Chronic migraineurs: an important subgroup of patients who visit emergency departments frequently.

Study Objective: We examine whether patients with frequent migraines represent a distinct subgroup of patients who visit emergency departments (EDs) frequently.

Methods: This population-based, cross-sectional study used fiscal year 1998 physician billing data from Ontario, Canada. "Frequent ED visitors" were individuals with at least 12 ED visits per year and were classified as either "frequent migraineurs" (> or =50% of ED visits for migraine) and "other frequent ED visitors.

Frequent users of emergency departments. Do they also use family physicians' services?

Objective: To determine whether frequent users of emergency department (ED) services use more or fewer primary care services than other ED patients.

Design: Population-based, observational, cross-sectional study.

Setting: Province of Ontario in 1997-1998.