# A Comparison of the Clinical Characteristics of Short-, Mid-, and Long-Term Mortality in Patients Attended by the Emergency Medical Services: An Observational Study

## TL;DR

This study compares the clinical features of patients who die within 30 days, 180 days, or 365 days after being treated by emergency medical services.

## Contribution

The study introduces and validates distinct predictive models for short-, mid-, and long-term mortality in EMS-treated patients.

## Key findings

- 30-day mortality had the highest predictive accuracy (AUC = 0.930), followed by 180-day (AUC = 0.852) and 365-day (AUC = 0.806) mortality.
- Noncumulative mortality rates were 10.8% at 30 days, 6.6% at 180 days, and 3.5% at 365 days.
- The study identifies prehospital predictors useful for predicting mortality across different time windows.

## Abstract

Aim: The development of predictive models for patients treated by emergency medical services (EMS) is on the rise in the emergency field. However, how these models evolve over time has not been studied. The objective of the present work is to compare the characteristics of patients who present mortality in the short, medium and long term, and to derive and validate a predictive model for each mortality time. Methods: A prospective multicenter study was conducted, which included adult patients with unselected acute illness who were treated by EMS. The primary outcome was noncumulative mortality from all causes by time windows including 30-day mortality, 31- to 180-day mortality, and 181- to 365-day mortality. Prehospital predictors included demographic variables, standard vital signs, prehospital laboratory tests, and comorbidities. Results: A total of 4830 patients were enrolled. The noncumulative mortalities at 30, 180, and 365 days were 10.8%, 6.6%, and 3.5%, respectively. The best predictive value was shown for 30-day mortality (AUC = 0.930; 95% CI: 0.919–0.940), followed by 180-day (AUC = 0.852; 95% CI: 0.832–0.871) and 365-day (AUC = 0.806; 95% CI: 0.778–0.833) mortality. Discussion: Rapid characterization of patients at risk of short-, medium-, or long-term mortality could help EMS to improve the treatment of patients suffering from acute illnesses.