Assessment of patient mobility improves the risk stratification of triage with the Emergency Severity Index: a prospective cohort study

Background and importance Formal triage may assign a low acuity to patients at high risk of deterioration and mortality. A patient's mobility can be easily assessed at triage. Objective To investigate if a simple assessment of mobility at triage can improve the Emergency Severity Index's (ESI) prediction of adverse outcomes. Design, setting and participants Prospective observational study of all patients attending the emergency department (ED) of a single academic hospital in Switzerland over a period of 3 weeks. Outcome measures and analysis Triage clinicians classified participants as having normal or impaired mobility at triage. Impaired mobility was defined as the lack of a stable independent gait, regardless of its cause or duration (e.g. any patient who needed help to walk). The primary outcome was 30-day mortality. We performed a survival analysis stratified by mobility and ESI level. We compared the performance of regression models including the ESI alone or in combination with mobility as predictors of mortality using the Bayesian information criterion (BIC). Main results 2523 patients were included in the study and 880 (34.9%) had impaired mobility. Patients with impaired mobility had a lower median 30-day survival in ESI levels 1-3. Survival of patients with normal mobility was similar regardless of their ESI level. Conclusion The assessment of mobility at triage improves the ESI algorithm's risk stratification.