Overall use of blood-thinning agents not improving despite more options

Since 1999, stroke survivors have been advised to use aspirin, prescription antiplatelet agents, or prescription anticoagulants to help avoid another stroke. Many large surveys of the U.S. population have reported the use of aspirin for secondary prevention, but commonly combine people with stroke and coronary artery disease, and only rarely report the use of antithrombotic agents other than aspirin.

In an article published in the January 2010 issue of the American Journal of Preventive Medicine, researchers analyze survey data over a 7-year period to determine whether true usage of all preventive therapies, including aspirin, is increasing.

The annual Medical Expenditure Panel Survey (MEPS) contains data on use of both aspirin and prescription medications. Each year, a MEPS panel is drawn from respondents from the previous year's National Health Interview Survey, a representative sample of the U.S. civilian non-institutionalized population with oversampling of minority populations and households with low family income.

In the seven annual MEPS data sets from 2000�, there were 4168 people who reported a cerebrovascular event. Pooling results across the 7 years, 57% were taking aspirin, 66% were using any antiplatelet agent, and 75% were using any antithrombotic agent. After excluding people who said that they were not taking aspirin because it was unsafe, 81% were using any antithrombotic agent.

Lead author Eric M. Cheng, MD, MS, and co-authors state, "Even though use of prescription antiplatelet medications is rising, aspirin remains the predominant antithrombotic agent used for secondary stroke prevention. There were no improvements in overall use of antithrombotic agents over the 7-year period. Use of aspirin, prescription antiplatelet agents, and use of any antiplatelet agent increased over the study period, but after dropping the first 2 years, no temporal trend was detected, indicating that temporal changes in usage of these agents had plateaued."

The authors also found that older non-Hispanic men were more likely to be taking antithrombotic agents. They conclude "Although the level of use of antithrombotic agents appears high, further research should investigate whether the remaining 20% truly have indications for antithrombotic therapy that outweigh any contraindications, and, if so, why they are not taking these medications, particularly among younger, female, and Hispanic patients.