In recent years, academic medical societies have increasingly issued recommendations and policy statements that seem motivated less by a commitment to scientific rigor and more by an adherence to fashionable ideologies.
The American Thoracic Society is unfortunately no exception to this trend. Its 2023 decision to abandon race‑adjusted reference equations for spirometry—long a straightforward physiological test—does not necessarily make the test more accurate, may not deliver better outcomes, and does not clearly improve certainty in a tool meant to elucidate lung mechanics. By prioritizing broad ideological narratives over data‑driven, objective measures, recent changes risk undermining the core purpose of this diagnostic test and ultimately fail to improve patient care, exchanging one set of uncertainties for another.
Spirometry measures the volume and flows produced after a forced exhalation from total lung capacity. Measurements include the Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC) (maximal amount exhaled), and the FEV1/FVC ratio. In the right clinical setting spirometry helps distinguish obstructive from restrictive lung physiology. Whether a value is “normal” depends on reference equations from healthy populations. These equations have always adjusted for height, age, and sex. And for two decades, they also included race-based adjustments given datasets consistently showing average FEV1 and FVC values differing across populations. Ironically, this change was an effort to make the equations, which had originally been based on data from Caucasians, more inclusive by including data from multiple ethnic groups while also having some physiologic rationale by accounting for the smaller Cormic index (smaller thorax for a given standing height) seen in observational studies of individuals of African descent as well as others. This approach, while imperfect, was accepted for diagnosing abnormal physiology.
Flash forward to recent times. In 2023, the ATS moved to eliminate race-based adjustment from the reference equations. Thirty-three workshop participants—drawn from both the ATS Pulmonary Function Test Committee and the ATS Health Equity and Diversity Committee—met over the issue. Thereafter an official statement was produced explaining “why race and ethnicity should no longer be considered factors in interpreting the results of spirometry.” If this change had improved diagnostic precision, it would have been welcome.
From the outset, the ATS statement framed the prior race‑adjusted equations as products of “structural racism,” despite their intent to improve accuracy by incorporating data from multiple populations. More than 90% of workshop participants nevertheless endorsed adopting a race-neutral reference equation, citing non-clinical benefits such as affirming that “race and ethnicity are not biological variables.” At the same time, ATS issued a word of caution within its own statement, acknowledging uncertain effects and potential harms with the new approach. Indeed, the full clinical consequences of removing race from the reference equations remain unknown. What is certain is that this change will reclassify some black patients with previously “low‑normal” values as abnormal, and some white patients previously labeled abnormal as normal.
No doubt, clinicians will still interpret pulmonary function tests (PFTs) in context, but this shift introduces new opportunities for misclassification without evidence that diagnostic accuracy or patient outcomes will improve. A patient with exertional dyspnea, for example, may now appear to have obstructive disease when the true cause is something else, like cardiac disease for example. The ATS document itself warns of potential harm because of the race-neutral equation, including, but not limited to unnecessary workups, inappropriate disease labeling, insurance or occupational consequences, and altered surgical risk assessments.
The central issue is simple: the recent race-neutral recommendations do not clearly improve diagnostic accuracy and introduce a different set of uncertainties into a test whose purpose is to clarify physiology. The change appears driven less by data and more by ideology. It risks undermining the primary function of any diagnostic tool, that is, providing clinicians with the best, most accurate information so they can provide exceptional care to their patients. While an argument could be made for improving the original reference-equation approach—or even abandoning it all together in favor of alternatives like using patients as their own baseline—any change should be driven by data supporting improved clinical accuracy for individual patients regardless of race, and not a particular political agenda.
Dr. Michael Depietro is a pulmonologist and Do No Harm member.
