Are community health interventions evaluated appropriately? A review of six journals

A systematic literature review of the physical and psychosocial correlates of Special Olympics participation among individuals with intellectual disability

BACKGROUND

Special Olympics (SO) is commonly cited to play an important role in the lives of individuals with intellectual disabilities (ID). The purpose of the current review was to (a) synthesise key findings regarding the physical, psychological/emotional, social and/or intellectual/cognitive correlates of SO participation for individuals with ID and (b) highlight limitations in the extant research as well as directions for future research.

METHOD

A systematic review of electronic databases was undertaken. A total of 46 articles were confirmed to meet study criteria. Quality assessments of included studies were conducted using checklists from the Scottish Intercollegiate Guidelines Network methodology checklists (SIGN 50; SIGN 2008).

RESULTS

There was a larger amount of support for physical, psychological/emotional and social outcomes as compared with cognitive/intellectual outcomes; however, many studies were confounded by measurement difficulties, sampling procedures and a lack of replicable methods, which hinder generalisation of results.

CONCLUSIONS

This review highlights the need for a continued critical focus on SO programme evaluation research with more rigorous and replicable methods.

Statistical analysis and handling of missing data in cluster randomised trials: protocol for a systematic review

INTRODUCTION

Cluster randomised trials (CRTs) randomise participants in groups, rather than as individuals, and are key tools used to assess interventions in health research where treatment contamination is likely or if individual randomisation is not feasible. Missing outcome data can reduce power in trials, including in CRTs, and is a potential source of bias. The current review focuses on evaluating methods used in statistical analysis and handling of missing data with respect to the primary outcome in CRTs.

METHODS AND ANALYSIS

We will search for CRTs published between August 2013 and July 2014 using PubMed, Web of Science and PsycINFO. We will identify relevant studies by screening titles and abstracts, and examining full-text articles based on our predefined study inclusion criteria. 86 studies will be randomly chosen to be included in our review. Two independent reviewers will collect data from each study using a standardised, prepiloted data extraction template. Our findings will be summarised and presented using descriptive statistics.

ETHICS AND DISSEMINATION

This methodological systematic review does not need ethical approval because there are no data used in our study that are linked to individual patient data. After completion of this systematic review, data will be immediately analysed, and findings will be disseminated through a peer-reviewed publication and conference presentation.

Ignoring the group in group-level HIV/AIDS intervention trials: a review of reported design and analytic methods

OBJECTIVES

Studies evaluating the efficacy of HIV/AIDS interventions often involve the random assignment of groups of participants or the treatment of participants in groups. These studies require analytic methods that take within-group correlation into account. We reviewed published studies to determine the extent to which within-group correlation was dealt with properly.

DESIGN

We reviewed group-randomized trials (GRTs) and individually randomized group treatment (IRGT) trials published in HIV/AIDS and general public health journals 2005-2009.

METHODS

At least two of the authors reviewed each article, recording descriptive characteristics, sample size estimation methods, analytic methods, and judgments about whether the methods took intraclass correlation into account properly.

RESULTS

Of those articles including sufficient information to judge whether analytic methods were correct, only 24% used only appropriate methods for dealing with the intraclass correlation. The percentages differed substantially for GRTs (41.7%) and IRGT trials (8.0%). Most of the articles (69.2%) also made no mention of a priori sample size estimation.

CONCLUSION

A majority of the articles in our review reported analyses ignoring the intraclass correlation. This practice may result in underestimated variance, inappropriately small P values, and incorrect conclusions about the effectiveness of interventions. Previous trials that were analyzed incorrectly need to be re-analyzed, and future trials should be designed and analyzed with appropriate methods. Also, journal reviewers and editors need to be aware of the special requirements for design and analysis of GRTs and IRGT trials and judge the quality of articles reporting on such trials according to appropriate standards.

Level of evidence in four selected rehabilitation journals

OBJECTIVE

To investigate the methodologic quality and level of evidence of publications in major peer-reviewed general rehabilitation journals (Archives of Physical Medicine and Rehabilitation [APMR], American Journal of Physical Medicine and Rehabilitation [AJPMR], Clinical Rehabilitation [CR], and Physical Therapy [PT]).

DESIGN

Descriptive, comparative.

MAIN OUTCOME MEASURES

All the articles published in AJPMR, APMR, CR, and PT between January 2005 and December 2009 were investigated. Type of study and level of evidence were recorded for all articles. Selection and assessment of articles were based on the title and abstract by 2 independent raters.

RESULTS

The most frequently published reports were randomized controlled trials (12.7%), followed by cross-sectional studies (12.1%), case reports/case series (10.3%), validation studies (9.3%), cohort studies (8.9%), clinical trials (7.5%), case-control studies (6.8%), and other study types (32.4%). When the articles were classified according to their level of evidence, level I studies most frequently appeared in CR (29.1%), followed by PT (11.0%), APMR (10.5%), and AJPMR (7.1%). Most of the meta-analyses (10) were in APMR, and there were none in AJPMR.

CONCLUSIONS

Randomized controlled trials and meta-analyses form only a small proportion of articles published in the current rehabilitation literature. The numbers of randomized controlled trials and meta-analysis are comparable with those in other fields.

Analysis of group randomized trials with multiple binary endpoints and small number of groups

The group randomized trial (GRT) is a common study design to assess the effect of an intervention program aimed at health promotion or disease prevention. In GRTs, groups rather than individuals are randomized into intervention or control arms. Then, responses are measured on individuals within those groups. A number of analytical problems beset GRT designs. The major problem emerges from the likely positive intraclass correlation among observations of individuals within a group. This paper provides an overview of the analytical method for GRT data and applies this method to a randomized cancer prevention trial, where multiple binary primary endpoints were obtained. We develop an index of extra variability to investigate group-specific effects on response. The purpose of the index is to understand the influence of individual groups on evaluating the intervention effect, especially, when a GRT study involves a small number of groups. The multiple endpoints from the GRT design are analyzed using a generalized linear mixed model and the stepdown Bonferroni method of Holm.

Internal and external validity of cluster randomised trials: systematic review of recent trials

OBJECTIVES

To assess aspects of the internal validity of recently published cluster randomised trials and explore the reporting of information useful in assessing the external validity of these trials.

DESIGN

Review of 34 cluster randomised trials in primary care published in 2004 and 2005 in seven journals (British Medical Journal, British Journal of General Practice, Family Practice, Preventive Medicine, Annals of Internal Medicine, Journal of General Internal Medicine, Pediatrics).

DATA SOURCES

National Library of Medicine (Medline) via PubMed.

DATA EXTRACTION

To assess aspects of internal validity we extracted data on appropriateness of sample size calculations and analyses, methods of identifying and recruiting individual participants, and blinding. To explore reporting of information useful in assessing external validity we extracted data on cluster eligibility, cluster inclusion and retention, cluster generalisability, and the feasibility and acceptability of the intervention to health providers in clusters.

RESULTS

21 (62%) trials accounted for clustering in sample size calculations and 30 (88%) in the analysis; about a quarter were potentially biased because of procedures surrounding recruitment and identification of patients; individual participants were blind to allocation status in 19 (56%) and outcome assessors were blind in 15 (44%). In almost half the reports, information relating to generalisability of clusters was poorly reported, and in two fifths there was no information about the feasibility and acceptability of the intervention.

CONCLUSIONS

Cluster randomised trials are essential for evaluating certain types of interventions. Issues affecting their internal validity, such as appropriate sample size calculations and analysis, have been widely disseminated and are now better addressed by researchers. Blinding of those identifying and recruiting patients to allocation status is recommended but is not always carried out. There may be fewer barriers to internal validity in trials in which individual participants are not recruited. External validity seems poorly addressed in many trials, yet is arguably as important as internal validity in judging quality as a basis for healthcare intervention.

Pragmatic randomised controlled trials in parenting research: the issue of intention to treat

STUDY OBJECTIVE

To evaluate trials of parenting programmes, regarding their use of intention to treat (ITT).

DESIGN

Individual trials included in two relevant Cochrane systematic reviews were scrutinised by two independent reviewers. Data on country of origin, target audience, trial type, treatment violations, use of ITT, and the management of missing data were extracted.

MAIN RESULTS

Thirty trial reports were reviewed. Three reported the use of an ITT approach to data analysis. Nineteen reported losing subjects to follow up although the implications of this were rarely considered. Insufficient detail in reports meant it was difficult to identify study drop outs, the nature of treatment violations, and those failing to provide outcome assessments. In two trials, study drop outs were considered as additional control groups, violating the basic principle of ITT.

CONCLUSIONS

It is recommended that future trial reports adhere to CONSORT guidelines. In particular ITT should be used for the main analyses, with strategies for managing treatment violations and handling missing data being reported a priori. Those conducting trials need to acknowledge the social nature of these programmes can sometimes result in erratic parent attendance and participation, which would only increase the chances of missing data. The use of approaches that can limit the proportion of missing data is therefore recommended.

Multilevel analysis of group-randomized trials with binary outcomes

OBJECTIVES

Many dental studies have assessed the effectiveness of community- or group-based interventions such as community water fluoridation. These cluster trials, of which group-randomized trials (GRTs) are one type, have design and analysis considerations not found in studies with randomization of treatments to individuals (randomized controlled trials, RCTs). The purpose of this paper is to review analytic methods used for the analysis of binary outcomes from cluster trials and to illustrate these concepts and analytical methods using a school-based GRT.

METHODS

We examine characteristics of GRTs including intra-class correlation (ICC), their most distinctive feature, and review analytical methods for GRTs including group-level analysis, adjusted chi-square test and multivariable analysis (mixed effect models and generalized estimating equations) for correlated binary data. We consider two- and three-level modeling of data from a cross-sectional cluster design. We apply the concepts reviewed using a GRT designed to determine the effect of incentives on response rates in a school-based dental study. We compare the results of analyses using methods for correlated binary data with those from traditional methods that do not account for ICC.

RESULTS

Application of traditional analytic methods to the dental GRT used as an example for this paper led to a substantial overstatement of the effectiveness of the intervention.

CONCLUSIONS

Ignoring the ICC among members of the same group in the analysis of public health intervention studies can lead to erroneous conclusions where groups are the unit of assignment. Special consideration is needed in the analysis of data from these cluster trials. Randomization of treatments to groups also should receive more consideration in the design of cluster trials in dental public health.

In defense of the randomized controlled trial for health promotion research

The overwhelming evidence about the role lifestyle plays in mortality, morbidity, and quality of life has pushed the young field of modern health promotion to center stage. The field is beset with intense debate about appropriate evaluation methodologies. Increasingly, randomized designs are considered inappropriate for health promotion research. We have reviewed criticisms against randomized trials that raise philosophical and practical issues, and we will show how most of these criticisms can be overcome with minor design modifications. By providing rebuttal to arguments against randomized trials, our work contributes to building a sound methodological base for health promotion research.

Lessons for cluster randomized trials in the twenty-first century: a systematic review of trials in primary care

BACKGROUND

Evidence suggests that cluster randomized trials are often poorly designed and analysed. There is little recent research on the methodologic quality of cluster randomized trials and none focuses on primary health care where these trials are increasingly common.

METHODS

We conducted a systematic review of recent cluster randomized trials in primary health care, searching the Cochrane Controlled Trials Register. We also searched for unpublished trials in conference proceedings, and the UK National Research Register. We assess methodologic quality using a checklist, articulate problems facing investigators conducting these trials, and examine the extent to which carrying out a cluster randomized trial (as opposed to an individually randomized trial) in primary care may reduce power.

RESULTS

We found 367 trial reports. Many trials were reported more than once. We characterize 152 independent cluster randomized trials in primary health care published between 1997 and 2000, and briefly describe 47 trials unpublished at December 2000. The quality of design and analysis was variable. Of published trials reporting sample size calculations 20% accounted for clustering in these calculations, 59% of published trials accounted for clustering in analyses. Unpublished trials were more recent and of higher quality. Reporting quality was better in journals reporting more cluster randomized trials. Many trial investigators reported problems with adherence to protocol, recruitment and type of intervention.

CONCLUSIONS

Methodologic quality of cluster randomized trials in primary health care is variable and reporting needs improvement. The use of cluster randomization should be indicated in the title or abstract so these kinds of trials are easier to identify. Communicating appropriate methodology to health care researchers continues to be a challenge. Cluster randomized trials should always be piloted and information from pilots and unsuccessful trials shared more widely.

Which resources should be used to identify RCT/CCTs for systematic reviews: a systematic review

BACKGROUND

Systematic reviewers seek to comprehensively search for relevant studies and summarize these to present the most valid estimate of intervention effectiveness. The more resources searched, the higher the yield, and thus time and costs required to conduct a systematic review. While there is an abundance of evidence to suggest how extensive a search for randomized controlled trials (RCTs) should be, it is neither conclusive nor consistent. This systematic review was conducted in order to assess the value of different resources to identify trials for inclusion in systematic reviews.

METHODS

Seven electronic databases, four journals and Cochrane Colloquia were searched. Key authors were contacted and references of relevant articles screened. Included studies compared two or more sources to find RCTs or controlled clinical trials (CCTs). A checklist was developed and applied to assess quality of reporting. Data were extracted by one reviewer and checked by a second. Medians and ranges for precision and recall were calculated; results were grouped by comparison. Meta-analysis was not performed due to large heterogeneity. Subgroup analyses were conducted for: search strategy (Cochrane, Simple, Complex, Index), expertise of the searcher (Cochrane, librarian, non-librarian), and study design (RCT and CCT).

RESULTS

Sixty-four studies representing 13 electronic databases met inclusion criteria. The most common comparisons were MEDLINE vs. handsearching (n = 23), MEDLINE vs. MEDLINE+handsearching (n = 13), and MEDLINE vs. reference standard (n = 13). Quality was low, particularly for the reporting of study selection methodology. Overall, recall and precision varied substantially by comparison and ranged from 0 to 100% and 0 to 99%, respectively. The trial registries performed the best with median recall of 89% (range 84, 95) and median precision of 96.5% (96, 97), although these results are based on a small number of studies. Inadequate or inappropriate indexing was the reason most cited for missing studies. Complex and Cochrane search strategies (SS) performed better than Simple SS.

CONCLUSION

Multiple-source comprehensive searches are necessary to identify all RCTs for a systematic review, although indexing needs to be improved. Although trial registries demonstrated the highest recall and precision, the Cochrane SS or a Complex SS in consultation with a librarian are recommended. Continued efforts to develop CENTRAL should be supported.

A systematic review of interventions to prevent childhood farm injuries

OBJECTIVE

The goal of the study was to systematically review the global body of evidence surrounding the effectiveness of interventions for the prevention of acute pediatric agricultural injuries. A specific focus was the effectiveness of the North American Guidelines for Children's Agricultural Tasks.

METHODS

Two reviewers independently screened studies and applied inclusion criteria on the basis of searches of 17 bibliographic databases (eg, Medline and Embase). We also screened reference lists of relevant studies and contacted experts in the area. Studies were included if they represented primary research, a comparison group was used, the study population included children or the intervention was directly applicable to children, and objective outcomes were reported. Two reviewers independently assessed the methodologic quality of included studies with the Downs and Black checklist. A qualitative analysis was performed because of extensive heterogeneity among studies.

RESULTS

We included 23 controlled studies, ie, 4 randomized, controlled trials, 5 controlled trials, and 14 quasiexperimental or observational studies. Only 8 of the relevant studies were published in peer-reviewed journals. School-based programs appeared to be effective at increasing short-term knowledge acquisition; outcomes were enhanced with active, hands-on participation, as opposed to passive activities. Safety day camps showed positive results for knowledge acquisition. Tractor training programs and community- and farm-based interventions showed mixed results. Studies examining the North American Guidelines for Children's Agricultural Tasks suggested that uptake improves if dissemination is accompanied by a farm visit from a safety specialist or if information about child development principles is provided in conjunction with the guidelines.

CONCLUSIONS

There is a lack of randomized, controlled trials and community-based trials in this area. Studies primarily examined intermediate outcomes, such as knowledge acquisition; few studies evaluated changes in injury rates. The interventions targeted at children and youths that were evaluated focused on educational interventions. There is both the need and potential for the development and evaluation of injury control interventions for children, particularly programs addressing lethal injuries to young/preschool-aged children.

Cardiovascular risk factors and motivation for a healthy life-style in a German community--results of the GP-based Oestringen study

This paper explores the motivation of patients towards a healthy life-style in a small community with a special general practice and community-based health education program in order to identify reasons for different motivations and barriers and to improve preventive measures and outcome. The last of six standardised health surveys carried out over 9 years in the five general practices was therefore combined with a questionnaire to explore the attitudes of a sample of patients from these practices (N = 1044) and all attendees of 11 health education courses (N = 153). In addition to the cardiovascular risk factors, data were collected on sociodemographic factors and motivations for health promotion. The results show that, over time, the risk factors of hypertension (P < 0.001) and smoking (P < 0.005) had decreased. Health-promoting activities were not associated with cardiovascular risk factors; the motivations "duty" and "staying young" correlated with gender (P < 0.05). Patients with good health and white collar professions were more active. About 20% specified specific barriers to health-related activities. As expected, the participants of an educational program were more highly motivated by "fun", "fitness" and "meaningfulness". This group was mainly female. Future preventive measures should take into account that motivation for health promotion depends more on psychosocial factors than on risk factors; frequent obstacles should be noticed in the community.

Ensuring the comparability of comparison groups: is randomization enough?

BACKGROUND

It is widely believed that baseline imbalances in randomized trials must necessarily be random. In fact, there is a type of selection bias that can cause substantial, systematic and reproducible baseline imbalances of prognostic covariates even in properly randomized trials. It is possible, given complete data, to quantify both the susceptibility of a given trial to this type of selection bias and the extent to which selection bias appears to have caused either observable or unobservable baseline imbalances. Yet, in articles reporting on randomized trials, it is uncommon to find either these assessments or the information that would enable a reader to conduct them. Nevertheless, there have been a few published reports that contain descriptions of either this type of selection bias or indicators that it may have occurred.

OBJECTIVE

To document that the same type of selection bias has been described in numerous randomized trials and therefore that it represents a problem deserving of greater attention.

STUDY SELECTION

Computerized searches were not useful in locating trials with one or more elements that contribute to or are indicative of selection bias in randomized trials. We limit our treatment to trials that were previously questioned for susceptibility to selection bias or for large baseline imbalances.

RESULTS

We found 14 randomized trials that appear to be suspicious for selection bias. This may represent only the tip of the iceberg, because the status of other trials is inconclusive.

CONCLUSIONS

Authors of clinical trial reports should be required to disclose sufficient details to allow for an assessment of both allocation concealment and selection bias. The extent to which a randomized study was susceptible to selection bias should be considered in determining the relative contribution it makes to any subsequent meta-analysis, policy or decision.

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.

Randomized trials and public health interventions: time to end the scientific double standard

Randomized controlled trials have become the acceptedstandard for testing the efficacy and safety of clinical treatments but are rarely used in evaluating public health interventions. This article reviews the types of interventions and outcomes for which randomized trials are necessary to provide a scientifically rigorous evaluation. It also presents the results from two trials analyzed both experimentally and observationally to illustrate why observational studies can yield highly biased findings. This article provides a brief historical account of controlled human experiments, which reveals a surprising earlier tradition of rigorous experimental studies in the social sciences. After contrasting that tradition with the status quo, this article concludes with a plea to reject the double scientific standard of what constitutes acceptable evidence of efficacy for clinical versus public health interventions.

The quality of research in sports journals

OBJECTIVE

To examine the evidence base of sports medicine research.

METHODS

A sample of four major journals that present core research in sport and exercise medicine (British Journal of Sports Medicine, Medicine and Science in Sports and Exercise, Journal of Sports Medicine and Physical Fitness, and Physical Therapy) was examined using assessment criteria taken from the READER method.

RESULTS

Randomised controlled trials comprised 10% or less of all original research articles. Observational/descriptive studies were the most commonly published study design. There was a highly significant difference (p<0.0001) in the contents of the four journals but when they were compared by categorising the better quality methods together (randomised control trial, case-control, and cohort studies), the difference was not significant (p = 0.09).

CONCLUSIONS

The overall pattern of publication type seems remarkably stable over medical journals, indicating that the quality of sports medicine research is comparable to that in other specialities.

Criteria for evaluating evidence on public health interventions

Public health interventions tend to be complex, programmatic, and context dependent. The evidence for their effectiveness must be sufficiently comprehensive to encompass that complexity. This paper asks whether and to what extent evaluative research on public health interventions can be adequately appraised by applying well established criteria for judging the quality of evidence in clinical practice. It is adduced that these criteria are useful in evaluating some aspects of evidence. However, there are other important aspects of evidence on public health interventions that are not covered by the established criteria. The evaluation of evidence must distinguish between the fidelity of the evaluation process in detecting the success or failure of an intervention, and the success or failure of the intervention itself. Moreover, if an intervention is unsuccessful, the evidence should help to determine whether the intervention was inherently faulty (that is, failure of intervention concept or theory), or just badly delivered (failure of implementation). Furthermore, proper interpretation of the evidence depends upon the availability of descriptive information on the intervention and its context, so that the transferability of the evidence can be determined. Study design alone is an inadequate marker of evidence quality in public health intervention evaluation.

Community interventions for reducing smoking among adults

BACKGROUND

Since smoking behaviour is determined by social context, the best way to reduce the prevalence of smoking may be to use community-wide programmes which use multiple channels to provide reinforcement, support and norms for not smoking.

OBJECTIVES

To assess the effectiveness of community interventions for reducing the prevalence of smoking.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group specialised register, MEDLINE (1966-August 2001) and EMBASE (1980-August 2001) and reference lists of articles.

SELECTION CRITERIA

Controlled trials of community interventions for reducing smoking prevalence in adult smokers. The primary outcome was smoking behaviour.

DATA COLLECTION AND ANALYSIS

Data were extracted by one person and checked by a second.

MAIN RESULTS

Thirty two studies were included, of which seventeen included only one intervention and one comparison community. Only four studies used random assignment of communities to either the intervention or comparison group. The population size of the communities ranged from a few thousand to over 100,000 people. Change in smoking prevalence was measured using cross-sectional follow-up data in 27 studies. The estimated net decline ranged from -1.0% to 3.0% for men and women combined (10 studies). For women, the decline ranged from -0.2% to + 3.5% per year (n=11), and for men the decline ranged from -0.4% to +1.6% per year (n=12). Cigarette consumption and quit rates were only reported in a small number of studies. The two most rigorous studies showed limited evidence of an effect on prevalence. In the US COMMIT study there was no differential decline in prevalence between intervention and control communities, and there was no significant difference in the quit rates of heavier smokers who were the target intervention group. In the Australian CART study there was a significantly greater quit rate for men but not women.

REVIEWER'S CONCLUSIONS

The failure of the largest and best conducted studies to detect an effect on prevalence of smoking is disappointing. A community approach will remain an important part of health promotion activities, but designers of future programmes will need to take account of this limited effect in determining the scale of projects and the resources devoted to them.

A Community-Based Program That Provides Free Choice of Intervention for Older People With Chronic Pain

This study sought to evaluate the efficacy of a community-based intervention program that provides free choice of intervention for improving outcomes for community-dwelling older people with chronic nonmalignant pain. A quasiexperimental before and after nonequivalent group design was used. The treated group was composed of 71 participants, and the untreated group was composed of 40 individuals. A 6-month follow-up measurement was included to determine the long-term effects of the program. The findings of the program showed significant benefits for those who completed the program compared with those who did not participate. Evaluation of the program suggested that an initial educational seminar had a positive impact that empowered the participants to make more informed choices regarding interventions for managing pain. Significant reduction in pain intensity and improved level of physical activity were reported by the participants at completion of the interventions. However, results of a 6-month follow-up showed that only the benefits for physical activity were maintained. The findings show that the present program improved the short-term outcomes for older people with chronic pain and has potential as a clinical option for accessible and low-cost pain management for older people with chronic pain.

Social capital and health: implications for public health and epidemiology

Public health and its "basic science", epidemiology, have become colonised by the individualistic ethic of medicine and economics. Despite a history in public health dating back to John Snow that underlined the importance of social systems for health, an imbalance has developed in the attention given to generating "social capital" compared to such things as modification of individual's risk factors. In an illustrative analysis comparing the potential of six progressively less individualised and more community-focused interventions to prevent deaths from heart disease, social support and measures to increase social cohesion faired well against more individual medical care approaches. In the face of such evidence public health professionals and epidemiologists have an ethical and strategic decision concerning the relative effort they give to increasing social cohesion in communities vs expanding access for individuals to traditional public health programs. Practitioners' relative efforts will be influenced by the kind of research that is being produced by epidemiologists and by the political climate of acceptability for voluntary individual "treatment" approaches vs universal policies to build "social capital". For epidemiologists to further our emerging understanding of the link between social capital and health they must confront issues in measurement, study design and analysis. For public health advocates to sensitise the political environment to the potential dividend from building social capital, they must confront the values that focus on individual-level causal models rather than models of social structure (dis)integration. The evolution of explanations for inequalities in health is used to illustrate the nature of the change in values.