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

Citation:

Caro JJ, Getsios D, Caro I, Klittich WS, O'Brien JA. Economic evaluation of therapeutic interventions to prevent type 2 Diabetes in Canada. Diabetic Medicine, 2004; 21 (11): 1,229-1,236. 

PubMed ID: 15498090
 
Study Design:
Cost-effectiveness study
Class:
M - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To compare the health and economic outcomes of using acarbose, an intensive lifestyle modification program, metformin or no intervention to prevent progression to type 2 diabetes in Canadians with impaired glucose tolerance (IGT). 

Inclusion Criteria:
  • Outcomes: IGT, diabetes, normal glucose tolerance (NGT), death
  • Interventions: Lifestyle modification; metformin, acarbose, no treatment
  • Costs: Direct costs only.
Exclusion Criteria:

Article exclusion criteria not mentioned.

Description of Study Protocol:
  • Recruitment: Published intervention trials
  • Design: Cost-effectiveness analysis using effectiveness and resource data derived from published intervention trials
  • Intervention: Lifestyle modification, metformin, acarbose or no intervention.

Statistical Analysis

  • Outcomes calculated for each strategy
  • Costs = treatment + screening for diabetes-related costs
  • Cost-effectiveness ratios: Ratio incremental costs to incremental health benefits; based on changes in life-expectancy (cost per year gained); transition to type 2 diabetes avoided (cost per type 2 diabetes case avoided)
  • Cost-effectiveness of screening asymptomatic population for IGT + acarbose treatment to detected cases
  • Sensitivity analysis.
Data Collection Summary:

Timing of Measurements

Not applicable.

Dependent Variables

  • Health outcomes
  • Economic outcomes.

Independent Variables

  • Acarbose
  • Intensive lifestyle modification program
  • Metformin
  • No intervention.

 

Description of Actual Data Sample:
  • Initial N: Cohort of 1,000 patients
  • Attrition (final N): 1,000
  • Age: Not mentioned
  • Ethnicity: Not mentioned
  • Location: Canada.
Summary of Results:
Variables No Treatment Metformin Acarbose Lifestyle Modification

Transition to Type 2 Diabetes (N)

542 490 468 425

NGT at End of Follow-Up (N)

242 272 283 306

Survival (Years)

12,756 12,897 12,954 13,067
Type 2 Diabetes-Free Time (Years) 6,674  7,153 7,369 7,797
Costs (Canadian $)        
IGT Treatment and Testing

$138,650

$551,825 $1,264,397 $3,610,840
Diabetes Costs $11,623,970

$10,211,295

$9,600,806 $8,385,094
Total Costs $11,762,620 $10,763,120 $10,865,204 $11,995,898
Incremental Costs
Relative to no intervention        
 

Canadian cost per patient

  -$999 -$897 +$233
Increments in years survival   0.14 0.20 0.31
Canadian cost per year gained   dominant dominant +$749
Relative to Metformin        
  Canadian cost per patient  

 

+$102 +1,232
Increments in years survival     0.06 0.17
Canadian cost per year gained     +$1,798 +7,252
Relative to Acarbose        
  Canadian cost per patient       +$1,130
Increments in years survival       0.11
Canadian cost per year gained       +9,988

Other Findings

  • Over a decade, 70 of 1,000 untreated patients are expected to die and 542 develop diabetes
  • Intensive lifestyle modification is estimated to prevent 117 cases of diabetes, while metformin would prevent 52 and acarbose 74 cases
  • The proportion of those who return to normal glucose tolerance also increases with any treatment
  • While lifestyle modification is more effective, it can increase overall costs depending on how it is implemented, whereas acarbose and metformin reduce costs by nearly $1,000 per patient
  • Lifestyle modification was cost effective, varying from $749 per life year gained vs. no treatment to about $10,000 per life year gained vs. acarbose
  • Acarbose costs somewhat more than metformin, but is more effective: $1,798 per life year gained
  • Sensitivity analysis: Most influential parameter is impact of treatment on risk of developing diabetes. 
Author Conclusion:
  • Treatment of IGT in Canada is a cost-effective way to prevent diabetes and may generate savings
  • Pharmacological treatment tended to be less costly, though maintained intensive lifestyle modification led to greatest health benefits at reasonable incremental costs.
Funding Source:
Industry:
Caro Research Institute:Concord,Nova Scotia, Quebec
Other:
University/Hospital: McGill University
Reviewer Comments:

Authors note the following limitations:

  • Characteristics of patients in the clinical trials may differ from those in the general population, potentially reducing the generalizability of the results
  • One published study on acarbose, one on metformin and two on lifestyle modifications. None of them compare all three strategies in a single study.
  • Patient compliance is not fully addressed.
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? No
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? No
  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? No
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? No
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? ???
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? ???
  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