KQ1: Do primary care-relevant prevention interventions (behaviorally-based) in normal weight children lead to improved health outcomes or sustained/short-term healthy BMI trajectories?

a. How well are healthy BMI trajectories or health outcomes maintained after an intervention is completed?

b. What are common elements of efficacious interventions for healthy BMI trajectories?

c. Does the efficacy of interventions vary between child subgroups (e.g., infants versus children or adolescents, sex, race-ethnicity, baseline cardiovascular risk status, low socio-economic status, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc)?

d. What are the adverse effects of primary care-relevant prevention in normal weight children (e.g., disordered eating, psychological distress such as anxiety, micronutrient deficits, abnormal growth trajectory, or growth restriction)?

e. Are there differences in adverse effects between child subgroups (e.g. infants versus children and adolescents, sex, race-ethnicity. baseline cardiovascular risk status, lower socio-economic status, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc)?

KQ2: Do weight management programs (behavioural, combined behavioural, pharmacological and surgical interventions) lead to BMI, weight, or adiposity stabilization or reduction in children and adolescents who are obese or overweight?

a. Do these weight management programs lead to other positive outcomes (e.g. improved behavioural or physiological measures, decreased childhood morbidity, improved childhood functioning, or reduced adult morbidity and mortality)?

b. Do specific components of the weight management programs influence the effectiveness of the programs?

c. Are there population (e.g. age, sex, race-ethnicity, low socio-economic status, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc) or environmental factors that influence the effectiveness of the weight management programs?

d. What are the adverse effects of weight management programs (behavioural, combined behavioural and pharmacological) attempting to stabilize or reduce BMI?

e. Are there differences in adverse effects between child subgroups (e.g. age, sex, race-ethnicity, low socio-economic status, severity of obesity, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc)?

KQ3: Do weight management programs (behavioural, combined behavioural and pharmacological or surgical) help children and adolescents who are initially obese or overweight maintain BMI, weight, or adiposity improvements after the completion of an active intervention?

a. Do these weight management programs lead to other positive outcomes (e.g. improved behavioural or physiological measures, decreased childhood morbidity, improved childhood functioning, or reduced adult morbidity and mortality)?

b. Do specific components of the weight management programs influence the effectiveness of the programs?

c. Are there population (e.g. age, sex, race-ethnicity (e.g. Canadian Aboriginal youth), lower socio-economic status, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc) or environmental factors that influence the effectiveness of the weight management programs?

d. What are the adverse effects of weight management programs (behavioural, combined behavioural, surgical and pharmacological) attempting to stabilize or maintain BMI?

e. Are there differences in adverse effects between child subgroups (e.g. age, sex, race-ethnicity, low socio-economic status, parental history of obesity, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc)?

KQ4a and KQ4b Risk Assessment Tools

Risk assessment tools are defined as those tools that combine known risk factors to identify risk of future obesity or of future health risk (e.g., diseases) associated with being obese now.

Normal weight children

KQ4a. What are the most effective (accurate and reliable) risk assessment tools identified in the literature to identify those at higher risk of obesity?

Obese or overweight children

KQ4b. What are the most effective (accurate and reliable) risk assessment tools identified in the literature to assess future health risk as a result of obesity?

Contextual Questions

CQ1. Is there evidence that the burden of disease, the risk/benefit ratio of prevention, the optimal prevention method, access, and implementation differ in any ethnic subgroups (e.g. Canadian Aboriginal youth) or by age (e.g.. infant, child, adolescent), rural and remote populations, or lower SES populations?

CQ2. What are the resource implications and cost effectiveness of overweight and obesity prevention in Canada?

CQ3. What are parents' and children’s values and preferences regarding overweight and obesity prevention?

CQ4. What process and outcome performance measures (indicators) have been identified in the literature to measure and monitor the impact of prevention for overweight and obesity?

Contextual Questions

CQ1. Is there evidence that the burden of disease, the risk/benefit ratio of prevention, the optimal prevention method, access, and implementation differ in any ethnic subgroups (e.g. Canadian Aboriginal youth) or by age (e.g.. infant, child, adolescent), rural and remote populations, or lower SES populations?

CQ2. What are the resource implications and cost effectiveness of overweight and obesity prevention in Canada?

CQ3. What are parents' and children’s values and preferences regarding overweight and obesity prevention?

CQ4. What process and outcome performance measures (indicators) have been identified in the literature to measure and monitor the impact of prevention for overweight and obesity?

CQ5. What are the most effective (accurate and reliable) risk assessment tools* identified in the literature to identify those at higher risk of obesity?

CQ6. What are the most effective (accurate and reliable) risk assessment tools* identified in the literature to assess future health risk as a result of obesity?

Our search will include EMBASE, MEDLINE, Cochrane, CINAHL, PsycINFO, from 1985 to June 2012.

Q 1a-c. Study designs that are permissible: RCTs or CCTs evaluating the effectiveness of prevention interventions in children, observational designs (prospective and retrospective cohorts, case-control studies, pre and post designs, all using a comparison group) and modeling studies will be included in the search. Although the literature for all study designs will be done simultaneously, only RCTs and CCTs will be included if there is sufficient evidence from these study designs.

Case reports, case series and chart reviews will be excluded.

Q 1d- e. All study designs are permissible, including non-controlled observational designs.

Obesity is a condition characterized by the accumulation of excess body fat or adipose tissue, resulting in disturbances in health. Though an imperfect measure, excess adiposity is most often approximated by calculation of the body mass index (BMI), utilizing measured height (m) and weight (kg) (weight/height^2). As BMI changes with growth in childhood and adolescence, classification of obesity in youth relies on the use of standardized curves and age and sex specific cut-off points. In the absence of standardized Canadian growth curves, Canadian clinicians have previously utilized the US Centre for Disease Control (CDC) curves published in 2000, while epidemiological studies including the recent Canadian Health Measures Survey (CHMS) utilized a set of cut-offs established by the International Obesity Task Force (IOTF). Recently, prompted by the availability of improved growth charts developed by the World Health Organization (WHO), the Canadian Paediatric Society, the College of Family Physicians of Canada, Dieticians of Canada and the Community Health Nurses of Canada have published a collaborative statement urging use of these new charts. From birth to five years, the WHO chart represents a growth standard based on the growth of healthy, breastfed infants living in conditions of good hygiene and included participants from diverse geographical regions. Thus, this new standard reflects normal human growth in an ethnically diverse sample appropriate for use in multiethnic communities such as Canada. The Canadian collaborative statement encourages growth monitoring in all children and recommends tracking of BMI rather than weight alone after 2 years of age. While trajectory in BMI is most important, cut-off points for overweight and obesity were assigned to alert the practitioner to the need for “further assessment, referral or intervention”. The recommended cut-offs for 5 – 19 years are greater than the 85th percentile for overweight and greater than the 97th percentile for obese. At 19 years of age, these coincide with adult cut-offs of 25 and 30 kg/m^2 for overweight and obesity respectively. In the pre-school years, a more conservative approach was applied with recommended cut-offs for children 2 – 5 years of greater than the 97th percentile for overweight and greater than the 99.9th percentile for obese.

BMI continues to be most widely used because of its relatively easy application and ability to predict presence of adverse health outcomes in adulthood. It is however an indirect measure of adiposity and has some limitations as it does not specifically measure the amount or location of body fat. Among adults, waist circumference is more closely related to obesity-related health consequences than BMI prompting the recommendation for classification in adults based on waist circumference cut-offs. There are preliminary data suggesting increased waist circumference is associated with CVRF but some data also suggests that waist circumference percentiles or waist/height add little to BMI Z score in the identification of CVRF in children. While different risk cut-offs for BMI in adults are suggested in some ethnic groups, it is recommended that the same cut-offs be applied across the pediatric population.

Children aged 0-18 who are normal weight, overweight or obese. Populations must either be unselected, selected for low cardiovascular disease risk, or selected for increased risk for specified conditions (cardiovascular disease, hypertension, dyslipidemia, or type 2 diabetes), or other risk factors such as parental obesity, low socio-economic status, maternal cigarette smoking in pregnancy, maternal diabetes, low birth weight, formula feeding, etc..

Exclude trials in which the sample is limited to children and youth with:

(1) eating disorders,

(2) pregnant/post-partum,

(3) overweight/obesity secondary to genetic or medical condition including Polycystic ovarian syndrome, hypothyroid, Cushings, GH deficiency, insulinoma, hypothalamic disorders (e.g. Froelich’s syndrome), Laurence-Moon-Biedi syndrome, Prader-Willi syndrome, weight gain secondary to medications (e.g. antipsychotics), or

(4) other idiosynchratic weight loss issues.

Interventions focusing on healthy BMI trajectories such as behaviorally-based interventions and complimentary/alternative therapies and drugs approved for weight loss by Health Canada or a combination of behavioural and pharmacological interventions.

.

No intervention control groups

Studies with interventions that could be feasible for conducting in primary care, or for referral from primary care

Exclude studies conducted in in-patient hospital settings, institutionalized settings, occupational settings, churches, and other settings deemed not generalizable to primary care, such as those with existing social networks among participants or the ability to offer intervention elements that could not be replicated in a health care setting, unless the intervention is primary care feasible

Primary outcomes

Health outcomes will include: morbidity (i.e. cardiovascular disease, type 2 diabetes, musculoskeletal disorders, all cancers, overall and cause specific mortality, quality of life including psychological distress and functioning), healthy BMI trajectory, and physiologic measures (e.g. glucose tolerance, fasting insulin and insulin resistance, blood pressure, lipid testing, and physical fitness).

Adverse outcomes include serious treatment-related harms at any time point after an intervention began (i.e., death, need for medical or psychiatric treatment, growth retardation) or other treatment-related harms reported in trials (including but not exclusive to risk of injury, pharmacological side effects).

Q1. No restriction on duration of treatment and time of follow-up or outcome assessment.

Q2 and 3. Outcomes reported at 6 months or longer with the exception of adverse events (harms) for which there is no time restriction.

Secondary outcomes

Intermediate outcomes include a reduction or stabilization in BMI, weight, or adiposity; also weight maintenance after an intervention has ended. Other intermediate outcomes include physiologic measures such as glucose tolerance, fasting insulin and insulin resistance, blood pressure, lipid testing, and physical fitness.

Adult outcomes (morbidity, mortality) will be searched but only included as part of background to inform decisions

Q1. No restriction on duration of treatment and time of follow-up or outcome assessment.

Q2 and 3. Outcomes reported at 6 months or longer with the exception of adverse events (harms) for which there is no time restriction.

Standard data extraction will include characteristics of included studies and all relevant outcome data.Data will be extracted only in studies where there is a weight-related outcome reported and report at baseline and post intervention data.

Risk of bias will be assessed using the Cochrane Risk of Bias tool for RCTs and quasi-experimental designs and the Newcastle Ottawa Scale will assess risk of bias for cohort and case control studies. Overall strength of evidence will be assess with GRADE.

Where data are available we will be performing meta-analysis for all questions. If data are not sufficient results will be reported using a narrative synthesis grouped by intervention and outcome for each key question.

For all KQs subgroup analyses by type of intervention would be performed (e.g. psychologically managed/supervised behavioural intervention and those that are not).

Subgroup analysis will be conducted for groups at high risk of obesity and related health issues.

The full review will be posted on the Canadian Task Force for Preventative Health Care website; a smaller version of the review will be submitted to publication and the Task Force has an active Knowledge Translation group who disseminate the new guidelines and supporting evidence

Donna Fitzpatrick-Lewis

McMaster University

1280 Main St. W. DTC Room 321

Hamilton, Ontario L8S 4K1

fitzd@mcmaster.ca

McMaster University

www.ephpp

Ms Donna Fitzpatrick-Lewis, McMaster University
Dr Donna Ciliska, McMaster University
Dr Leslea Peirson, McMaster University
Dr Parminder Raina, McMaster University

Dr Patricia Parkin, Canadian Task Force on Preventative Health Care and Hospital for Sick Kids, Toronto, Ontario, Canada

05 September 2012

01 April 2013

Canadian Institute of Health Research and the Public Health Agency of Canada

None known

None

English

Canada

Subject indexing assigned by CRD

Adolescent; Child; Humans; Obesity; Overweight; Secondary Prevention

Q2 and 3 are updating the USPSTF review: Whitlock EP, O’Connor EA, Williams SB, Beil TL, Lutz KW. Effectiveness of Primary Care Interventions for Weight Management in Children and Adolescents: An Updated, Targeted Systematic Review for the USPSTF. Evidence Synthesis No. 76. AHRQ Publication No. 10-05144-EF-1. Rockville, Maryland: Agency for Healthcare Research and Quality, January 2010.

02 August 2012

07 March 2013