Skip to main content

Table 2 Mean for resistance at 5 Hz, resistance at 20 Hz, reactance at 5 Hz, impedance at 5 Hz, and resonant frequency stratified by sex and age

From: Reference values of impulse oscillometry (IOS) for healthy Chinese children aged 4–17 years

IOS parameters Boy [M(P25–P75)] Girl [M(P25–P75)] Z P
Preschoolers
 R5, kPa/L/s 0.88 (0.66–1.12) 0.83 (0.62–1.09) − 1.409 0.159
 R20, kPa/L/s 0.57 (0.41–0.78) 0.52 (0.39–0.71) − 2.438 0.015
 X5, kPa/L/s − 0.29 (− 0.4 to − 0.19) − 0.29 (− 0.39 to − 0.17) − 0.682 0.495
 Z5, kPa/L/s 0.93 (0.70–1.18) 0.885 (0.67–1.16) − 1.203 0.229
 R5–R20, kPa/L/s 0.27 (0.18–0.38) 0.28 (0.17–0.41) − 0.229 0.819
 Fres, Hz 19.44 (17.57–21.33) 20.03 (17.74–21.94) − 2.021 0.043
School-ages
 R5, kPa/L/s 0.67 (0.49–0.88) 0.62 (0.45–0.84) − 3.626 0.000
 R20, kPa/L/s 0.47 (0.34–0.6125) 0.42 (0.32–0.59) − 3.790 0.000
 X5, kPa/L/s − 0.19 (− 0.27 to − 0.13) − 0.19 (− 0.27 to − 0.13) − 0.890 0.374
 Z5, kPa/L/s 0.70 (0.52–0.92) 0.65 (0.48–0.88) − 3.306 0.001
 R5–R20, kPa/L/s 0.18 (0.11–0.28) 0.18 (0.11–0.27) − 0.584 0.584
 Fres, Hz 17.5 (15.00–19.89) 17.94 (15.19–19.82) − 2.803 0.005
Teenagers
 R5, kPa/L/s 0.28 (0.24–0.35) 0.36 (0.31–0.43) − 9.395 0.000
 R20, kPa/L/s 0.23 (0.19–0.29) 0.28 (0.23–0.34) − 7.505 0.000
 X5, kPa/L/s − 0.09 (− 0.11 to − 0.07) − 0.11 (− 0.14 to − 0.09) − 8.296 0.000
 Z5, kPa/L/s 0.30 (0.26–0.37) 0.37 (0.32–0.44) − 9.659 0.000
 R5–R20, kPa/L/s 0.06 (0.03–0.09) 0.08 (0.05–0.12) − 5.959 0.000
 Fres, Hz 13.09 (10.31–15.49) 13.755 (11.08–16.09) − 2.743 0.006
  1. R5 = resistance at 5 Hz, R20 = resistance at 20 Hz, X5 = reactance at 5 Hz, Fres = resonant frequency, Z5 = impedance at 5 Hz, R5–R20 = fall in resistance between R5 and R20