Analysis of the early warning score to detect critical or high-risk patients in the prehospital setting

  • Francisco Martín-RodríguezEmail author
  • Miguel Ángel Castro-Villamor
  • Carlos del Pozo Vegas
  • José Luis Martín-Conty
  • Agustín Mayo-Iscar
  • Juan Francisco Delgado Benito
  • Pablo del Brio Ibañez
  • Pedro Arnillas-Gómez
  • Carlos Escudero-Cuadrillero
  • Raúl López-Izquierdo


The early warning score can help to prevent, recognize and act at the first signs of clinical and physiological deterioration. The objective of this study is to evaluate different scales for use in the prehospital setting and to select the most relevant one by applicability and capacity to predict mortality in the first 48 h. A prospective longitudinal observational study was conducted in patients over 18 years of age who were treated by the advanced life support unit and transferred to the emergency department between April and July 2018. We analyzed demographic variables as well as the physiological parameters and clinical observations necessary to complement the EWS. Subsequently, each patient was followed up, considering their final diagnosis and mortality data. A total of 349 patients were included in our study. Early mortality before the first 48 h affected 27 patients (7.7%). The scale with the best capacity to predict early mortality was the National Early Warning Score 2, with an area under the curve of 0.896 (95% CI 0.82–0.97). The score with the lowest global classification error was 10 points with sensitivity of 81.5% (95% CI 62.7–92.1) and specificity of 88.5% (95% CI 84.5–91.6). The early warning score studied (except modified early warning score) shows no statistically significant differences between them; however, the National Early Warning Score 2 is the most used score internationally, validated at the prehospital scope and with a wide scientific literature that supports its use. The Prehospital Emergency Medical Services should include this scale among their operative elements to complement the structured and objective evaluation of the critical patient.


Prehospital care Early warning score Prognosis Early mortality Clinical research 



This study was funded by Gerencia Regional de Salud de Castilla y León (Grant no. GRS 1678/A/18).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Statement of human and animal rights

“All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.” The study was approved by the Clinical Research Ethics Committee at the Río Hortega University Hospital, and the University Clinic Valladolid (Spain), with registration codes #PI 18-010 and #PI 18-895.

Informed consent

Informed consent was obtained from all individual participants included in the study (in the case that the patient due to its seriousness could not grant the consent, a family member or tutor was spoken to, and in the latter case in the subsequent hospital follow-up, informed consent is made).


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Copyright information

© Società Italiana di Medicina Interna (SIMI) 2019

Authors and Affiliations

  • Francisco Martín-Rodríguez
    • 1
    • 2
    Email author return OK on get
  • Miguel Ángel Castro-Villamor
    • 3
  • Carlos del Pozo Vegas
    • 4
  • José Luis Martín-Conty
    • 5
  • Agustín Mayo-Iscar
    • 6
  • Juan Francisco Delgado Benito
    • 7
  • Pablo del Brio Ibañez
    • 8
  • Pedro Arnillas-Gómez
    • 9
  • Carlos Escudero-Cuadrillero
    • 9
  • Raúl López-Izquierdo
    • 10
  1. 1.Advanced Clinical Simulation Center, Faculty of MedicineValladolid UniversityValladolidSpain
  2. 2.Prehospital Emergency Medical Services, Advanced Medical Life SupportCastilla y LeónSpain
  3. 3.Advanced Clinical Simulation Center, Faculty of MedicineValladolid UniversityValladolidSpain
  4. 4.Emergency DepartmentHospital Clínico Universitario de ValladolidValladolidSpain
  5. 5.Faculty of Occupational Therapy, Speech Therapy and NursingCastilla la Mancha UniversityTalavera de la ReinaSpain
  6. 6.Department of Statistics and Operative Research, Faculty of MedicineValladolid UniversityValladolidSpain
  7. 7.Prehospital Emergency Medical Services, Advanced Medical Life SupportSalamancaSpain
  8. 8.Emergency DepartmentHospital Universitario Rio Hortega de ValladolidValladolidSpain
  9. 9.Prehospital Emergency Medical Services, Advanced Medical Life SupportValladolidSpain
  10. 10.Emergency DepartmentHospital Universitario Rio Hortega de ValladolidValladolidSpain

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