Impact of Using Global Lung Initiative Race-neutral Equations for Chronic Respiratory Disease in Western India.

Abstract

The Global Lung Initiative (GLI) race-neutral equations are considered to be race agnostic, using inverse probability weight, and have lower limits of normality (LLN) different from the GLI mixed equations. In this observational study, we analyzed the impact of using GLI equations to interpret spirometry of 1,169 patients with chronic respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), COPD suspects, small airway obstruction, posttubercular lung disease, and preserved ratio with impaired spirometry (PRISm) (46% females, average age 46 years). Predicted normal and the LLN using GLI equations were significantly higher than those using Indian equations. The GLI race-neutral equations changed the category in 35.17% of males and 42.64% of females compared to Indian equations. The GLI mixed equations categorized a greater percentage of patients to have a mixed ventilatory pattern compared to the GLI race-neutral equations. There was a significant change in the grading of the severity of COPD using Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages based on the percentage of predicted values of FEV1. Although GLI race-neutral equations have greater concordance with Indian equations than GLI Mixed equations, these substantially overdiagnose abnormal ventilatory patterns on spirometry in adult Indians in western India with chronic respiratory disease. A substantial number of patients with normal or obstructive patterns on spirometry are recategorized to have mixed or restrictive patterns. The use of GLI race-neutral equations increases the severity of airflow limitation in COPD patients. GLI race-neutral predictions for FEV1 result in substantially fewer patients demonstrating postbronchodilator responsiveness (PBDR).