Overreliance on spirometry to identify emphysema resulted in underdiagnosed cases in blacks, especially men, based on secondary data analysis of 2,674 individuals.
“Over the past few years, there has been a growing debate about the use of race adjustment in diagnostic algorithms and equations commonly used in medicine,” lead author Gabrielle Yi-Hui Liu, MD, said in an interview. time said. “While racial or ethnic differences in clinical measures and outcomes were previously widely believed to be inherent differences between populations, there is now greater recognition of how racism, socioeconomic status, and environmental exposure contribute to these racial differences. We initially addressed this The study of interest was designed to examine the use of ethnic-specific spirometry reference equations and how use of spirometry in general leads to ethnic differences.”
“Previous studies have shown that the use of race-specific spirometry This study adds to the evidence that the equation may exacerbate racial inequalities in health care outcomes due to poor awareness of early disease in black adults,” Suman Pal, MBBS, University of New Mexico, Albuquerque, said in an interview.
“By examining the key ways in which systemic factors in medicine, such as race-specific equations, exacerbate racial inequities in health care, this study is a timely A moment of national reckoning,” said Parr, who was not involved in the study. A secondary analysis of data from the CARDIA Lung study (Coronary Artery Risk Development in Young Adults) was performed.
The primary outcome of the study was the prevalence of emphysema among participants with various normal spirometry results, stratified by sex and ethnicity. Normal results include a forced expiratory volume in 1 second (FEV1)-forced vital capacity (FVC) ratio greater than or equal to 0.7 or greater than or equal to the lower limit of normal. Participants were also stratified according to the percentage of predicted FEV1, using race-specific reference equations, with FEV1 between 80% and 99% of predicted value, or FEV1 between 100% and 120% of predicted value.
Study population included 485 black men, 762 black women, 659 white men who underwent CT scans (2010-2011) and spirometry (obtained 2015-2016) in the CARDIA study and 768 white women. The mean age of the pulmonary function test participants was 55 years.
After stratification by FEV1-FVC ratio, a total of 5.3% of participants had emphysema. Black men had a significantly higher prevalence than white men (12.3% vs. 4.0%; relative risk, 3.0), and black women had a significantly higher prevalence than white women (5.0% vs. 2.6%; RR, 1.9).
The association between black race and emphysema risk remained, but decreased, when researchers used race-neutral estimates.
When participants were stratified by race-specific predicted percent FEV1, 6.5% of individuals with race-specific FEV1 between 80% and 99% had emphysema. After controlling for factors including age and smoking, emphysema was more prevalent among black men than white men (15.5% vs 4.0%) and black women compared to white women (6.6% vs 3.4%)
Race differences persisted in males, with race-specific FEV1 between 100% and 120% of predicted value. Of these, 4.0% suffered from emphysema. Black men had a significantly higher prevalence than white men (13.9% vs. 2.2%), but black and white women had similar prevalence (2.6% vs. 2.0%).
The race-neutral equation reduced but not eliminated these differences, the researchers said. the researchers pointed out. “Given that imaging was obtained 5 years prior to spirometry and that emphysema is an irreversible finding, this may lead to an overall underestimation of the prevalence of emphysema.”
Spirometry alone misses cases
“We were surprised by the large rate of emphysema seen in black men in the cohort with normal lung function,” Liu said in an interview said in an interview. “We did not expect to find that more than one in eight black men with FEV1 predicted between 100% and 120% had emphysema—more than six times the rate of white men with the same range of FEV1.”
“One point is that using only spirometry to diagnose COPD, we may miss a lot of people with compromised respiratory health or true lung disease,” Liu said. In clinical practice, “Physicians should consider CT scans in patients with normal lung function and respiratory symptoms such as cough or shortness of breath. If emphysema is found, physicians should discuss mitigating any potential risk factors and consider COPD medications such as inhalation
“Our findings also support the use of race-neutral reference equations to interpret spirometry rather than race-specific equations. Racial differences in the incidence of emphysema in “normal” FEV1 [expected between 80% and 120%] were attenuated or eliminated when FEV1 was calculated using a race-neutral equation. This suggests that race-specific equations are worsening lung health in black adults,” Liu explained.
“We need to continue researching other tools that can be used to assess respiratory health and diagnose COPD, Also keeping in mind how these tools may affect racial disparities,” Liu said. “Our study shows that our reliance on FEV1/FVC ratio and spirometry such as FEV1 is missing in some people with respiratory symptoms and CT evidence of lung disease, and this is not Black adults in America disproportionately impact. “Going forward,” it will be important to find better tools to identify people with compromised respiratory health or early manifestations of disease, so that we can intercept chronic lung disease before it becomes clinically apparent, and patients suffer severe lung damage . “
The CARDIA study was supported by the National Heart, Lung and Blood Institute in collaboration with the University of Alabama at Birmingham, Northwestern University, the University of Minnesota and the Kaiser Foundation Research Institute. Liu was supported by the National Funding from the Institute of Health. Researcher has no financial conflicts to disclose. Pal has no financial conflicts to disclose.
This article originally appeared on MDedge.com, It is part of the Medscape Professional Network.
