Reference values of impulse oscillometry (IOS) for healthy Chinese children aged 4-17 years.

Objective: To establish the predicted value of pulmonary function determined by impulse oscillometry (IOS) in children (4-17 years old) in China.

Methods: A total of 6270 healthy children aged 4-17 years in China were included. The Master Screen IOS pulmonary function device (Jaeger Co, Germany) was used to detect the respiratory impedance (Zrs), resonant frequency (Fres), respiratory system resistance (Rrs) and respiratory system reactance (Xrs) at various oscillation frequencies, and the indices above were analysed.