Preventing cardiovascular disease among Canadians: is the treatment of hypertension or dyslipidemia cost-effective?

BACKGROUND AND OBJECTIVES: The direct health care costs associated with treating hypertension and dyslipidemia continue to grow in most western countries, including Canada. Despite the proven effectiveness of hypertension and lipid therapies to prevent cardiovascular disease, the cost-effectiveness of long-term primary prevention, as currently advocated by Canadian treatment guidelines, remains to be determined.
METHODS: Therapeutic efficiency, defined as person-years of treatment per year of life saved (YOLS) and the cost-effectiveness of treatment were estimated for groups of Canadian adults, 40 to 74 years of age. The clinical indications for treatment were based on the Canadian national guidelines in 2005. Analyses focused on those without cardiovascular disease or diabetes using risk factor data from the Canadian heart health surveys and drug data from a national study, the MyHealthCheckUp survey. The expected impact of therapy was based on published results: statins would result in a 40% drop in low-density lipoprotein cholesterol and a 6% increase in high-density lipoprotein cholesterol, while hypertension therapy would result in a 6.4% drop in systolic and a 5.6% drop in diastolic blood pressure.
RESULTS: The estimated daily cost of statins was $1.98 versus $1.72 for antihypertensives. Overall, 2.33 million patients would be treated with lipid therapy and 2.34 million with antihypertensives. The average cost-effectiveness of lipid therapy would be approximately $16,700 per YOLS while hypertension therapy would be approximately $37,100 per YOLS. Lifelong lipid and hypertension therapy would be associated with 1.1 million and 472,000 life years saved at a national cost of $18.3 billion and $17.5 billion, respectively. However, hypertension treatment for some groups of Canadians appeared relatively expensive (more than $50,000 per YOLS) including men or women younger than 50 years of age. Despite attractive cost-effectiveness ratios, treatment appeared relatively inefficient (person-years of treatment per YOLS more than 100 years) for statin therapy among women younger than 50 years of age, and hypertension treatment for women younger than 60 years of age and men younger than 50 years of age.
CONCLUSIONS: Given Canadian guidelines, the treatment of dyslipidemia or hypertension in primary prevention appears economically attractive overall. However, for some groups of individuals, the forecasted future benefits appear to be relatively small given the many years of treatment that are required.