The use of race/ethnicity in medicine to explain and interpret pulmonary function test (PFT) differences between individuals may contribute to biased medical care and research. Furthermore, it may perpetuate health disparities and structural racism, according to a study published in the journal CHEST®.
Current practices of PFT measurement and interpretation, are imperfect in their ability to accurately describe the relationship between function and health outcomes, according to Nirav R. Bhakta, MD, University of California,San Francisco, and colleagues.
The authors summarized arguments against using race-specific equations, while voicing genuine concerns about removing race from PFT interpretations, and described knowledge gaps and critical questions needing to be addressed for remediation of health disparities.
“Leaving out the perspectives of practicing pulmonologists and physiologists has global relevance for increasingly multicultural communities in which the range of values that represent normal lung function is uncertain,” Dr. Bhakta said in an interview.
A lesson in history
Tracing the history of spirometry, the authors stated that observations about vital lung capacity showing differences attributable to height, age, sex, and occupation (e.g., typesetter vs. firefighter) were then extended to include social classes and ultimately race. Whites showed greater average vital capacity for the same sex, height, and age than non-Whites.
While some investigators pointed to environmental sources (such as early life nutrition, respiratory illness, air pollution, exercise, and altitude), research into their mechanisms and magnitudes of effect was not pursued, but rather “a narrative of innate differences took hold,” Dr. Bhakta and colleagues reported.
That sort of narrative risks comparison with those used to uphold slavery and structural racism in the past. More recently, such a narrative was used to deny disability claims of Welsh versus English White miners, and was expanded to interpret algorithms designed to predict expected lung function.
Use of standing height questioned
The current practice of using normalized standard height for lung function comparisons misses racial and ethnic differences in the proportion of sitting height to standing height shown in multiple studies, the authors stated. These comparisons may ignore effects on standing height of early-life nutrition, genetics, lung-specific factors such as respiratory infections and exposures to indoor and outdoor pollution, physical activity, and high altitude. Using sitting height instead of standing height reduces lung volume differences up to 50% between White and Black populations, they noted, and socioeconomic variables, such as poverty and immigration status, accounted further for the differences seen. Population differences disappeared by as much as 90% when chest measurements used to estimate surface area or volume were more finely detailed.
The researchers warned, however, that, “because current clinical and policy algorithms rely so heavily on the comparison of an individual’s observed lung function to that which is expected for similar people without typical respiratory disease, an abrupt change to not using race/ethnicity, if not paired with education and a reform of existing algorithms and policies, is also expected to have risks on average to groups of non-White individuals.”
That could lead to potential challenges for some groups ranging from the ability to obtain employment in certain occupations, to being considered for potentially curative lung resections, or having access to home assisted ventilation and rehabilitation programs. “An abrupt change to not using race/ethnicity and taking a society’s overall average as the reference range also has the potential to lead to delayed care, denial of disability benefits, and higher life insurance premiums to White individuals.”