Patient Characteristics Associated with Nocturnal Emergency Department Visits for Asthma

STUDY OBJECTIVES: To identify patient characteristics associated with nocturnal emergency department (ED) visits for asthma. METHODS: Asthmatic patients 18 to 55 years of age who visited Ontario EDs between April 1, 2003 and March 31, 2004, were identified through an administrative clinical database. Patients' time of ED presentation was analyzed for circadian pattern using histogram and polynomial regression. Risk of nocturnal visit …