Methodologic issues in policy modeling for cardiovascular disease.

Clinical decision models are intended to guide the choices of individual clinicians; policy models are intended to guide the choices of persons and organizations that affect the aggregate allocations of resources to health care problems. Although it is difficult to identify any single policymaker in the United States who can alter the aggregate effect of the millions (or billions) of individual clinical decisions, there are many potential users of policy models: payers, providers, state and local health departments, the National Institutes of Health, professional organizations, hospitals and producers of medical devices, among others. Policy models deal with populations of individuals, may be static or dynamic and may be descriptive or prescriptive. Two types of policy models that have been applied to cardiovascular disease with a focus on coronary artery bypass surgery are discussed: 1) economic evaluation models, specifically cost-effectiveness, cost utility and cost-benefit analyses; and 2) population simulation models. Cost-effectiveness models are preferable for reasons that are discussed.