Aspirin Use in Newly Diagnosed Diabetes Patients Remains Controversial

Prior research has analyzed the cost-effectiveness of aspirin for warding off CVD among the overall population. "These studies concluded that aspirin use was cost-saving or cost-effective," write Rui Li, PhD, from the Division of Diabetes Translation, Centers for Disease Control and Prevention, Atlanta, Georgia, and colleagues. "It is not known if the same conclusion holds for persons with diabetes." 

The current study was designed to document the cost-effectiveness during a lifetime of aspirin therapy (80 mg daily) in those aged 40 years and older with a recent Type 2 diabetes diagnosis. Researchers used a validated cost-effectiveness model to simulate Type 2 diabetes' progression and its complications: nephropathy, neuropathy, retinopathy, coronary heart disease, and stroke. The model projects the patients' costs for standard care and for standard care plus aspirin from diagnosis until death, or until the age of 94 years.

According to the model, those with Type 2 diabetes who used aspirin live longer for a relatively lower expense.

• Patients undergoing aspirin therapy achieved 0.31 life years (LYs) or 0.19 quality-adjusted LYs (QALYs).
• The gain came at an incremental cost of $1,700.
• Aspirin use had an incremental cost-effectiveness ratio of $5,428 per LY gained, or $8,801 per QALY gained.
• For women, the incremental cost-effectiveness ratio was $13,833/QALY compared with $5,752 in men, or $22,259/QALY vs $3633, respectively, depending on study parameters.

Patients receiving aspirin lowered their cumulative incidence of coronary heart disease events by 3.91%, reducing the rate of deaths from coronary heart disease by 4.65%. However, subjects' cumulative incidence of stroke increased by 0.51%, elevating the stroke mortality rate by 0.28%.

Although the investigators concluded that ongoing aspirin therapy is cost-effective, they did not find it to be cost-saving.

"First, aspirin's effect on gastrointestinal bleeding increased the total medical costs of the group taking aspirin. Second, the aspirin treatment group lived longer and required additional resources for treatment of diabetes and hypertension," the authors write. "Third, aspirin treatment affects diabetes macrovascular complications but not microvascular ones."

The use of aspirin to ward off CVD is still controversial and merits further study, according to the investigators. In 2 large, randomized trials recently published in the Journal of the American Medical Association and the British Medical Journal, respectively -- namely, the Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes trial and the Prevention of Progression of Arterial Disease and Diabetes trial -- low-dose aspirin use did not prevent cardiovascular events.

"Future clinical trials are needed to better understand if aspirin is efficacious for people with Type 2 diabetes; additional cost-effectiveness analyses, accounting for these studies, might be needed," the authors write.

Diabetes Care. Published online March 23, 2010.