NC: Behavior Change Strategies (2007-2008)

Citation:

Wing RR, Marcus MD, Epstein LH, Jawad A. A "family-based" approach to the treatment of obese type II diabetic patients. J Consult Clin Psychol. 1991 Feb; 59 (1): 156-162.

PubMed ID: 2002132
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

The purpose of this study was to test the effectiveness of a "family-based approach" for obese type 2 diabetic subjects.

Inclusion Criteria:
  • Type 2 diabetic patients and their overweight spouses
  • More than 20% above ideal body weight and aged 30 to 65 years
  • Meet the National Diabetes Data Group (1979) criteria for type 2 diabetes
  • Spouses were required to be more than 15% above ideal body weight and aged 30 to 70 years
  • $150 deposit was required, which could be earned back in full.
Exclusion Criteria:
Description of Study Protocol:
  • Recruitment: Newspaper advertisements were used to recruit type 2 diabetic patients and their overweight spouses
  • Design: Subjects were randomly assigned to one of two treatment conditions: Together (subjects and spouses treated together) or Alone (subjects treated alone)
  • Intervention: Both groups participated in a 20-week behavioral weight-control program, with 12 weekly sessions and four bi-weekly sessions (Weeks 14, 16, 18 and 20). Follow-up meetings were held at Weeks 24, 28, 40 and 72.

Statistical Analysis

  • Repeated-measures analysis of variance (ANOVA) were used to compare the two treatment conditions over time on measures of weight, glycemic control and calorie intake
  • Rank order correlations were used to asses the relationship between changes in patients and their spouses.
Data Collection Summary:

Timing of Measurements

All measures were obtained at baseline, after the 20-week program and at one-year follow-up (week 72).

Dependent Variables

  • Weight: Measured using a balance beam scale
  • Body Mass Index (BMI) was calcualted
  • Glycosylated hemoglobin (HbA1): Assessed by column chromatography
  • Fasting blood sugar (FBS): Analyzed with a Beckman Glucose Analyzer
  • Eating behavior: Reported at pre-treatment and post-treatment. All subjects completed a three-day eating diary, which was analyzed using the MR FIT database.
  • Exercise: Assessed with the Paffenburger Activity Questionnaire
  • Eating Behavior Inventory (EBI): Used to assess adherence to the weight control strategies
  • Marital adjustment: Assessed with the Dyadic Adjustment Scale.

Independent Variables

Together condition.

Control Variables

Alone condition.

Description of Actual Data Sample:
  • Initial N: 49 patients, 49 spouses
  • Attrition (final N): 42 (87.7%) patients completed, 42 (86.5%) of the spouses completed the study.

Baseline Characteristics of Patients

Variable

Alone Condition
Mean, SD

Together Condition
Mean, SD

Male/Female
10/13
8/12
Age (years)
51.2, 7.3
53.6, 7.7
Weight (lbs)
227.5, 40.8
213.5, 43.4
Percentage Overweight
158.5, 25.5
152.4, 72.4
BMI
36.64, 5.77
35.68, 5.76
Glycosylated Hemoglobin
10.3, 2.0
9.5, 2.4
Fasting Blood Sugar (mg/dL)
226, 78
205, 72
Number on Diet
4
7
Number on Oral
12
11
Number on Insulin
7
2

Baseline Characteristics of Spouses

Variable

Alone Condition
Mean, SD

Together Condition
Mean, SD

Age (years)
51.6, 9.9
53.4, 8.3
Weight (lbs)
210.9, 40.5
208.5, 41.5
Percentage Overweight
140.9, 19.9
142.7, 24.0
BMI
32.5, 4.62
33.20, 5.41
Glycosylated Hemoglobin
7.3, 1.4
7.1, 1.4
Fasting Blood Sugar (mg/dL)
121
114
Number Diabetic
5
4

Location

Pittsburgh, PA.

Summary of Results:

Variables

Alone (N=23) Together (N=20)
Measures and Confidence Intervals

Time Effect

Time X Group

Mean

SD Mean

SD

Weight (lbs) Change pre- to post
-19.9
18.2
-19.1
11.2
P<0.001 P>0.10

Change pre- to one-year

-11.6

22.9
-7.0

11.7

P<0.005

P>0.10

Body Mass Index

Change pre- to post

-3.10

2.66
-3.22

1.90

P<0.001

P>0.10

Change pre- to one-year
-1.76
3.42
-1.13
1.99
P<0.005 P>0.10
 

Change pre- to post-

-2.1
2.1
-1.2
1.9

P<0.001

P>0.10

Glycosylated Hemoglobin (percentage)

Change pre- to one-year

-0.7

2.7
-0.1

1.9

P>0.10

P>0.10

Fasting Blood Sugar (mg/dL) Change pre- to post-
-64
83
-50
52
P<0.001 P>0.10

Change pre- to one-year

-36

85
-11

61

P<0.06

P>0.10

Calories Consumed Pre-treatment
2,225
75.3
1,893
469
   

Post-treatment

1,308

288
1,382

417

P<0.001

P<0.05

Percentage of Calories from Fat

Pre-treatment

40.4

5.9
40.9

7.2

 

 

Post-treatment
34.3
7.0
32.8
10.2
P<0.001 P>0.10
Calories Expended in Exercise each Week Pre-treatment
682
641
743
694
   
Post-treatment
1,409
1,232
1,528
988
P<0.001 P>0.10

One-year follow-up

1,251

1,275
1,148

752

P<0.005

P>0.10

Eating Behavior Inventory

Pre-treatment

69.9

9.9
69.7

12.3

 

 

Post-treatment
89.5
12.9
88.5
11.3
P<0.001 P>0.10
One-year follow-up
83.0
12.1
78.8
12.7
P<0.001 P>0.10

Eating Behavior Inventory-Spouse Support Items

Pre-treatment

50.3

9.8
57.9

13.7

 

 

Post-treatment
59.8
12.8
68.5
11.3
P<0.001 P>0.10
One-year follow-up
56.3
10.1
58.4
10.5
P<0.05 P>0.10

Other Findings

  • Spouses in the Together Condition lost more weight than did patients
  • The caloric intake data reported do not correspond well with the weight-loss data.
Author Conclusion:

This study found no evidence that treating patients together with their spouses and targeting both for weight loss was more effective than treating patients alone. However, the use of the together program was effective for female patients, whereas male patients did better when treated alone.

Funding Source:
Government: NIH, NIDDK
Reviewer Comments:
  • Small study (N=49)
  • Interesting concept of treating patients with spouses
  • Limited results.
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? Yes
  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? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  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? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  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? ???
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? ???
  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? N/A
  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? Yes
  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)? N/A
  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? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
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