Table 1.
The basic data statistics for each test item and the statistics of their permutation importance. The test items are sorted by their mean importance. The data statistics for Sex (M/F) show the numbers of males and females. Note: CI, confidence interval; STD, standard deviation; DDR, desaturation distance ratio; mMRC, modified British medical research council; FEV1, predicted forced expiratory volume in 1s (%); RV, residual volume; TLC, total lung capacity; BNP, brain natriuretic peptide; GDF-15, growth differentiation factor-15; DLCO, diffusing capacity of the lungs for carbon monoxide; VC, vital capacity; VA, alveolar volume; DE/DI, the ratio of mean lung density at the end of expiration (E) to the end of inspiration (I); FeNO, fractional exhaled nitric oxide; LAA, low-attenuation area; ALB, albumin; NDE/NDI, the ratio of normal density at the end of expiration (E) to the end of inspiration (I); DSP, distance–saturation product; CAT, COPD assessment test; BMI, body mass index.
| Data Statistics | Importance Index | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | STD | Mean | Min | 1st Quartile | Median | 3rd Quartile | Max | 95% CI (Lower–Upper) | |
| Sex (M/F) | 309/97 | 0.051 | −0.200 | −0.013 | 0.024 | 0.100 | 0.400 | −0.013–0.116 | |
| # of Cigarettes/Day | 16.28 | 14.10 | 0.038 | −0.100 | 0.000 | 0.048 | 0.051 | 0.211 | 0.008–0.068 |
| Age | 70.15 | 9.57 | 0.035 | −0.095 | 0.000 | 0.049 | 0.053 | 0.190 | 0.003–0.066 |
| Whole Body Phase Angle () | 5.07 | 0.76 | 0.028 | −0.238 | 0.000 | 0.048 | 0.064 | 0.143 | −0.011–0.066 |
| DDR/s | 5.91 | 6.09 | 0.024 | −0.095 | 0.000 | 0.000 | 0.050 | 0.095 | 0.003–0.046 |
| mMRC | 0.68 | 0.89 | 0.023 | −0.143 | 0.000 | 0.000 | 0.051 | 0.190 | −0.012–0.058 |
| FEV1 | 2.19 | 0.64 | 0.017 | −0.095 | 0.000 | 0.048 | 0.048 | 0.105 | −0.005–0.040 |
| %RV/TLC (%) | 95.52 | 16.81 | 0.015 | −0.095 | 0.000 | 0.000 | 0.048 | 0.095 | −0.005–0.035 |
| Pack Years | 28.17 | 20.67 | 0.014 | −0.100 | 0.000 | 0.000 | 0.050 | 0.095 | −0.011–0.039 |
| BNP (pg/mL) | 38.08 | 49.48 | 0.013 | −0.050 | 0.000 | 0.000 | 0.050 | 0.095 | −0.007–0.032 |
| GDF-15 (pg/mL) | 1245 | 853 | 0.008 | −0.050 | −0.048 | 0.000 | 0.048 | 0.105 | −0.017–0.032 |
| Spinal Muscles (Left) (mm2) | 1550 | 436 | 0.007 | −0.053 | 0.000 | 0.000 | 0.000 | 0.100 | −0.008–0.023 |
| %DLCO | 96.25 | 27.25 | 0.007 | −0.050 | 0.000 | 0.000 | 0.048 | 0.053 | −0.008–0.023 |
| Grip Strength (Left) (Kg) | 29.43 | 8.51 | 0.005 | −0.100 | 0.000 | 0.000 | 0.048 | 0.105 | −0.018–0.028 |
| Eosinophil | 3.63 | 4.60 | 0.005 | −0.050 | 0.000 | 0.000 | 0.000 | 0.053 | −0.008–0.018 |
| %FEV1 (%) | 85.28 | 21.28 | 0.005 | −0.050 | 0.000 | 0.000 | 0.012 | 0.050 | −0.010–0.019 |
| VC (L) | 3.33 | 0.81 | 0.003 | −0.050 | 0.000 | 0.000 | 0.000 | 0.100 | −0.013–0.018 |
| %DLCOVA (%) | 88.32 | 38.08 | 0.002 | −0.050 | 0.000 | 0.000 | 0.000 | 0.050 | −0.007–0.011 |
| DE/DI | 0.96 | 0.03 | 0.002 | −0.050 | 0.000 | 0.000 | 0.000 | 0.095 | −0.011–0.016 |
| %VC (%) | 99.95 | 17.04 | 0.002 | −0.050 | 0.000 | 0.000 | 0.000 | 0.050 | −0.009–0.014 |
| FeNO (ppb) | 33.70 | 31.40 | 0.002 | −0.050 | 0.000 | 0.000 | 0.000 | 0.095 | −0.011–0.016 |
| LAA (%) | 0.23 | 0.04 | 0.000 | −0.050 | 0.000 | 0.000 | 0.000 | 0.050 | −0.015–0.015 |
| ALB (g/dL) | 4.20 | 0.31 | 0.000 | −0.050 | 0.000 | 0.000 | 0.000 | 0.053 | −0.013–0.013 |
| NDE/NDI | 0.92 | 0.03 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 | — |
| FEV1% (%) | 66.62 | 12.29 | −0.000 | −0.050 | 0.000 | 0.000 | 0.000 | 0.050 | −0.015–0.015 |
| Spinal Muscles (Right) (mm2) | 1586 | 437 | −0.003 | −0.050 | 0.000 | 0.000 | 0.000 | 0.000 | −0.008–0.003 |
| DSP | 38,082 | 8404 | −0.003 | −0.053 | 0.000 | 0.000 | 0.000 | 0.050 | −0.012–0.007 |
| Lowest SpO2 (%) | 91.98 | 3.83 | −0.003 | −0.050 | 0.000 | 0.000 | 0.000 | 0.048 | −0.012–0.006 |
| 6MWT (m) | 412.40 | 85.02 | −0.005 | −0.053 | 0.000 | 0.000 | 0.000 | 0.050 | −0.015–0.005 |
| Charlson Index | 0.96 | 1.04 | −0.006 | −0.100 | −0.048 | 0.000 | 0.048 | 0.095 | −0.032–0.021 |
| CAT | 10.87 | 7.44 | −0.007 | −0.095 | −0.048 | 0.000 | 0.012 | 0.050 | −0.027–0.012 |
| BMI (kg/m2) | 22.73 | 3.60 | −0.010 | −0.200 | 0.000 | 0.000 | 0.000 | 0.050 | −0.037–0.017 |