At what coronary risk level is it cost-effective to initiate cholesterol lowering drug treatment in primary prevention?

Background The entire risk factor profile should be taken into account when considering initiating cholesterol lowering drug treatment. Recent treatme nt guidelines are therefore based on the absolute risk of coronary heart di sease. We estimated at what coronary risk it is cost-effective to initiate cholesterol lowering drug treatment in primary prevention for men and women of different ages in Sweden. Methods The cost-effectiveness was estimated as the incremental cost per qu ality-adjusted life-year (QALY) gained of cholesterol lowering drug treatme nt. Treatment was assumed to lower the risk of coronary heart disease by 31 %. The analysis was carried out from a societal perspective including both direct and indirect costs of the intervention and morbidity, and the full f uture costs of decreased mortality. The coronary risk, in a Markov model of coronary heart disease, was raised until the cost per QALY gained correspo nded to a specific threshold value per QALY gained. Three different thresho ld values were used: $40 000, $60 000 and $100 000 per QALY gained. Results The risk cut-off value for when treatment is cost-effective varied with age and gender. If society is willing to pay $60 000 to gain a QALY it was cost-effective to initiate treatment if the 5-year-risk of coronary he art disease exceeded 2.4% for 35-year-old men, 4.6% for 50-year-old men, an d 10.4% for 70-year-old men. The corresponding risk cut-off values for wome n were 2.0%, 3.5% and 9.1%. Conclusions The results can serve as a basis for treatment guidelines based on cost-effectiveness. (C) 2001 The European Society of Cardiology.