The long-term cost-effectiveness of clopidogrel plus aspirin in patients undergoing percutaneous coronary intervention in Sweden.
BACKGROUND
The Percutaneous Coronary Intervention-Clopidogrel in Unstable Angina to Prevent Recurrent Events (PCI-CURE) study, which examined the effect of adding clopidogrel to aspirin versus aspirin alone in patients with unstable coronary artery disease (CAD) undergoing PCI, found a relative risk reduction in cardiovascular deaths and myocardial infarction among those treated with clopidogrel. In addition, a within-trial cost-effectiveness analysis showed favorable costs per event avoided. However, to estimate the long-term effects, a modeling approach is necessary.


OBJECTIVE
The purpose of this study was to estimate the long-term cost-effectiveness of treating patients undergoing PCI with clopidogrel plus aspirin in Sweden.


METHODS
A Markov model was developed. Transition probabilities were estimated based on a register of patients treated in the coronary care units at 74 (out of 78) hospitals throughout Sweden. Patients were assumed to be treated for 1 year with an effect based on data from the PCI-CURE study. Costs were collected from published sources and recalculated to year-2004 Euros (Euro 1.00 = USD 1.24). Life-years gained were used as the measure of effectiveness. The perspective was that of the Swedish society, with a separate analysis using a health care cost perspective.


RESULTS
After inclusion and exclusion criteria were applied, 3474 patients were included in the model analysis. The model predicted a net gain in survival of 0.04 year per patient when adding clopidogrel. This yielded a net increase of Euros 449 if only direct costs were included; with indirect costs, the net increase was Euros 332. The resulting cost-effectiveness ratios were Euros 10,993 and Euros 8127 per life-year gained.


CONCLUSIONS
The predicted cost-effectiveness ratios were well below the threshold values generally considered cost-effective. Adding clopidogrel to aspirin appeared to be cost-effective in this model analysis of patients with unstable CAD undergoing PCI in Sweden.
Lindgren
Peter
P
Department of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden. peter.lindgren@imm.ki.se
Stenestrand
Ulf
U
Malmberg
Klas
K
Jönsson
Bengt
B
D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D001241:Aspirin / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use; D000077144:Clopidogrel; D003198:Computer Simulation; D003327:Coronary Disease / Q000191:economics / Q000628:therapy; D003362:Cost-Benefit Analysis; D004334:Drug Administration Schedule; D016527:Drug Costs; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D018803:Models, Economic; D009010:Monte Carlo Method; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000191:economics* / Q000627:therapeutic use; D013997:Time Factors
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin