New research out Monday may provide more insight into how many Americans were sickened by covid-19 during the earliest days of the pandemic, when access to testing was extremely limited. It estimated that at least 2 million people called out from work due to illness in mid-April—around double the number of people who stayed home sick during the same period last year.
The authors of the study, published in JAMA Internal Medicine, looked at data from the Current Population Survey (CPS), a monthly telephone survey of around 60,000 households conducted by the Census Bureau. CPS data is routinely used to track the country’s rate of employment. The survey also asks people if they had taken time off from work the week prior because of their “own illness/injury/medical problems.”
From January to February 2020, the number of people who called out sick remained in line with previous years. But March’s numbers saw a small rise relative to last year, while April’s numbers took a sharp jump up, the researchers found. Based on the CPS data, an estimated 920,000 people called out sick in April 2019; in April 2020, 2.02 million people did the same.
The findings have their limitations. It’s not possible to know exactly why so many more people called out sick this April, for instance. Some people may have called out sick to take care of another person in their family, though the survey does include that reason as an option. Others may have called out not because they actually felt sick but because they were anxious or worried about catching covid-19 at work.
But the spike in work absenteeism does line up with the smaller recorded spikes of cases and hospitalizations from covid-19 in the U.S. that were happening at the same time. And if anything, this may be an underestimate of how many people were sickened around then, the authors said.
For one, the figures by definition don’t account for people not working at the time, a number that got bigger as the country began to enact lockdowns that temporarily suspended many businesses. Over 20 million Americans are thought to have lost their jobs from March to April, based on the same CPS data.
Given the fear by some people of losing their job, the authors noted, it’s possible that many people who were sick with covid-19 still worked that month. The expansion of remote work may have also enabled many to keep working while sick. And since the survey only asked about one week, it’s likely that even more people called out sick in April who weren’t counted by the CPS data.
In any case, the April numbers are still the highest ever recorded in the history of the CPS since it was established in 1976, the authors wrote. Along with other data, it supports the idea that people in the most vulnerable populations of the U.S. have been the most exposed to the coronavirus. The rate of absenteeism rose much higher among immigrant workers than U.S.-born workers (in typical times, immigrant workers call out sick less often that non-immigrants). Workers over 55 or with a lower education status also called out sick more this April relative to last year, compared to younger workers and to workers with less formal education.
“I’ve seen firsthand covid-19's impact on the critically ill patients in our ICU, and we’ve known that many more were also ill at home,” lead author Adam Gaffney, a pulmonary and critical care specialist at Harvard Medical School and president of Physicians for a National Health Program, said in a statement released by the advocacy group. “But our study indicates that the pandemic has sickened many more people than we had realized, especially vulnerable employees like immigrants.”
This isn’t the only study to find indirect evidence of widespread covid-19 infections this spring. Antibody studies in places like New York City, for instance, have shown levels of earlier infection much higher than the recorded case toll, while other research has consistently found an undercount of deaths attributed to the coronavirus, based on the tally of excess deaths this year relative to the recent past.