Gemfibrozil cost-benefit study : targeting subgroups for effective hyperlipidaemia drug therapy

This cost-benefit analysis attempts to translate the clinical findings of the Helsinki Heart Study (HHS) and published results regarding additional cardiovascular conditions into economic terms meaningful to US managed care providers. The study has the following 3 key objectives: to define the cost effectiveness of gemfibrozil in the prevention of coronary heart disease (CHD); to assess the net impact of gemfibrozil on total treatment costs for CHD; and to identify those patient groups for whom gemfibrozil therapy is most cost effective. In order to reach these findings a cost-effectiveness model was constructed based on original clinical data provided by the HHS, published findings for CHD risk and cost of treatment in the US, expert opinion and extension of HHS to other cardiovascular conditions, and documented costs and treatment protocols of US Medicaid and privately managed health care programmes. The model was applied to the California Medicaid (Medi-Cal) programme to estimate costs of hyperlipidaemia therapy using gemfibrozil. In parallel, savings to Medi-Cal from averted coronary events were estimated. From these data, the net expected savings to Medi-Cal were calculated. The probability of experiencing CHD varies with cholesterol level, age, sex and risk factors such as smoking, hypertension and diabetes. Therefore, it is possible to use risk-factor profiles to define groups of individuals with low, moderate or high risk of experiencing acute myocardial infarction (AMI) or sudden cardiac death. The probability of a cardiac event within 5 years ranges from 1.1% in a 45-year-old low risk male to over 36% in a 55-year-old high risk male. The average total cost of CHD care was found to be US$22,271 within 5 years. Using the probability of a CHD event to calculate the expected 5-year cost of CHD care produces a range from US$242 in the 45-year-old low risk male to US$8084 in the 55-year-old high risk male. Treatment with gemfibrozil reduces the probability of AMI and sudden cardiac death events by 34%, as demonstrated in the HHS. Therefore, the corresponding probability ranges are reduced to 0.7% in the 45-year-old low risk male and 27.3% in the 55-year-old high risk male after treatment with gemfibrozil. The expected cost of a coronary event is reduced by US$82 and US$1997, respectively.