The Contribution of Covid-19 to Ardsrelated Mortality in the United States

ABSTRACT

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is the major manifestation of severe respiratory failure due to COVID-19 and is present in the majority of COVID-19-related deaths in autopsy studies. Thus, the COVID-19 pandemic is expected to change substantially the epidemiology of ARDS. However, the contribution of COVID-19 to ARDS-related mortality in the United States (US) is unknown. METHOD(S) We used the CDC WONDER Multiple Cause of Death Data set to identify decedents with a diagnosis of ARDS during 2015-2019, and with a diagnosis of COVID-19, ARDS, or both during 2020. ARDS and COVID-19 were identified by ICD-10 codes J80 and J071, respectively. Negative binomial regression was used on the 2015-2019 data to forecast the number of ARDS-related deaths in 2020. We then compared the number of observed vs expected ARDS-related deaths in 2020. In addition, we examined the reporting of a diagnosis of COVID-19 among decedents with ARDS and the proportion of a diagnosis of ARDS among those with COVID-19. The latter analyses were then repeated across the Department of Health and Human Services (HHS) Regions. RESULT(S) In 2020, there were 51,184 ARDS-related deaths, 384,536 COVID-19-related deaths, and 41,606 deaths with both in the US. The predicted number of ARDSrelated deaths for 2020 was 10,851 (95% CI 9,714-12,120). The ratio of the observed vs expected ARDS-related deaths was 4.71 (95% CI 4.62-4.82). A diagnosis of ARDS was reported in 10.8% of all COVID-19 related deaths, ranging from 8.2% (HHS Regions 1 & 7) to 16.1% (HHS Region 2). COVID-19-related deaths have contributed to 81.3% of observed ARDS-related deaths in 2020, varying from 68.8% (HHS Region 10) to 91.5% (HHS Region 2). CONCLUSION(S) The number of ARDS-related deaths in the US increased nearly 5-fold in 2020, due to the contribution of ARDS among COVID-19 decedents. However, ARDS was reported only in about 1 in 10 COVID-19-related deaths, with the frequency of ARDS diagnosis varying nearly 2-fold across HHS Regions. Our findings suggest that the major rise in ARDS-related deaths in the US in 2020 is nevertheless an underestimate of the actual toll of ARDS-related mortality that year, likely reflecting substantial underdocumentation and possibly underrecognition of ARDS among COVID-19 decedents.