Cost-effectiveness of lovastatin varied by age, sex, and nonlipid CHD risk factors
ACP J Club. 1995 Nov-Dec;123:84. doi:10.7326/ACPJC-1995-123-3-084
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Hamilton VH, Racicot FE, Zowall H, Coupal L, Grover SA. The cost-effectiveness of HMG-CoA reductase inhibitors to prevent coronary heart disease. Estimating the benefits of increasing HDL-C. JAMA. 1995 Apr 5;273:1032-8.
To evaluate the lifetime cost-effectiveness of a common 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, lovastatin, for the treatment of high blood cholesterol levels.
Cost data were added to a validated coronary heart disease (CHD) model that estimated the benefits of lifelong risk-factor modification.
Cost data derived from Canadian sources. Health-related event data derived from Canadian and U.S. sources.
The intervention group consisted of men and women aged 30 to 70 years who were free of CHD, had total serum cholesterol levels equal to the 90th percentile of the U.S. distribution in their age and sex group, and had high-density lipoprotein cholesterol (HDL-C) levels equal to the mean of the U.S. distribution in their age and sex group. Information on these lipid levels was derived from the U.S. National Health and Nutrition Examination Survey. Nonsmokers with diastolic blood pressure (DBP) ≤ 80 mm Hg were defined as low risk; smokers with DBP ≥ 100 mm Hg were defined as high risk.
Lovastatin, 20 mg/d. It was predicted, on the basis of the results of the Expanded Clinical Evaluation of Lovastatin [EXCEL] Study, that this dosage would decrease patients' total serum cholesterol levels by a mean of 17% and increase HDL-C levels by a mean of 7%.
Main cost and outcome measures
Estimates of increased life expectancy because of cholesterol modification of total serum cholesterol and HDL-C levels, the lifetime cost of lipid therapy and non-CHD costs, and the cost-effectiveness of lovastatin assessed by cost (in Canadian dollars) per year of life saved, discounted by 5%.
High-risk men who started lovastatin at age 30, 50, and 70 years gained 2.03, 1.43, and 0.23 years of life, respectively. High-risk women who started lovastatin at these ages gained 1.03, 1.02, and 0.37 years of life, respectively. High-risk men who start lovastatin at age 30, 40, 50, 60, or 70 years would obtain cost-effectiveness ratios of $35 785, $22 297, $20 882, $27 872, and $50 079, respectively. The corresponding ratios for high-risk women would be $105 708, $61 891, $42 313, $36 627, and $43 127. The cost-effectiveness ratios, including the beneficial effects of HDL-C, were a mean of 40% lower than the ratios that excluded HDL-C effects.
The cost-effectiveness of lovastatin varied by age and sex and was sensitive to nonlipid CHD risk factors.
Sources of funding: Health and Welfare Canada; Dairy Bureau of Canada; Merck Frosst Canada Incorporated.
For article reprint: Dr. S.A. Grover, Centre for the Analysis of Cost-Effective Care, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4, Canada. FAX 514-934-8293.
The study by Hamilton and colleagues builds on the literature that shows lipid reduction to be more cost-effective than many other preventive and therapeutic services. The study combines an epidemiologic model based on the strengths of the Framingham and EXCEL studies with cost projections done using standard clinical economic methods. Because the authors sought to project lifetime costs and outcomes in the absence of a long-term longitudinal study of the effects of lovastatin, it was necessary to simulate these results.
Hamilton and colleagues conclude that cholesterol reduction should not be started in men until the age of 35 years and in women until the age of 45 years and that cholesterol reduction is cost-effective for middle-aged adults with elevated cholesterol levels. On the controversial issue of cholesterol reduction for elderly persons, the authors suggest that lovastatin is cost-effective in these persons and therefore appropriate. This conclusion differs from that of some other investigators, and Hamilton and colleagues suggest that this is because their calculation of the cost of lovastatin for the remaining lifetime is low (although dispensing fees are not considered). Like the debate in the United States about mammography for women aged 40 to 50 years, the recommendations about younger persons show the ethical and public policy controversy that emerges when improved outcomes are available but may not be of sufficient magnitude to be justified by cost-effectiveness analysis.
Because both costs and styles of practice are different in the United States, readers will wonder whether the cost-effectiveness results are applicable outside of Canada. Hamilton and colleagues emphasize that their results are similar to those of U.S. studies, but a sensitivity analysis using U.S. costs and practice styles would be reassuring.
In contrast to most cost-effectiveness studies, Hamilton and colleagues include the cost of caring for other diseases resulting from longer survival. These costs, however, would make cholesterol reduction seem more costly, and their exclusion would have made these results even more conclusive in support of aggressive use of lipid-lowering agents in middle-aged and elderly persons.
John M. Eisenberg, MD
Georgetown University Medical CenterWashington, DC, USA