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Table 3 Densitometric progression adjusted for lung volume using linear regression

From: Detection of emphysema progression in alpha 1-antitrypsin deficiency using CT densitometry; Methodological advances

Variable

Linear regression models

Intercept, mean ± SE (95% CI)

t

p value

Annual change

WL Perc15

ΔPCP = -12.12*ΔCTVol -3.57

-3.57 ± 0.83 (-5.48, -1.65)

-3.72

0.0004

-1.79

WL VI-950

ΔVI-950 = 2.54* ΔCTVol + 1.94

1.94 ± 0.44 (1.07, 2.81)

4.45

< 0.0001

0.97

WL VI-910

ΔVI-910 = 6.58* ΔCTVol + 2.28

2.28 ± 0.57 (1.15, 3.42)

4.01

0.0002

1.14

  1. WL, whole lung; Perc15, 15th percentile point (measured in Hounsfield Units); VI-950, voxel index at a threshold of -950HU (measured in %); VI-910, voxel index at a threshold of -910HU (measured in %); Δ, change over study period; SE, standard error; 95% CI, 95% confidence interval; annual change, change outcome measure from baseline to follow-up incorporating adjustment for lung volume, estimated from the intercept (ΔCTVol = 0).
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Respiratory Research

ISSN: 1465-993X

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