Mixed linear models on differences in DLNO and secondary end-points between MasterScreen and HypAir devices

VariablesCoefficient95% CIp-value
Primary end-point
DLNO mL·min−1·mmHg−124.021.7 to 26.3<0.0001
Secondary end-points
DLCO mL·min−1·mmHg−1−0.03−0.57 to 0.120.20
 Alveolar volume L0.480.45 to 0.52<0.0001
 Breath-hold time s−0.33−0.42 to −0.24<0.0001
 Inspiratory volume L0.008−0.028 to 0.0260.66
 κNO s−1−1.08−1.21 to −0.94<0.0001
 κCO s−1−0.0035−0.004 to −0.003<0.0001
 KNO mL·min−1·mmHg−1·L−12.21.9 to 2.5<0.0001
 KCO mL·min−1·mmHg−1·L−1−0.41−0.46 to −0.37<0.0001
 ΔFANO ppm−4.40−5.15 to −3.66<0.0001
 ΔFACO %−0.015−0.016 to −0.013<0.0001
 NO, expired/inspired ratio−0.017−0.012 to −0.014<0.0001
 O2, expired/inspired ratio0.0120.005 to 0.0190.0014
 CO, expired/inspired ratio−0.007−0.012 to −0.0020.0063
 He, expired/inspired ratio−0.054−0.058 to −0.050<0.0001

Data are presented as mean (95% confidence interval). Positive coefficients means that HypAir gave larger measurements than MasterScreen. DLCO: diffusing capacity of the lung for CO; DLNO: diffusing capacity of the lung for NO; κCO: permeability factor for CO; κNO: permeability factor for NO; KNO: transfer coefficient of the lung for NO; KCO: transfer coefficient of the lung for CO; FACO: fractional concentration of CO from the alveolar space; FANO: fractional concentration of NO from the alveolar space; ΔFACO (expired–inspired CO concentration); ΔFANO (expired–inspired NO concentration). Ratios of expired to inspired gas concentrations are also shown.