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How well do workplace COVID-19 screens work? And do they discriminate?

A novel survey highlights strengths, drawbacks, and trade-offs of employee health screening

For All Spring 2021 | October 20, 2020

Author

Douglas Clement Managing Editor (former)

Article Highlights

  • Unique survey reveals trade-offs and concerns raised by workplace screening tools
  • Screening techniques likely identify many workers as high-risk on any given day; methods vary in sensitivity
  • Demographic groups report symptoms at different rates, raising issues of workplace equity
How well do workplace COVID-19 screens work? And do they discriminate?
Illustration of workers going through COVID-19 screenings
Sophia Foster-Dimino

Many employers have implemented symptom screening protocols to safeguard employees and customers. Employees may have their temperature taken and/or answer questions about potential symptoms or high-risk behaviors.

These screening practices raise a number of difficult issues. Do they accurately detect infection? Are some questions or techniques more accurate? Do they disproportionately flag some demographic groups, potentially leading to workplace discrimination?

A recent working paper from the Minneapolis Fed’s Opportunity & Inclusive Growth Institute sheds light on these questions, using results from a nationally representative survey that asks about employment status, financial security, COVID-19 symptoms, health status, and personal efforts to avoid infection. The paper’s authors, economists Krista Ruffini of Georgetown University, Aaron Sojourner of the University of Minnesota, and Abigail Wozniak, director of the Institute, point to drawbacks and benefits of various forms of screening and provide guidance on factors employers should consider when designing workplace safeguards.

Key considerations for employers

First, workplace screens “will likely identify many workers as high-risk on any given day.” Depending on the screening technique, as many as 7 percent of workers could be flagged as possibly infected.

How a survey is designed and the number and type of symptoms that employees are asked about will affect which individuals are identified as possibly sick. This raises issues of discrimination.

Second, the screening method matters. How a survey is designed and the number and type of symptoms that employees are asked about will affect which individuals are identified as possibly sick. This raises issues of discrimination, since different demographic groups report symptoms at different rates.

Third, although indirect evidence suggests that positive screen rates are higher than actual infection rates, workplace screens can nonetheless serve “as an important public health tool.” Positive screens could lead workers to engage in protective health behaviors that lower overall disease rates. Moreover, in the absence of routine medical testing, screens are likely to be widely used.

STUDY AUTHORS

KRISTA RUFFINI, Assistant Professor, Georgetown University McCourt School of Public Policy (2021); AARON SOJOURNER, Associate Professor, Carlson School of Management, University of Minnesota; ABIGAIL WOZNIAK, Director, Opportunity & Inclusive Growth Institute

Finally, the economists discuss several points for employers to consider, including the importance of using methods that do not inadvertently encourage misreporting. Also, firms should weight the choice between screens that provide higher false negatives with fewer demographic disparities and those that yield lower false negatives but more disparities. Another consideration: The harms and benefits of particular strategies may change as local caseloads change.

The COVID Impact Survey

The researchers analyzed data from the COVID Impact Survey (CIS), a nationally representative survey conducted in three waves of roughly 8,000 respondents each between April and June 2020. The survey asked individuals about fever- and COVID-19-related symptoms, exposure to COVID-19, behaviors to avoid infection, and labor market engagement. About half of respondents provided their current temperature.

From these results, the researchers develop seven COVID-19 screens, varying in type and number of symptoms queried. One screen is a simple thermometer check of temperatures 99 degrees or higher. Another asks about COVID-19 symptoms from a 17-item checklist. Screens differ in detection levels, over time, and for different demographic groups.

One salient finding: “A substantial share of the workforce would screen positive under any of the screens,” and results varied widely among the different screens. Over half of respondents said they’d experienced at least one COVID-19-related symptom that week, for example, but just 4 percent registered temperatures of 99 degrees or higher on a specific day.

Positive rates were fairly level over time and considerably lower when screens required two or more symptoms. These survey results are likely higher than an actual workplace screen would find, note the researchers, since workers may tend to underreport symptoms fearing loss of jobs (and income) if they screen positive. Also, many CIS questions use a week-long look-back period, while actual screens are for a specific workday.

Are screens reliable? Do they discriminate?

The wide range of positive results across the seven screens raises the question of reliability. After all, the researchers’ data do not include results from a medical test for COVID-19 infection. Importantly, no single question or screen is perfect. And employers should not rely exclusively on temperature-taking when screening workers.

Examining whether workplace screens have disparate demographic impacts is “crucial,” say the economists. If a particular screen flags one racial, ethnic, age, or gender group more often than another, it may unfairly deprive those workers of their livelihoods. Yet if a screen regularly fails to catch infected workers of a given group, that group could be exposed to greater probability of infection.

The CIS finds that groups do indeed differ in their rates of measured and reported symptoms. Women and young workers are more likely to report elevated temperature. Non-Hispanic Whites, women, and young workers are more likely to report at least two fever symptoms.

Trade-offs and dilemmas

To encourage truthful responses to workplace screens, employers may want to assure workers that they won’t lose income should they be flagged positive by a screen.

This paper is the only study to date to examine U.S. COVID-19 workplace screening techniques, and its value is enhanced through the unique information provided by the nationwide CIS.

It highlights the trade-offs and dilemmas that employers will face as they implement workplace screening. Broad questionnaires will flag high percentages of employees as potential COVID-19 cases. Requiring more than one reported symptom for a positive result will permit more employees to enter the workplace. But demographic groups report symptoms at different rates, raising equity considerations.

To encourage truthful responses, employers may want to assure workers that they won’t lose income should they be flagged positive by a screen. And employers should be aware that screens with higher negative rates have fewer demographic disparities, and the converse. Whatever the employer’s choice, “the design of these screens … affects how many, and which, workers screen positive.”


Douglas Clement
Managing Editor (former)

Douglas Clement is a managing editor at the Minneapolis Fed, where he writes about research conducted by economists and other scholars associated with the Minneapolis Fed and interviews prominent economists.