A Comparative Study of the European Coal and Steel Community (ERS 1993) and the Global Lung Initiative (2017) Reference Equations used for Diffusion Capacity Testing in an Irish Population

Title: A Comparative Study of the European Coal and Steel Community (ERS 1993) and the Global Lung Initiative (2017) Reference Equations used for Diffusion Capacity Testing in an Irish Population
Author(s): A Bukhari O McGuinness A McGowan L Cormican
Institution: Respiratory and Sleep Diagnostic Department, Connolly Hospital
Poster: Click to view poster
Category: General Respiratory and Sleep
Abstract: This study compares two reference equations used for Single breath diffusing capacity (DLCO) testing; the 1993 update of (ECSC) and the 2017 (GLI). Data was retrospectively collected from 240 patient DLCO tests, half of which were females, carried out in Connolly Hospital.
Both reference values for each patient were analyzed using both reference equation sets and the average percentage difference between the two was calculated. The impact on clinical classification of the severity of DLCO was also investigated.
An average difference of 12.23% between reference values was found in females, and 5.42% in males. This demonstrates that the ECSC percentage predicted values were lower than the GLI, with potential for over diagnosis. These results were clinically significant as the difference is greater than 5%. Hence, an average of 23% of females and 8% males were misclassified based on their severity of DLCO.
In conclusion, a clinically significant difference exists between the ECSC and GLI reference equations. Respiratory departments should strongly consider changing to GLI (2017) to avoid misdiagnosis.