Chapel Hill, NC - A new analysis for aspirin in the primary prevention of CVD finds that the treatment is cost-effective for women over the age of 65 [1].

"For lower-risk women 55 years and younger, without additional stroke risk factors, aspirin does not appear to be beneficial and cannot be recommended based on the available evidence," said lead author Dr Michael Pignone (University of North Carolina, Chapel Hill) and colleagues, who published the findings in the February 12, 2007 issue of the Archives of Internal Medicine.

Developing effective treatment strategies for women is essential for reducing the burden for CVD, but the effect of therapies in women have been understudied. The effectiveness of aspirin for primary prevention of CVD events in women is controversial, Pignone says.

Studies have been mixed, with some showing benefit in stroke prevention, but not MI.

"Given the data, a cost-utility analysis might be helpful in deciding which women have sufficient CVD risk to warrant risk-reduction therapy with aspirin," Pignone says.

"Cost-effectiveness analysis compares different potential uses of dollars and quality-of-life adjustments. The best thing is that these global measures give the benefits and downsides and give a complete picture of the net effects of intervention," Pignone said in an interview with heartwire.

The study examined the effectiveness of low-dose aspirin compared with no aspirin in cohorts of moderate-risk 65-year-old women (systolic BP 120 mm Hg; cholesterol 184 mg/dL; HDL-C 40 mg/dL; and no smoking, diabetes, or atrial fibrillation). This subject would have an estimated 10-year-total CHD risk of 7.5% and a 10-year stroke risk of 2.8%.

Aspirin produced 10 963 QALYs for moderate-risk women with a mean cost of $3145. No treatment produced QALYs of 10 957 and mean costs of $3069. The cost per additional QALY gained with aspirin was $13 300.

When researchers looked at how other variables affected the model, they found that starting aspirin at age 55 was less effective and more costly than no treatment at all.

For women 75 years and older, it improved to a cost of $2532.

In 65-year-old women with increased stroke risk due to elevated blood pressure, aspirin was more effective and less costly than no treatment.

On the downside, researchers found that risk of gastrointestinal bleeding had an "important effect" and increased the cost significantly.

According to Dr Sid Smith (University of North Carolina, Chapel Hill), the study findings are "what we would expect to find but still are important because cost constraints are taking center stage."

He told heartwire that other cost models might want to look at studies that compare higher aspirin doses.