PWM: Peer Modeling to Reduce Childhood Obesity (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To provide an overview and highlight the success of the Committed to Kids program, a medical, psychosocial, nutrition and exercise intervention for the treatment of adolescent obesity.

Inclusion Criteria:

Adolescents (13-17 years of age) ranging from overweight/mildly obese (85th to 95th percentile age adjusted BMI and 121% to 149% ideal body weight (IBW)) to severely obese (>97th percentile age adjusted BMI and >200% IBW).

BMI from US Centers for Disease Control and Prevention (Rosner 1998); IBW from NCHS (Hamill 1979).

Exclusion Criteria:

None specified.

Description of Study Protocol:

Program characterized by integrated, 4 level approach that encourages short term (12 weeks) goal setting, quarterly feedback, motivational techniques to improve health behaviors.

During 1 year program, adolescents and families attend weekly, 2 hour comprehensive sessions where they receive medical supervision, nutrition instruction, fitness counseling, exercise, and behavior modification.

Program materials color coded according to initial level of obesity:

  • red = severe obesity,
  • yellow = moderate obesity (defined as >95th percentile BMI and 150%-200% IBW,
  • green = overweight or mild obesity.

Exercise and diet prescriptions individualized based on level of obesity.

Program workbooks divided into

  • Phase I: Beginner (weeks 1-12)
  • Phase II: Intermediate (weeks 13-25)
  • Phase III: Advanced (weeks 26-38)
  • Phase IV: Expert (weeks 39-52). Free membership in Kids Club awarded at end of expert phase.

Medical therapy consists of complete medical history, physical exam, DEXA body composition, exercise tolerance (VO2 max), baseline lab evaluation. Weight, blood pressure, resting heart rate, symptoms, complaints monitored weekly. Quarterly evaluations of height, weight, BMI, %IBW, waist/hip circumference, bioelectrical impedance, skinfolds, physical activity rating, self esteem, depression, self efficacy ratings.

Medical nutrition therapy consists of diet history, intake visit, lab assessment of growth and current weight status. Dietician establishes initial 12-week weight loss goal at intake visit based on %IBW and BMI. Energy restriction used if necessary.

Prescription for green level participants includes balanced hypocaloric diet (BHD) of 1200-2000 kcal/day, reteaching of normal portion sizes.

Prescription for red and yellow level includes protein-modified fast diet (total energy 1000 kcal/day, high protein, reduced carbohydrate and fat).

Nutrition education conducted in group sessions with family and friends; participation encouraged. Sessions include identification of food groups/nutrients, cooking demonstrations, label reading/shopping, dining out tips, etc.

Physical activity education includes Moderate Intensity Progressive Exercise Program intervention. Includes guidelines for exercise frequency, duration, and intensity; series of 52 interactive group sessions, specific recommendations for type or modality of exercise based on individual overweight level. Exercise instruction conducted at each visit by clinical exercise physiologist and includes fitness counseling.

Workbooks and exercise videos used.

Behavior modification protocol includes beginning each session with discussion highlighting accomplishments, giving positive reinforcement, introducing behavior modification skills, discussin topics such as self-monitoring, goal setting, attitudes, etc.

Incentive items given quarterly as positive reinforcement for short-term goals.

Special events organized to encourage participation.

Statistical Analysis

not discussed.

Data Collection Summary:

Dependent

  • BMI,
  • %IBW

Independent

  • Program enrollment

Control Variables

  • age
Description of Actual Data Sample:

Original Sample: 93 adolescents aged 13.1 to 17.7 years.

Withdrawals/Drop-Outs: 37 (40%).

Final Sample: 56 patients (22 boys, 34 girls) participated in evaluations (60.7%).

Location: Not specified.

Race/Ethnicity: 44 white (79%), 12 African-American (21%).

SES: Not specified.

Summary of Results:

Subjects reduced BMI from 32.3 ± 1.3 at baseline to 29.35 ± 1.9 at 10 weeks and further to 28.2 ± 1.2 at 1 year.

%IBW reduced from 177 ± 34.0 at baseline to 156.2 ± 23.7 at 10 weeks and further to 141.9 ± 20.1 at 1 year (P<.001).

Author Conclusion:

Integrated, 4 level approach is successful in treatment of overweight because:

  • sessions are designed to entertain and promote initial success
  • program features parent training methods in short, interactive sessions
  • diet intervention results in noticeable weight loss in severely obese adolescents that motivates continuation; improved exercise tolerance promotes increased physical activity
  • program team provides constant feedback; program is conducted in groups of families.
Funding Source:
University/Hospital: Louisiana State University, Pennington Biomedical Research Center, Children's Hospital of New Orleans
Reviewer Comments:

Weaknesses:

  • paper did not focus on specifics of actual study, more of an overview of a successful intervention protocol
  • no controls
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A