Beyond ten-year risk: a cost-effectiveness analysis of statins for the primary prevention of cardiovascular disease

Background: Cholesterol guidelines typically prioritize primary prevention statin therapy based on 10-year risk of cardiovascular disease. The advent of generic pricing may justify expansion of statin eligibility. Moreover, 10-year risk may not be the optimal approach for statin prioritization. We estimated the cost-effectiveness of expanding preventive statin eligibility and evaluated novel approaches to prioritization from a Scottish health sector perspective. Methods: A computer simulation model predicted long-term health and cost outcomes in Scottish adults aged ≥40 years. Epidemiologic analysis was completed using the Scottish Heart Health Extended Cohort, Scottish Morbidity Records, and National Records of Scotland. A simulation cohort was constructed with data from the Scottish Health Survey 2011 and contemporary population estimates. Treatment and cost inputs were derived from published literature and health service cost data. The main outcome measure was the lifetime incremental cost-effectiveness ratio (ICER), evaluated as cost (GBP 2020) per quality-adjusted life year (QALY) gained. Three approaches to statin prioritization were analyzed: 10-year risk scoring using the ASSIGN score, age-stratified (Age-Strat) risk thresholds to increase treatment rates in younger individuals, and absolute risk reduction (ARR)-guided therapy to increase treatment rates in individuals with elevated cholesterol levels. For each approach, two policies were considered: one which treats the same number of individuals as an ASSIGN score ≥20% (ASSIGN 20, Age-Strat 20, ARR 20) and one which treats the same number as an ASSIGN score ≥10% (ASSIGN 10, Age-Strat 10, ARR 10). Results: Compared to ASSIGN 20, reducing the risk threshold for statin initiation to 10% expanded eligibility from 804,000 (32% of CVD-free adults aged ≥40 years) to 1,445,500 individuals (58%). This policy would be cost-effective (ICER: £12,300/QALY, 95% CI: £7,690/QALY-£26,500/QALY). Incremental to ASSIGN 20, ARR 20 produced around 8,800 QALYs and was cost-effective (£7,050/QALY, 95% CI: £4,560/QALY-£10,700/QALY). Incremental to ASSIGN 10, ARR 10 produced around 7,950 QALYs and was cost-effective (£11,700/QALY, 95% CI: £9,250/QALY-£16,900/QALY). Both age-stratified risk threshold strategies were dominated (i.e., more expensive and less effective than alternative treatment strategies). Conclusions: Generic pricing has rendered preventive statin therapy cost-effective for many adults. Absolute risk reduction-guided therapy is more effective than 10-year risk scoring and is cost-effective