The standard range of peak expiratory flow rates of Korean children

Background: The importance in asthma management of monitoring of peak expiratory flow rate (PEFR) has been emphasized. Objective: For effective asthma management in Korean children, we established reference ranges for the PEFR in children 4-18 years of age. Methods: The Mini Wright Peak Flow Meter (MWPFM) and spirometry were used in this study. All tests were conducted using a standardized method recommended by the American Thoracic Society. Results: From a total sample of 2,389 children, 826 (34.5%) were excluded based on our exclusion criteria. For both sexes, the PEFR increased with height, age, weight, sitting height and body surface area (BSA). Height and BSA were found to be better predictors of PEFR than the other parameters. The correlation coefficient between FEV₁ and PEFR using the MWPFM was 0.886 (p <.001). The reference values of PEFR for height in our study were higher for both sexes than for those previously reported in Korea (p <.005). When we compared our results with those from other countries, the values for boys of the same height were lower than those for European children, but higher than those for African and Turkish children (p <.001). Conclusions: We have established reference values for PEFR obtained by MWPFM in Korean children in Seoul, and have provided the percentile curves for PEFR as a function of height to assist clinical practices in treating children with asthma in Korea.