Factors associated with the decision to hospitalize patients after transient ischemic attack before publication of prediction rules

Background and Purpose - One important criterion for hospitalizing patients after transient ischemic attack (TIA) is the short-term risk of stroke. Before publication of prediction rules for stroke after TIA, physician judgment was required to make a decision about hospitalization. We sought to identify factors associated with the decision to admit patients with TIA from the emergency department (ED) and to see whether those at highest risk of stroke were selected for admission. Methods - All patients diagnosed with TIA in the ED of 16 hospitals in the Kaiser-Permanente Medical Care Plan over a 1-year period before publication of prediction rules were included (n=1707). Risk of subsequent stroke was stratified according to a validated prediction rule (ABCD(2) score), and the decision to admit was correlated with these risk scores. Factors associated with admission in univariate analysis were included in a logistic regression model. Results - Overall, 243 patients with TIA (14%) were admitted. Admission weakly correlated with the ABCD(2) score ( rank biserial R-2=0.036; 10.0% at low 2-day risk of stroke admitted versus 20.3% at high risk). Seven variables were independently associated with a decision to admit after TIA: prior TIA, speech impairment, weakness, gait disturbance, history of atrial fibrillation, symptoms on arrival to ED, and use of ticlopidine. Conclusions - In this cohort of patients with TIA, the decision to admit was weakly correlated with risk of subsequent stroke as measured by the ABCD(2) score, and several risk factors for stroke were not important for the decision to admit. Before publication of prediction rules for stroke after TIA, physicians were not identifying the majority of patients at highest risk of stroke for admission.