Pharmacoeconomic evaluation of risk factors for cardiovascular disease: an epidemiological perspective.

Over the past 30 years the identification of high blood pressure and hypercholesterolaemia as major predictors of cardiovascular disease has led to an increasing expenditure on healthcare costs in pharmacological treatment of these risk factors. Most of the cost has been due to antihypertensive treatment, but evidence from randomised trials of the benefits of cholesterol-lowering drugs, along with the introduction of therapies with fewer side effects, suggests that expenditure on cholesterol treatment will rise dramatically. Cost-effectiveness analyses can aid decision making in the use of these treatments. For both hypertension and hypercholesterolaemia, the most favourable cost-effectiveness ratios were found in late middle age, in men compared to women, at the highest level of the risk factor, and in subjects with multiple risk factors. The most cost-effective treatments appear to be those which were the cheapest and which also produced the largest reductions in the risk factor. However, certain findings were based on assumptions which may be invalid. The most important of these in hypertension, and to a lesser extent in hypercholesterolaemia, is that different treatments have similar effects on morbidity and mortality for a given level of risk reduction. Experimental evidence that might confirm or refute this is not available for most treatments of hypertension. Moreover there are no trials in women or in the elderly of cholesterol-lowering treatments. The burden of disease due to these risk factors has been underestimated, and further research is required to establish the benefits of treatment on prevention of conditions such as heart failure, peripheral vascular disease, and vascular dementia.