Screening for hypercholesterolemia among Canadians: how much will it cost? [published erratum appears in Can Med Assoc J 1991 Mar 1;144(5):545] OBJECTIVE: To determine the cost of screening all Canadians aged 30 years or more without coronary heart disease (CHD) for hypercholesterolemia. DATA SOURCES: The expected results of initial screening of the serum cholesterol level were estimated on the basis of 1986 Canadian census data and the 1978 Canada Health Survey. The results of repeat testing were estimated on the basis of data from the Lipid Research Clinics Prevalence Study. Lipid profile results were extrapolated from tests at the Montreal General Hospital's clinical chemistry laboratory. Laboratory costs and primary care practitioner costs were provided by the Canadian Society of Clinical Chemists and provincial fee schedules respectively. MAIN RESULTS: Among 12,479,356 Canadians free of CHD 48.7% would be identified as being at high risk, 4.8% would be identified as being at moderate risk, and 46.6% would be reassured that their lipid risk for CHD was low. The total cost of implementing the program in the first year would be $432 million to $561 million ($325 million for laboratory tests and $107 million to $236 million for visits to primary care practitioners). CONCLUSION: The substantial cost of implementing a nationwide screening program must be weighed against the expected benefits to ensure that the final result is both practical and economically feasible. 