fewer children . Based on the effect size and the previously established relationship between communication and susceptibility to tobacco and alcohol use , it was determined that the intervention effect could be translated into a future 5 to 10 % decrease in susceptibility for these smaller families . CONCLUSIONS A culturally sensitive family-based intervention for migrant Hispanic youth was found to be effective in increasing perceived parent-child communication in families with fewer children . It is expected that increases in this important protective factor will lead to later observed decreases in tobacco and alcohol use The present study was design ed to test the feasibility , acceptability , and effectiveness of a 15-session smoking prevention intervention with a predominantly hispanic ( 74 % ) sample of seventh- grade students ( N=471 ) in eight urban schools in the New York area . The smoking prevention curriculum teaches social resistance skills within the context of a broader intervention promoting general personal and social competence and was implemented in this study by regular classroom teachers . Results of logistic regression analyses provided preliminary evidence of the efficacy of this type of smoking prevention strategy with urban minority youth when implemented with a reasonable degree of fidelity . The significance of these findings is that they provide support for the generalizability of an approach previously found to be effective with white middle-class population s to a predominantly hispanic inner-city population A  grade five through eight substance abuse prevention program , later incorporated into the Michigan Model for Comprehensive School Health Education , was developed , implemented , and evaluated . Results focus on students who received seven lessons on alcohol in grade six , and eight lessons on tobacco , alcohol , marijuana , and cocaine in grade seven taught by their regular classroom teachers ( after a 6-hour training in the social pressures resistance skills curriculum ) . Students ( N = 442 ) received either two years of the program or none , and completed individually-coded question naires . Repeated measures analysis of variance result ed in significant treatment by occasion interactions on the use of alcohol , cigarettes , marijuana , cocaine , and other drugs , as well as on knowledge . At the end of grade seven , program students '  rates of substance use had increased significantly less and knowledge of alcohol pressures , effects , and skills to resist had increased significantly more than those of comparison students The research community has criticized Drug Abuse Resistance Education ( D.A.R.E. ) because the extant literature indicates a lack of evidence that the elementary school program prevents drug use . Yet D.A.R.E. continues to be the most widely implemented drug use prevention program in the United States and has considerable community support . To date , the junior high D.A.R.E. program has not been evaluated . The Minnesota DARE PLUS Project is a r and omized trial of 24 schools and communities . During 1999 - 2001 , students in eight schools will receive the junior high D.A.R.E. curriculum in 7th grade ; eight schools also will receive the curriculum as well as additional parent involvement , peer leadership , and community components in the 7th and  8th grade s ; and eight schools will serve as controls . This article describes the background and conceptualization , the curriculum and additional intervention components , and the evaluation methods of the DARE PLUS Project BACKGROUND In longitudinal smoking prevention studies , a difficulty in evaluating treatment effects is underst and ing whether bias is associated with those who do not complete the study . This study presents the significant predictors of attrition and suggests how to reduce attrition bias in evaluating program effects . METHODS Survival analysis methods were used to assess factors associated with attrition at different time points of the study . RESULTS Results of the analysis indicate that those who drop out tend to be of lower academic achievement , have lower tobacco and health knowledge , and have lower social influence/resistance skills knowledge , and are more likely to be smokers and to be marijuana users . Blacks are more likely to drop out than the other ethnic groups . Gender is not a significant predictor for dropout . The dropout rates among the treatment conditions are significantly different . CONCLUSIONS The findings of this study demonstrate that attritions in longitudinal smoking prevention studies are not at r and om . By considering the characteristics of dropouts , one can reduce attrition bias using available procedures and can take appropriate strategies for reducing dropout rates in future smoking prevention studies OBJECTIVE To examine the long-term effects of an intervention combining teacher training , parent education , and social competence training for children during the elementary grade s on adolescent health-risk behaviors at age 18 years . DESIGN Nonr and omized controlled trial with follow-up 6 years after intervention . SETTING Public elementary schools serving high-crime areas in Seattle , Wash. PARTICIPANTS Of the fifth- grade students enrolled in participating schools , 643 ( 76 % ) were given written parental consent for the longitudinal study and 598 ( 93 % ) were followed up and interviewed at age 18 years . INTERVENTIONS A full intervention provided in grade s 1 through 6 of 5 days of in-service training for teachers each intervention year , developmentally appropriate parenting classes offered to parents when children were in grade s 1 through 3 and 5 through 6 , and developmentally adjusted social competence training for children in grade s 1 and 6 . A late intervention , provided in grade s 5 and 6 only , paralleled the full intervention at these grade s. MAIN OUTCOME MEASURES Self-reported violent and nonviolent crime , substance use , sexual activity , pregnancy , bonding to school , school achievement , grade repetition and school dropout , suspension and /or expulsion , and school misbehavior ; delinquency charges from court records ; grade point average ; California Achievement Test scores : and disciplinary action reports from school records . RESULTS Fewer students receiving full intervention than control students reported violent delinquent acts ( 48.3 % vs 59.7 % ; P=.04 ) , heavy drinking ( 15.4 % vs 25.6 % ; P=.04 ) , sexual intercourse ( 72.1 % vs 83.0 % ; P=.02 ) , having multiple sex partners ( 49.7 % vs 61.5 % ; P=.04 ) , and pregnancy or causing pregnancy ( 17.1 % vs 26.4 % ; P=.06 ) by age 18 years . The full intervention student group reported more commitment ( P=.03 ) and attachment ( P=.006 ) to school , better academic achievement ( P=.01 ) , and less school misbehavior ( P=.02 ) than control students . Late intervention in grade s 5 and 6 only did not significantly affect health-risk behaviors in adolescence . CONCLUSIONS A package of interventions with teachers , parents , and children provided throughout the elementary grade s can have enduring effects in reducing violent behavior , heavy drinking , and sexual intercourse by age 18 years among multiethnic urban children . Results are consistent with the theoretical model guiding the intervention and support efforts to reduce health-risk behaviors through universal interventions in selected communities or schools serving high-crime neighborhoods OBJECTIVE To test the efficacy of 2 programs design ed to reduce high-risk behaviors among inner-city African American youth . DESIGN Cluster r and omized trial . SETTING Twelve metropolitan Chicago , Ill , schools and the communities they serve , 1994 through 1998 . PARTICIPANTS Students in grade s 5 through 8 and their parents and teachers . INTERVENTIONS The social development curriculum ( SDC ) consisted of 16 to 21 lessons per year focusing on social competence skills necessary to manage situations in which high-risk behaviors occur . The school/community intervention ( SCI ) consisted of SDC and school-wide climate and parent and community components . The control group received an attention-placebo health enhancement curriculum ( HEC ) of equal intensity to the SDC focusing on nutrition , physical activity , and general health care . MAIN OUTCOME MEASURES Student self-reports of violence , provocative behavior , school delinquency , substance use , and sexual behaviors ( intercourse and condom use ) . RESULTS For boys , the SDC and SCI significantly reduced the rate of increase in violent behavior ( by 35 % and 47 % compared with HEC , respectively ) , provoking behavior ( 41 % and 59 % ) , school delinquency ( 31 % and 66 % ) , drug use ( 32 % and 34 % ) , and recent sexual intercourse ( 44 % and 65 % ) , and improved the rate of increase in condom use ( 95 % and 165 % ) . The SCI was significantly more effective than the SDC for a combined behavioral measure ( 79 % improvement vs 51 % ) . There were no significant effects for girls . CONCLUSIONS Theoretically derived social-emotional programs that are culturally sensitive , developmentally appropriate , and offered in multiple grade s can reduce multiple risk behaviors for inner-city African American boys in grade s 5 through 8 . The lack of effects for girls deserves further research This paper reports on the evaluation of a culturally grounded prevention intervention targeting substance use among urban middle-school students . The curriculum consists of 10 lessons promoting antidrug norms and teaching resistance and other social skills , reinforced by booster activities and a media campaign . Three versions were delivered : Mexican American , combined African American and European American , and Multicultural . Thirty-five middle schools were r and omly assigned to 1 of the 3 versions or the control . Students completed baseline and follow-up question naires over a 2-year period ( total 6,035 respondents ) . Analyses utilizing a generalized estimating equations approach assessed the overall effectiveness of cultural grounding and the cultural matching hypothesis . Support was found for the intervention 's overall effectiveness , with statistically significant effects on gateway drug use as well as norms , attitudes , and resistance strategies but with little support for the cultural matching hypothesis . Specific contrasts found the Mexican American and Multicultural versions impacted the most outcomes Objective : To assess the effect of an antismoking intervention focusing on adolescents in lower education . Students with lower education smoke more often and perceive more positive norms , and social pressure to smoke , than higher educated students . An intervention based on peer group pressure and social influence may therefore be useful to prevent smoking among these students . Design : Group r and omised controlled trial . Setting : 26 Dutch schools that provided junior secondary education . Subjects : 1444 students in the intervention and 1118 students in the control group , all in the first grade , average age 13 years . Intervention : Three lessons on knowledge , attitudes , and social influence , followed by a class agreement not to start or to stop smoking for five months and a class based competition . Main outcome measures : Comparison of smoking status before and immediately after and one year after the intervention , using multilevel analysis . Results : In the intervention group , 9.6 % of non-smokers started to smoke , in the control group 14.2 % . This leads to an odds ratio of 0. 
    Output:
    
The more-inclusive meta-analyses suggest that school-based smoking prevention programs can have significant and practical effects in both the short- and the long-term .
Findings suggest that school-based smoking prevention programs can have significant long-term effects if they : 1 ) are interactive social influences or social skills programs ; that 2 ) involve 15 or more sessions , including some up to at least ninth grade ; that 3 ) produce substantial short-term effects .
The effects do decay over time if the interventions are stopped or withdrawn , but this is true of any kind of intervention