COVID-19 Preliminary Case Series: Characteristics of EMS Encounters with Linked Hospital Diagnoses

Few studies have examined the prehospital presentation, assessment, or treatment of patients diagnosed with coronavirus disease 2019 (COVID-19). The objective of this preliminary report is to describe prehospital encounters for patients with a COVID-19 hospital diagnosis and/or COVID-19 EMS suspicion versus those with neither a hospital diagnosis nor EMS suspicion of the disease.

This case series evaluated electronic patient care records from EMS agencies participating in a large national bi-directional data exchange. All records for 9-1-1 responses between March 1 and April 19, 2020, resulting in transport to a hospital, with at least one ICD-10 outcome returned via the data exchange were included. Hospital ICD-10 codes used to determine COVID-19 diagnoses included B97.2, B97.21, B97.29, B34.2, and U07.1. COVID-19 EMS suspicion was defined as a documented EMS primary or secondary impression of COVID-19, or indication of COVID-19 suspicion in the prehospital free-text narrative. Comparisons were stratified by COVID-19 hospital diagnosis and COVID-19 EMS suspicion. Descriptive and comparative statistics are presented.

There were 84,540 EMS patient records with linked hospital ICD-10 codes included. Of those, 814 (1%) patients had a COVID-19 hospital diagnosis. Overall, COVID-19 EMS suspicion was documented for 3,204 (4%) patients. A COVID-19 EMS suspicion was documented for 636 (78%) of hospital diagnosed COVID-19 patients. Those with COVID-19 hospital diagnoses were more likely to present with tachycardia, tachypnea, hypoxia, and fever during the EMS encounter. EMS responses for patients diagnosed with COVID-19 were also more likely to originate from a skilled nursing/assisted living facility. EMS PPE (eye protection, mask, or gown) use was more frequently documented on records of patients who had hospital diagnosed COVID-19.

In this large sample of prehospital encounters, EMS COVID-19 suspicion demonstrated sensitivity of 78% and positive predictive value of 20% compared with hospital ICD-10 codes. These data indicate that EMS suspicion alone is insufficient to determine appropriate utilization of PPE.