***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: PROBLEM Tobacco use is a major contributor to deaths from chronic diseases . The findings from the Global Youth Tobacco Survey ( GYTS ) suggest that the estimate of a doubling of deaths from smoking ( from 5 million per year to approximately 10 million per year by 2020 ) might be an underestimate because of the increase in smoking among young girls compared with adult females , the high susceptibility of smoking among never smokers , high levels of exposure to secondh and smoke , and protobacco indirect advertising . REPORTING PERIOD COVERED This report includes GYTS data collected during 2000 - 2007 from 140 World Health Organization ( WHO ) member states , six territories ( American Samoa , British Virgin Isl and s , Guam , Montserrat , Puerto Rico , and the U.S. Virgin Isl and s ) , two geographic regions ( Gaza Strip and West Bank ) , one United Nations administered province ( Kosovo ) , one special administrative region ( Macau ) , and one Commonwealth ( Northern Mariana Isl and s ) . For countries that have repeated GYTS , only the most recent data are included . For countries with multiple survey sites , only data from the capital or largest city are presented . DESCRIPTION OF SYSTEM GYTS is a school-based survey of a defined geographic site that can be a country , a province , a city , or any other geographic entity . GYTS uses a st and ardized methodology for constructing sampling frames , selecting schools and classes , preparing question naires , conducting field procedures , and processing data . GYTS st and ard sampling methodology uses a two-stage cluster sample design that produces sample s of students in grade s associated with students aged 13 - 15 years . Each sampling frame includes all schools ( usually public and private ) in a geographically defined area containing any of the identified grade s. In the first stage , the probability of schools being selected is proportional to the number of students enrolled in the specified grade s. In the second sampling stage , classes within the selected schools are selected r and omly . All students in selected classes attending school the day the survey is administered are eligible to participate . Student participation is voluntary and anonymous using self-administered data collection procedures . The GYTS sample design produces independent , cross-sectional estimates that are representative of each site . RESULTS The findings in this report indicate that the level of cigarette smoking between boys and girls is similar in many sites ; the prevalence of cigarette smoking and use of other tobacco products is similar ; and susceptibility to initiate smoking among never smokers is similar among boys and girls and is higher than cigarette smoking in the majority of sites . Approximately half of the students reported that they were exposed to secondh and smoke in public places during the week preceding the survey . Approximately eight in 10 favor a ban on smoking in public places . Approximately two in 10 students own an object with a cigarette br and logo on it , and one in 10 students have been offered free cigarettes by a tobacco company representative . Approximately seven in 10 students who smoke reported that they wanted to stop smoking . Approximately seven in 10 students who smoked were not refused purchase of cigarettes from a store during the month preceding the survey . Finally , approximately six in 10 students reported having been taught in school about the harmful effects of smoking during the year preceding the survey . INTERPRETATION The findings in this report suggest that interventions that decrease tobacco use among youth ( e.g. , increasing excise taxes , media campaigns , school programs in conjunction with community interventions , and community interventions that decrease minors ' access to tobacco ) must be broad-based , focused on boys and girls , and have components directed toward prevention and cessation . If effective programs are not developed and implemented soon , future morbidity and mortality attributed to tobacco probably will increase . PUBLIC HEALTH ACTION The synergy between countries in passing tobacco-control laws , regulations , or decrees ; ratifying the WHO Framework Convention on Tobacco Control ; and conducting GYTS offers a unique opportunity to develop , implement , and evaluate comprehensive tobacco-control policy that can be helpful to each country . The challenge for each country is to develop , implement , and evaluate a tobacco-control program and make changes where necessary Background : We investigated longitudinally the prevalence of smoking according to three stages of smoking ( never smoking , experimenting the smoking , and regular smoking ) , the rates of transition from one stage to another one , and determinant predictors of transition through these stages of smoking . Methods : Of all 10th grade students in Tabriz , 1785 students were r and omly selected and assessed twice , with a 12-month interval , with respect to the changes of stage . The predictor variables were measured when the students were in the 10th grade . Logistic regression and principal component analysis were used to analysis data at grade 11 . Findings : Of 1785 students , 14.3 % ( CI 95 % : 12.3 - 16.4 ) and 2.8 % ( CI 95 % : 2.0 - 4.0 ) of the never smokers became experimenters and regular smokers , respectively and 16.5 % ( CI 95 % : 12.4 - 21.7 ) of the experimenters became regular smokers . Among never smokers , participating in smoker groups ( OR=1.24 ) , having smoker friends ( OR=1.85 ) and a positive attitude towards smoking ( OR=1.22 ) predicted experimentation ; and participating in smokers groups ( OR=1.35 ) and a lower socioeconomic class ( OR=0.36 ) predicted regular smoking . Among experimenters , students having general high risk behaviors ( OR=2.56 ) and participating in smoker groups ( OR=2.58 ) were distinguished as those who progressed to regular smoking in follow-up . Conclusion : Programs aim ed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages , and targeting participation in smoker groups The goal of this study was to assess the effects of a school-based smoking prevention programme that used both a video and peer-led discussion groups among Romanian junior high school students aged 13 - 14 years . The programme embraced the social influence approach and concentrated on enhancing self-efficacy and the acquisition of cigarette refusal skills . Twenty schools were r and omly assigned to the control and experimental conditions , result ing in 55 participating classes from the seventh grade ( 28 in the control group and 27 in the experimental group ) . Pretest and 9 months follow-up data on weekly smoking initiation and psychosocial variables were collected from 1071 students .  Multilevel logistic regression analyses demonstrated a significant effect of the programme on adolescents ' smoking behaviour after 9 months . At post-test , weekly smoking onset was 4.5 % in the experimental group versus 9.5 % in the control group . Furthermore , the programme had significant effects on smoking-related beliefs . In the experimental group , this result ed in a more negative attitude towards smoking , increased social self-efficacy levels and a more negative intention towards smoking . These findings show that short-term effects of the smoking prevention programme can be realized in Romania . More studies are needed to analyse how to maintain these effects over time The entire early adolescent population of the 15 communities that constitute the Kansas City ( Kansas and Missouri ) metropolitan area has participated in a community-based program for prevention of drug abuse since September 1984 . The Kansas City area is the first of two major metropolitan sites being evaluated in the Midwestern Prevention Project , a longitudinal trial for primary prevention of cigarette , alcohol , and marijuana use in adolescents . The project includes mass media programming , a school-based educational program for youths , parent education and organization , community organization , and health policy components that are introduced sequentially into communities during a 6-year period . Effects of the program are determined through annual assessment s of adolescent drug use in schools that are assigned to immediate intervention or delayed intervention control conditions . In the first 2 years of the project , 22,500 sixth- and seventh- grade adolescents received the school-based educational program component , with parental involvement in homework and mass media coverage . Analyses of 42 schools indicate that the prevalence rates of use for all three drugs are significantly lower at 1-year follow-up in the intervention condition relative to the delayed intervention condition , with or without controlling for race , grade , socioeconomic status , and urbanicity ( 17 % vs 24 % for cigarette smoking , 11 % vs 16 % for alcohol use , and 7 % vs 10 % for marijuana use in the last month ) , and the net increase in drug use prevalence among intervention schools is half that of delayed intervention schools This study evaluated the substance initiation effects of an intervention combining family and school-based competency-training intervention components . Thirty-six rural schools were r and omly assigned to 1 of 3 conditions : ( a ) the classroom-based Life Skills Training ( LST ) and the Strengthening Families Program : For Parents and Children 10 - 14  , ( b ) LST only , or ( c ) a control condition . Outcomes were examined 1 year after the intervention posttest , using a substance initiation index ( SII ) measuring lifetime use of alcohol , cigarettes , and marijuana and by rates of each individual substance . Planned intervention-control contrasts showed significant effects for both the combined and LST-only interventions on the SII and on marijuana initiation . Relative reduction rates for alcohol initiation were 30.0 % for the combined intervention and 4.1 % for LST only This study tests the impact of an in-school mediated communication campaign based on social marketing principles , in combination with a participatory , community-based media effort , on marijuana , alcohol and tobacco uptake among middle-school students . Eight media treatment and eight control communities throughout the US were r and omly assigned to condition . Within both media treatment and media control communities , one school received a research -based prevention curriculum and one school did not , result ing in a crossed , split-plot design . Four waves of longitudinal data were collected over 2 years in each school and were analyzed using generalized linear mixed models to account for clustering effects . Youth in intervention communities ( N = 4,216 ) showed fewer users at final post-test for marijuana [ odds ratio ( OR ) = 0.50 , P = 0.019 ] , alcohol ( OR = 0.40 , P = 0.009 ) and cigarettes ( OR = 0.49 , P = 0.039 ) , one-tailed . Growth trajectory results were significant for marijuana ( P = 0.040 ) , marginal for alcohol ( P = 0.051 ) and non-significant for cigarettes ( P = 0.114 ) . Results suggest that an appropriately design ed in-school and community-based media effort can reduce youth substance uptake . Effectiveness does not depend on the presence of an in-school prevention curriculum Much research has been done in developing and implementing smoking prevention programs ; however , few studies have focused on urban Black population s. In November of 1989 , a comprehensive prevention program was implemented to decrease the incidence of new smokers within the adolescent population in a Black community . The program combined a school-based curriculum with a comprehensive media intervention . All components of the program were financed by business leaders from the targeted community . There were two experimental conditions : one group participated in a school-based intervention and were prompted to participate in a multi-media intervention and the other group had access to the multi-media intervention ; however , they were not prompted to participate . A key finding was that the rate of smoking decreased for all children involved in the intervention . The authors present a model that can be employed to prevent other high-risk behaviors within the Black population OBJECTIVE To test whether the Communities That Care ( CTC ) prevention system reduced levels of risk and  adolescent problem behaviors community-wide 6 years after installation of CTC and 1 year after study -provided re sources ended . DESIGN A community r and omized trial . SETTING Twenty-four small towns in 7 states , matched within state , r and omly assigned to control or intervention condition in 2003 . PARTICIPANTS A panel of 4407 fifth- grade students was surveyed annually through 10th grade from 2004 to 2009 . INTERVENTION A coalition of community stakeholders received training and technical assistance to install CTC , used epidemiologic data to identify elevated risk factors and depressed protective factors in the community , and implemented programs to address their community 's elevated risks from a menu of tested and effective programs for youths aged 10 to 14 years , their families , and schools . OUTCOME MEASURES Levels of risk and incidence and prevalence of tobacco , alcohol , and other drug use ; delinquency ; and violent behavior by grade 10 . RESULTS Mean levels of targeted risks increased less rapidly between grade s 5 and 10 in CTC than in control communities and were significantly lower in CTC than control communities in grade 10 . The incidence of delinquent behavior , alcohol use , and cigarette use and the prevalence of current cigarette use and past-year delinquent and violent behavior were significantly lower in CTC than in control communities in grade 10 . CONCLUSIONS Using the CTC system can produce enduring reductions in community-wide levels of risk factors and problem behaviors among adolescents beyond the years of supported implementation , potentially contributing to long-term public health benefits . TRIAL REGISTRATION clinical trials.gov Identifier : NCT01088542 OBJECTIVE Experimental evaluation of comprehensive community wide programme to prevent  adolescent tobacco use .  DESIGN Eight pairs of small Oregon communities ( population 1700 to 13 500 ) were r and omly assigned to receive a school based prevention programme or the school based programme plus a community programme . Effects were assessed through five annual surveys ( time 1–5 ) of seventh and ninth grade ( ages 12–15 years ) students . INTERVENTION The community programme included : ( a ) media advocacy , ( b ) youth anti-tobacco activities , ( c ) family communications about tob 
    Output:
    
While , precise out-come of integrated out of school/school-based interventions were not percepti-ble but this study 's findings implied that outside of school intervention could strengthen school-based tobacco prevention programs .
Integration of outside and inside of school-based programs may boost probability of obtaining favorable outcomes and success rate in practice