MNT: Effectiveness of MNT for Obesity (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To explore whether intensive treatment produced greater weight loss and weight stability compared with less intensive treatment and to define a reasonable level of input from health care personnel to reach adequate treatment results.
Inclusion Criteria:

Patients had been referred to clinic for obesity, with complications and diagnoses like type 2 diabetes, HTN, dyslipoproteinemia, PCOS, sleep apnea.

Exclusion Criteria:
None specifically mentioned.
Description of Study Protocol:

Recruitment

Patients were referred to clinic for obesity.

Design

Randomized Clinical Trial.

Blinding used (if applicable)

Not used - lab tests.

Intervention (if applicable)

Both programs included behaviour modification, nutrition counselling, VLCD (200 kcal/day for 19 days, 800 kcal/day for other days = 25 days) and a continuous measuring of metabolic and anthropometrical status, but they differed regarding the treatment intensiveness.  Group 1 received continuous intensive treatment with planned group meetings every fortnight during the first year and 6 group meetings the second year.  Group 2 had planned group meetings every 3rd month.

Statistical Analysis

In case of skewed distributions of variables, logarithmic transformation was performed.  Statistical analyses based on treatment effects to 3, 6, 12 and 24 months within and between groups.  Analysis methods are paired and unpaired t tests. 

Data Collection Summary:

Timing of Measurements

Anthropometric and metabolic data were measured every 3 months in both groups.

Dependent Variables

  • BMI
  • Height
  • Weight
  • Laboratory tests:  blood glucose, serum insulin
  • Blood pressure  

Independent Variables

  • Both programs included behaviour modification, nutrition counselling, VLCD (200 kcal/day for 19 days, 800 kcal/day for other days = 25 days) and a continuous measuring of metabolic and anthropometrical status, but they differed regarding the treatment intensiveness.  Group 1 received continuous intensive treatment with planned group meetings every fortnight during the first year and 6 group meetings the second year.  Group 2 had planned group meetings every 3rd month.

  • Dietary compliance not measured

  • Self-monitoring of behavior

Control Variables

 

Description of Actual Data Sample:

Initial N: 43 subjects included in the study, 22 in Group 1, 21 in Group 2.

Attrition (final N):    17 in Group 1, 15 in Group 2 after 2 years

Age:  aged 24 - 60 years, mean age Group 1:  40.7 years, Group 2:  39.4 years

Ethnicity: not mentioned

Other relevant demographics:

Anthropometrics:  There were no significant differences between groups

Location:  Sweden

 

Summary of Results:

 

Attendance Weight reduction, 12 months Weight reduction, 24 months

 

High

-7.4 +/- 8.7, n = 21 -8.0 +/- 8.4, n = 20

Low

-4.5 +/- 5.5, n = 11

-4.1 +/- 6.9, n = 12

95% CI

-3.0 to 8.8

-1.4 to 9.2

Other Findings

There was no evidence that a more intensive treatment promotes a larger weight reduction.

Weight reduction after 1 year:  group 1:  -7.6 +/- 0.97 kg, BMI -2.6 +/- 0.3, group 2:  -6.4 +/- 1.16 kg, BMI -2.2 +/- 0.4.

Weight reduction after 2 years:  group 1:  -6.8 +/- 1.4 kg, BMI -2.4 +/- 0.3, group 2:  -8.6 +/- 1.6 kg, BMI -3.0 +/- 0.3.

The dropout rate was 26%. 

Author Conclusion:
This study has not directly evaluated changes in food habits, physical activities and lifestyle.  Focus has been on evaluating 2 programs, using more or less intensive treatment, trying to optimize the input of work from health care personnel to reach adequate treatment results.  There was no significant difference in weight reduction, compliance, or dropout rate between groups.  Thus, there was no evidence that a more intensive treatment promotes a larger weight reduction.  This observation is important from an economical point of view when setting up treatment programs.  However, there seemed to be a positive association between high attendance at all interventions and weight reduction.  To measure the metabolic and anthopometric status during the treatment and to give continuous feedback to the subjects seem to be important factors.
Funding Source:
Reviewer Comments:
Inclusion/exclusion criteria not well described.  Small sample sizes.  VLCD diet not realistic - 200 kcals/day.  More focus on the behavioral intervention, both groups received VLCD.
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? ???
  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? ???
  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? 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? Yes
  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.) Yes
  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? ???
  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? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? ???
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  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