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MNT: Weight Management (2015)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To explore the relationship between weight loss and costs of lifestyle interventions within healthcare in overweight adults.
Inclusion Criteria:
  • RCT
  • Overweight or obese subjects
  • Caucasians
  • Aged 18 years or more
  • At least one intervention group incorporated a dietary and physical activity component
  • Healthcare setting or by healthcare professionals (at least half of the studies included dietitians)
  • At least 20 participants per group
  • Reported or able to calculate percentage change in body weight or BMI one year after baseline
  • Ability to estimate costs of intervention (via contact moments and total contact time)
  • Published between January 1990 and November 2007
  • English language.
Exclusion Criteria:
  • If included subjects only had glucose intolerance T2DM
  • Other serious diseases
  • Meal replacements
  • Free food
  • Weight loss medications
  • Surgery.
Description of Study Protocol:

Design

Systematic review.

Intervention

Lifestyle interventions for weight loss.

Statistical Analysis

  • Intervention costs were calculated using Dutch reference prices (cumulative costs per participant), expressed in 2007 Euros
  • Costs were for actual resources used 
  • Regression analyses (intention to treat)
  • Asymptomatic regression model.  
Data Collection Summary:

Timing of Measurements

  • Weight at baseline
  • Weight at one year.

Dependent Variables

  • Weight change after one year
  • Cost of intervention.

Independent Variables

Lifestyle intervention for weight loss.

Control Variables

Inclusion criteria stated.

Description of Actual Data Sample:
  • Initial N: N=19 studies describing 31 interventions; mean N=79 subjects (range: 20 to 294)
  • Attrition (final N): Mean attrition of 23% at one year (range: 0% to 48%)
  • Anthropometrics:  Mean baseline weight of 91±5kg.

 

Summary of Results:

Key Findings

  • Mean costs during one year was €236±213, with a mean percentage weight loss at one year of 4.9±2.7% (range 0% to 9.7% loss)
  • Higher intervention costs were associated with more weight loss, but with increasing costs, extra weight loss leveled off. Costs of intervention explained 47% variance in the weight loss. An increment in cost of €50 was associated with an extra weight reduction of 2.5% form €0 to €50, with 0.7% from €100 to €150 and 0.1% from €200 to €250.  
Author Conclusion:
Lifestyle interventions in overweight adults in a healthcare setting are relatively cheap and that higher costs are associated with more weight loss, up to a point.  
Funding Source:
Government: Dutch Ministry of Health, Welfare and Sport
Reviewer Comments:
It is unclear if all studies include a dietitian. Based on information provided in Appendix 2, only half of the studies identify if a dietitian was included.
Quality Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about? Yes
  3. Is the problem addressed in the review one that is relevant to dietetics practice? Yes
  4. Will the information, if true, require a change in practice? Yes
 
Validity Questions
  1. Was the question for the review clearly focused and appropriate? Yes
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? Yes
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? Yes
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? Yes
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? Yes
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? Yes
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? Yes
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included? Yes
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed? Yes
  10. Was bias due to the review's funding or sponsorship unlikely? N/A