The effect of a community action intervention on adolescent smoking rates in rural australian towns: the CART project. Cancer Action in Rural Towns

A scoping review of whole-of-community interventions on six modifiable cancer prevention risk factors in youth: A systems typology

Whole-of-community interventions delivered across entire geospatial areas show promise for improving population health for youth cancer prevention. The aims of this scoping review were to synthesize the whole-of-community intervention literature on six modifiable risk factors in youth for cancer prevention (alcohol use, diet, obesity, physical activity, sun exposure, tobacco use) and to develop and apply a typology describing the inclusion of fundamental control system functional characteristics. A systematic search was conducted in PubMed, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, and Scopus for studies published to the end of 2019. Eligible studies included a geospatially defined whole-of-community intervention; youth 0-18 years; and at least one of the six cancer risk factor outcomes. An iterative process was undertaken to create a typology describing the functions for whole-of-community interventions guided by systems theory, and the typology was used to code the included interventions. A total of 41 interventions were included. Most interventions (43.9%) assessed multiple cancer risk factors. Few interventions provided fundamental functions necessary for community system coordination: sensor, controller, effector. Although communities are a patchwork quilt of microsystems where individuals interact in geographically bounded places nested within larger whole systems of influence, a control systems approach has not been used to frame the literature. Whole-of-community interventions can be characterized by the fundamental system functions necessary for coordinating population health improvement. Future whole-of-community intervention efforts should draw on fundamental knowledge of how systems operate and test whether adoption of the key functions is necessary for whole-of-community population health improvement.

Tobacco cessation interventions for young people

BACKGROUND

Most tobacco control programmes for adolescents are based around prevention of uptake, but teenage smoking is still common. It is unclear if interventions that are effective for adults can also help adolescents to quit. This is the update of a Cochrane Review first published in 2006.

OBJECTIVES

To evaluate the effectiveness of strategies that help young people to stop smoking tobacco.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register in June 2017. This includes reports for trials identified in CENTRAL, MEDLINE, Embase and PsyclNFO.

SELECTION CRITERIA

We included individually and cluster-randomized controlled trials recruiting young people, aged under 20 years, who were regular tobacco smokers. We included any interventions for smoking cessation; these could include pharmacotherapy, psycho-social interventions and complex programmes targeting families, schools or communities. We excluded programmes primarily aimed at prevention of uptake. The primary outcome was smoking status after at least six months' follow-up among those who smoked at baseline.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of candidate trials and extracted data. We evaluated included studies for risk of bias using standard Cochrane methodology and grouped them by intervention type and by the theoretical basis of the intervention. Where meta-analysis was appropriate, we estimated pooled risk ratios using a Mantel-Haenszel fixed-effect method, based on the quit rates at six months' follow-up.

MAIN RESULTS

Forty-one trials involving more than 13,000 young people met our inclusion criteria (26 individually randomized controlled trials and 15 cluster-randomized trials). We judged the majority of studies to be at high or unclear risk of bias in at least one domain. Interventions were varied, with the majority adopting forms of individual or group counselling, with or without additional self-help materials to form complex interventions. Eight studies used primarily computer or messaging interventions, and four small studies used pharmacological interventions (nicotine patch or gum, or bupropion). There was evidence of an intervention effect for group counselling (9 studies, risk ratio (RR) 1.35, 95% confidence interval (CI) 1.03 to 1.77), but not for individual counselling (7 studies, RR 1.07, 95% CI 0.83 to 1.39), mixed delivery methods (8 studies, RR 1.26, 95% CI 0.95 to 1.66) or the computer or messaging interventions (pooled RRs between 0.79 and 1.18, 9 studies in total). There was no clear evidence for the effectiveness of pharmacological interventions, although confidence intervals were wide (nicotine replacement therapy 3 studies, RR 1.11, 95% CI 0.48 to 2.58; bupropion 1 study RR 1.49, 95% CI 0.55 to 4.02). No subgroup precluded the possibility of a clinically important effect. Studies of pharmacotherapies reported some adverse events considered related to study treatment, though most were mild, whereas no adverse events were reported in studies of behavioural interventions. Our certainty in the findings for all comparisons is low or very low, mainly because of the clinical heterogeneity of the interventions, imprecision in the effect size estimates, and issues with risk of bias.

AUTHORS' CONCLUSIONS

There is limited evidence that either behavioural support or smoking cessation medication increases the proportion of young people that stop smoking in the long-term. Findings are most promising for group-based behavioural interventions, but evidence remains limited for all intervention types. There continues to be a need for well-designed, adequately powered, randomized controlled trials of interventions for this population of smokers.

Lessons from complex interventions to improve health

Complexity-resulting from interactions among many component parts-is a property of both the intervention and the context (or system) into which it is placed. Complexity increases the unpredictability of effects. Complexity invites new approaches to logic modeling, definitions of integrity and means of standardization, and evaluation. New metaphors and terminology are needed to capture the recognition that knowledge generation comes from the hands of practitioners/implementers as much as it comes from those usually playing the role of intervention researcher. Failure to acknowledge this may blind us to the very mechanisms we seek to understand. Researchers in clinical settings are documenting health improvement gains made as a consequence of complex systems thinking. Improvement science in clinical settings has much to offer researchers in population health.

Evaluation of systems-oriented public health interventions: alternative research designs

The need to provide sound evidence of the costs and benefits of real-world public health interventions has driven advances in the development and analysis of designs other than the controlled trial in which individuals are randomized to an experimental condition. Attention to methodological quality is of critical importance to ensure that any evaluation can accurately answer three fundamental questions: (a) Has a change occurred, (b) did the change occur as a result of the intervention, and (c) is the degree of change significant? A range of alternatives to the individual randomized controlled trial (RCT) can be used for evaluating such interventions, including the cluster RCT, stepped wedge design, interrupted time series, multiple baseline, and controlled prepost designs. The key features and complexities associated with each of these designs are explored.

Community engagement to reduce inequalities in health: a systematic review, meta-analysis and economic analysis

Background

Community engagement has been advanced as a promising way of improving health and reducing health inequalities; however, the approach is not yet supported by a strong evidence base.

Objectives

To undertake a multimethod systematic review which builds on the evidence that underpins the current UK guidance on community engagement; to identify theoretical models underpinning community engagement; to explore mechanisms and contexts through which communities are engaged; to identify community engagement approaches that are effective in reducing health inequalities, under what circumstances and for whom; and to determine the processes and costs associated with their implementation.

Data sources

Databases including the Cochrane Database of Systematic Reviews (CDSR), The Campbell Library, the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment (HTA) database, the NHS Economic Evaluation Database (NHS EED) and EPPI-Centre’s Trials Register of Promoting Health Interventions (TRoPHI) and Database of Promoting Health Effectiveness Reviews (DoPHER) were searched from 1990 to August 2011 for systematic reviews and primary studies. Trials evaluating community engagement interventions reporting health outcomes were included.

Review methods

Study eligibility criteria: published after 1990; outcome, economic, or process evaluation; intervention relevant to community engagement; written in English; measured and reported health or community outcomes, or presents cost, resource, or implementation data characterises study populations or reports differential impacts in terms of social determinants of health; conducted in an Organisation for Economic Co-operation and Development (OECD) country. Study appraisal: risk of bias for outcome evaluations; assessment of validity and relevance for process evaluations; comparison against an economic evaluation checklist for economic evaluations. Synthesis methods: four synthesis approaches were adopted for the different evidence types: theoretical, quantitative, process, and economic evidence.

Results

The theoretical synthesis identified key models of community engagement that are underpinned by different theories of changes. Results from 131 studies included in a meta-analysis indicate that there is solid evidence that community engagement interventions have a positive impact on health behaviours, health consequences, self-efficacy and perceived social support outcomes, across various conditions. There is insufficient evidence – particularly for long-term outcomes and indirect beneficiaries – to determine whether one particular model of community engagement is likely to be more effective than any other. There are also insufficient data to test the effects on health inequalities, although there is some evidence to suggest that interventions that improve social inequalities (as measured by social support) also improve health behaviours. There is weak evidence from the effectiveness and process evaluations that certain implementation factors may affect intervention success. From the economic analysis, there is weak but inconsistent evidence that community engagement interventions are cost-effective. By combining findings across the syntheses, we produced a new conceptual framework.

Limitations

Differences in the populations, intervention approaches and health outcomes made it difficult to pinpoint specific strategies for intervention effectiveness. The syntheses of process and economic evidence were limited by the small (generally not rigorous) evidence base.

Conclusions

Community engagement interventions are effective across a wide range of contexts and using a variety of mechanisms. Public health initiatives should incorporate community engagement into intervention design. Evaluations should place greater emphasis on long-term outcomes, outcomes for indirect beneficiaries, process evaluation, and reporting costs and resources data. The theories of change identified and the newly developed conceptual framework are useful tools for researchers and practitioners. We identified trends in the evidence that could provide useful directions for future intervention design and evaluation.

Funding

The National Institute for Health Research Public Health Research programme.

Tobacco cessation interventions for young people

BACKGROUND

Most tobacco control programmes for adolescents are based around prevention of uptake, but teenage smoking is still common. It is unclear if interventions that are effective for adults can also help adolescents to quit. This is the second update of a Cochrane review first published in 2006.

OBJECTIVES

To evaluate the effectiveness of strategies that help young people to stop smoking tobacco.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register in February 2013. This includes reports for trials identified in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and PsyclNFO.

SELECTION CRITERIA

We included randomized controlled trials, cluster-randomized controlled trials and other controlled trials recruiting young people, aged less than 20, who were regular tobacco smokers. We included any interventions; these could include pharmacotherapy, psycho-social interventions and complex programmes targeting families, schools or communities. We excluded programmes primarily aimed at prevention of uptake. The primary outcome was smoking status after at least six months follow-up among those who smoked at baseline.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed the eligibility of candidate trials and extracted data. Included studies were evaluated for risk of bias using standard Cochrane methodology. Where meta-analysis was appropriate, we estimated pooled risk ratios using a Mantel-Haenszel fixed-effect method, based on the quit rates at longest follow-up.

MAIN RESULTS

Twenty-eight trials involving approximately 6000 young people met our inclusion criteria (12 cluster-randomized controlled trials, 14 randomized controlled trials and 2 controlled trials). The majority of studies were judged to be at high or unclear risk of bias in at least one domain. Many studies combined components from various theoretical backgrounds to form complex interventions.The majority used some form of motivational enhancement combined with psychological support such as cognitive behavioural therapy (CBT) and some were tailored to stage of change using the transtheoretical model (TTM). Three trials based mainly on TTM interventions achieved moderate long-term success, with a pooled risk ratio (RR) of 1.56 at one year (95% confidence interval (CI) 1.21 to 2.01). The 12 trials that included some form of motivational enhancement gave an estimated RR of 1.60 (95% CI 1.28 to 2.01). None of the 13 individual trials of complex interventions that included cognitive behavioural therapy achieved statistically significant results, and results were not pooled due to clinical heterogeneity. There was a marginally significant effect of pooling six studies of the Not on Tobacco programme (RR of 1.31, 95% CI 1.01 to 1.71), although three of the trials used abstinence for as little as 24 hours at six months as the cessation outcome. A small trial testing nicotine replacement therapy did not detect a statistically significant effect. Two trials of bupropion, one testing two doses and one testing it as an adjunct to NRT, did not detect significant effects. Studies of pharmacotherapies reported some adverse events considered related to study treatment, though most were mild, whereas no adverse events were reported in studies of behavioural interventions.

AUTHORS' CONCLUSIONS

Complex approaches show promise, with some persistence of abstinence (30 days point prevalence abstinence or continuous abstinence at six months), especially those incorporating elements sensitive to stage of change and using motivational enhancement and CBT. Given the episodic nature of adolescent smoking, more data is needed on sustained quitting. There were few trials with evidence about pharmacological interventions (nicotine replacement and bupropion), and none demonstrated effectiveness for adolescent smokers. There is not yet sufficient evidence to recommend widespread implementation of any one model. There continues to be a need for well-designed adequately powered randomized controlled trials of interventions for this population of smokers.

State-of-the-art and future directions in multilevel interventions across the cancer control continuum

We conducted literature searches and analyses to describe the current state of multilevel intervention (MLI) research and to identify opportunities to advance cancer control and prevention. We found single-level studies that considered other contextually important levels, and multilevel health-care systems research and community-wide studies. This literature is characterized by limited reporting of theoretical, contextual, temporal, and implementation factors. Most MLIs focus on prevention and screening, rather than diagnosis, treatment, or survivorship. Opportunities relate to 1) dynamic, adaptive emergent interventions and research designs that evolve over time by attending to contextual factors and interactions across levels; 2) analyses that include simulation modeling, or multimethod approaches that integrate quantitative and qualitative methods; and 3) translation and intervention approaches that locally reinvent MLIs in different contexts. MLIs have great potential to reduce cancer burden by using theory and integrating quantitative, qualitative, participatory, and transdisciplinary methods that continually seek alignment across intervention levels, pay attention to context, and adapt over time.

Community interventions for preventing smoking in young people

BACKGROUND

Cigarette smoking is one of the leading causes of preventable death in the world. Decisions to smoke are often made within a broad social context and therefore community interventions using coordinated, multi-component programmes may be effective in influencing the smoking behaviour of young people.

OBJECTIVES

To determine the effectiveness of multi-component community based interventions in influencing smoking behaviour, which includes preventing the uptake of smoking in young people.

SEARCH STRATEGY

The Tobacco Addiction group's specialised register, Medline and other health, psychology and public policy electronic databases were searched, the bibliographies of identified studies were checked and raw data was requested from study authors. Searches were updated in August 2010.

SELECTION CRITERIA

Randomized and non randomized controlled trials that assessed the effectiveness of multi-component community interventions compared to no intervention or to single component or school-based programmes only. Reported outcomes had to include smoking behaviour in young people under the age of 25 years.

DATA COLLECTION AND ANALYSIS

Information relating to the characteristics and the content of community interventions, participants, outcomes and methods of the study was extracted by one reviewer and checked by a second. Studies were combined in a meta-analysis where possible and reported in narrative synthesis in text and table.

MAIN RESULTS

Twenty-five studies were included in the review and sixty-eight studies did not meet all of the inclusion criteria. All studies used a controlled trial design, with fifteen using random allocation of schools or communities. One study reported a reduction in short-term smoking prevalence (twelve months or less), while nine studies detected significant long-term effects. Two studies reported significantly lower smoking rates in the control population while the remaining thirteen studies showed no significant difference between groups. Improvements were seen in secondary outcomes for intentions to smoke in six out of eight studies, attitudes in five out of nine studies, perceptions in two out of six studies and knowledge in three out of six studies, while significant differences in favour of the control were seen in one of the nine studies assessing attitudes and one of six studies assessing perceptions.

AUTHORS' CONCLUSIONS

There is some evidence to support the effectiveness of community interventions in reducing the uptake of smoking in young people, but the evidence is not strong and contains a number of methodological flaws.

Youth tobacco use cessation: 2008 update

In this paper, an empirical review of 64 teen tobacco use cessation studies is provided. Examined include program contents, delivery modalities, number of contacts, and expected quit rates. In addition, means of recruitment and retention of smokers in programming are discussed. Also, promising contemporary methods of teen smoking cessation are examined, including use of pharmacologic adjuncts, electronic technology, and cigarette price increases (and no smoking policy). Conclusions are made regarding implications for developing and implementing teen tobacco use cessation programs.

Evaluation of a multi-component community tobacco intervention in three remote Australian Aboriginal communities

OBJECTIVES

To assess the effect of community tobacco interventions in Aboriginal communities.

METHODS

The study consisted of a pre- and post-study of the effect of a multi-component tobacco intervention conducted in six Aboriginal communities in the Northern Territory (NT). The intervention included sports sponsorship, health promotion campaigns, training health professionals in the delivery of smoking cessation advice, school education about tobacco, and policy on smoke-free public places. The study was conducted in three intervention communities and three matched control communities. Surveys were used to measure changes in prevalence of tobacco use, changes in knowledge, and attitudes to cessation in intervention communities.

RESULTS

Tobacco consumption decreased in one intervention community compared with the matched control community; the trends of consumption (as measured by tobacco ordered through points of sale) in these communities were significantly different (t = -4.5, 95% CI -33.6 - (-12.5), p < or = 0.01). Community samples in intervention communities included 920 participants. There was no significant change in the prevalence of tobacco use, although knowledge of the health effects of tobacco and readiness to quit increased.

CONCLUSIONS

Although it is difficult to demonstrate a reduction in tobacco consumption or in the prevalence of tobacco use as a result of multi-component community tobacco interventions delivered in Aboriginal communities, such interventions can increase awareness of the health effects of tobacco and increase reported readiness to cease tobacco use.

Limitations of the randomized controlled trial in evaluating population-based health interventions

Population- and systems-based interventions need evaluation, but the randomized controlled trial (RCT) research design has significant limitations when applied to their complexity. After some years of being largely dismissed in the ranking of evidence in medicine, alternatives to the RCT have been debated recently in public health and related population and social service fields to identify the trade-offs in their use when randomization is impractical or unethical. This review summarizes recent debates and considers the pragmatic and economic issues associated with evaluating whole-population interventions while maintaining scientific validity and credibility.

Tobacco cessation interventions for young people

BACKGROUND

Teenage smoking prevalence is around 15% in developing countries (with wide variation from country to country), and around 26% in the UK and USA. Although most tobacco control programmes for adolescents are based around prevention of uptake, there are also a number of initiatives to help those who want to quit. Since those who do not smoke before the age of 20 are significantly less likely to start as adults, there is a strong case for programmes for young people that address both prevention and treatment.

OBJECTIVES

To evaluate the effectiveness of strategies that help young people to stop smoking tobacco.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Tobacco Addiction Group's Specialized Register, MEDLINE, EMBASE, PsyclNFO, ERIC, CINAHL, and the bibliographies of identified trials. We also searched the 'grey' literature (unpublished materials), and contacted authors and experts in the field where necessary.

SELECTION CRITERIA

Types of studies: Randomized controlled trials, cluster-randomized controlled trials and controlled trials.

TYPES OF PARTICIPANTS

Young people, aged less than 20, who are regular tobacco smokers. Types of interventions: The interventions ranged from simple ones such as pharmacotherapy, targeting individual young people, through complex programmes targeting people or organizations associated with young people (for example, their families or schools), or the community in which young people live. We included cessation programmes but excluded programmes primarily aimed at prevention of uptake. Types of outcome measures: The primary outcome was smoking status at six months follow up, among those who smoked at baseline. We report the definition of cessation used in each trial (e.g seven- or thirty-day point prevalence abstinence, or sustained or prolonged abstinence), and we preferred biochemically verified cessation when that measure was available.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed the eligibility of candidate trials identified by the searches, and extracted data from them. We categorized included trials as being at low, medium or high risk of bias, based on concealment of allocation, blinding (where applicable) and the handling of attrition and losses to follow up. We conducted limited meta-analyses of some of the trials, provided that it was appropriate to group them and provided that there was minimal heterogeneity between them. We estimated pooled odds ratios using the Mantel-Haenszel method, based on the quit rates at longest follow up for trials with at least six months follow up from the start of the intervention.

MAIN RESULTS

We found 15 trials, covering 3605 young people, which met our inclusion criteria (seven cluster-randomized controlled trials, six randomized controlled trials and two controlled trials). Three trials used or tested the transtheoretical model (stages of change) approach, two tested pharmacological aids to quitting (nicotine replacement and bupropion), and the remaining trials used various psycho-social interventions, such as motivational enhancement or behavioural management. The trials evaluating TTM interventions achieved moderate long-term success, with a pooled odds ratio (OR) at one year of 1.70 ( 95% confidence interval (CI) 1.25 to 2.33) persisting at two-year follow up with an OR of 1.38 (95% CI 0.99 to 1.92). Neither of the pharmacological intervention trials achieved statistically significant results (data not pooled), but both were small-scale, with low power to detect an effect. The three interventions (5 trials) which used cognitive behavioural therapy interventions did not individually achieve statistically significant results, although when the three Not on Tobacco trials were pooled the OR 1.87; (95% CI 1.00 to 3.50) suggested some measure of effectiveness. Although the three trials that incorporated motivational interviewing as a component of the intervention achieved a pooled OR of 2.05 (95% CI 1.10 to 3.80), the impossibility of isolating the effect of the motivational interviewing in these trials meant that we could not draw meaningful inferences from that analysis.

AUTHORS' CONCLUSIONS

Complex approaches show promise, with some persistence of abstinence (30 days point prevalence abstinence at six months), especially those incorporating elements sensitive to stage of change. There were few trials with evidence about pharmacological interventions (nicotine replacement and bupropion), and none demonstrated effectiveness for adolescent smokers. Psycho-social interventions have not so far demonstrated effectiveness, although pooled results for the Not on Tobacco trials suggest that that this approach may yet prove to be effective; however, their definition of cessation (one or more smoke-free days) may not adequately account for the episodic nature of much adolescent smoking. There is a need for well-designed adequately powered randomized controlled trials for this population of smokers, with a minimum of six months follow up and rigorous definitions of cessation (sustained and biochemically verified). Attrition and losses to follow up are particularly problematic in trials for young smokers, and need to be kept to a minimum, so that management and interpretation of missing data need not compromise the findings.

Determinants of stages of smoking uptake among secondary school students

With the uptake of cigarette smoking hypothesised to occur through a series of contemplation and action stages, we sought to investigate what factors are associated with the contemplation of smoking among secondary school students in Queensland, Australia. A series of four cross-sectional surveys were conducted among secondary schools in Queensland in 1993, 1996, 1999 and 2002. Respondents (n = 9993) were asked about the stages of smoking. Nearly half (43%) of secondary school students reported some contemplation of smoking. Increased levels of smoking contemplation were observed among females, earlier survey years, Junior level students, students with average or below average scholastic ability, those prepared to go out with a smoker, those with recent alcohol experience, those who had influenced other students to smoke or had not discouraged other students smoking. The results of this study provide further information about the factors relevant to stages of smoking uptake among secondary school students and the influence that students may have on their peers.

Prevention of smoking-related deaths in the United States

BACKGROUND

Tobacco is the leading cause of death in the United States. The majority of people who smoke begin before age 18.

OBJECTIVE

Determine the number of smoking-attributable deaths and years of potential life lost (YPLL) in adults that might be saved through interventions to reduce smoking prevalence among children and adolescents.

METHODS

Calculation of the smoking-attributable mortality and years of potential life lost by age 85 among the cohort of people aged 18 in 2000.

RESULTS

By age 85, there would be 127,670 smoking-attributable deaths among women and 284,502 deaths among men, for a total 412,172 smoking-attributable deaths in the United States among the cohort of 3,964,704 people aged 18 years alive in 2000. Through large-scale multimedia campaigns and a $1 increase in the price per pack of cigarettes, smoking prevalence could be reduced by 26% and would result in an annual savings of 108,466 lives and 1.6 million YPLL.

CONCLUSIONS

Interventions to decrease smoking prevalence among children and adolescents can have large effects on adult mortality.

Mounting a community-randomized trial: sample size, matching, selection, and randomization issues in PRISM

This paper discusses some of the processes for establishing a large cluster-randomized trial of a community and primary care intervention in 16 local government areas in Victoria, Australia. The development of the trial in terms of design factors such as sample size estimates and the selection and randomization of communities to intervention or comparison is described. The intervention program to be implemented in Program of Resources, Information and Support for Mothers (PRISM) was conceived as a whole community approach to improving support for all mothers in the first 12 months after birth. A cluster-randomized trial was thus the design of choice from the outset. With a limited number of communities available, a matched-pair design with eight pairs was chosen. Sample size estimates, adjusting for the cluster randomization and the pair-matched design, showed that with eight pairs, on average, 800 women from each community would need to respond to provide sufficient power to determine a 3% reduction in the prevalence of maternal depression 6 months after birth-a reduction deemed to be a worthwhile impact of the intervention to be reliably detected at 80% power. The process of selecting suitable communities and matching them into pairs required careful collection of data on numbers of births, size of the local government areas (LGAs), and an assessment of the capacity of communities to implement the intervention. Ways of dealing with boundary issues associated with potential contamination are discussed. Methods for the selection of feasible configurations of sets of pairs and the ultimate allocation to intervention or comparison are provided in detail. Ultimately, all such studies are a balancing act between selecting the minimum number of communities to detect a meaningful outcome effect of an intervention and the maximum size budget and other resources allow.

Design and analysis of group-randomized trials: a review of recent practices

We reviewed group-randomized trials (GRTs) published in the American Journal of Public Health and Preventive Medicine from 1998 through 2002 and estimated the proportion of GRTs that employ appropriate methods for design and analysis. Of 60 articles, 9 (15.0%) reported evidence of using appropriate methods for sample size estimation. Of 59 articles in the analytic review, 27 (45.8%) reported at least 1 inappropriate analysis and 12 (20.3%) reported only inappropriate analyses. Nineteen (32.2%) reported analyses at an individual or subgroup level, ignoring group, or included group as a fixed effect. Hence increased vigilance is needed to ensure that appropriate methods for GRTs are employed and that results based on inappropriate methods are not published.

Community interventions for preventing smoking in young people

BACKGROUND

Decisions to smoke are made within a broad social context. Community interventions use co-ordinated, widespread, multi-component programmes to try and influence behaviour.

OBJECTIVES

To determine the effectiveness of community interventions in preventing the uptake of smoking in young people.

SEARCH STRATEGY

The Tobacco Addiction group specialised register, Medline and other health, psychology and public policy electronic databases were searched, the bibliographies of identified studies were checked and contact was made with content area specialists. Searches were updated in September 2002.

SELECTION CRITERIA

Randomised and non randomised controlled trials that assessed the effectiveness of multi-component community interventions compared to no intervention or to single component or school-based programmes only. Reported outcomes had to include smoking behaviour in young people under the age of 25 years.

DATA COLLECTION AND ANALYSIS

Information relating to the characteristics and the content of community interventions, participants, outcomes and methods of the study was extracted by one reviewer and checked by a second. Studies were combined using qualitative narrative synthesis.

MAIN RESULTS

Seventeen studies were included in the review, 46 studies did not meet all of the inclusion criteria. All studies used a controlled trial design, with six using random allocation of schools or communities. Of thirteen studies which compared community interventions to no intervention controls, two, which were part of cardiovascular disease prevention programmes, reported lower smoking prevalence. Of three studies comparing community interventions to school-based programmes only, one found differences in reported smoking prevalence. One study reported a lower rate of increase in prevalence in a community receiving a multi-component intervention compared to a community exposed to a mass media campaign alone. One study reported a significant difference in smoking prevalence between a group receiving a media, school and homework intervention compared to a group receiving the media component only.

REVIEWER'S CONCLUSIONS

There is some limited support for the effectiveness of community interventions in helping prevent the uptake of smoking in young people.