MNT: Weight Management (2015)

Citation:

Verheijden MW, Van der Veen JE, Bakx JC et al. Stage-matched nutrition guidance: Stages of change and fat consumption in Dutch patients at elevated cardiovascular risk. J Nutr Educ Behav. 2004; 36: 228-237.

PubMed ID: 15707545
 
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:
To assess the effects of stage-matched nutrition counseling on stage of change and fat (total and unsaturated) intake.
Inclusion Criteria:
  • Patients of nine medical practices in the Netherlands
  • Between the ages of 40 years to 70 years old
  • Diagnosis of hypertensiondiabetes type 2 or both
  • From these eligible participants, selection for the study was based on both:
    • Serum cholesterol 240mg per dL or higher based on two measurements within one week
    • Total fat intake of 37% or more of energy (kcal) or saturated fat intake of 12% or more energy (kcal).
Exclusion Criteria:
Not specified other than those not meeting the inclusion criteria.
Description of Study Protocol:

Recruitment

Participants were recruited through their normal medical practice in any of nine locations of the Nijmegen Department of Family Medicine Practice Network in the Netherlands. This is part of the Nijmegen Monitoring Project with the Continuous Morbidity Registration.

Design

The controlled clinical intervention study consisted of intervention and control groups based on practice level as the method of randomization. Participants were classified into one of the stages of change (pre-contemplation, contemplation, preparation, action or maintenance) via a questionnaire and assessed at six months and 12 months.

  • Control group received the usual care from their family physician, which includes general nutrition counseling
  • Intervention group received nutrition counseling based on their stage of change with respect to reducing total fat intake. A maximum of three consultations (10 minutes each) was provided by the family physician to provide motivation. Most patients received three consultations with the RD (30 minutes to 40 minutes for the initial consultation and 10 minutes to 15 minutes for other consultations).

Intervention

Counseling was provided by physician and dietitian based on patients stage of change and apparent readiness to make changes to their fat intake vs. usual care.

Statistical Analysis

SAS program version 6.12 (SAS Institute Inc, Cary, NC), including T-test, chi-square test and multi-level regression analysis. P>0.05 was considered significant.

 

Data Collection Summary:

Timing of Measurements

Patients were assessed at baseline, six months and 12 months.

Dependent Variables

  • Movement in stage of change
  • Total fat intake (percent kcal)
  • Saturated fat intake (percent kcal).

Independent Variables

  • Age
  • Sex.

Control Variables

Intervention group vs. control group assignment was based on medical practice location.

Description of Actual Data Sample:

Initial N

N=143 recruited; 142 enrolled.

Attrition (Final N)

  • Initial data: N=71 participants each in the intervention group (17 male, 54 female) and control group (21 male, 50 female)
  • Six months: One intervention and five control patients lost to follow-up
  • 12 months: Four intervention and nine control patient lost to follow-up
  • Total of 13% attrition.

Age

Subjects were 40 years to 70 years old (mean 60±7 years).

Ethnicity

Dutch.

Other Relevant Demographics

Diagnoses of total subject population (N=143):

  • Hypertension: N=131
  • Diabetes type 2: N=9
  • Both: N=3.

Anthropometrics

Groups were very similar.

Location

Netherlands.

 

Summary of Results:

Key Findings

  • The difference in movement through stages of change between intervention and control group was significant in the initial phase and the second phase (P=0.03 each) but not when viewed from baseline to 12 months (P=0.26)
    • At six months stage of change from post-preparation to pre-action (MD plus two RD visits):
      • Intervention subjects:
        • Regressed: 1%
        • Progressed: 31%
        • No movement: 68%.
      • Control subjects:
        • Regressed: 4%
        • Progressed: 14%
        • No movement: 82%.
    • Between six and 12 months (one RD visit):
      • Intervention subjects:
        • Regressed: 12%
        • Progressed: 12%
        • No movement: 76%.
      • Control subjects:
        • Regressed: 10%
        • Progressed: 31%
        • No movement: 59%.
    • Overall zero to 12 months:
      • Intervention subjects:
        • Regressed: 5%
        • Progressed: 34%
        • No movement: 61%.
      • Control subjects:
        • Regressed: 10%
        • Progressed: 42%
        • No movement: 48%.
  • Fat intake and saturated fat intake decreased throughout the study for all participants but was larger in the intervention group (-6.3% kcal) than the control group (-2.1% kcal), P<0.005.

Other Findings

  • Counseling for 11 patients in the intervention group was discontinued because they did not progress through the stages of change
  • The percentages of patients in each of the five stages of change (P=0.16) did not differ significantly between the intervention group and the control group
  • Very few patients were classified in the action stage at baseline (0% control, 3% intervention).
Author Conclusion:
This study showed that six months after enrollment in the study, a higher percentage of patients (31%) had moved from pre-action to post-preparation as a result of stage-matched nutrition counseling than as a result of the usual care (14%).
These findings suggest that continuity of care for patients at elevated cardiovascular risk is essential for changing dietary behavior and for keeping people in the action stage or maintenance stage for fat reduction.
Funding Source:
Industry:
Bayer Inc.
Pharmaceutical/Dietary Supplement Company:
University/Hospital: Wageningen University, University Medical Centre, University of Nijmegen
Not-for-profit
Netherlands Heart Foundation
Other non-profit:
Reviewer Comments:
  • Laboratory lipid analyses were sponsored by Bayer
  • Researchers also found less dropout rate in the intervention group (5.6%) vs. the control group (12.5%)
  • Small sample size considering there were five stages of change were represented among each group of N=71.
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? Yes
  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.) Yes
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? Yes
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? Yes
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
  5.2. 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? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? Yes
  5.5. In diagnostic study, were test results blinded to patient history and other test results? No
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? 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
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? No
  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? 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
  7.2. 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)? 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? 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