# Discordance in Spirometric Interpretations Based on Korean and Non-Korean Reference Equations

## TL;DR

This study compares spirometric interpretations using Korean and non-Korean reference equations, finding significant differences in results.

## Contribution

The study highlights significant discordance in spirometric interpretations when using Korean versus non-Korean reference equations.

## Key findings

- The mean differences in FEV1% and FVC% between the two Korean equations were 2.0 ± 1.3% and 3.5 ± 2.2%.
- Morris's equation showed the greatest FEV1% difference from Choi's equation at 32.9 ± 8.5%.
- Knudson's equation showed the greatest FVC% difference from Choi's equation at 10.5 ± 6.5%.

## Abstract

Korean regression models for spirometric reference values are different from those of other ethnic groups. The purpose of this study was to evaluate discordance in spirometric interpretations based on using Korean reference equations versus non-Korean reference equations.

Spirometry was performed on 825 Korean male workers from April 2009 to November 2011. The spirometric patterns and disease severity were evaluated using two Korean equations (Choi's and Lee's) and three equations for Caucasians (NHANES III, Morris's, and Knudson's), and the results of Choi's equation were compared with the non-Korean equations. The spirometric patterns were defined as normal, restrictive, and mild and moderate obstructive.

The mean differences in the FEV1% and FVC% between the two Korean equations were 2.0 ± 1.3% and 3.5 ± 2.2%, respectively. Morris's equation had the greatest difference in the FEV1% from Choi's equation: 32.9 ± 8.5%. Knudson's equation had the greatest difference in the FVC% from Choi's equation: 10.5 ± 6.5%.

The two Korean equations shared similar characteristics of spirometric interpretation. The spirometric interpretations of Choi's equation were significantly different from those of Morris's equation and Knudson's equation.