Table 4.
Variable | Annual change, mean ± SE (95% CI) | t | p value for annual rate | p value for volume |
Whole lung analysis | ||||
WL Perc15 | -2.13 ± 0.44 (-3.01, -1.24) | -4.82 | < 0.0001 | < 0.0001 |
WL VI-950 | 0.90 ± 0.19 (0.52, 1.29) | 4.72 | < 0.0001 | < 0.0001 |
WL VI-910 | 1.16 ± 0.25 (0.66, 1.65) | 4.67 | < 0.0001 | < 0.0001 |
Single slice analysis | ||||
UZPerc15 | -2.02 ± 0.53 (-3.08, -0.97) | -3.82 | 0.0003 | < 0.0001 |
UZ VI-950 | 0.60 ± 0.21 (0.18, 1.02) | 2.84 | 0.0057 | < 0.0001 |
UZ VI-910 | 0.94 ± 0.33 (0.29, 1.59) | 2.88 | 0.0051 | < 0.0001 |
LZ Perc15 | -1.93 ± 0.58 (-3.07, -0.78) | -3.34 | 0.0013 | < 0.0001 |
LZ VI-950 | 1.02 ± 0.32 (0.39, 1.65) | 3.22 | 0.0019 | < 0.0001 |
LZ VI-910 | 1.34 ± 0.38 (0.58, 2.1) | 3.52 | 0.0007 | < 0.0001 |
Targeted sampling | ||||
UT Perc15 | -2.54 ± 0.62 (-3.77, -1.32) | 4.13 | < .0001 | < 0.0001 |
UT VI-950 | 0.67 ± 0.22 (0.24, 1.10) | 3.11 | 0.0027 | < 0.0001 |
UT VI-910 | 1.28 ± 0.44 (0.42, 2.15) | 2.95 | 0.0042 | < 0.0001 |
MT Perc15 | -2.94 ± 0.49 (-3.91, -1.97) | -6.04 | < 0.0001 | < 0.0001 |
MT VI-950 | 1.20 ± 0.24 (0.73, 1.67) | 5.08 | < 0.0001 | < 0.0001 |
MT VI-910 | 1.78 ± 0.35 (1.08, 2.47) | 5.12 | < 0.0001 | < 0.0001 |
LT Perc15 | 2.85 ± 0.61 (-4.07, -1.64) | -4.68 | < 0.0001 | < 0.0001 |
LT VI-950 | 1.28 ± 0.26 (0.76, 1.80) | 4.96 | < 0.0001 | < 0.0001 |
LT VI-910 | 1.57 ± 0.29 (0.99, 2.15) | 5.37 | < 0.0001 | < 0.0001 |
WL, whole lung; UZ, upper zone single slice; LZ, lower zone single slice; ATl, apical third; MT, middle third; LT, lower third; SE, standard error; 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 %). The random coefficient model consists of outcome measurement as the dependent variable, time (year) as the fixed effect, volume as a time-dependent covariate, intercept and time (year) as random effects. The slope (coefficient for time variable) from the model is the estimated annual change adjusted for volume.