COVID-19 Hospital Mortality Rates in 2020 Remained Stable Over 6 Months After Initial Decline

Rates of in-hospital mortality among COVID-19 patients fell 38% between March 2020 and May 2020, but there was little further decline through November 2020, according to a study published in JAMA Network Open. The study is most comprehensive analysis to date of changes in hospital mortality throughout the pandemic, reviewing data on more than 20,000 patients admitted to hospitals for COVID-19 over 9 months, according to the Institute for Health Metrics and Evaluation at the University of Washington.

“Understanding why mortality rates changed is important for clinicians working to improve outcomes for patients hospitalized with COVID-19,” said Gregory Roth, MD, MPH, the study's lead author and an associate professor of medicine at the Institute for Health, in a press release. “Further analysis is needed to understand the drivers more precisely, but it speaks to a crucial need for information sharing and identifying hospital best practices that can prevent mortality rates from increasing again, particularly during possible future waves of COVID-19 infections.”

The investigators analyzed records from the American Heart Association's COVID-19 Cardiovascular Disease Registry, which include 107 hospitals in 31 states. They found mortality rates for patients in the registry were 19.1% in March and April, 11.9% in May and June, 11% in July and August, and 10.8% from September through November. Nearly one-third of patients were admitted to intensive care, and 1 in 5 were placed on mechanical ventilation.

The study was intended to uncover the most likely cause of the observed trend by controlling for patient age, sex, comorbidities, and severity of disease when the patient was admitted. However, they found that none of these factors fully explained the decline in mortality rates. They also found only small changes in patient characteristics during the observed period, including a small decrease in age, an increase in proportion of women, and an increase in BMI.

“Our findings suggest that the decline in mortality could be due to overloaded hospitals and changes in treatment,” Roth said in the release. “With more variants circulating, and many countries still struggling with overloaded hospitals and scarce resources, the more we know about this the better.”

REFERENCE

Researchers publish most comprehensive study yet of COVID-19 hospital mortality [news release]. EurekAlert; May 3, 2021. Accessed May 4, 2021. https://eurekalert.org/pub_releases/2021-05/ifhm-rpm050321.php