MNT: Weight Management (2015)

Citation:

Willaing I, Ladelund S, Jorgensen T, Simonsen T, Nielsen LM. Nutritional counselling in primary health care: a randomized comparison of an intervention by general practitioner or dietician. European Journal of Cardiovascular Prevention and Rehabilitation, 2004; 11: 513-520. 

PubMed ID: 15580064
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To compare health effects and risk reduction in two different strategies of nutritional counseling in primary health care for patients at high risk of ischemic heart disease.

Inclusion Criteria:
  • High BMI (greater than 30)
  • Large waist circumference (greater than 102cm for men, greater than 88cm for women)
  • Dyslipidemia (total cholesterol greater than 7mmol per L or total cholesterol greater than 6mmol per L and HDL-cholesterol less than 0.9mmol per L or triglycerides greater than 2.5mmol per L or blood pressure greater than 140/80 or familiar disposition for ischemic heart disease or cardiovascular disease)
  • Type 2 diabetes.
Exclusion Criteria:
  • Mentally ill
  • Intellectually handicapped
  • Pregnant
  • Needed an interpreter
  • Under 18 years old.
Description of Study Protocol:

Recruitment

Study took place in Copenhagen County between April, 2000 and December, 2001. General practitioners in the locale were asked to participate in the study. Due to the need for geographic proximity to the practices of the two dietitians, only general practitioners in a restricted area were asked. Very few declined, but the researchers aimed for general practitioners that they expected to be motivated.

Patients were opportunistically screened for risk factors for ischemic heart disease and, if eligible, were invited to participate in the study.

Design 

Cluster randomized trial. General practitioners were randomized by computer-generated random numbers.

Intervention

  • Randomized to give nutritional counseling or to refer patients to a dietitian
  • Subjects received nutritional counseling in five counseling sessions by a general practitioner or dietitian over 12 months
  • Each general practitioner was supposed to include or refer 10 to 15 patients within five months
  • Intervention by general practitioners consisted of the usual treatment after one day of training in motivational interviewing, with the initial counseling session lasting 30 minutes and follow-up sessions lasting 12 minutes
  • Intervention by the dietitian consisted of individualized counseling based on indication for referral, dietary history and habitual diet routines; counseling focused on principles of good nutrition; advice on food shopping; cooking methods; meal planning and exercise; restriction of dietary energy, fat and cholesterol, with the initial counseling session lasting one hour and follow-up sessions lasting 30 minutes.

Statistical Analysis

  • Binary data at baseline and follow-up as well as dropout were analyzed using Alternating Logistic Regression
  • Continuous data at baseline and follow-up were analyzed with linear regression in the normal distribution
  • All analyses were performed as intention to treat analyses
  • Health effects were measured in all patients by changes in weight, BMI, waist circumference and blood lipids
  • Data on consumption of medicine and use of primary health care were analyzed using Pearson's chi-square test.

 

Data Collection Summary:

Timing of Measurements

Height, weight, BMI, waist circumference and blood pressure were measured at each counseling session. LDL and HDL cholesterol, total cholesterol and triglycerides were measured at inclusion and at six and 12 months.

Dependent Variables

  • Weight
  • Waist circumference
  • Blood lipids
  • Risk of cardiovascular disease was calculated by the Copenhagen Risk Score, a linear predictor from a Cox regression of the age of event on a set of risk factors (sex, HDL and total cholesterol, systolic blood pressure, smoking status, BMI, diabetes status, familial disposition and previous heart disease).

Independent Variables

  • General practitioners were randomized to give nutritional counseling or refer patients to a dietitian
  • Patients received nutritional counseling by general practitioner or dietitian over 12 months.

Control Variables

  • Data on use of medicine and primary health care was obtained from central registers
  • Patients answered questionnaire about their cohabitation status, education, occupation, self-rated health, physical activity, smoking status, use of alcohol and dietary habits
  • Food frequency questionnaire was also completed.

 

Description of Actual Data Sample:

Initial N  

60 general practitioners, two dietitians, 503 patients. After randomization, one general practitioner dropped out of the dietitian group and eight general practitioners dropped out of the general practitioner group.

Attrition (Final N) 

29 general practitioners in the referral to dietitian group and 22 in the general practitioner group. 312 for counseling by dietitians and 191 for counseling by general practitioners were included. 209 for counseling by dietitians and 130 for counseling by general practitioners completed the study (339 patients, 67% overall).

Age 

Mean age dietitian group was 50 years, mean age general practitioner group was 54 years.

Anthropometrics

The two patient groups did not differ with regard to odds for dropout, dietary habits, physical activity, sociodemographic variables, use of alcohol or cardiovascular risk. Compared with the general practitioner group, significantly more patients in the dietitian group were included with excessive waist circumference, and significantly fewer were included with dyslipidemia.

Location

Copenhagen County, Denmark.

 

Summary of Results:

Variables

Completers:
GP Group
Completers: RD Group P-Value All Patients:
GP Group
All Patients:
RD Group
P-Value
Mean weight reduction (kg)
-2.4
-4.5
0.02
-2.5
-3.2
0.19
Mean BMI reduction
-0.88
-1.60
0.02
-0.88
-1.14
0.22
Mean waist circumference reduction (cm)
-3.26
-4.17
0.24
-2.98
-2.87
0.92
Mean total cholesterol reduction (mmol per L)
-0.45
-0.58
0.57
-0.45 
-0.56
0.51
Mean increase of HDL cholesterol (mmol per L)

0.13

0.03

0.003
0.12
0.02

0.0009

Mean reduction of LDL cholesterol (mmol per L)
-0.41
-0.35
0.72
-0.42
-0.39
0.81
Mean reduction of triglycerides (mmol per L)
-0.18
-0.68
0.11
-0.19
-0.67
0.06

Mean reduction of Copenhagen Risk Score

-0.1909

-0.0715

0.01
-0.1369
-0.0559

0.02

Other Findings

  • Both groups obtained a significant reduction of weight, waist circumference and BMI, as well as total cholesterol, LDL cholesterol and triglycerides.
  • Weight loss was larger in the dietitian group (mean 4.5kg vs. 2.4kg) and increase of HDL-cholesterol was larger in the general practitioner group (mean 0.13mmol per L vs. 0.03mmol per L).
  • The reduction of the cardiovascular risk score was significantly larger in the general practitioner group (P=0.0005).
  • Other health outcomes were not significantly different. 
  • The dietitians performed the intervention throughout the period with no interference needed from the investigators, while most general practitioners needed frequent reminders to counsel patients regularly: At least three written reminders, and for some, a number of telephone calls and five to 10 written reminders.
Author Conclusion:

A general practitioner or a dietitian could provide nutritional counseling in general practice with slightly different outcomes with regard to weight reduction and change in lipids. General practitioners more effectively obtained risk reduction in relation to risk of ischemic heart disease. However, general practitioners needed thorough encouragement to maintain a treatment program of 12 months. It seems relevant to suggest that the general practitioner is responsible for addressing relevant risk factors, but in the case of obesity or other condition that requires long-term prevention, the general practitioner should have the possibility of referring to a dietitian.

Funding Source:
Government: Copenhagen County
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:

Recruitment methods may have led to bias in general practitioner selection. Time used for intervention differed in the tw groups but this was accepted as realistic practice. Statistically significant differences between groups at baseline.

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? ???
2. Was the selection of study subjects/patients free from bias? ???
  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? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
  3. Were study groups comparable? No
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) 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? 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
  3.3. 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
  3.4. 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
  3.5. 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? Yes
4. Was method of handling withdrawals described? Yes
  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%.) 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
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  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? Yes
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  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.) Yes
  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.) Yes
  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? 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
  6.2. 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? 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
  6.6. 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
  6.7. 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? 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
  8.1. 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)? 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
  8.5. 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
  8.6. 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
  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. 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? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes