A centuries-old device is still used in modern clinics to estimate a person’s lung function. The spirometer measures how much air a person can breathe in and forcefully breathe out, and how fast they do so. Their lung function is then calculated relative to a predicted normal range.
What’s considered normal varies depending on a person’s age, sex, height, and race, and the algorithm used to estimate lung function typically places Black people at lower severity of lung disease than people of other races.
Spirometry test results are used to rank the severity of lung diseases such as chronic obstructive pulmonary disorder (COPD), determine whether people are eligible for firefighter jobs, or for disability payments.
In the last few years, efforts to adopt race-free equations have led researchers to recommend switching from an older, race-based equation known as GLI-2012 to a race-neutral one named GLI-Global.
But the move has not been uncontroversial. When the American Thoracic Society endorsed the updated equation earlier this year, the organization also “called for an assessment of how this would actually affect patients and in what ways this would affect their care, as well as other decisions attached to pulmonary function testing,” said James Diao, an internal medicine resident at Brigham and Women’s Hospital.
In a new study, Diao and his colleagues used data from more than 350,000 people in the National Health and Nutrition Examination Survey (NHANES), U.K. Biobank, the Multi-Ethnic Study of Atherosclerosis, and the Organ Procurement and Transplantation Network to make that assessment.
Impact of the change
In their recent NEJM paper, the researchers reported that using the updated lung function equation would affect millions of Americans, and the impact differed among racial groups. In NHANES data, for example, the new equation reclassified 3.2 million people. About 2.6 million people, most of whom were Black, Hispanic, or White, were newly identified as having obstructive lung disease, while about 565,000 were no longer categorized as such, mostly Asian and people who did not fit standard race and ethnicity categories.
Changes such as this drastically alter military disability compensation, eligibility for jobs such as in firefighting, or other areas where lung function is tested. Organizations using the new equation could mean billions of dollars being allocated differently than when the older, race-based equation was in use. The changes are likely to affect “a pretty large swath of the US population,” Diao said.
But just how large is still uncertain. The Department of Veterans Affairs, for instance, has questioned the NEJM study’s estimates and said they expect the re-worked math to have a smaller impact on people’s lives.
What journalists should know
At present, the race-free equation known as GLI-Global is the only one endorsed by the American Thoracic Society and the European Respiratory Society. But there’s no mechanism for them to enforce this recommendation. “It’s entirely up to the institution,” Diao said. “With all of these recommendations, the national society sets them and then they have no enforcement.”
Possible story leads
- Advocacy and solutions: Cover the stories of groups that may be advocating for the adoption of new equations in your local health care system.
- Local angles: Cash-strapped medical facilities may not have the resources to buy new machines with updated, race-free equations. Some hospitals may choose to take the output from an old spirometer and re-do the math for each patient, but this approach hasn’t been studied for its effectiveness. Check how your local hospital is trying to keep up with the latest recommendations.
- Policy: The Department of Energy, Veterans’ Affairs, Social Security Administration, and the National Firefighting Professionals’ Association are just a few of many organizations that set their own recommendations on how to estimate lung function. Each might have distinct approaches to updating their procedures.
- Environmental health: Lung function equations may be used to identify patients eligible for clinical trials or determine insurance premiums. The tests can also be used to determine workers’ eligibility in any job that involves exposure to silica or cotton dust, including agriculture, mining, or construction.
