***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 AIM To evaluate the effectiveness of a school-based substance abuse prevention program developed in the EU-Dap study ( EUropean Drug Addiction Prevention trial ) . MATERIAL S AND METHODS Cluster R and omized Controlled Trial . Seven European countries participated in the study ; 170 schools ( 7079 pupils 12 - 14 years of age ) were r and omly assigned to one of three experimental conditions or to a  control condition during the school year 2004/2005 . The program consisted of a 12-h curriculum based on a comprehensive social influence approach . A pre-test  survey assessing past and current substance use was conducted before the implementation of the program , while a post-test survey was carried out about 18 months after the pre-test . The association between program condition and change in substance use at post-test was expressed as adjusted prevalence odds ratio ( POR ) , estimated by multilevel regression models . RESULTS Persisting beneficial program effects were found for episodes of drunkenness ( any , POR=0.80 ; 0.67 - 0.97 ; frequent , POR=0.62 ; 0.47 - 0.81 ) and for frequent cannabis use in the past 30 days ( POR=0.74 ; 0.53 - 1.00 ) , whereas daily cigarette smoking was not affected by the program as it was at the short-term follow-up . Baseline non-smokers that participated in the program progressed in tobacco consumption to a lower extent than those in the control condition , but no difference was detected in the proportion of quitters or reducers among baseline daily smokers . CONCLUSION The experimental evaluation of an innovative school curriculum based on a comprehensive social influence approach , indicated persistent positive effects over 18 months for alcohol abuse and for cannabis use , but not for cigarette smoking OBJECTIVE To extend the findings of the first Development and Assessment of Nicotine Dependence in Youth study by using diagnostic criteria for tobacco dependence and a biochemical measure of nicotine intake . The first study found that symptoms of dependence commonly appeared soon after the onset of intermittent smoking . DESIGN A 4-year prospect i ve study . SETTING Public schools in 6 Massachusetts communities . PARTICIPANTS A cohort of 1246 sixth- grade students . INTERVENTIONS Eleven interviews . MAIN OUTCOME MEASURES Loss of autonomy over tobacco as measured by the Hooked on Nicotine Checklist , and tobacco dependence as defined in International Classification of Diseases , 10th Revision ( ICD-10 ) . RESULTS Among the 217 inhalers , 127 lost autonomy over their tobacco use , 10 % having done so within 2 days and 25 % having done so within 30 days of first inhaling from a cigarette ; half had lost autonomy by the time they were smoking 7 cigarettes per month . Among the 83 inhalers who developed ICD-10-defined dependence , half had done so by the time they were smoking 46 cigarettes per month . At the interview following the onset of ICD-10-defined dependence , the median salivary cotinine concentration of current smokers was 5.35 ng/mL , a level that falls well below the cutoff used to distinguish active from passive smokers . CONCLUSIONS The most susceptible youths lose autonomy over tobacco within a day or 2 of first inhaling from a cigarette . The appearance of tobacco withdrawal symptoms and failed attempts at cessation can precede daily smoking ; ICD-10-defined dependence can precede daily smoking and typically appears before consumption reaches 2 cigarettes per day This paper measures tobacco polices in statewide representative sample s of secondary and mixed schools in Victoria , Australia and Washington , US ( N = 3,466 students from 285 schools ) and tests their association with student smoking . Results from confounder-adjusted r and om effects ( multi-level ) regression models revealed that the odds of student perception of peer smoking on school grounds are decreased in schools that have strict enforcement of policy ( odds ratio ( OR ) = 0.45 ; 95 % CI : 0.25 to 0.82 ; p = 0.009 ) . There was no clear evidence in this study that a comprehensive smoking ban , harsh penalties , remedial penalties , harm minimization policy or abstinence policy impact on any of the smoking outcomes The aim was to comprehensively examine school-based tobacco policy status , implementation and students ' perceived smoking at school in regard to gender-specific differences in smoking behavior . We conducted a multilevel-based study to assess two-level effects for smoking among 2350 grade s three to six students in 26 r and omly selected elementary schools in southern Taiwan . A series of multilevel models were analyzed separately for male and female students . The school-level variables appear to be related to smoking behavior in male students . Among males , the risk of ever-smoking was significantly associated with those schools without antitobacco health education activities or curricula [ adjusted odds ratio ( aOR ) = 6.23 , 95 % confidence interval ( CI ) : 2.55 - 15.24 ] , with a high perceived smoking rate ( aOR = 3.08 , 95 % CI : 1.41 - 6.72 ) and located in a mountainous region ( aOR = 2.53 , 95 % CI : 1.15 - 5.58 ) . The risk of ever-smoking among females was significantly associated with those schools without antitobacco activities or curricula ( aOR = 3.10 , 95 % CI : 1.27 - 7.55 ) . As compared with female counterparts , the specific school that the male students attended had a positive significant effect on the risk of being ever-smokers . The findings suggest that effective tobacco policy implementation should be considered in elementary schools that are currently putting children at the greatest risk for cigarette smoking , especially in regard to male students BACKGROUND The prevalence of adolescent smoking has been increasing rapidly in China .  Theory-based smoking prevention programmes in schools may be an effective approach in preventing smoking among Chinese adolescents . METHODS A school-level cluster r and omized controlled trial was conducted among 7th and 8th grade students ( N = 2343 ) in four junior high schools in southern China during 2004 - 06 .  The theory-based , multi-level intervention was compared with the st and ard health curriculum . Outcome measures comprised changes in students ' smoking-related knowledge , attitudes and behaviour . RESULTS The mean knowledge scores from baseline to the 1- and 2-year follow-ups increased more in the intervention group than in the control group , whereas there was little change in attitude scores . At the 1-year follow-up ( the total sample ) , the interventions reduced the probability of baseline experimental smokers ' escalating to regular smoker [ 7.9 vs 18.3 % ; adjusted odds ratio ( OR ) 0.34 , 95 % confidence interval ( CI ) 0.12 - 0.97 , P = 0.043 ] , but did not reduce the probability of baseline non-smokers ' initiating smoking ( 7.9 vs 10.6 % ; adjusted OR 0.86 , 95 % CI 0.54 - 1.38 , P = 0.538 ) . At the 2-year follow-up ( only 7th grade students ) , similar proportions of baseline non-smokers initiated smoking in the intervention group and the control group ( 13.5 vs 13.1 % ) , while a possibly lower proportion of baseline experimental smokers escalated to regular smoking in the intervention group than the control group ( 22.6 vs 40.0 % ; adjusted OR 0.43 , 95 % CI 0.12 - 1.57 , P = 0.199 ) . CONCLUSIONS This multi-level intervention programme had a moderate effect on inhibiting the escalation from experimental to regular smoking  among Chinese adolescents , but had little effect on the initiation of smoking . The programme improved adolescents ' smoking-related knowledge , but did not change their attitudes towards smoking AIMS To determine the impact of a school-based harm minimization smoking intervention compared to traditional abstinence-based approaches . DESIGN , SETTING AND PARTICIPANTS A school-based cluster r and omized trial was conducted in Perth , Western Australia in 30 government high schools from 1999 to 2000 . Over 4000 students were recruited to participate and schools were assigned r and omly to either the harm minimization intervention or a st and ard abstinence-based programme . INTERVENTION The harm minimization intervention comprised eight 1-hour lessons over 2 years , quitting support from school nurses and enactment of policies to support programme components . Comparison schools implemented st and ard abstinence-based programmes and policies . MEASURES Cigarette smoking was categorized at two levels : regular smoking , defined as smoking on 4 or more days in the previous week ; and 30-day smoking as any smoking within the previous month . FINDINGS At immediate post-test ( 20 months post-baseline ) , after accounting for baseline differences , school-level clustering effects , socio-economic status , gender and family smoking , intervention students were less likely to smoke regularly [ OR = 0.51 , 95 % confidence interval ( CI ) = 0.36 , 0.71 ] or to have smoked within the previous 30 days ( OR = 0.69 , 95 % CI = 0.53 , 0.91 ) . CONCLUSION The school-based adolescent harm minimization intervention appears to have been more effective than the abstinence-based social influences programme at reducing regular smoking Social environment risk factors present in schools and 
    Output:
    
Despite a comprehensive literature search , and rigorous evaluation of studies , we found no evidence to support STPs .