Pediatric Weight Management

PWM: Individual Child Counseling (2006)

Citation:

Epstein LH, Valoski A, Wing RR, McCurley J. Ten-year outcomes of behavioral family-based treatment for childhood obesity. Health Psychology. 1994, 13:373-383.

PubMed ID: 7805631
 
Study Design:
Narrative Review
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Negative NEGATIVE: See Quality Criteria Checklist below.
Research Purpose:

Primary purpose: Report 10-year treatment outcomes of four randomized treatment studies.

Secondary purpose: Identify variables associated with long-term weight regulation.

Inclusion Criteria:

Inclusion criteria for this review: participation in one of the four previous studies. In general, the inclusion criteria included:

  • child 6-12 years of age
  • child 20-100% overweight for age, sex, and height
  • No current psyciatric diagnosis or reament
  • No learning disability
  • One parent willing to participate in treatment with the child
  • (for exercise studies) subjects could not have a medical problems which prohibited exercise

For specific inclusion critiera see:

Study 1: Epstein LH, Valoski A, Wing RR, McCurley J. Ten-year follow-up of behavioral, family-based treatment for obese children. JAMA 1990; 264: 2519-2523.

Study 2: Epstein LH, Wing RR, Koeske R, Valoski A. Effects of diet plus exercise on weight change in parents and children. Journal of Consulting and Clinical Psychology 1984; 52:429-437.

Study 3: Epstein LH, Wing RR, Koeske R, and Valoski A. Effect of parent weight on weight loss in obese children.  Journal of Consulting and Clinical Psychology.  54(3):  400-401, 1986.

Study 4: Epstein LH, Koeske R, Wing RR. Adherence to exercise in obese children. Journal of Cardiac Rehabilitation. 4:185-195.

(Note, Study 4 was not analyzed as it deals primarily with exercise rather than diet aspects of childhood weight loss.)

Exclusion Criteria:

For this article, participants were not included if they were not part of the above 4 studies.

For the exclusion criteria for each study, see the above references.

Description of Study Protocol:

Recruitment

Subjects recruited for weight-control studies at the University of Pittsburgh, PA.

Design

The basic designs of the four included studies are described in the following table (adapted from Table 1 in the article).

Question / Comparison Groups

Intervention Target

Goals for Change

Amount of Exercise (target calorie expenditure)

Study 1: Are treatments designed to target and reinforce habit change and weight loss in obese parents and children together superior to treatments targeting children alone?

Parent and Child

Parent and child

Habits

Eating

Weight

Self determined

Child only

Child only

Habits

Eating

Weight

Self determined

Nonspecific

Not specified

Attendance

Self determined

Study 2: Comparison of intervention focusing on diet alone versus diet-plus-life-style exercise in a sample of overweight children and parents

Diet and information

Child only

Habits

Eating

Weight

Not specified

Diet and lifestyle exercise

Child only

Habits

Eating

Weight

Exercise

1400-2800

Study 3: What is the role of parent weight in the treatment of childhood obesity?

At least one obese parent

Child only

Habits

Eating

Weight

Exercise

300-750

No obese parents

Child only

Habits

Eating

Weight

Exercise

300-750

Study 4: What form of exercise is best suited for long-term weight maintenance?

Diet and aerobic

Parent and child

Habits

Eating

Exercise

300-900

Diet and lifestyle

Parent and child

Habits

Eating

Exercise

300-900

Diet and calisthenics

Parent and child

Habits

Eating

Exercise

Not specified

Blinding used (if applicable)

Blinding not used.

Intervention (if applicable)

Intervention consisted of the basic diet and family intervention approach with different formats for including parents and different exercise regimes.

Statistical Analysis

Data were combined across studies. Different contrasts required different statistical procedures:

  1. Analysis of covariance was used to assess interstudy changes from year 5 to year 10.
  2. Chi-square analysis used to assess group differences of sustained increases or decreases of 20% overweight and the percent of children obese or overweight.
  3. A combination of correlational analysis and analysis of variance techniques used to determine the effects of confounding variables (such as smoking).
  4. Multiple regression technique (backward regression procedure) used to identify variables contributing to 10-year outcomes.
  5. Basic descriptive statistics were used to compare baseline values for comparing subjects who developed psychiatric disorders with those who did not.
Data Collection Summary:

Timing of Measurements

For this study, the key timing was the 5-year and 10-year outcome measurements.

Dependent Variables

  • Child weight outcomes: BMI and percentage over BMI (BMI referenced to the 50th percentile for age)
  • Percentage of children with at least 20% increase or decrease in weight over 10 years.

Independent Variables

  • Diet (measured using modified version of the Food Frequency Questionnaire)
  • Activity (caloric expenditure measured using the Paffenbarger Index)
  • Program Adherence (measured how often subjects used program techniques, measured using a questionnaire used for this purpose)
  • Environmental support for eating and exercise (measured using scales developed by Sallis, Growwman, Pinski, Patterson and Nader (1987))
  • Environmental factors, including:
    • subject's current living situation
    • subject's meal pattern
    • weight of people with whom the subject normally eats
    • exercise pattern of people with whom the subject normally exercises
    • subject's perception of the general activity level of the people with whom the subject lives

Control Variables

  • smoking
  • participation in other weight managment programs
  • psychiatric disorders
Description of Actual Data Sample:

 

Initial N: 185 families

Attrition (final N): Data from 158 families were available at 10 year follow-up (85%)

Age: children aged 6-12 years at time of treatment

Family Structure: All families were intact.

Ethnicity: not specified

Other relevant demographics: Family SES was, on average, middle-class (45.2 ± 2.0 on Hollingshead index).

Anthropometrics: In all studies except for Study 3, at least one parent was obese (in Study 3 parent weight was an independent variable).

Location: STudies occurred at the University of Pittsburgh, PA

 

Summary of Results:

Five types of results were reported:

  1. Group changes in percent overweight at 5 and 10 years
  2. Maintenance of decrease of at least 20% weight at 5 and 10 years
  3. Obese versus non-obese status at 10 years
  4. The effect of confounding variables
  5. Predictors of change in overweight at 10 years

Group Changes in Percent Overweight

Study/Comparison Groups Significant Group Differences at 5 years Significant Group Differences at 10 years
Study 1: parent/child, child only, non-specified control

parent/child group > non-specified control

(F(1, 145 = 12.94, p<.001)

parent/child > child only

(F(1, 145 = 5.15, p=.025)

parent/child group > non-specified control

(F(1, 145 = 7.11, p=.009)

No difference between parent/child and child only groups

parent/child group decreased percentage overweight by 15.3% while controls increased percentage overweight by 7.6%

Study 2: diet and information, diet and lifestyle exercise

no group differences

both groups decreased percent overweight

no group differences

both groups decreased percent overweight

Study 3: at least one obese parent, no obese parents   trend for children of non-obese parents to do better, though difference was not statistically significant (F(1, 145) = 2.44, p=.12)
Study 4: diet and aerobics, diet and lifestyle exercise, diet and calisthenics  

diet and aerobics > calisthenics

-19.7% vs +12.2% (F(1, 145 = 7.18, p=.008)

diet and lifestyle > calisthenics

-10.9% vs +12.2% (F(1, 145 = 3.90, p=.05)

Changes from 5 to 10 years also significant between aerobics or lifestyle versus calisthenics group.

Maintenance of At Least 20% Decrease from Baseline Percentage Overweight

At 10 years, the percentage of children who maintained 20% decrease in percent overweight from baseline differed among groups (X2(18, N=158)=31.84, p=.02). The following table compares the percent of children in each treatment group who either maintained at least a 20% decrease from their initial percent overweight or who gained at least 20% over their initial percent overweight.

Study/Comparison Groups

Maintained at least 20% decrease

At least 20% increase

Study 1

Parent/Child

43

14

Child only

22

28

Non-specified control

29

38

Study 2

Diet and information

20

20

Diet and lifestyle exercise

31

0

Study 3

At least one obese parent

33

33

No obese parents

16

6

Study 4

Diet and aerobic

58

8

Diet and lifestyle

64

14

Diet and calisthenics

20

20

Total N (N=158)

53

32

Overall Percent

33.5

20.3

Percent Obese after 10 Years

30% of the children across the four studies were not obese after 10 years. No significant differences were detected by group.

Confounding Variables

Smoking and the presence of other weight-control group participation made no difference in 10 year outcomes.

However, the authors compared 10 year treatment outcomes of subjects who had psychiatric problems with those who did not. Using non-parametric comparisons, the authors found that children who developed psychiatric disorders:

  • tended to be lighter at baseline
  • changed weight less between 5 and 10 year measurement
  • were more likely to have mothers who were less obese
  • were more likely to have fathers who were more obese at baseline

Factors Predicting Long-Term (10 year) Weight Loss

The best predictor of maintenance of weight loss at 10 years was maintenance of weight loss at 5 years (r2=.52--accounting for 52% of the variance).

When 5-year change was excluded from the predictive equation, other variables (accounting for 34% of the variance were important for predicting success in maintaining weight loss.

Children were more likely to be successful in maintaining weight loss at 10 years following treatment when:

  • they were girls
  • they had a greater percent overweight at baseline
  • fewer meals were eaten at home
  • fewer overweight people were living at home
  • they were better at self monitoring
  • they received less "good eating" encouragement from family members
  • they received more discouragement from friends to eat poorly
  • they exercised with their roommate
  • they received less rewards from exercising from their roommate.

All the above variables were significant (p<.05) and r2=.341

Author Conclusion:

In summary, the results of these studies provide support for the family-based behavioral treatment of childhood obesity. These studies provide the first evidence that weight regulation in children can be achieved and maintained over extended periods from childhood through adolescence to adulthood.

Study 1 suggested that in intact families effects are improved for children by including a parent with the child in treatment.

Study 4 suggested that exercise enhances the long-term effects of diet interventions.

Funding Source:
University/Hospital: University of Pittsburg's School of Medicine
Reviewer Comments:

Strengths

  • strong designs across studies
  • long-term follow-up

Weaknesses

  • Predictive equations at 10 years are probably different than we would see in other programs (e.g., other research indicates that eating outside the home is associated with increased overweight, the fact that the 10 year predictive equations find the opposite is probably due to the over sampling of obese parents in the sample--hence the presence of obesigenic households.
  • Concern that the way in which families are recruited and the type of famlies (middle-class, intact families) makes generalizability questionable. Disappointing that the authors do not discuss this.
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? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
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? No
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
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) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? Yes
  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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.4. Were reasons for withdrawals similar across groups? ???
  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? N/A
  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? Yes
  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? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? No
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  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? Yes
  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? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  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)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  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? No
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes