Background: Inpatient admission rates and the resources required upon admission to the hospital were studied as a function of the type of referral to the emergency department (ED) of a university hospital. Methods: We retrospectively analyzed data concerning patients who were treated in the ED of the University of Leipzig Medical Center in 2019. The following data were recorded: process data, type of referral, hospital admission vs. discharge from the ED, and leading symptom according to classification as ???trauma??? or ???non-trauma.??? For all admitted patients, the Patient Clinical Complexity Level (PCCL), length of hospital stay, and intensive care (yes/no) with or without ventilation were recorded. Results: Data on 34 178 patients (50.9 ?? 22.2 years, 53.8% male) were analyzed; 28.8% of patients were referred because of ???trauma,??? and the remaining 71.2% for ???non trauma???. The most common sources of referral were the rescue and emergency medical services (47.7%) and the patients themselves (self-referrals, 44.7%); 7.6% of the patients were referred by a resident doctor or general practitioner (physician). 62.6% were discharged from the ED after diagnosis and treatment, while 37.4% were admitted to the hospital. In comparison with self-referred patients as a baseline, the likelihood of inpatient admission was higher when the patient was referred by a physician (adjusted odds ratio [OR] 2.2), by the emergency rescue service without an emer gency physician (OR 3.4), by an emergency physician (OR 9.3), or by the helicopter rescue service (OR 44.1). 49.1% of patients with trauma referred themselves to the ER, and 36% were referred by the emergency rescue service. Older and male patients were more likely to be admitted to the hospital, especially for non-trauma. 30.4% of the admitted patients required intensive care, and 35.5% of the patients in intensive care required ventilation. Conclusion: Whether a patient is admitted to the hospital depends on the source of the referral and the leading symptom on arrival in the ED. One in every six self-referred patients is admitted to the hospital, particularly when the reason for presenting to the ER is non-traumatic and some of them go on to receive intensive care. The high percentage (around 95%) of self-referred trauma patients that are discharged from the ED presumably indicates that they were referred mainly for the exclusion of dangerous conditions, and/or that appropriate care options are lacking in the community setting.
