['The objective of this study was to determine factors that impact emergency department (ED) utilization among the most frequent ED users.', 'This prospective observational study consisting of questionnaires was conducted in an urban ED with an annual census of 95000 patients. A convenience sample of the top 1% of adult frequent users (≥9 ED visits in the previous 12 months) was enrolled from February 2009 to March 2010. Patients were excluded because of intoxication, altered mental status, or acute psychosis.', 'A total of 115 patients were enrolled, with an average age of 44 years and median number of 22 ±13 ED visits in the preceding 12 months. Seventy-eight percent of frequent users reported adequate health insurance coverage, and 75% reported one or more chronic medical conditions. Despite the high rates of insured patients, 75% identified the ED as their primary health care site. Half of the cohort had 2 or more hospital admissions over the past 12 months, of which 24% were patients with end-stage renal disease.'] Do the most frequent ED patients carry insurance and a significant burden of disease?