Use of specialized coagulation testing in the evaluation of patients with acute ischemic stroke

Objective: To investigate the use and appropriateness of specialized coagul ation tests in the evaluation of patients with acute ischemic stroke and id entify factors that influence test ordering. Background: Coagulation abnorm alities are a rare but recognized cause of ischemic stroke. Methods: Patien t demographics, stroke risk factors, history of venous thrombosis or miscar riage, family history of stroke, and the results of specialized tests for c oagulation disorders were recorded for a consecutive series of ischemic str oke patients over age 18 admitted to an academic medical center over 3 year s (n = 674). Factors associated with testing were identified with univariat e analyses in a random sample of two-thirds of the patients (n = 450). Mult ivariate logistic regression modeling was then used to identify variables i ndependently associated with testing and then validated in the remaining pa tients (n = 224). Results: Of the 31% of patients (n = 208) tested for coag ulopathies, 29% (n = 60) were tested when the result was unlikely to influe nce therapeutic decisions. Historical factors associated with an increased incidence of a coagulopathy, such as history of venous thrombosis or miscar riage, were not commonly documented. The absence of small-artery atheroscle rosis (OR 0.36, 95% CI 0.17 to 0.76) and younger age (OR 0.89 per year, 95% CI 0.87 to 0.92) were independently related to the frequency of specialize d coagulation testing. Conclusions: One-third of specialized coagulation te sts were ordered when the test results were unlikely to affect therapeutic decisions. Age was the only clinical factor increasing the likelihood of a coagulopathy that appeared to influence ordering of specialized coagulation tests.