OBJECTIVES: POLARIS is a 26-week, double-blind, randomised study comparing the efficacy of rosuvastatin (RSV) 40 mg with atorvastatin (ATV) 80 mg in high-risk patients (known CHD or CHD-risk equivalent, as defined by NCEP ATP III) with hypercholesterolaemia. Using a secondary prevention model, results from POLARIS were used to estimate longer-term costs and benefits. METHODS: Efficacy data from POLARIS (TC, HDL-C, TG) were used as input to the model. Markov models were run in 4-year cycles over 20 years, from age 55 to 76 years for men and women separately. Secondary CHD risk was based on Framingham data (d'Agostino et al. AHJ 2000) but calibrated to British Regional Heart Study (Brindle et al. BMJ 2003). Estimates for life expectancy, health-care costs and quality-adjusted life years (QALYs) were assigned to patients as they transitioned through the model. RESULTS: RSV 40 mg improved levels of TC and HDL-C more than ATV 80 mg (–41% vs –39%; + 11.0 vs + 6.2%, respectively).The model predicts that more secondary CHD events and deaths are avoided with RSV 40mg compared with ATV 80 mg in both high-risk men and women; hence, more life-years and QALYs are generated and event costs are lower. More patients survive on treatment and therefore total costs with RSV 40 mg are slightly higher. Cost per life year gained (men: £ 1113, women: £ 1065) and QALY gained (men: £ 2091, women: £ 3079) are favourable for RSV 40 mg. CONCLUSIONS: RSV 40 mg is likely to be more effective both clinically and economically than ATV 80 mg for the secondary prevention of CHD.