How Switching to Race-Neutral Lung Function Equations Would Affect Disease Classification, Firefighting Job Prospects and VA Disability Benefits | 2024 ATS

Using a race-neutral assessment of lung function test would reclassify 428,000 more Black patients as having moderate-to-severe chronic pulmonary and move Black and Asian patients up on the lung transplant list, according to data presented this weekend at the 2024 American Thoracic Society (ATS) International Conference in San Diego.

Adjusting the assessment of test results and what normal means according to race has been called into question throughout American healthcare as ideas of race as a biological category have been abandoned and replaced with seeing it mainly as a social construct. Revision of race-based kidney disease formulas have led to much shorter wait times for Black kidney transplant candidates.

Last year, ATS issued a policy statement rejecting the previous practice of using race and ethnicity-specific reference equations for lung function interpretation. Using race to interpret lung function tests perpetuates “false ideas that race distinguishes people on the basis of innate and immutable features,” the statement said, and also “potentially contributes to medical harms from the lack of attention to modifiable risk factors for reduced pulmonary function resulting from racism.” With some reservations, the ATS statement endorsed the use of the Global Lung Function Initiative (GLI) average equation, known as GLI-Global, as a race-neutral average reference equation for assessing lung function tests.

James A. Diao, M. Phil.

In technically virtuosic effort of data gathering and analysis James A. Diao, M.Phil., a student in a joint program at Harvard Medical School and the Massachusetts Institute of Technology, and a large team of researchers set out to compare the effects of using the GLI-Global equation with the effects of using the 2012 Global Lung Function Initiative (GLI-2012) that adjusted tests according to the race. They use function data from five large cohorts to make the comparison, including two versions of the National Health and Nutrition Examination Survey, the U.K. Biobank, the Multi-Ethnic Study of Atherosclerosis and the Organ Procurement and Transplantation Network. All together they had lung function test results from nearly 370,000 people to work with. They applied the GLI-2012 and the GLI-Global equations to those results and then analyzed how they would affect lung health classifications for a variety of purposes. Next, they extrapolated those results to the U.S. population to create an estimate of how many people in the U.S. might be affected if the race-neutral GLI-Global equations were used, as ATS recommends, instead of GLI-2012.

In addition to COPD severity, Diao and his colleagues calculated the effects on using GLI-Global instead of GLI-2012 on classification of obstructive (asthma and COPD) and nonobstructive pulmonary impairment; disqualification from being a firefighter; medical impairment ratings that are used to determine disability compensation; Department of Veterans Affairs disability payments and placement on the U.S. lung transplant list.

Their calculations showed that using GLI-Global equations instead of GLI-2012 would result in 110,000 more Black individuals being classified as having obstructive impairment, 349,000 more Hispanic individuals and 2.1 million more White individuals. For nonobstructive impairment (which can lead to follow-up that identifies restrictive conditions that limit the lungs’ ability to expand), the switch to GLI-Global equations would result in 2.34 million more Black individuals being classified as having nonobstructive impairment, but 1.37 million fewer Hispanic individuals, 5.3 million fewer White individuals and 304 fewer Asian individuals and those from other groups.

They calculated that GLI-Global would increase the number of Black individuals disqualified from firefighting jobs by 754,000 and Asian and people in other groups by 72,000. In contrast, their math shows that 181,000 more Hispanic individuals and 1.27 million more White individuals.

VA disability payments are governed, in part, on lung function tests. Using the GLI-Global equations would increase the annual payments to Black veterans collectively by $1.1 billion and decrease payments to White veterans by 524 million. Diao and his co-investigators calculated that among the 216,000 Black veterans who would stand to benefit from the greater disability payment, annual compensation would increase by $1,991 for 37% of them, by $4,110 for 41%, by $9,740 for 19% and by $27,600 for 2.9%. They projected that VA disability compensation for White veterans would decrease by 1.1%. Among the 150,000 White veterans who would be affected, the annual compensation would decrease $1,991 for 28.8% of them and by $4,110 for the other 71.2%.

Diao and his colleagues found that of the 1,399 people on the U.S. lung transplant waiting list in 2020, 1243 of them would have had their position on that list change had GLI-Global equations been used instead of GLI-2012 equations. Asian and Black candidates would have moved up, on average, by 21.2 positions with GLI-Global, which would have translated into 4.3 fewer days of expected wait time. Hispanic and White lung transplant candidates would have moved back, on average, by 4.3 positions, which would have meant an additional 1.1 days of waiting time.