This study is to evaluate a tool capable of improved risk prediction regarding the 30-day mortality. The primary objective of this study is hospitalization, ICU-admission, morbidity and mortality in correlation with external validation of International Early Warning Score (IEWS) and decision-making processes regarding diagnosis, treatment and disposition in the ED.

Most emergency departments (EDs) perform an initial risk stratification of patients, called triage. Triage defines the process of systematically grouping patients according to their treatment priority on the base of algorithms in an environment with scarce health care resources. To this date no gold standard in triage risk stratification has been established. Most of the existing triage systems rely on the measurement of vital signs and a list of chief complaints. All of these systems have their shortcomings, especially in nonspecific ED presentations and in older patients. The primary objective of this study is hospitalization, ICU-admission, morbidity and mortality in correlation with external validation of International Early Warning Score (IEWS) and decision-making processes regarding diagnosis, treatment and disposition in the ED.

In this national single centre, prospective, consecutive, observational all-comers study patients entering the ED undergo triage and will be verbally informed about the study. First, each patient's vital signs (respiratory rate, oxygen saturation, heart rate, blood pressure, temperature) are measured and pain is rated on a scale of 0 to 10. In addition, the patient's level of consciousness is assessed using the AVPUC scale (alert, new confusion, verbal, pain, unresponsive, new confusion). Patients are asked to rate their own mobility between stable walking without aids or limited mobility with aids (walking aid, wheelchair, lying down). In addition, the patient's mobility is observed by the triage staff. The probability that the patient will be admitted as an inpatient is then assessed. A Clinical Frailty Scale (CFS) is also completed for patients over 65. After triage, patients are transferred to the treatment unit. Patients in need of immediate therapy, such as analgesia, will receive therapy before start of the interview. Patients will then be approached by a member of the study personnel and will be asked "which symptoms are you experiencing at the moment?". The question will be repeated 3 times, Answers will be recorded by ticking boxes in the CRF for a predefined list of 37 symptoms. Then, patients will be asked "which of the symptoms you reported is most important to you?". Patients are asked for their opinion on whether they should be discharged home after emergency treatment or whether they should stay in the hospital. Patients over the age of 65 are asked the following: "generally asked: what matters most to you at the moment?" and "why is that important for you?".

Then, the attending senior physicians are asked how injured/ill they rate the patients on a scale from 0 (not ill/injured) to 10 (very ill/injured). The senior physicians are asked questions about decision-making in the emergency department. With regard to diagnostics, they are asked what type of diagnostic decision is involved (simple or complex decision), whether there was time pressure when making the diagnostic decision and which factors formed the basis for their diagnostic decision (list of 14 factors, numbered according to importance if applicable). Regarding therapy, respondents were also asked what type of therapeutic decision was involved (simple or complex decision), whether there was time pressure in making the therapeutic decision, and which factors formed the basis for their therapeutic decision (list of 14 factors, numbered according to importance if applicable). Then the disposition of the patient (ambulatory or hospitalized) is defined. For ambulant patients, senior physicians are asked which factors formed the basis for their ambulant disposition (list of 9 factors, numbered according to importance if applicable). For hospitalized patients, the senior physicians are asked which factors were the basis for their inpatient disposition (list of 17 factors, numbered according to importance if applicable). Finally, the attending physicians are asked who made the disposition decision.

Follow-up to assess 30-day and 1-year mortality rate and date of death will start one year after the end of the inclusion period.

Inclusion Criteria:

• Patients presenting to the ED of the University Hospital Basel over a timecourse of 9 weeks in 2022, 2024, 2026

Exclusion Criteria:

• Obstetric, ophthalmologic, and paediatric patients will not be included
• unwillingness to participate
• insufficient ability to communicate with the study personnel.

The study population will consist of all patients presenting to the ED of the University Hospital Basel and awaiting triage.