Aspirin use is low among United States outpatients with coronary artery disease

The goal of the present study was to assess national trends and patterns of aspirin use among outpatients with coronary artery disease. Although there is strong evidence that the use of aspirin reduces the risk of death and recurrent events in patients with coronary artery disease, current national patterns of aspirin use are unknown.

We used data from the 1980 to 1996 National Ambulatory Medical Care Surveys. These surveys provide a nationally representative sample of physician activities during patient visits to physician offices. We evaluated the report of aspirin as a new or continuing medication in 10 942 visits to cardiologists and primary care physicians by patients with coronary artery disease. We evaluated trends in the use of aspirin for 1980 to 1996 and used logistic regression to identify independent predictors of aspirin use for 1993 to 1996. Aspirin use in outpatient visits by persons with coronary artery disease without reported contraindications increased from 5.0% in 1980 to 26.2% in 1996. Large increases occurred in the early 1990s. Independent predictors of aspirin use in 1993 to 1996 were male patient gender (29% versus 21% for females), patient age of <80 years (28% versus 17% for age of >/=80 years), and presence of hyperlipidemia (45% versus 24% for patients without hyperlipidemia; all comparisons P<0. 001). Cardiologists (37%) were more likely to report aspirin use than were internists (20%), family physicians (18%), or general practitioners (11%; P<0.001). These effects persisted after we controlled for potential confounders with the use of logistic regression.

Although aspirin use in patients with coronary artery disease has increased dramatically, it remains suboptimum. Low rates of aspirin use and variations in use suggest a need to better translate clinical recommendations into practice.