Decision-making using absolute cardiovascular risk reduction and incremental cost-effectiveness ratios : a case study

Abstract

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. AIM: 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. Singleexit 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. using a high-dose statin, the cost-effective ratio was R12.81 per percentage ofrisk 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. CONCLUSION: This model demonstrates a method to compare different therapeutic strategies to reduce cardiovascular risk with their cost-effective ratios.