A Race-neutral Approach to the Interpretation of Lung Function Measurements

Area of Science:

• Pulmonary Medicine
• Biostatistics
• Public Health

Background:

• Historically, race and ethnicity-specific equations for lung function interpretation assumed differences were due to thoracic size, potentially marginalizing certain populations.
• Environmental and social determinants of pulmonary function are understudied.
• Race-based spirometry equations may perpetuate health disparities.

Purpose of the Study:

• To develop a race-neutral reference equation for spirometry interpretation.
• To investigate if body proportions (sitting height, Cormic index) predict lung function better than race/ethnicity.
• To create globally applicable, race-neutral spirometry equations.

Main Methods:

• Reanalysis of National Health and Nutrition Examination Survey (NHANES) III data (n=6,984) using sitting height and Cormic index.
• Reanalysis of Global Lung Function Initiative (GLI) data (n=74,185) with inverse-probability weighting.
• Development of race-neutral GLI global (2022) equations.

Main Results:

• Sitting height slightly improved statistical precision but did not explain racial/ethnic spirometry differences in NHANES III.
• The new GLI global (2022) equations, not requiring race/ethnicity selection, showed comparable fit to GLI 2012 'other' equations.
• GLI global (2022) equations provide wider limits of normal.

Conclusions:

• A single global spirometry equation can reflect diverse lung function within and between populations.
• Interpreting spirometry with GLI global equations requires considering individual symptoms and medical history.
• These race-neutral equations aim for more equitable clinical, employment, and insurance decisions.