Over 75 Percent of Long Covid Patients Were Not Hospitalized for Initial Illness, Study Finds

More than three-quarters of Americans diagnosed with long Covid were not sick enough to be hospitalized for their initial infection, a new analysis of tens of thousands of private insurance claims reported on Wednesday.

The researchers analyzed data from the first few months after doctors began using a special diagnostic code for the condition that was created last year. The results paint a sobering picture of long Covid’s serious and ongoing impact on people’s health and the American health care system.

Long Covid, a complex constellation of lingering or new post-infection symptoms that can last for months or longer, has become one of the most daunting legacies of the pandemic. Estimates of how many people may ultimately be affected have ranged from 10 percent to 30 percent of infected adults; a recent report from the U.S. Government Accountability Office said that between 7.7 million and 23 million people in the United States could have developed long Covid. But much remains unclear about the prevalence, causes, treatment and consequences of the condition.

The new study adds to a growing body of evidence that, while patients who have been hospitalized are at greater risk for long Covid, people with mild or moderate initial coronavirus infections — who make up the vast majority of coronavirus patients — can still experience debilitating post-Covid symptoms including breathing problems, extreme fatigue and cognitive and memory issues.