Nearly HALF of all Americans hospitalized for COVID-19 may have mild cases or be asymptomatic, study suggests
- A new study looked at COVID-19 patients admitted to VA hospital across the country from March 2020 to June 2021.
- Patients were considered moderately or severely ill if their oxygen saturation fell below 94%
- Until early January 2021, 36% of patients had mild or asymptomatic cases
- This figure rose to 48% in June 2021, after vaccines became widespread and the Delta variant became dominant
- Researchers say this means about half of patients are mildly ill or hospitalized for some other reason and learned they had Covid after hospitalization
Nearly half of Americans hospitalized because of COVID-19 may have mild cases or be asymptomatic, a new study suggests.
Researchers looked at patients who had been hospitalized at medical gallops within the Department of Veterans Affairs (VA) health care system since the start of the pandemic.
They found that before COVID-19 vaccines were widely available and the Delta variant was the dominant strain, 64 percent of hospitalized patients were considered moderately or severely ill.
However, after the vaccine rollout got underway and Delta was dominant, the proportion of critically ill patients dropped to 52 percent.
The team, from VA Boston Healthcare System and Tufts University, in Medford Massachusetts, say this means just under half of patients currently in the hospital have mild cases or have been hospitalized for an entirely different reason and it was subsequently discovered that she had COVID-19.
A new study found that until early January 2021, 64% of hospitalized patients were moderately ill, their oxygen saturation level (SpO2) dropped below 94%. This figure dropped to 52% in June 2021, after vaccines became widespread and the Delta variant became dominant
Researchers say this means about half of 96,000 patients hospitalized in the US are mildly ill or admitted for some other reason and learned they had Covid after hospitalization
Public health experts have previously stated that hospitalizations are the measure that best defines how well the US is doing against COVID-19.
According to the Department of Health and Human Services, 96,870 virus patients occupy hospital beds across the country, the highest figure since February 2021.
But researchers say the figure doesn’t reveal how many are critically ill in hospital and how many happened to discover they had COVID-19 while in the hospital.
For the research, published Monday on pre-print site Research Square, the team looked at patients admitted to VA hospitals between March 1, 2020 and June 30, 2021.
All patients were required to have a lab test confirming COVID-19 infection 14 days prior to or during hospitalization.
Researchers defined moderate to severe Covid by looking at oxygen saturation (SpO2) levels.
Normal oxygen levels are about 95 percent, so patients were considered critically ill when levels fell below 94 percent a day between a day before and two weeks after a positive test.
Oxygen levels that were higher were considered to have mild or asymptomatic disease.
Over the study period, more than 47,000 Covid patients were examined in more than 100 VA hospitals in the US
The results showed that from March 2020 to early January 2021 — before the COVID-19 vaccines were available to most Americans and before the Delta variant became dominant — 36 percent of patients had mild or asymptomatic cases.
However, this share grew after the injection rollout expanded and the Delta strain caused the most infections.
Between mid-January 2021 and June 2021, 48 percent of patients admitted to hospitals were mildly ill or had visited hospitals for some other reason and only found out they were infected after being tested.
This means that potentially half of all hospitalized patients are not seriously ill.
The researchers say their study has limitations, including that VA patients are not representative of the general population because most patients are male and no children were involved in the study.
But they added that the data likely shows that vaccines are effective at preventing serious illness, that the Delta variant is more transmissible but not more dangerous, and that hospitalizations can be misleading.
“The proportion of hospital admissions attributable to severe COVID-19 has changed with vaccine availability, so an increasing number of mild and asymptomatic cases are being included in hospital admissions statistics,” the authors wrote.
The addition of simple measures of disease severity to the case definition of a SARS-CoV-2 hospitalization is an uncomplicated and objective change that should enhance the value of the SARS-CoV-2 disease burden tracking metric. improve.’