***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 In school-based research , usually the nature of the intervention or other practical factors indicate that assignment of treatment be done by school or classroom rather than by individual student . In this situation , r and omization of schools ( or classrooms ) and analysis by school means ( or classroom means ) provide a firm statistical basis for internal validity of the study . When the number of schools available is small , this approach is not practicable , and therefore the investigator must be both more creative in developing solutions and more cautious in interpreting the results . This article provides a number of suggestions which the authors hope will assist the field in dealing with such circumstances . The authors stress that the best approach to assessing treatment effect is a well- design ed , properly analyzed r and omized experiment . The suggestions in this article attempt to indicate how one might make the most that one can from more limited data This article review s major risk factors for cigarette smoking , alcohol , and other drug abuse and promising community-based approaches to primary prevention . In a longitudinal experimental study , 8 representative Kansas City communities were assigned r and omly to program ( school , parent , mass media , and community organization ) and control ( mass media and community organization only ) conditions . Programs were delivered at either 6th or 7th grade , and panels were followed through Grade 9 or 10 . The primary findings were ( a ) significant reductions at 3 years in tobacco and marijuana use and ( b ) equivalent reductions for youth at different levels of risk . This study provides evidence that a comprehensive community program-based approach can prevent the onset of substance abuse and that the benefits are experienced equally by youth at high and low risk CONTEXT Home-visitation services have been promoted as a means of improving maternal and child health and functioning . However , long-term effects have not been examined . OBJECTIVE To examine the long-term effects of a program of prenatal and early childhood home visitation by nurses on women 's life course and child abuse and neglect . DESIGN R and omized trial . SETTING Semirural community in New York . PARTICIPANTS Of 400 consecutive pregnant women with no previous live births enrolled , 324 participated in a follow-up study when their children were 15 years old . INTERVENTION Families received a mean of 9 home visits during pregnancy and 23 home visits from the child 's birth through the second birthday . DATA SOURCES AND MEASURES : Women 's use of welfare and number of subsequent children were based on self-report ; their arrests and convictions were based on self-report and archived data from New York State . Verified reports of child abuse and neglect were abstract ed from state records . MAIN RESULTS During the 15-year period after the birth of their first child , in contrast to women in the comparison group , women who were visited by nurses during pregnancy and infancy were identified as perpetrators of child abuse and neglect in 0.29 vs 0.54 verified reports ( P<.001 ) . Among women who were unmarried and from households of low socioeconomic status at initial enrollment , in contrast to those in the comparison group , nurse-visited women had 1.3 vs 1.6 subsequent births ( P=.02 ) , 65 vs 37 months between the birth of the first and a second child ( P=.001 ) , 60 vs 90 months ' receiving Aid to Families With Dependent Children ( P=.005 ) , 0.41 vs 0.73 behavioral impairments due to use of alcohol and other drugs ( P=.03 ) , 0.18 vs 0.58 arrests by self-report ( P<.001 ) , and 0.16 vs 0.90 arrests disclosed by New York State records ( P<.001 ) . CONCLUSIONS This program of prenatal and early childhood home visitation by nurses can reduce the number of subsequent pregnancies , the use of welfare , child abuse and neglect , and criminal behavior on the part of low-income , unmarried mothers for up to 15 years after the birth of the first child OBJECTIVES The purpose of this study was to implement and evaluate the effectiveness of a long-term tobacco use prevention program for junior high school students that used college undergraduate change agents  and telephone boosters . METHODS A psychosocial intervention combining refusal skills training , contingency management , and other tobacco use prevention method ologies such as telephone and mail boosters was implemented in 11 junior high schools in San Diego County , California . Eleven other junior high schools served as controls . Of the 2668 participants , 57 % were White/non-Hispanic , 24 % were Hispanic , and 19 % were of other racial/ethnic groups . College undergraduates served as change agents for both the classroom and booster interventions , the latter of which was delivered in the third ( ninth- grade ) year of the program . RESULTS At the end of the third year , the prevalence of tobacco use within the past month was 14.2 % among the intervention students and 22.5 % among the controls , yielding an odds ratio of 0.71 for analysis at the school level . CONCLUSIONS Both college undergraduate change agents and direct one-to-one telephone interventions appear to provide cost-effective tobacco-related behavior modification Tobacco and drug use remain major public health concerns . The aim of this study was to evaluate the effectiveness of a school health intervention program using life skills training ( LST ) to reduce tobacco and drug use among Thai high school students . A r and omized pretest and post-test comparative design was used to evaluate the effectiveness of the LST program . A total of 170 Thai students in grade s 7 - 12 were r and omly selected . The students in the control group received the tobacco and drug education curriculum normally provided ; the intervention group received a LST program that provided information and skills specifically related to drug and tobacco use . Students in the school health intervention program had statistically significant positive effects regarding knowledge level , attitudes , and the development of refusal , decision-making , and problem-solving skills . The results showed that a LST program was effective for preventing tobacco and drug use in Thai high school students 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 This paper evaluates a smoking prevention intervention aim ed at vocational school students , consisting of an existing Dutch in-school program ( three lessons each lasting 50 min ) and a computer-based tailored out-of-school program ( three tailored letters with smoking prevention messages mailed to students ' homes ) . Nineteen schools that already participated in the in-school program were r and omly assigned to the in-school or to the combined in-school and out-of-school condition . The remaining 17 schools were r and omly assigned to the out-of-school condition or to the control group . Effect outcomes were assessed at 6 , 12 and 18 months after a pre-test , and were based on initiation among never-smokers and continuation among ever-smokers . Twelve months after the pre-test ( post-test 2 ) , the in-school intervention was successful in preventing  vocational school students from continuing to smoke , compared with students in the control condition [ odds ratio ( OR ) = 0.49 ; 95 % confidence interval ( CI ) = 0.29 - 0.84 ] . Eighteen months after the pre-test ( post-test 3 ) , the tailored out-of-school intervention was successful in preventing smoking initiation , compared with students in the control condition ( OR = 0.42 ; 95 % CI = 0.18 - 0.96 ) . The effect of the combined approach was not larger than the sum of the effects of the in-school and the out-of-school effects In this article , we examine the impact of two universal , grade 1 preventive interventions on the onset of tobacco smoking as assessed in early adolescence . The classroom-centered ( CC ) intervention was design ed to reduce the risk for tobacco smoking by enhancing teachers ' behavior management skills in first grade and , thereby , reducing child attention problems and aggressive and shy behavior-known risk behaviors for later substance use . The family-school partnership ( FSP ) intervention targeted these early risk behaviors via improvements in parent-teacher communication and parents ' child behavior management strategies . A cohort of 678 urban , predominately African-American , public school students were r and omly assigned to one of three Grade 1 classrooms at entrance to primary school ( age 6 ) . One classroom featured the CC intervention , a second the FSP intervention , and the third served as a control classroom . Six years later , 81 % of the students completed audio computer-assisted self-interviews . Relative to controls , a modest attenuation in the risk of smoking initiation was found for students who had been assigned to either the CC or FSP intervention classrooms ( 26 % versus 33 % ) ( adjusted relative risk for CC/control contrast=0.57 , 95 % confidence interval ( CI ) , 0.34 - 0.96 ; adjusted relative risk for FSP/control contrast=0.69 , 95 % CI , 0.50 - 0.97 ) . Results lend support to targeting the early antecedent risk behaviors for tobacco smoking The entire 
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I conclude that school-based programs can have long-term effects of practical importance it they : include 15 or more sessions over multiple years , including some in high school ; use the social influence model and interactive delivery methods ; include components on norms , commitment not to use , intentions not to use , and training and practice in the use of refusal and other life skills ; and use peer leaders in some role .
School-based programs of this type can reduce smoking onset by 25–30 % , and school plus community programs can reduce smoking onset by 35–40 % by the end of high school .
Some early childhood programs that do not have smoking prevention as their main aim , including home nursing , the Good Behavior Game , the Positive Action program and others , seem to change the developmental trajectories of children so that they are less likely to engage in multiple problem behaviors , including smoking , as adolescents .