Cost effectiveness of adding ezetimibe to atorvastatin therapy in patients not at cholesterol treatment goal in Canada.
BACKGROUND
This analysis compared the cost effectiveness of adding ezetimibe to atorvastatin therapy versus atorvastatin titration or adding cholestyramine (a resin) for patients at high risk of a coronary artery disease (CAD) event who did not reach target cholesterol levels on their current atorvastatin dosage. The primary analysis focused on 65-year-old patients with low-density lipoprotein cholesterol (LDL-C) levels of 3.1 or 3.6 mmol/L with a treatment goal of <2.5 mmol/L, classified as very high risk according to the 2000 Canadian Guidelines for Management and Treatment of Hyperlipidaemia.


METHODS
A previously developed Markov model was utilised to capture the cost and clinical consequences of lipid-lowering therapy in primary and secondary prevention of CAD. Comparisons between treatment strategies were made using ICERs (cost per QALY) from a Canadian Ministry of Health perspective. The effects of lipid-lowering therapies were based on clinical trial data. The risks of CAD events were estimated using Framingham Heart Study risk equations. Treatment costs and the costs of acute and long-term care for CAD events were included in the analysis. Costs (Canadian dollar, 2002 values) and outcomes were discounted at 5% per annum.


RESULTS
Ezetimibe added to atorvastatin therapy compared with treatment with the most common fixed atorvastatin daily dosage (10 mg) or with common atorvastatin titration strategies (up to 20 mg daily; up to 40 mg daily) resulted in cost per QALY estimates ranging from 25,344 to 44,332 Canadian dollars. The addition of ezetimibe to atorvastatin therapy was less costly and more effective than the addition of cholestyramine (dominant).


CONCLUSIONS
Our analysis suggests that adding ezetimibe to atorvastatin for patients not achieving treatment goals with their current atorvastatin dose produces greater clinical benefits than treatment with a fixed-dose atorvastatin or atorvastatin titration at an increased overall cost. The cost-effectiveness ratios provide strong evidence for the adoption of ezetimibe within the Canadian healthcare system.
Kohli
Michele
M
i3 Innovus, Burlington, Ontario, Canada.
Attard
Cheryl
C
Lam
Annette
A
Huse
Daniel
D
Cook
John
J
Bourgault
Chantal
C
Alemao
Evo
E
Yin
Donald
D
Marentette
Michael
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000924:Anticholesteremic Agents / Q000008:administration & dosage*; D000069059:Atorvastatin; D001384:Azetidines / Q000008:administration & dosage* / Q000191:economics; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D000069438:Ezetimibe; D005260:Female; D006538:Heptanoic Acids / Q000008:administration & dosage* / Q000191:economics; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011758:Pyrroles / Q000008:administration & dosage* / Q000191:economics
D000924:Anticholesteremic Agents; D001384:Azetidines; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D006538:Heptanoic Acids; D011758:Pyrroles; D000069059:Atorvastatin; D000069438:Ezetimibe