. 2020 Oct 6;11:554679. doi: 10.3389/fphys.2020.554679

TABLE 5.

Correlation between impulse oscillometry and DI (n = 42).

	Correlation coefficient	Raw P-value	False discovery rate
Unadjusted pearson correlation coefficients
Log(R5)	0.24	0.115	0.173
LogR20)	0.26	0.102	0.173
Log(R5–R20)	0.20	0.188	0.226
Log(AX)	0.26	0.099	0.173
−Log(−X5)	–0.17	0.280	0.280
Log(Fres)	0.32	0.041	0.173
Partial pearson correlations controlling for age, sex, height, and BMI
Log(R5)	0.32	0.050	0.066
Log(R20)	0.20	0.239	0.239
Log(R5–R20)	0.33	0.044	0.066
Log(AX)	0.34	0.041	0.066
−Log(−X5)	–0.32	0.055	0.066
Log(Fres)	0.44	0.007	0.042
Partial pearson correlations controlling for first five PCs of 22 covariates*
Log(R5)	0.41	0.015	0.023
Log(R20)	0.28	0.101	0.101
Log(R5–R20)	0.41	0.015	0.023
Log(AX)	0.51	0.002	0.006
−Log(−X5)	–0.48	0.037	0.044
Log(Fres)	0.59	0.0002	0.001

PCs, principal components; R5, resistance at 5 Hz (total respiratory resistance); R5–R20, frequency dependence of Rrs (R5 minus R20, peripheral respiratory resistance); R20, resistance at 20 Hz (central respiratory resistance); X5, reactance at 5 Hz (peripheral reactance); AX, area under the reactance curve below resonant frequency; Fres, resonant frequency. *22 covariates include age, sex, height, BMI, 11 spirometry variables (FEV₁, ΔFEV₁, %prΔFEV₁, FVC, ΔFVC, %prΔFVC, FEV₁/FVC, PEF, FEF_50%, FEF₂₅_–_75%, FEF_75%), and seven lung volume measures (TLC, RV, RV/TLC, FRC, ERV, IC, IC/TLC). False discovery rates were calculated within each adjustment group to account for six tests performed.