NC: Behavior Change Strategies (2007-2008)

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

The purpose of the study is:

  • To determine the frequency and effectiveness of behavorial goal choices in the self-management (SM) of diabetes
  • To test goal-setting theory hypothesis that self-selection and behavorial specificity of goals are key to enhancing persistence.
Inclusion Criteria:
  • Type 2 diabetics
  • Participants 25 years old or older
  • English-speaking.
Exclusion Criteria:
  • Participants less than 25 years old
  • Type I diabetics.
Description of Study Protocol:

Recruitment

  • The participants were recruited from 52 physicians in 30 practice settings
  • The participants meeting the inclusion criteria were sent an invitation letter, a brochure and a postcard to return if they did not want to participate
  • Patients were called and invited to participate.

Design

Physicians were stratified by size of practice and location (urban or rural), then randomized by the statistician.

Blinding Used

The was no blinding.

Intervention

  • Participants arrived 30 to 35 minutes before the primary care visit. The goal-setting session was done during the participant's medical care visits and delivered through a computerized touch-screen CD-ROM session.
  • Each participant completed a dietary intake and a physical activity assessment, which compared the participant's answer to recomended guidelines 
  • The participants developed a SM action plan, which consisted of a behavior change goal in the area of diet or exercise 
  • The participants selected specific activities to support the goal and identified barriers and chose strategies to overcome those barriers
  • A care manager met for eight to 10 minutes with the participant to review the goals and discuss additional strategies
  • Participants received one follow-up call two weeks after the initial visit to review progress and provide feedback on goal progression.

Statistical Analysis

  1. One-way ANOVA for normally-distributed continuous variables. Age, fat intake, fruit and vegetable consumption, were used to compare the three groups: Fat reduction, fruit and vegetable consumption and physical activity.
  2. Tukey multiple comparison adjustment was used to determine specific between-group-differences
  3. Kruskall-Wallis test was used to examine the difference of non-normally-distributed variables such as the number of comorbid illness among participants within the three groups
  4. X2 test was used for dichotomous variables such as gender and marital status. The physical activity measures were completed using X2.
  5. F tests was used to compare outcome changes from baseline for all three groups 
  6. The direct difference before and after goal-setting represented the changes in fat intake and fruit and vegetable consumption
  7. Odds ratios were used to describe the changes in physical activity outcomes.
Data Collection Summary:

Timing of Measurements

Baseline and six months.

Dependent Variables

  • Variable One: Fat intake, measured by the Block Dietary Data Systems (BDDS) "Fat Screener"
  • Variable Two: Fruit and vegetable intake was measured by the seven-item BDDS "Fruit/Vegetable Screener"
  • Variable Three: Physical activity was measured by a modified version of the Behavorial Risk Factor Surveillance System, 11-item questions.

Independent Variables

  • Age
  • Gender
  • Ethnicity
  • Education
  • Annual income
  • Marital status
  • Diagnosed comorbid conditions.

Control Variables

  • Feedback
  • Frequency
  • Self-selection
  • Behavorial goals.
Description of Actual Data Sample:
  • Initial N: 469 participants randomized to intervention were included in this analysis
  • Attrition (final N): 422 participants (5% of participants selected smoking cessation as the goal and were therefore excluded and 5% had no six-month follow-up data and were excluded)
  • Mean age: 62 years.

Ethnicity

  • 83% white non-Hispanic
  • 10.8% Hispanic
  • 5% other.

Other Relevant Demographics

  • Female: 51%
  • Married: 69%
  • Less than high school education: 13%
  • High school graduate: 26%
  • One to three years of college: 32%
  • Gollege or grad school: 29%
  • Income under $10,000: 12%
  • Income from $10,000 to $29,999: 27%
  • Income from $30,000 to $49,999: 28%
  • Income over $50,000: 33%.

Anthropometrics

Not described.

Location

Not mentioned.

Approximately 49% of the participants selected the physical activity goal, while approximately 24% selected the increase fruit and vegetables goal and 27% selected reduce fat goal. 

Goal selection did not differ by demographic or medical characteristics.

Summary of Results:

Table One: Patient Characteristics at Baseline

Patient Characteristics Reduce Goals at Baseline (N=112) Increase Fruit Goals at Baseline (N=100)  Increase Physical Activity at Baseline (N=210)
P-Value
Diet Fat consumption Mean
22.27
19.18
20.49
0.028
SD
7.78
8.98
8.48
Fruit and vegetable consumption Mean
13.50
10.65
12.40
<0.0001
SD
4.94
3.59
4.61
Physical Activity Days of vigorous activity per 7 days
0.42
0.34
0.29
<0.0001
Days of moderate activity per 7 days
0.49
0.45
0.37
<0.0001
 

Significant Differences at Baseline by Goal Selection Between Groups

  • Reduce fat and increase fruit and vegetables (P=0.008)
  • Reduce fat and increase fruit and vegetables (P<0.001) plus increase fruit and vegetables and increase physical activity (P<0.001)
  • Reduce fat and increase fruit and vegetables (P<0.001) plus reduce fat and increase physical activity (P<0.001) plus increase fruit and vegetables and increase physical activity (P=0.016)
  • Reduce fat and increase physical activity (P<0.001) plus increase fruit and vegetables and increase physical activity   (P<0.001).

Table Two: Comparison Between Baseline and Six Months for Reduce Fat Goal (27% of Participants)

Variables

Baseline (N=112)
Mean and SD

Six Months (N=92)
Mean and SD

Statistical Significance of Group Difference

Fat Consumption

22.27 (7.78)

18.42 (7.99)

P<0.0001

Fruit and Vegetable Consumption

13.50 (4.94)
14.12 (5.07)
P=0.0967

Vigorous Activity

0.42

0.46

P=0.4594

Moderate Activity

0.49

0.55

P=0.0917

Table Three: Comparison Between Baseline and Six Months for Increase Fruits and Vegetable Goal (24% Participants)

Variables Baseline (N=100) Six Months (N=90) Significance

Fat Consumption

19.18 (8.99)
16.84 (8.75)
P=0.0029

Fruit and Vegetable Consumption

10.65 (3.59)
12.70 (4.11)
P<0.0001

Vigorous Activity

0.34
0.36
P=0.288

Moderate Activity

0.45
0.48
P=0.4515

Table Four: Comparison Between Baseline and Six Months for Increase Physical Activity Goal (49% Participants)

Variables Baseline (N=210) Six Months (N=169) Significance

Fat Consumption

20.49 (8.49)
19.09 (7.80)
P=0.0058

Fruit and Vegetable Consumption

12.40 (4.61)
12.86 (5.20)
P=0.0587

Vigorous Activity

0.29
0.37
P=0.0002

Moderate Activity

0.37
0.42
P=0.0156

Other Findings

  • P-value for comparing changes of outcome among the three goal-selection groups
    • Fat consumption: P=0.00088
    • Fruit and vegetable consumption: P=0.075
    • Vigorous activity: P=0.1634
    • Moderate activity: P=0.6921.
  • Goal selection did differ by reports of baseline behavior. Participants who selected increase physical activity, reduce fat consumption or increase fruit and vegetable consumption were significantly and respectively less active, consumed more dietary fat and ate fewer fruits and vegetables.
  • Participants who selected a reduced-fat goal showed significantly larger decrease than did those that selected physical activity or fruit and vegetable goals
  • Participants who selected a fruit and vegetable goal showed signficant changes in fruit and vegetable consumption
  • Participants who selected a physical activity goal demonstrated significant changes in days of moderate and vigorous physical activity.
Author Conclusion:

The study investigated the goal-setting process and the six-month behavorial changes. The results supported the hypothesis that the participants' active participation in selecting and setting goals would lead to the selection of a goal from the area that could use the most improvement and the goal that was most personally appropriate.

The second hypothesis, that participants would demonstrate the greatest amount of change relative to their self-selected goal behavior was only partially supported. Those who selected reduce fat intake as a goal reduced fat intake to a significantly greater degree than did those who selected physical activity or fruit and vegetable consumption goals. Although the statistically significant differences in physical activity and fruit and vegetable consumption by goal-selection were not found, these groups had the greatest change from baseline to six months. The lack of significance could be due to the fact that the participants identified an initial baseline goal but in actuality changed other behaviors without recording them.

This study demonstrated that goal-selection and specification, based on information related to multiple health behaviors, can be completed via computer assistance.

Funding Source:
Government: HHS
Reviewer Comments:
  • The author clearly stated the purpose of the study which was;
    • To determine the frequency and the effectiveness of behavorial goal choices in the self-managment of diabetes
    • To test the goal-setting theory hypothesis that self-selection and behavorial specificity of goals can persist over a six-month period.
  • Significant differences by goal-selection were reported at baseline. The author explained the effect of the goal-selection on changes in behavior at baseline and six months later. Significant differences as well as those that only approached significance were explained.
  • The author identified the study limitations:
    • The methodology had limits, therefore, the study results should be interpreted with caution
    • The study objective of self-selection of behavorial goals were met, however the goals were assessed by self-report. The author identified the limitations of self-report in the discussion.
    • The author recognized the limited number of ethnic minorities in the study, but also acknowledged that the sample was representative of the region
    • The statistician and the staff were not blinded to the intervention.
  • Dropouts were not adequately explained. The group that selected increase physical activity, had a 20% drop-out rate at six months.  
  • The author did not present any data on control participants who did not set goals and were not assessed on behavior change outcomes. It would have been informative for the author to present the baseline information for the control group. Baseline demographics, diet and physical activity on the control group would have added information for comparison between the intervention group and the control group.
  • No information related to length of time patients had diabetes was provided.
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
  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
  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
  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
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
  1. Was the research question clearly stated? Yes
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.1. 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
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
  1.3. Were the target population and setting specified? Yes
  2. Was the selection of study subjects/patients free from bias? 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
  2.1. 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
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? 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
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  3. Were study groups comparable? ???
3. Were study groups comparable? ???
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  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? ???
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) 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? ???
  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? ???
  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
  3.5. 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
  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. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? 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%.) No
  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
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.4. Were reasons for withdrawals similar across groups? ???
  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
  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. 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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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.) No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? 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
  5.4. 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
  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. 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
  6.1. 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? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  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
  6.4. 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? ???
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  6.6. Were extra or unplanned treatments described? ???
  6.6. Were extra or unplanned treatments described? ???
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  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
  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. 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
  7.1. 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
  7.2. 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
  7.3. 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
  7.4. 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
  7.5. 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
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? 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? No
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? 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
  8.2. 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
  8.3. 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)? No
  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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  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? 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? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
  9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? 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. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? No
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes