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MNT: Weight Management (2015)


van Baal PHM, van den Berg M, Hoogenveen RT, Vijgen SMC, Engelfriet PM. Cost-effectiveness of a low-calorie diet and Orlistat for obese persons: Modeling long-term health gains through prevention of obesity-related chronic disease. Value Health. 2008; 11(7): 1033-1040.

PubMed ID: 18494748
Study Design:
Cost-effectiveness study
M - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To assess the cost-effectiveness of pharmacologic treatment of obesity in combination with a low-calorie diet by linking quality of life to this occurrence of obesity-related diseases rather than assuming a direct effect of obesity on quality of life.

Inclusion Criteria:
  • Dutch individuals
  • Age between 20 years and 70 years
  • BMI 30kg/m2 or higher.
Exclusion Criteria:
  • Age less than 20 years or more than 70 years
  • BMI less than 30kg/m2.
Description of Study Protocol:


Population model based on the population of the Netherlands between the ages of 20 years and 70 years with a BMI greater than 30kg/m2


Cost-benefit analysis.

Statistical Analysis
  • Probabilistic sensitive analysis. The model was run 500 times to assess the effect of uncertainly regarding some of the input parameters on outcomes.
  • Univariate sensitive analysis was used to investigate the robustness of the results to some key parameters and assumptions.
Data Collection Summary:

Timing of Measurements

The RIVM Chronic Disease Model was used to project the differences in QALY and lifetime health-care costs because of the effects of pharmacologic and dietary interventions on BMI.

Dependent Variables

  • QALY gained
  • Incremental cost-effectiveness ratios (ICER); calculated using discounted yearly differences in outcomes between the intervention and the current practice scenarios added over the time interval modeled at 80 years.

Independent Variables

Obesity treatment (Orlistat in combination with a low-calorie diet, a low-calorie diet or no treatment).


Description of Actual Data Sample:
  • Initial N: N=1,138,000 (population of the Netherlands between 20 years and 70 years of age with a BMI 30kg/m2 or more)
  • Attrition (final N): N=1,138,000
  • Age: Ages 20 years to 70 years
  • Ethnicity: Dutch
  • Anthropometrics: BMI 30kg/m2 or more
  • Location: Bilthoven, The Netherlands.


Summary of Results:

Key Findings

  • QALY gained were 17 for the low-calorie diet only intervention and 31 for the low-calorie diet in combination with Orlistat intervention
  • Life years gained were 18 years for the low-calorie diet only intervention and 34 years for the low-calorie diet in combination with Orlistat intervention
  • Incremental costs (incremental intervention costs and incremental lifetime health-care costs) per QALY gained were €17,900 for the low-calorie diet-only intervention compared to no intervention
  • Incremental costs per QALY gained were €58,800 for the low-calorie diet plus Orlistat intervention compared to the low-calorie diet only intervention
  • When a direct relationship was assumed between BMI and quality of life, the ICER was decreased to €6,000 per QALY gained for the low-calorie diet only intervention and to €24,100 for the low-calorie diet plus Orlistat intervention.


Author Conclusion:
  • Prevention of obesity, by decreasing the incidence of co-morbid diseases, will result in increases in life expectancy and decreasing in health care costs. The life years gained come at a price as later in life people suffer from other diseases that decrease quality of life and increase healthcare utilization
  • This model only assumed improvements in quality of life indirectly through a reduced risk of the development of obesity-related diseases
  • Effects on the cost because of lost productivity were not assessed
  • A crude classification of BMI was used by classifying BMI into three categories (normal, overweight and obese) and not considering BMI as a continuous variable
  • Weight loss maintenance in this study was assumed to be effective in the long term
  • Both a low-calorie diet and a low-calorie diet in combination with Orlistat have higher cost-effectiveness ratio if no direct effect of BMI on quality of life is assumed and only effects of weight loss through obesity-related diseases are taken into account. As a result, the addition of Orlistat treatment loses much of its attractiveness. A diet alone should be the first option for policymakers in combating obesity.
Funding Source:
Government: Dutch Ministry of Health, Welfare and Sports
Reviewer Comments:
Costs reported in Euros at the 2005 exchange rate.
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? Yes