Objective: To determine whether patients who sought care at a public hospital emergency department and left without being seen by a physician needed immediate medical attention and whether they obtained care after leaving.

Design: Follow-up study of patients who left without being seen and of patients who waited to be seen by a physician.

Setting: A public hospital's emergency department in Torrance, Calif.

Patients: All patients who registered for care and left without being seen (n = 186) and a 20% random sample of patients who waited until they were seen (n = 211) in a 2-week period during spring 1990.

Main outcome measures: At time of presentation: triage nurse urgency assessment, clinical acuity rating, and self-reported health status. At follow-up: hospitalization rates.

Results: Patients who left reported that they had waited 6.4 hours before leaving; those who stayed reported a 6.2-hour wait before being seen. There were no differences between those who left and those who stayed in chief complaint, triage nurse assessment, acuity ratings, or self-reported health status. Forty-six percent of those who left were judged to need immediate medical attention, and 29% needed care within 24 to 48 hours. Eleven percent of those who left were hospitalized within the next week, and three patients required emergency surgery. Nine percent of those who waited to be seen were hospitalized. Forty-nine percent of patients who left did not see a physician during the 1-week follow-up period.

Conclusion: Overcrowding in this public hospital's emergency department restricts access to needed ambulatory medical care for the poor and uninsured.