Cardiovascular risk factor prevention in black school children: the "Know Your Body" evaluation project

Examining subgroup effects by socioeconomic status of public health interventions targeting multiple risk behaviour in adolescence

BACKGROUND

Multiple risk behaviour (MRB) refers to two or more risk behaviours such as smoking, drinking alcohol, poor diet and unsafe sex. Such behaviours are known to co-occur in adolescence. It is unknown whether MRB interventions are equally effective for young people of low and high socioeconomic status (SES). There is a need to examine these effects to determine whether MRB interventions have the potential to narrow or widen inequalities.

METHODS

Two Cochrane systematic reviews that examined interventions to reduce adolescent MRB were screened to identify universal interventions that reported SES. Study authors were contacted, and outcome data stratified by SES and intervention status were requested. Risk behaviour outcomes alcohol use, smoking, drug use, unsafe sex, overweight/obesity, sedentarism, peer violence and dating violence were examined in random effects meta-analyses and subgroup analyses conducted to explore differences between high SES and low SES adolescents.

RESULTS

Of 49 studies reporting universal interventions, only 16 also reported having measured SES. Of these 16 studies, four study authors provided data sufficient for subgroup analysis. There was no evidence of subgroup differences for any of the outcomes. For alcohol use, the direction of effect was the same for both the high SES group (RR 1.26, 95% CI: 0.96, 1.65, p = 0.09) and low SES group (RR 1.14, 95% CI: 0.98, 1.32, p = 0.08). The direction of effect was different for smoking behaviour in favour of the low SES group (RR 0.83, 95% CI: 0.66, 1.03, p = 0.09) versus the high SES group (RR 1.16, 95% CI: 0.82, 1.63, p = 0.39). For drug use, the direction of effect was the same for both the high SES group (RR 1.29, 95% CI: 0.97, 1.73, p = 0.08) and the low SES group (RR 1.28, 95% CI: 0.84, 1.96, p = 0.25).

CONCLUSIONS

The majority of studies identified did not report having measured SES. There was no evidence of subgroup difference for all outcomes analysed among the four included studies. There is a need for routine reporting of demographic information within studies so that stronger evidence of effect by SES can be demonstrated and that interventions can be evaluated for their impact on health inequalities.

Effect of educational interventions on health in childhood: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to summarize the findings of randomized controlled trials (RCTs) investigating any potential effects of educational interventions on health in childhood.

STUDY DESIGN

Meta-analysis.

METHODS

PubMed, Embase, and the Cochrane Library databases were searched to identify all RCTs that fit our analysis through May 2016. Weighted mean difference (WMD) was used to measure the effect of educational interventions in childhood by using a random effects model.

RESULTS

Thirty RCTs reporting data on 35,296 children were included in the meta-analysis. The summary WMD indicated that children who received educational interventions had lower levels of body mass index (BMI) (WMD: -0.15; 95% CI: -0.24 to -0.05; P = 0.003), BMI z-score (WMD: -0.03; 95% CI: -0.05 to -0.02; P < 0.001), waist circumference (WMD: -0.97; 95% CI: -1.95 to -0.00; P = 0.050), triceps skinfold (WMD: -1.39; 95% CI: -2.41 to -0.37; P = 0.008), systolic blood pressure (WMD: -1.13; 95% CI: -2.20 to -0.07; P = 0.037), total cholesterol (WMD: -4.04; 95% CI: -7.18 to -0.90; P = 0.012), and triglyceride (WMD: -2.62; 95% CI: -4.33 to -0.90; P = 0.003). However, educational interventions were found to have little or no significant impact on the waist-to-hip ratio, diastolic blood pressure, high-density lipoprotein, and low-density lipoprotein.

CONCLUSIONS

The study findings prove the positive effects of educational interventions on BMI, BMI z-score, waist circumference, triceps skinfold, systolic blood pressure, total cholesterol, and triglyceride.

Effect of educational interventions on health in childhood: A meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this study was to summarize the evidences from randomized controlled trials (RCTs) investigating the effects of educational interventions in overweight/obesity childhood by using meta-analytic approach.

METHODS

PubMed, Embase, and the Cochrane Library databases were searched from the inception to April 2018. Weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were used to measure the effects of educational interventions during childhood in the random-effects models.

RESULTS

Thirty RCTs reporting data on 35,296 children were included in the meta-analysis. The summary WMD indicated that children received educational interventions had lower levels of body mass index (BMI) (WMD: -0.15; 95% CI: -0.24 to -0.05; P = .003), BMI z-score (WMD: -0.03; 95% CI: -0.05 to -0.02; P < .001), waist circumference (WMD: -0.97; 95% CI: -1.95 to -0.00; P = 0.050), triceps skinfold (WMD: -1.39; 95% CI: -2.41 to -0.37; P = .008), systolic blood pressure (WMD: -1.13; 95% CI: -2.20 to -0.07; P = .037), total cholesterol (WMD: -4.04; 95% CI: -7.18 to -0.90; P = .012), and triglyceride (WMD: -2.62; 95% CI: -4.33 to -0.90; P = .003). However, educational interventions were not associated with the levels of waist-to-hip ratio, diastolic blood pressure, high-density lipoprotein, and low-density lipoprotein.

CONCLUSION

The study findings elucidate the positive effects of educational interventions on BMI, BMI z-score, waist circumference, triceps skinfold, systolic blood pressure, total cholesterol, and triglyceride.

The association of fitness and school absenteeism across gender and poverty: a prospective multilevel analysis in New York City middle schools

PURPOSE

One-fifth to one-third of students in high poverty, urban school districts do not attend school regularly (missing ≥6 days/year). Fitness is shown to be associated with absenteeism, although this relationship may differ across poverty and gender subgroups.

METHODS

Six cohorts of New York City public school students were followed up from grades 5 to 8 during 2006/2007-2012/2013 (n = 349,381). Stratified three-level longitudinal generalized linear mixed models were used to test the association between changes in fitness and 1-year lagged child-specific days absent across gender and poverty.

RESULTS

In girls attending schools in high/very high poverty areas, greater improvements in fitness the prior year were associated with greater reductions in absenteeism (P = .034). Relative to the reference group (>20% decrease in fitness composite percentile scores from the prior year), girls with a large increase in fitness (>20%) demonstrated 10.3% fewer days absent (incidence rate ratio [IRR] 95% confidence interval [CI]: 0.834, 0.964), followed by those who had a 10%-20% increase in fitness (9.2%; IRR 95% CI: 0.835, 0.987), no change (5.4%; IRR 95% CI: 0.887, 1.007), and a 10%-20% decrease in fitness (3.8%; IRR 95% CI: 0.885, 1.045). In girls attending schools in low/mid poverty areas, fitness and absenteeism also had an inverse relationship, but no clear trend emerged. In boys, fitness and absenteeism had an inverse relationship but was not significant in either poverty group.

CONCLUSIONS

Fitness improvements may be more important to reducing absenteeism in high/very high poverty girls compared with low/mid poverty girls and both high/very high and low/mid poverty boys. Expanding school-based physical activity programs for youth particularly in high poverty neighborhoods may increase student attendance.

The effects of school-based lifestyle interventions on body mass index and blood pressure: a multivariate multilevel meta-analysis of randomized controlled trials

Primary prevention of childhood obesity and related hypertension is warrant given that both risk factors are intertwined and track into adulthood. This systematic review and meta-analysis assess the impact of school-based lifestyle interventions on children's body mass index (BMI) and blood pressure. We searched databases and prior reviews. Eligibility criteria were the following: randomized controlled trial design, evaluation of a school-based intervention, targeting children aged 4-12 years, reporting on BMI and/or related cardiovascular risk factors, reporting data on at least one follow-up moment. The effects on BMI, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were evaluated by means of univariate and multivariate three-level random effects models. A total of 85 RCTs (91 papers) were included in the meta-analyses. In univariate models, the pooled effects were -0.072 (95%CI: -0.106; -0.038) for BMI, -0.183 (95%CI: -0.288; -0.078) for SBP and -0.071 (95%CI: -0.185; 0.044) for DBP. In multivariate analyses, the pooled effects of interventions were -0.054 (95%CI: -0.131; 0.022) for BMI, -0.182 (95%CI: -0.266; -0.098) for SBP and -0.144 (95%CI: -0.230; -0.057) for DBP. Parental involvement accentuated the beneficial effects of interventions. School-based lifestyle prevention interventions result in beneficial changes in children's BMI and blood pressure, and the effects on the latter may be stronger than and accrue independently from those in the former.

A Community-Based Physical Education and Activity Intervention for African American Preadolescent Girls: A Strategy to Reduce Racial Disparities in Health

Physical activity habits fostered and developed early in life tend to persist into adulthood, reducing the incidence of chronic diseases associated with a sedentary lifestyle in later life. This is of particular importance for racial and ethnic minority populations who experience significant disparities in rates of chronic disease. Thus, promoting physical activity in minority children is an effective strategy for reducing these health disparities. Unfortunately, however, recommendations for effective implementation of such programs are sorely lacking. This article describes the development and implementation of Lively Ladies, a physical education and activity intervention targeted to low-income, preadolescent, African American girls in a community-based youth services organization. Low-income, minority girls face the catch-22 situation of being at higher risk for physical inactivity while having limited or no access to physical fitness programs. This article demonstrates that community-based youth organizations can play an important role in changing this situation. The authors’ experience with Lively Ladies indicates the effectiveness of a theory-based program addressing modifiable psychosocial and environmental determinants of behavior. They provide recommendations to guide future design and implementation of community-based physical education and activity interventions for a population group that tends to have increased risk for physical inactivity and limited access to fitness programs and facilities.

Parental Influence on Models of Primary Prevention of Cardiovascular Disease in Children

BACKGROUND

Lifestyle behaviors such as overeating and physical inactivity contribute significantly to CVD, the leading cause of morbidity and mortality among adults globally. CVD risk factors that begin in children often track into adulthood. Parents are believed to influence the health behaviors of their children.

OBJECTIVE

To review the literature on parental influence on children's health beliefs and behaviors, particularly eating and exercise behaviors as indicators of CV health, school-based CVD risk reduction programs, and racial/ethnic, gender and socioeconomic considerations for models of primary prevention of CVD in children.

METHODS

Seventeen studies that included parents as either a source of information, change agent or participant in a CVD risk reduction intervention were identified searching the Medline, CINAHL and PsycINFO databases from 1980 through 2002.

RESULTS

Children's lifestyle health beliefs and behaviors are significantly influenced by positive parental modeling and involvement in exercise and healthy eating; parental influence on children's behavior lasts beyond adolescence; parents are effective teachers of health habits at home when prompted by health educators; and parental influences vary by ethnicity/race, socioeconomics and gender.

CONCLUSIONS

A broader base of knowledge that is socioculturally sensitive must be developed about what parents and children believe is healthy, how parents model beliefs and behaviors for their children, and how to build self-efficacy for positive health behaviors.

Educational interventions in childhood obesity: a systematic review with meta-analysis of randomized clinical trials

OBJECTIVE

To assess the effectiveness of educational interventions including behavioral modification, nutrition and physical activity to prevent or treat childhood obesity through a systematic review and meta-analysis of randomized trials.

METHOD

A search of databases (PubMed, EMBASE and Cochrane CENTRAL) and references of published studies (from inception until May 2012) was conducted. Eligible studies were randomized trials enrolling children 6 to 12 years old and assessing the impact of educational interventions during 6 months or longer on waist circumference, body mass index (BMI), blood pressure and lipid profile to prevent or treat childhood obesity. Calculations were performed using a random effects method and pooled-effect estimates were obtained using the final values.

RESULTS

Of 22.852 articles retrieved, 26 trials (23.617 participants) were included. There were no differences in outcomes assessed in prevention studies. However, in treatment studies, educational interventions were associated with a significant reduction in waist circumference [-3.21 cm (95%CI -6.34, -0.07)], BMI [-0.86 kg/m(2) (95%CI -1.59, -0.14)] and diastolic blood pressure [-3.68 mmHg (95%CI -5.48, -1.88)].

CONCLUSIONS

Educational interventions are effective in treatment, but not prevention, of childhood obesity and its consequences.

A systematic review of intervention effects on potential mediators of children's physical activity

Background

Many interventions aiming to increase children’s physical activity have been developed and implemented in a variety of settings, and these interventions have previously been reviewed; however the focus of these reviews tends to be on the intervention effects on physical activity outcomes without consideration of the reasons and pathways leading to intervention success or otherwise.

To systematically review the efficacy of physical activity interventions targeting 5-12 year old children on potential mediators and, where possible, to calculate the size of the intervention effect on the potential mediator.

Methods

A systematic search identified intervention studies that reported outcomes on potential mediators of physical activity among 5-12 year old children. Original research articles published between 1985 and April 2012 were reviewed.

Results

Eighteen potential mediators were identified from 31 studies. Positive effects on cognitive/psychological potential mediators were reported in 15 out of 31 studies. Positive effects on social environmental potential mediators were reported in three out of seven studies, and no effects on the physical environment were reported. Although no studies were identified that performed a mediating analysis, 33 positive intervention effects were found on targeted potential mediators (with effect sizes ranging from small to large) and 73% of the time a positive effect on the physical activity outcome was reported.

Conclusions

Many studies have reported null intervention effects on potential mediators of children’s physical activity; however, it is important that intervention studies statistically examine the mediating effects of interventions so the most effective strategies can be implemented in future programs.

Effects of Promoting Health Among Teens on Dietary, Physical Activity and Substance Use Knowledge and Behaviors for African American Adolescents

BACKGROUND

African Americans are disproportionately affected by cardiovascular disease and cancer. Health promotion interventions hold promise for reducing health disparities.

PURPOSE

Promoting Health Among Teens (PHAT) is a brief, culturally tailored health education intervention to decrease cardiovascular disease and cancer risk for African Americans. This study evaluated the effects of PHAT for African American adolescents ages 14 to 17 in four eastern cities in the USA.

METHODS

A randomized controlled design (N = 1,654) was used to determine differences in health knowledge, diet, physical activity, and substance use behaviors between PHAT participants and a sexual health promotion control group. Data were collected at baseline, three, six, and twelve months post intervention. Growth curve modeling was used to detect differences in health knowledge, dietary behaviors, physical activity, and substance use between PHAT and control group participants.

RESULTS

PHAT participants had significantly greater knowledge gains but modest behavior changes compared to control group participants.

DISCUSSION

PHAT is a promising intervention to increase knowledge and address selected health behaviors in African American youth.

TRANSLATION TO HEALTH EDUCATION PRACTICE

Future attempts to execute PHAT should continue its emphasis on knowledge building while increasing intervention dosage and modifying length of time for intervention sessions.

Interactive Multimedia for Promoting Physical Activity (IMPACT) in Children

OBJECTIVE

To develop and examine the efficacy of a computer-based interactive multimedia curriculum for promoting physical activity in fourth grade children.

RESEARCH METHODS AND PROCEDURES

The participants were 209 fourth grade children (mean age of 9.5 +/- 0.4 years) from four schools. Two schools received an 8-week multimedia intervention delivered by interactive CD-ROM, supplemented by four classroom and four homework assignments. Two control schools received educational CD-ROMS not related to health outcomes. Measures conducted before and after intervention included height, weight, percentage body fat (bioimpedance analysis), physical activity (5-day accelerometry), and psychosocial aspects of physical activity by questionnaire. All outcomes were examined using general linear models.

RESULTS

There was a significant treatment effect for obesity reduction in girls but not in boys. There were no significant treatment effects on total physical activity by accelerometry (total counts per minute), but there was an overall treatment effect on reducing percent of time in moderate-intensity activity (16.5% to 15% of the time) and significant sex-by- treatment interactions for light-intensity activities (reduction in boys from 78% to 75% of the time and an increase in girls from 78% to 81% of the time). There were marginal/significant treatment effects for improvements in behavioral outcomes, including self-efficacy (p = 0.06), social norms (p = 0.07), and outcome expectancies (p = 0.049).

DISCUSSION

The interactive multimedia curriculum favored an improvement in obesity indices in girls and was associated with subtle changes in physical activity in girls and general improvement in psychosocial outcomes related to physical activity.

Putting the pieces together: an integrated model of program implementation

Considerable evidence indicates that variability in implementation of prevention programs is related to the outcomes achieved by these programs. However, while implementation has been conceptualized as a multidimensional construct, few studies examine more than a single dimension, and no theoretical framework exists to guide research on the effects of implementation. We seek to address this need by proposing a theoretical model of the relations between the dimensions of implementation and outcomes of prevention programs that can serve to guide future implementation research. In this article, we focus on four dimensions of implementation, which we conceptualize as behaviors of program facilitators (fidelity, quality of delivery, and adaptation) and behaviors of participants (responsiveness) and present the evidence supporting these as predictors of program outcomes. We then propose a theoretical model by which facilitator and participant dimensions of implementation influence participant outcomes. Finally, we provide recommendations and directions for future implementation research.

Putting the pieces together: an integrated model of program implementation

Considerable evidence indicates that variability in implementation of prevention programs is related to the outcomes achieved by these programs. However, while implementation has been conceptualized as a multidimensional construct, few studies examine more than a single dimension, and no theoretical framework exists to guide research on the effects of implementation. We seek to address this need by proposing a theoretical model of the relations between the dimensions of implementation and outcomes of prevention programs that can serve to guide future implementation research. In this article, we focus on four dimensions of implementation, which we conceptualize as behaviors of program facilitators (fidelity, quality of delivery, and adaptation) and behaviors of participants (responsiveness) and present the evidence supporting these as predictors of program outcomes. We then propose a theoretical model by which facilitator and participant dimensions of implementation influence participant outcomes. Finally, we provide recommendations and directions for future implementation research.

Systematic Review of Interventions to Increase Physical Activity and Physical Fitness in African-Americans

Objective.

To identify characteristics of effective interventions designed to increase physical activity (PA) or fitness among African-Americans.

Data Sources.

Articles published between 1985 and 2006.

Study Inclusion Criteria.

Studies reporting PA or fitness change data in African-American participants were included.

Data Extraction.

Information on study design, intervention, data collection methods, and outcomes was extracted using a standardized form.

Data Synthesis.

Studies were ranked on quality and were summarized separately for adults and children.

Results.

We identified 29 studies in adults and 14 studies in children. Most were randomized controlled trials. All but six specifically targeted African-Americans; comparisons of effectiveness in African-Americans vs. others were not possible. Methodological heterogeneity limited comparisons of findings across studies. In adults, most studies showed significant within-group pre-post improvements in PA, but only 10 studies found differences between intervention and comparison groups. Most studies in children were null.

Conclusions.

Effective programs in adults were from randomized controlled trials and involved structured exercise programs. Studies with explicit cultural adaptations did not necessarily result in better PA outcomes. Additional studies are needed with larger sample sizes, longer follow-up, attention controls, strategies informed by proven behavior change theories, and objective PA assessment.

School-based smoking prevention programs with the promise of long-term effects

I provide a systematic review of trials of school-based smoking prevention programs that had at least 15 sessions, preferably with some in high school, that reported significant short-term effects, and that included long-term follow-up. This is supplemented with a description of some other programs that produce short-term effects that portend large long-term effects. I conclude that school-based programs can have long-term effects of practical importance it they: include 15 or more sessions over multiple years, including some in high school; use the social influence model and interactive delivery methods; include components on norms, commitment not to use, intentions not to use, and training and practice in the use of refusal and other life skills; and use peer leaders in some role. School-based programs of this type can reduce smoking onset by 25-30%, and school plus community programs can reduce smoking onset by 35-40% by the end of high school. Some early childhood programs that do not have smoking prevention as their main aim, including home nursing, the Good Behavior Game, the Positive Action program and others, seem to change the developmental trajectories of children so that they are less likely to engage in multiple problem behaviors, including smoking, as adolescents. This review makes it clear that effective school-based smoking prevention programs exist and can be adopted, adapted and deployed with success - and should be.

Clinical review: behavioral interventions to prevent childhood obesity: a systematic review and metaanalyses of randomized trials

CONTEXT

The efficacy of lifestyle interventions to encourage healthy lifestyle behaviors to prevent pediatric obesity remains unclear.

OBJECTIVE

Our objective was to summarize evidence on the efficacy of interventions aimed at changing lifestyle behaviors (increased physical activity, decreased sedentary activity, increased healthy dietary habits, and decreased unhealthy dietary habits) to prevent obesity.

DATA SOURCES

Data sources included librarian-designed searches of nine electronic databases, references from included studies and reviews (from inception until February 2006), and content expert recommendations.

STUDY SELECTION

Eligible studies were randomized trials enrolling children and adolescents assessing the impact of interventions on both lifestyle behaviors and body mass index (BMI).

DATA EXTRACTION

Two reviewers independently abstracted data on methodological quality, study characteristics, intervention components, and treatment effects.

DATA ANALYSIS

We conducted random-effects metaanalyses, quantified inconsistency using I(2), and conducted planned subgroup analyses for each examined outcome.

DATA SYNTHESIS

Regarding target behaviors, the pooled effect size for physical activity (22 comparisons; n = 9891 participants) was 0.12 [95% confidence interval (CI) = 0.04-0.20; I(2) = 63%], for sedentary activity (14 comparisons; n = 3003) was -0.29, (CI = -0.35 to -0.22; I(2) = 0%), for healthy dietary habits (14 comparisons, n = 5468) was 0.00 (CI = -0.20; 0.20; I(2) = 83%), and for unhealthy dietary habits (23 comparisons, n = 9578) was -0.20 (CI = -0.31 to -0.09; I(2) = 34%). The effect of these interventions on BMI (43 comparisons, n = 32,003) was trivial (-0.02; CI = -0.06-0.02; I(2) = 17%) compared with control. Trials with interventions lasting more than 6 months (vs. shorter trials) and trials with postintervention outcomes (vs. in-treatment outcomes) yielded marginally larger effects.

CONCLUSION

Pediatric obesity prevention programs caused small changes in target behaviors and no significant effect on BMI compared with control. Trials evaluating promising interventions applied over a long period, using responsive outcomes, with longer measurement timeframes are urgently needed.

Implementation matters: a review of research on the influence of implementation on program outcomes and the factors affecting implementation

The first purpose of this review was to assess the impact of implementation on program outcomes, and the second purpose was to identify factors affecting the implementation process. Results from over quantitative 500 studies offered strong empirical support to the conclusion that the level of implementation affects the outcomes obtained in promotion and prevention programs. Findings from 81 additional reports indicate there are at least 23 contextual factors that influence implementation. The implementation process is affected by variables related to communities, providers and innovations, and aspects of the prevention delivery system (i.e., organizational functioning) and the prevention support system (i.e., training and technical assistance). The collection of implementation data is an essential feature of program evaluations, and more information is needed on which and how various factors influence implementation in different community settings.

Os efeitos do treinamento de força sobre os fatores de risco da síndrome metabólica

INTRODUÇÃO: Medidas não-farmacológicas, como a atividade física, vêm sendo recomendadas para prevenção e tratamento de doenças crônicas não transmissíveis. OBJETIVO: Realizar revisão da literatura para verificar os mecanismos por meio dos quais o treinamento de força provoca alterações metabólicas e celulares, agindo positivamente sobre os fatores de risco da síndrome metabólica. METODODOLOGIA: Foram utilizadas as bases de dados Medline, Scielo, Science Direct e Capes. A busca foi restrita aos últimos 10 anos. Os termos utilizados para pesquisa foram: obesity, dislipidemy,hypertension, diabetes mellitus, metabolic syndrome, resistance training, weight lifting, exercise. RESULTADOS: O treinamento de força atua sobre parâmetros metabólicos e celulares promovendo efeitos positivos no controle e na prevenção dos fatores de risco relacionados à síndrome metabólica, tais como diminuição do peso corporal, aumento da sensibilidade à insulina, aumento da tolerância à glicose, diminuição dos níveis pressóricos de repouso e melhoria do perfil lipídico. CONCLUSÃO: A revisão dos artigos científicos apresentados fornece dados que permitem concluir que o treinamento de força pode contribuir de forma efetiva na diminuição dos fatores de risco relacionados à síndrome metabólica.

Interventions to prevent obesity in children and adolescents: a systematic literature review

OBJECTIVE

Preventive measures to contain the epidemic of obesity have become a major focus of attention. This report reviews the scientific evidence for medical interventions aimed at preventing obesity during childhood and adolescence.

DESIGN

A systematic literature review involving selection of primary research and other systematic reviews. Articles published until 2004 were added to an earlier (2002) review by the Swedish Council on Technology Assessment in Health Care.

METHODS

Inclusion criteria required controlled studies with follow-up of at least 12 months and results measured as body mass index, skinfold thickness or the percentage of overweight/obesity. Children could be recruited from normal or high-risk populations.

RESULTS

Combining the new data with the previous review resulted in an evaluation of 24 studies involving 25 896 children. Of these, eight reported that prevention had a statistically significant positive effect on obesity, 16 reported neutral results and none reported a negative result (sign test; P=0.0078). Adding the studies included in five other systematic reviews yielded, in total, 15 studies with positive, 24 with neutral and none with negative results. Thus, 41% of the studies, including 40% of the 33 852 children studied, showed a positive effect from prevention. These results are unlikely to be a random chance phenomenon (P=0.000061).

CONCLUSION

Evidence shows that it is possible to prevent obesity in children and adolescents through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity.

Position of the American Dietetic Association: individual-, family-, school-, and community-based interventions for pediatric overweight

The American Dietetic Association (ADA), recognizing that overweight is a significant problem for children and adolescents in the United States, takes the position that pediatric overweight intervention requires a combination of family-based and school-based multi-component programs that include the promotion of physical activity, parent training/modeling, behavioral counseling, and nutrition education. Furthermore, although not yet evidence-based, community-based and environmental interventions are recommended as among the most feasible ways to support healthful lifestyles for the greatest numbers of children and their families. ADA supports the commitment of resources for programs, policy development, and research for the efficacious promotion of healthful eating habits and increased physical activity in all children and adolescents, regardless of weight status. This is the first position paper of ADA to be based on a rigorous systematic evidence-based analysis of the pediatric overweight literature on intervention programs. The research showed positive effects of two specific kinds of overweight interventions: a) multicomponent, family-based programs for children between the ages of 5 and 12 years, and b) multicomponent, school-based programs for adolescents. Multicomponent programs include behavioral counseling, promotion of physical activity, parent training/modeling, dietary counseling, and nutrition education. Analysis of the literature to date points to the need for further investigation of promising strategies not yet adequately evaluated. Furthermore, this review highlights the need for research to develop effective and innovative overweight prevention programs for various sectors of the population, including those of varying ethnicities, young children, and adolescents. To support and enhance the efficacy of family- and school-based weight interventions, community-wide interventions should be undertaken; few such interventions have been conducted and even fewer evaluated.

Reducing obesity and related chronic disease risk in children and youth: a synthesis of evidence with 'best practice' recommendations

Childhood obesity is a global epidemic and rising trends in overweight and obesity are apparent in both developed and developing countries. Available estimates for the period between the 1980s and 1990s show the prevalence of overweight and obesity in children increased by a magnitude of two to five times in developed countries (e.g. from 11% to over 30% in boys in Canada), and up to almost four times in developing countries (e.g. from 4% to 14% in Brazil). The goal of this synthesis research study was to develop best practice recommendations based on a systematic approach to finding, selecting and critically appraising programmes addressing prevention and treatment of childhood obesity and related risk of chronic diseases. An international panel of experts in areas of relevance to obesity provided guidance for the study. This synthesis research encompassed a comprehensive search of medical/academic and grey literature and the Internet covering the years 1982-2003. The appraisal approach developed to identify best practice was unique, in that it considered not only methodological rigour, but also population health, immigrant health and programme development/evaluation perspectives in the assessment. Scores were generated based on pre-determined criteria with programmes scoring in the top tertile of the scoring range in any one of the four appraisal categories included for further examination. The synthesis process included identification of gaps and an analysis and summary of programme development and programme effectiveness to enable conclusions to be drawn and recommendations to be made. The results from the library database searches (13,158 hits), the Internet search and key informant surveys were reduced to a review of 982 reports of which 500 were selected for critical appraisal. In total 158 articles, representing 147 programmes, were included for further analysis. The majority of reports were included based on high appraisal scores in programme development and evaluation with limited numbers eligible based on scores in other categories of appraisal. While no single programme emerged as a model of best practice, synthesis of included programmes provided rich information on elements that represent innovative rather than best practice under particular circumstances that are dynamic (changing according to population subgroups, age, ethnicity, setting, leadership, etc.). Thus the findings of this synthesis review identifies areas for action, opportunities for programme development and research priorities to inform the development of best practice recommendations that will reduce obesity and chronic disease risk in children and youth. A lack of programming to address the particular needs of subgroups of children and youth emerged in this review. Although immigrants new to developed countries may be more vulnerable to the obesogenic environment, no programmes were identified that specifically targeted their potentially specialized needs (e.g. different food supply in a new country). Children 0-6 years of age and males represented other population subgroups where obesity prevention programmes and evidence of effectiveness were limited. These gaps are of concern because (i) the pre-school years may be a critical period for obesity prevention as indicated by the association of the adiposity rebound and obesity in later years; and (ii) although the growing prevalence of obesity affects males and females equally; males may be more vulnerable to associated health risks such as cardiovascular disease. Other gaps in knowledge identified during synthesis include a limited number of interventions in home and community settings and a lack of upstream population-based interventions. The shortage of programmes in community and home settings limits our understanding of the effectiveness of interventions in these environments, while the lack of upstream investment indicates an opportunity to develop more upstream and population-focused interventions to balance and extend the current emphasis on individual-based programmes. The evidence reviewed indicates that current programmes lead to short-term improvements in outcomes relating to obesity and chronic disease prevention with no adverse effects noted. This supports the continuation and further development of programmes currently directed at children and youth, as further evidence for best practice accumulates. In this synthesis, schools were found to be a critical setting for programming where health status indicators, such as body composition, chronic disease risk factors and fitness, can all be positively impacted. Engagement in physical activity emerged as a critical intervention in obesity prevention and reduction programmes. While many programmes in the review had the potential to integrate chronic disease prevention, few did; therefore efforts could be directed towards better integration of chronic disease prevention programmes to minimize duplication and optimize resources. Programmes require sustained long-term resources to facilitate comprehensive evaluation that will ascertain if long-term impact such as sustained normal weight is maintained. Furthermore, involving stakeholders in programme design, implementation and evaluation could be crucial to the success of interventions, helping to ensure that needs are met. A number of methodological issues related to the assessment of obesity intervention and prevention programmes were identified and offer insight into how research protocols can be enhanced to strengthen evidence for obesity interventions. Further research is required to understand the merits of the various forms in which interventions (singly and in combination) are delivered and in which circumstances they are effective. There is a critical need for the development of consistent indicators to ensure that comparisons of programme outcomes can be made to better inform best practice.

Quality control for interviews to obtain dietary recalls from children for research studies

Quality control is an important aspect of a study because the quality of data collected provides a foundation for the conclusions drawn from the study. For studies that include interviews, establishing quality control for interviews is critical in ascertaining whether interviews are conducted according to protocol. Despite the importance of quality control for interviews, few studies adequately document the quality control procedures used during data collection. This article reviews quality control for interviews and describes methods and results of quality control for interviews from two of our studies regarding the accuracy of children's dietary recalls; the focus is on quality control regarding interviewer performance during the interview, and examples are provided from studies with children. For our two studies, every interview was audio recorded and transcribed. The audio recording and typed transcript from one interview conducted by each research dietitian either weekly or daily were randomly selected and reviewed by another research dietitian, who completed a standardized quality control for interviews checklist.Major strengths of the methods of quality control for interviews in our two studies include: (a) interviews obtained for data collection were randomly selected for quality control for interviews, and (b) quality control for interviews was assessed on a regular basis throughout data collection. The methods of quality control for interviews described may help researchers design appropriate methods of quality control for interviews for future studies.

A preliminary survey of health education in Indiana home schools

The total US school enrollment of 52.7 million students in 1998 excluded an estimated 1.2 million students educated in their homes. In 1989, some 1,148 home school families enrolled with the Indiana Department of Education. Just over a decade later, some 18,260 home school families had registered, and this number continues to increase. Despite knowledge about the growing numbers of families choosing to home school, limited empirical data exists of how health education is presented in home schools or the needs of home school educators who teach health education. This preliminary study examined health education content areas taught by home school educators in Indiana. An instrument was developed, piloted, and administered to a random sample of 600 home school educators. Results indicated most home school educators taught a variety of health education topics. Three topics--first aid, physical activity and fitness, and nutrition and diet--were taught most frequently in the health curriculum of home schools. Violence prevention, suicide prevention, and consumer health were covered less frequently in the health curriculum. Health was typically taught in a nonstructured, teachable moment format. Implications for coordinated school health programs and suggestions for further research are discussed.

Review and analysis of evaluation measures used in nutrition education intervention research

The purpose of this review is to provide a summary of the kinds of evaluation measures used in 265 nutrition education intervention studies conducted between 1980 and 1999 and an analysis of psychometric issues arising from such a review. The data are summarized in terms of tables for interventions with each of six key population groups: preschool children, school-aged children, adults, pregnant women and breast-feeding promotion, older adults, and inservice preparation of professionals and paraprofessionals. Measures evaluating knowledge and skills or behavioral capabilities were most widely used in studies with preschool, school-aged, and inservice populations (50%-85%) and less widely used in studies with the other groups, particularly breast-feeding promotion (5%). Measures of potential psychosocial mediators or correlates of behavior such as outcome expectancies, self-efficacy, or behavioral intention were used in 90% of behaviorally focused studies with school-aged children and in about 20% of studies with adults. Dietary intake measures were used in almost all studies, primarily food recalls, records, and quantitative food frequency questionnaires. Short frequency instruments involving only foods targeted in the intervention such as fruits and vegetables are increasingly being used. Measures of specific observable behaviors are also increasingly being used. Physiologic parameters were used in about 33% of behaviorally focused interventions with school-aged children and adults, 20% with older adults, and 65% with pregnant women and/or their infants. Criterion validity of newly developed intake instruments and content validity of instruments measuring mediating variables were reported in the majority (range 50%-90%) of studies. Reliability and stability of measures of mediating variables were reported in 50% to 75% of studies, with reliability coefficients mostly about .6 to .7. Two major conclusions from this review are that evaluation measures should be appropriate to the purpose, duration, and power of the intervention and that measures should have adequate validity and reliability in relation to both the outcomes and characteristics of the target audience. Major implications are that considerable preliminary work needs to be done before any intervention study to develop and test evaluation instruments so that they are appropriate and have adequate psychometric properties, and cognitive testing of published instruments with each new target audience is essential. We will then be better able to make judgments about the effectiveness of nutrition education.

Energy expenditure, physical activity, and obesity in children

Although there are physiologic and genetic influences on the various components of energy metabolism and body weight regulation, and a major portion of individual differences in body weight can be explained by genetic differences, it seems unlikely that the increased global prevalence of obesity has been driven by a dramatic change in the gene pool. It is more likely and more reasonable that acute changes in behavior and environment have contributed to the rapid increase in obesity and that genetic factors may be important in the deferring individual susceptibilities to these changes. The most striking behavioral changes that have occurred have been an increased reliance on high-fat and energy-dense "fast foods," with larger portion sizes, coupled with an ever-increasing sedentary lifestyle. The more sedentary lifestyle is caused by an increased reliance on technology and labor-saving devices, which has reduced the need for physical exertion for everyday activities. Examples of energy-saving devices that have resulted in a secular decline in physical activity include: Increased use of automated transport rather than walking or biking Central heating and use of automated equipment, such as washing machines, in the household. Reduction in physical activity in the workplace because of computers, automated equipment, and electronic mail. Increased use of television and computers for entertainment and leisure activities. Use of elevators and escalators rather than stairs. Increased concern for crime, which has reduced the likelihood of outdoor playing. Poor urban planning that does not provide adequate biking paths or even sidewalks in some communities. Thus, the increasing prevalence, numerous health risks, and astounding economic costs of obesity clearly justify widespread efforts toward prevention efforts. These prevention efforts should begin in childhood because the behaviors are learned and continue through the lifetime.

The effect of cardiovascular health promotion on health behaviors in elementary school children: an integrative review

This report provides on an integrative review of health promotion studies relevant to elementary school children published between 1986 and 1998. The 22 research articles represented several disciplines including public health and nursing. The studies varied in research design, sample characteristics, and approaches to health education. The most common interventions targeted behavioral risk factors for cardiovascular disease, but it also was evident from the literature that family and community involvement both played a significant role in health behaviors of children. Health promotion studies were under-represented in the nursing literature, a gap that creates an impetus to study children and families to identify the ways they learn primary preventive behaviors.

Effects of strength training on intra-abdominal adipose tissue in obese prepubertal girls

PURPOSE

The purpose of this study was to determine the effects of strength training on fat distribution and its relationship to glucose tolerance in obese prepubertal girls.

METHODS

A strength training intervention study was designed in which the children exercised three times per week for 5 months. Twelve healthy, obese prepubertal girls (ages 7-10 yr, > 95th percentile weight for height) were enrolled in the study. Body composition was measured by dual-energy x-ray absorptiometry and computed tomography, and glucose tolerance was measured by a 3-h oral glucose tolerance test at baseline and after training.

RESULTS

Significant increases in height, weight, fat-free mass, fat mass, and subcutaneous abdominal adipose tissue occurred after training (P < 0.05), whereas intra-abdominal adipose tissue (IAAT) remained stable (N = 11). Insulin area was highly correlated with IAAT before (r = 0.91) and after (r = 0.90) training (both P < 0.01, N = 9).

CONCLUSION

In growing obese prepubertal girls undergoing a strength training program, IAAT remains unchanged, whereas subcutaneous abdominal fat and total body fat increased; insulin area is related to IAAT in these children.

Cardiovascular disease insulin risk in Mexican-American and Anglo-American children and mothers

OBJECTIVE

To evaluate the relationship between insulin levels and cardiovascular risk factors in children and determine whether it varies among ethnic groups.

METHODS

Cardiovascular risk factors and insulin levels were compared in 144 Mexican-American and Anglo-American mother-child pairs, when the children were 11 years of age.

RESULTS

Although mean age did not differ between ethnicities, Mexican-American mothers and children both had a greater body mass index (mothers: 29.2 +/- 6.2 vs 27.2 +/- 7.9; children: 21.7 +/- 4.7 vs 19.7 +/- 4.6) and sum of skinfolds than did Anglo-Americans. Triglycerides, very low-density lipoprotein cholesterol, fasting insulin, and cholesterol/high-density lipoprotein ratio were higher, while high-density lipoprotein cholesterol was lower in both Mexican-American adults and children compared with Anglo-Americans. After adjusting for measures of obesity, only high-density lipoprotein cholesterol levels remained significantly lower in Mexican-Americans. For both adults and children, higher quartiles of insulin levels were associated with significantly higher triglycerides, blood pressure and lower high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol/apolipoprotein B levels (estimate of dense low-density lipoprotein size). A summary variable representing cardiovascular risk factors present in adult syndrome X patients was higher in both Mexican-American adults and children than in Anglo-Americans.

CONCLUSION

Mexican-American children and adults have higher levels of many cardiovascular risk factors, and this appears related to higher insulin levels and overweight. Appropriate nutrition, weight control, and exercise at early ages could be important in slowing the development of atherosclerosis.

Heart healthy eating behaviors of children following a school-based intervention: a meta-analysis

The purpose of this meta-analysis was to estimate the effects of school-based interventions on heart healthy eating behaviors of fourth and fifth grade students. The overall effect size (d value) across 12 studies was .24. The 95% confidence interval ranged from .174 to .301. It can be concluded that the school-based cardiovascular health promotion programs had a significant effect on the heart healthy eating behaviors of student participants. Recommendations include identification of reliable measures and inclusion of culturally diverse populations in future studies.

Guidelines for school and community programs to promote lifelong physical activity among young people. National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and prevention

Regular physical activity is linked to enhanced health and to reduced risk for all-cause mortality and the development of many chronic diseases in adults. However, many U.S. adults are either sedentary of less physically active than recommended. Children and adolescents are more physically active than adults, but participation in physical activity declines in adolescence. School and community programs have the potential to help children and adolescents establish lifelong, healthy physical activity patterns. This report summarizes recommendations for encouraging physical activity among young people so that they will continue to engage in physical activity in adulthood and obtain the benefits of physical activity throughout life. These guidelines were developed by CDC in collaboration with experts from universities and from national, federal, and voluntary agencies and organizations. They are based on an in-depth review of research, theory, and current practice in physical education, exercise science, health education, and public health. The guidelines include recommendations about 10 aspects of school and community programs to promote lifelong physical activity among young people policies that promote enjoyable physical activity and social environments that encourage and enable physical activity; physical education curricula and instruction; health education curricula and instruction; extracurricular physical activity programs that meet the needs and interests of students; involvement of parents and guardians on physical activity instruction and programs for young people; personnel training; health services for children and adolescents; developmentally appropriate community sports and recreation programs that are attractive to young people; and regular evaluation of physical activity instruction, programs, and facilities.

Guidelines for school health programs to promote lifelong healthy eating

Healthy eating patterns in childhood and adolescence promote optimal childhood health, growth, and intellectual development; prevent immediate health problems, such as iron deficiency anemia, obesity, eating disorders, and dental caries; and may prevent long-term health problems, such as coronary heart disease, cancer, and stroke. School health programs can help children and adolescents attain full educational potential and good health by providing them with the skills, social support, and environmental reinforcement they need to adopt long-term, healthy eating behaviors. This report summarizes strategies most likely to be effective in promoting healthy eating among school-age youths and provides nutrition education guidelines for a comprehensive school health program. These guidelines are based on a review of research, theory, and current practice, and they were developed by CDC in collaboration with experts from universities and from national, federal, and voluntary agencies. The guidelines include recommendations on seven aspects of a school-based program to promote healthy eating: school policy on nutrition, a sequential, coordinated curriculum, appropriate instruction for students, integration of school food service and nutrition education, staff training, family and community involvement, and program evaluation.

Nutritional status outcomes for children: ethnic, cultural, and environmental contexts

The objective of this literature review was to explore the relationship between nutritional status outcomes among ethnically diverse children and cultural and environmental contexts. Articles form the literature on anthropometric/body composition measure, diet, and physiologic outcomes among ethnically diverse children were identified through on-line literature searches and references from articles reviewed. These studies were critically reviewed and selected if they reported findings resulting from use of accepted methodologies. Explanations consistent with evaluation of results from the studies and reports were developed by synthesis of the findings. Children from underserved, ethnically diverse population groups were at increased risk for obesity, increased serum lipid levels, and dietary consumption patterns that do not meet the Dietary Guidelines for Americans. More than 80% of all US children consume more than the recommended amount of total fat and saturated fat. These factors, which were noted during childhood, may track into adolescence, placing these children at increased risk for the early onset of chronic diseases such as non-insulin-dependent diabetes mellitus, cardiovascular disease, hypertension, and some forms of cancer. Although federally funded food assistance programs are changing rapidly, currently they provide foods that, when eaten as recommended, exceed the Dietary Guidelines for these children. Future interventions to improve the health and nutritional status of our nation's children, especially those from underserved, ethnically diverse groups, should be culturally appropriate and implemented at the levels of individuals, families, and communities.

Obesity in children: recent advances in energy metabolism and body composition

In this paper we review recent advances in energy metabolism and body composition studies in prepubescent children and the relationship to childhood obesity. Our review on energy expenditure focusses on studies of total energy expenditure using doubly labeled water, the role of energy expenditure in the development of obesity, and the determinants of resting energy expenditure in children. The relatively few studies that have examined the regulation of energy and macronutrient intake in children are also reviewed. In terms of body composition, we focus on recent methodological studies that have developed existing techniques for application to the pediatric population, including dual energy X-ray absorptiometry and bioelectrical resistance. Lastly, we review existing information relating to measurement and alteration of body fat distribution in children.

The effect of two types of teacher training on implementation of Smart Choices: a tobacco prevention curriculum

This study examined the implementation phase of a four-year research project to test the effectiveness of strategies to increase diffusion of Smart Choices, a school-based tobacco prevention program. The impact on curriculum implementation of two approaches to teacher training are compared. School districts were randomly assigned to a live workshop training or video training condition. The outcome of the evaluation was teachers' implementation of Smart Choices. Results show a lower proportion of video-trained teachers implemented the curriculum, but overall completeness and fidelity of implementation for those teachers who did teach the curriculum were comparable for the two groups. Video-trained teachers, however, were less likely to use brainstorming and student presentations/role plays, two of the methods prescribed by the curriculum. Implications of the results for teacher training are discussed.

Project SPARK. Effects of physical education on adiposity in children

Project SPARK evaluates multiple effects of a health-related physical education (PE) program for elementary school students. Seven schools were randomly assigned to one of three conditions: usual PE or control, trained classroom teachers, or PE specialists. The intervention was implemented throughout the fourth and fifth grades. Data are available from one cohort of 550 children who were measured in the fall and spring of both grades. Adiposity was assessed by triceps and calf skinfolds, and body mass index (BMI) was also measured. Data at each measurement point were analyzed by ANOVAs, covarying for baseline values. At no measurement point were there significant group differences in total skinfold. At both fifth grade measurement points for boys and girls, however, there was a trend for the control group to have higher skinfold values than the two intervention groups. At the final measure, the difference between the highest and lowest groups was about 3 mm for girls and 2 mm for boys. BMIs were significantly lower at some measurement points for boys and girls, but this could be due to increased lean body mass in intervention students. After two years, there was a trend for the children exposed to the PE intervention to have lower levels of body fat, but the differences were not significant.

Ten unanswered questions regarding comprehensive school health promotion

The past two decades witnessed dramatic growth in support for comprehensive school health promotion. Yet, many questions about its effectiveness and feasibility remain unanswered. This article poses several research and policy questions, the answers to which may help to shape the future of school health programs in this country.

Childhood prevention of essential hypertension

Childhood prevention of essential hypertension requires knowledge of alterable determinants of blood pressure in children; these include obesity and sodium intake and perhaps physical activity and intake of potassium and calcium. Altering these determinants may involve two general preventive strategies. The first is a population strategy, which attempts to lower blood pressure (or keep it from rising) among all children. Population strategies may require educating children to active participants in changing their behaviors (active approach) or may merely change their environment (passive approach). The second general strategy aims to focus on children at high risk of developing hypertension as adults. To determine the usefulness of this high-risk strategy, more information is needed about prediction of adult blood pressure from childhood values and about the efficacy of interventions to control blood pressure levels in high-risk children.

Cardiovascular risk stability: from grade school to high school

School-based, cardiovascular risk reduction programs have increased dramatically over the past decade. Though a wide range of evaluation plans have been implemented, limited longitudinal data are available to estimate the effectiveness of these risk reduction programs. The purposes of this study were to describe the stability of risk factors, the changes in cardiovascular risk from grade school to high school, and the differences in risk between gender. The sample (N = 195) of high school students was developed from three cohorts of elementary school students who participated in a risk reduction program in the sixth grade. Three to six years had elapsed since the students participated in the risk reduction program, thus providing a longitudinal view of participants' risk. Subject risk for obesity and high cholesterol level was stable although significant changes were noted for heart rate recovery and blood pressure. The only gender difference in risk was for elevated cholesterol level among female students. Nursing implications are presented.

Synthesis of cardiovascular behavioral research for youth health promotion

The National Heart, Lung, and Blood Institute (NHLBI) has funded school and family-based research studies for more than a decade. The scientific background for focusing on the major cardiovascular health behaviors with youth is reviewed, as well as the importance of the components in the school health program as a framework for the multiple considerations in school health research. A synthesis of 10 NHLBI funded studies is presented including the sociodemographic characteristics of study populations, study designs, interventions, measures, and results. The studies address single or multiple behaviors, elementary and high school age groups, and multiple ethnic/racial groups, and test various combinations of curriculum, parental involvement, and environmental changes (including school food service).