Canadian Cost-Effectiveness of Coronary Artery Calcium Screening Based on the Multi-Ethnic Study of Atherosclerosis

Background: Cost-effectiveness of testing for coronary artery calcium (CAC) relative to other treatment strategies is not established in Canada.

Objectives: The purpose of this study was to evaluate the cost-effectiveness of using CAC score-guided statin treatment compared with universal statin therapy among intermediate-risk, primary prevention patients eligible for statins.

Methods: A state transition, microsimulation model used data from Canadian sources and the Multi-Ethnic Study of Atherosclerosis to simulate clinical and economic consequences of cardiovascular disease from a Canadian publicly funded health care system perspective. In the CAC score-guided treatment arm, statins were started when CAC ≥1. Outcome of interest was the incremental cost-effectiveness ratio at 5 and 10 years; an incremental cost-effectiveness ratio <$50,000 per quality-adjusted life year (QALY) gained was considered cost-effective. Sensitivity analyses examined uncertainty in model parameters.

Results: Compared with universal statin treatment at 5 and 10 years, CAC score-guided statin treatment was projected to increase mean costs by $326 (95% CI: $325-$326) and $172 (95% CI: $169-$175), increase mean QALYs by 0.01 (95% CI: 0.01-0.01) and 0.02 (95% CI: 0.02-0.02), and cost $54,492 (95% CI: $52,342-$56,816) and $8,118 (95% CI: $7,968-$8,279) per QALY gained, respectively. The model was most sensitive to statin cost, CAC testing cost, adherence to statin monitoring, and disutility associated with daily statin use. At 5 years, CAC score-guided statin treatment was cost-effective when CAC test costs ranged from $80 to $160 in different scenarios.

Conclusions: CAC score-guided statin initiation in comparison to universal statin treatment was borderline cost-neutral at 5 years and cost-effective at 10 years in statin-eligible Canadian patients at intermediate cardiovascular disease risk.