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MNT: Cost Effectiveness, Cost-benefit, or Economic Savings of MNT (2009)

Citation:

Palmer AJ, Roze S, Valentine WJ, Spinas GA, Shaw JE, Zimmet PZ. Intensive lifestyle changes or metformin in patients with impaired glucose tolerance: Modeling the long-term health economic implications of the diabetes prevention program in Australia, France, Germany, Switzerland, and the United Kingdom. Clin Ther. 2004; 26: 304-321.

 

PubMed ID: 15038953
 
Study Design:
Cost-effectiveness analysis
Class:
M - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

Health economic modeling techniques were used to establish whether implementing the active treatments used in the Diabetes Prevention Program (DPP) would be cost-effective in Australia, France, Germany, Switzerland and the United Kingdom.

Inclusion Criteria:
  • Original DPP participants
  • Overweight patients with impaired glucose tolerance.
Exclusion Criteria:

Not reported.

Description of Study Protocol:
  • Recruitment: Recruitment of DPP study participants and additional study participants not reported.  
  • Design: Cost-effectiveness analysis
    • A Markov model simulated three states: Impaired glucose tolerance (IGT); type 2 diabetes mellitus; deceased-using probabilities from the Diabetes Prevention Program and published data
    • Country-specific direct costs were used throughout.
  • Intervention: From the DPP; Metformin (plus standard lifestyle advice) or intensive lifestyle changes vs. standard lifestyle advice only
  • Statistical analysis: 95% confidence intervals were used in the sensitivity analysis.
Data Collection Summary:

Timing of Measurements

Trial period lasted three years.

Dependent Variables

  • Number of years free of diabetes, percentage of patients developing diabetes, life expectancy and total lifetime costs per patient (including costs of implementing the different interventions in country specific settings and the global costs of being in the states of IGT and type 2 diabetes were calculated for each treatment arm
  • Incremental cost-effectiveness ratios calculated in terms of costs per life-year gained between the treatment arms. 

Independent Variables

Three treatment arms of the DPP were compared

  1. Intensive lifestyle changes: With goals of great or equal to 7% weight loss or weight maintenance and greater or equal 150 minutes per week of physical activity. Consisted of a 16-lesson, goal-oriented education program that taught behavioral self-management strategies for weight loss and physical activity.
  2. Meformin plus standard advice on diet and exercise: Metformin use with target doses 850mg BID. Diet and exercise delivered as written information and in a yearly 30-minute individual consultation. Participants were reviewed annually by a medical case manager.
  3. Control group: Patients took placebo instead of metformin. They received standard advice on diet and exercise (same as metformin group) and an annual review session by a medical case manager.

Control Variables

All costs were expressed in year-2002 Euros. 

Description of Actual Data Sample:
  • Initial N: 3,234 DPP participants randomized. Cohort of patients in this analysis constructed to resemble the DPP study population.
  • Age: Mean age 50.6 years
  • Other relevant demographics: Mean body weight, 94.2kg
  • Location: Australia, France, Germany, Switzerland and United Kingdom.
Summary of Results:

Study Arm Years Free of Type 2 Diabetes Total Lifetime Costs
Australia; Control
8.11
27,171
Australia; Lifestyle
9.90
26,535
Australia; Metformin
8.98
27,127
France; Control
8.15
35,160
France; Lifestyle
9.94
34,705
France; Metformin
9.02
34,916
Germany; Control
8.19
33,547
Germany; Lifestyle
10.00
32,963
Germany; Metformin
9.08
33,282
Switzerland; Control
8.22
49,472
Switzerland; Lifestyle
10.04
48,436
Switzerland; Metformin
9.11
48,917
United Kingdom; Control
8.04
17,632

United Kingdom; Lifestyle

9.81

18,653

United Kingdom; Metformin

8.90

18,010

Other Findings

  • Assuming only within-trial effects and costs of interventions, both metformin and intensive lifestyle changes improved life expectancy vs. control
  • Mean improvements in non-discounted life expectancy were 0.11 and 0.22 years for metformin and intensive lifestyle changes, respectively
  • Both interventions were associated with cost savings versus control in all countries except the United Kingdom, where a small increase in costs was observed in both intervention arms
  • When a lifetime effect of interventions was assumed, incremental improvements in life expectancy were 0.35 and 0.90 years for metformin and intensive lifestyle changes, respectively
  • Results were sensitive to probabilities of developing type 2 diabetes, the projected long-term duration of effect of interventions after the three-year trial period, the relative risk of mortality for type 2 diabetes compared with impaired glucose tolerance and the costs of implementing the interventions.
Author Conclusion:

Based on probabilities from the DPP and published data, in this model analysis, incorporation of the DPP interventions into clinical practice in five developed countries was projected to lead to an increase in diabetes-free years of life, improvements in life expectancy, and either cost savings or minor increases in costs compared with standard lifestyle advice in a population with impaired glucose tolerance. Thus, financial constraints should not prevent the implementation of diabetes mellitus prevention programs.

Funding Source:
Industry:
Merck-Sante (Lyon France)
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:

Cohort of patients resembling DPP not well described. Authors note the following limitations:

  • Degree of uncertainty in translating data from a carefully controlled clinical trial in one country to routine clinical practice in another
  • No direct non-medical or indirect costs were included in the estimation of the costs of the DPP interventions
  • Variation by country did not adequately reflect country-specific practice patterns.
Quality Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  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
  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
  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
  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
  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? N/A
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? N/A
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? ???
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? ???
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? N/A
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? N/A
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? 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
  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
  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
  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
  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
  10. Was bias due to the review's funding or sponsorship unlikely? Yes