Decision-making using absolute cardiovascular risk reduction and incremental cost-effectiveness ratios: a case study.
BACKGROUND
Many clinical guidelines have adopted a multifactorial cardiovascular risk assessment to identify high-risk individuals for treatment. The Framingham risk chart is a widely used risk engine to calculate the absolute cardiovascular risk of an individual. Cost-effective analyses are typically used to evaluate therapeutic strategies, but it is more problematic for a clinician when faced with alternative therapeutic strategies to calculate cost effectiveness.


OBJECTIVE
We used a single simulated-patient model to explore the effect of different drug treatments on the calculated absolute cardiovascular risk.


METHODS
The Framingham risk score was calculated on a hypothetical patient, and drug treatment was initiated. After every drug introduced, the score was recalculated. Single-exit pricing of the various drugs in South Africa was used to calculate the cost of reducing predicted cardiovascular risk.


RESULTS
The cost-effective ratio of an antihypertensive treatment strategy was calculated to be R21.35 per percentage of risk reduction. That of a statin treatment strategy was R22.93 per percentage of risk reduction. U sing a high-dose statin, the cost-effective ratio was R12.81 per percentage of risk reduction. Combining the antihypertensive and statin strategy demonstrated a cost-effective ratio of R23.84 per percentage of risk reduction. A combination of several drugs enabled the hypothetical patient to reduce the risk to 14% at a cost-effective ratio of R17.18 per percentage of risk reduction.


CONCLUSIONS
This model demonstrates a method to compare different therapeutic strategies to reduce cardiovascular risk with their cost-effective ratios.
Department of Internal Medicine, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
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JA
Ker
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Oosthuizen
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Rheeder
D000959:Antihypertensive Agents / Q000191:economics / Q000627:therapeutic use; D002317:Cardiovascular Agents / Q000191:economics* / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000191:economics* / Q000209:etiology / Q000517:prevention & control*; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D016527:Drug Costs; D004359:Drug Therapy, Combination; D006305:Health Status Indicators; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000191:economics / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D017410:Practice Guidelines as Topic; D011314:Preventive Health Services / Q000191:economics*; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D013019:South Africa; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D002317:Cardiovascular Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors