Comparison of Out-of-Hospital Cardiac Arrests and Fatalities in the Metro Detroit Area During the COVID-19 Pandemic With Previous-Year Events

It is difficult to overstate the impact of the coronavirus disease 2019 (COVID-19) pandemic. As of November 30, 2020, there were more than 63 million documented infections and approximately 1.5 million deaths worldwide.1 COVID-19 outbreaks have been especially acute in certain regions in the United States. In Michigan, 360 449 confirmed infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, have occurred since the first documented cases on March 10, 2020.2 Nearly 33% of these cases occurred in the metropolitan Detroit area (Macomb, Oakland, and Wayne counties), an area with a combined population of 3.9 million.2 Reports from Italy,3 France,4 and New York5 have documented marked increases in out-ofhospital cardiac arrests (OHCAs) attended by emergency medical services (EMS) in areas with significant COVID-19 burdens. We examined whether a similar phenomenon occurred in the metropolitan Detroit area during the peak of the outbreak by using data from the Michigan EMS Information System.


Introduction
It is difficult to overstate the impact of the coronavirus disease 2019 (COVID-19) pandemic. As of November 30, 2020, there were more than 63 million documented infections and approximately 1.5 million deaths worldwide. 1 COVID-19 outbreaks have been especially acute in certain regions in the United States. In Michigan, 360 449 confirmed infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, have occurred since the first documented cases on March 10, 2020. 2 Nearly 33% of these cases occurred in the metropolitan Detroit area (Macomb, Oakland, and Wayne counties), an area with a combined population of 3.9 million. 2 Reports from Italy, 3 France, 4 and New York 5 have documented marked increases in out-ofhospital cardiac arrests (OHCAs) attended by emergency medical services (EMS) in areas with significant COVID-19 burdens. We examined whether a similar phenomenon occurred in the metropolitan Detroit area during the peak of the outbreak by using data from the Michigan EMS Information System.

Methods
Nontraumatic OHCA calls in Macomb, Oakland, and Wayne counties between January 1 and May 31 of both 2019 and 2020 were identified from the Michigan EMS Information System. Basic Life Support and Medical First Response records were excluded to eliminate duplicate counting of events.
Weekly per capita OHCA incidence rates (events per 100 000 population) were calculated for each year. We also calculated weekly per capita SARS-CoV-2 incidence rates per 100 000 population for the 3 counties using the official count of confirmed cases from the Michigan Department of Health and Human Services. 2 We used χ 2 tests to compare demographic and clinical characteristics of OHCA events after Michigan's stay-at-home order (March 23 through May 31, 2020) with the same period in 2019. This cross-sectional study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines. Because this study was a public health surveillance activity authorized by a public health authority, it did not require institutional review board approval per 45 CFR 46.102(l) (2). Patient informed consent for this study was waived per the State of Michigan Public Health Code (Michigan Public Health Code Act, PA 368 of 1978 Sec. 1101). Two-sided P < .05 was used to test statistical significance. All analyses were performed using SAS statistical software, version 9.4 (SAS Institute Inc).
The Figure shows the incidence of OHCA events per capita from January through May of 2019 and 2020 along with the incidence of confirmed COVID-19 cases in 2020. Beginning in early March 2020 (week 12), a marked increase in the incidence of OHCAs was observed compared with the previous year. The spike in OHCAs lags slightly behind but closely mirrors the epidemic curve of

Discussion
Southeast Michigan experienced marked increases in both the number of OHCA calls and the prehospital fatality rates for OHCA. In 2020, OHCA disproportionately increased among older individuals, Blacks, and residents of skilled nursing facilities. This study was limited to prehospital records; definitive causes of death are not known and it is not clear from these data whether the increase arose as a direct effect of COVID-19 infection or from indirect effects of the pandemic on utilization of EMS. 6 Further investigation is needed to characterize the phenomena underlying these associations to design interventions to mitigate the impacts of the ongoing COVID-19 pandemic.