Temporal Patterns of Hospital Admissions for Transient Ischemic Attack: A Retrospective Population-based Study in the Emilia-Romagna Region of Italy.

Acute cerebrovascular events are not randomly distributed over time but show specific temporal circadian, weekly, and seasonal patterns of occurrence. However, most studies have concentrated on stroke and little is known about transient ischemic attack (TIA). This study aimed to explore the existence of a temporal pattern of TIAs admitted to the hospital and to verify whether this could be influenced by the presence of the most common risk factors such as hypertension, type 2 diabetes mellitus, and dyslipidemia. The analysis included all hospital admissions (January 1998 – December 2006), recorded in a database of the Emilia Romagna region (RER) of Italy and in particular 43642 patients with the ICD-9-CM codes for TIA (mean ± SD age 76.8 ± 11.5 years, 45.5% males). TIA was most frequent in autumn and winter and less common in spring and summer (p<0.0001), with the highest number of cases in October and the lowest in February. TIA was most frequent on Monday and least on Sunday (p