Predicted normal values of pulmonary function tests in normal Korean children

ABSTRACT

PURPOSE: Pulmonary function tests are useful and important methods for evaluating patients with respiratory diseases. To assess lung function, we need to establish normal values of lung function, which vary according to population, age, gender and growth, particularly in children. This study was undertaken to establish normal predicted values of pulmonary function tests and to predict renewed reference values by spirometry in Korean school children. METHODS: Spirometric forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced expiratory flow at 25% to 75% of FVC (FEF25%-75%), and peak expiratory flow rate (PEFR) were measured in 406 healthy elementary school children (age, 6-12 years old) in May, 2012. Multiple linear regression analysis was performed for each spirometric parameter against age, height, weight and body surface area (BSA) separately for boys and girls, and derived reference equations and coefficients for all the spirometric parameters. RESULTS: All the measured spirometric parameters were significantly correlated with age, height, weight, and BSA. FVC was higher in boys aged 6-10 years than girls at ages matched. Height showed the highest correlation coefficient for all the spirometric parameters followed by BSA, weight and age in both genders. The normal predicted values of FVC and FEV1 at 130 cm in this study using renewed reference equations were approximately in the middle compared to previous studies. CONCLUSION: We reported here the renewed reference equations for normal predicted values of pulmonary function tests with high coefficients of determination based on updated data in healthy Korean children.