FIGURE 3.
Bland–Altman plot of the difference in lung clearance index taken from the traditional end-point of 1/40th of the starting concentration (LCI2.5) between Exhalyzer D (nitrogen (N2ExD)) and Innocor (sulfur hexafluoride (SF6Inn)) in a) participants with cystic fibrosis (CF) and b) healthy control (HC) participants. The solid line is the mean difference between devices (4.5 in CF and 0.92 in HC) and the dotted lines represent the limits of agreement (0.08–8.92 in CF and −0.38–2.22 in HC). The difference between devices becomes disproportionately larger with a higher (worse) LCI.