OBJECTIVES: An analysis is being carried out to assess the impact of clinical parameters, over and above the treatment effect, in an evaluation of coronary heart disease (CHD) in German males. METHODS: This analysis is part of a study which uses the Coronary Heart Disease Risk Assessment Model (CHD RAM), a decision analytical model, to evaluate the cost-effectiveness of cholesterol-lowering agents for the primary prevention of CHD in German males. Although the wider study considers data for men in eight five year age groups ranging from 35-39 to 70-74 years, the clinical sensitivity analysis focuses on the 50-55 age group for three doses of cerivastatin, a cholesterol-lowering agent. Baseline data were primarily obtained from the published literature and expert opinion. The clinical parameters being assessed are compliance rate profiles, smoking behaviour, mean body mass index and systolic blood pressure. These will be assessed in terms of their impact on CHD risk and life years gained. This will be estimated by initial low density lipoprotein (LDL) cholesterol and the initial ratio of total cholesterol (TC) to high density lipoprotein (HDL) cholesterol. RESULTS: Analyses will be conducted for each clinical parameter varying the parameters by appropriate amounts. This will assess the robustness of the model and the impact of key clinical parameters on baseline results. CONCLUSIONS: By separating behavioural factors from treatment effect, the study will determine if clinical parameters play a major role in primary prevention of CHD with cholesterol-lowering agents.