Table 2.
Characteristics of patients without COPD substratified by FEV1 decline
| Demographics for FEV1 decline groups non-COPD
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| FEV1 decline group | Group 1 n=50
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Group 2 n=5
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Group 3 n=10
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Group 4 n=22
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Across all groups | Statistic groups 1 and 4 | ||||||||||||
| No decline (decline of <−0.1% predicted per year) | Decline of −0.1 to <−0.5 | Decline of −0.5 to <−1.0 | Decline of at least −1.0 | |||||||||||||||
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| N | % | Mean | SD | N | % | Mean | SD | N | % | Mean | SD | N | % | Mean | SD | P-value | P-value | |
| Never smokers | 34 | 48.0% | 3 | 60.0% | 6 | 60.0% | 16 | 72.7% | 0.882 | 0.688 | ||||||||
| Index patient | 24 | 48.0% | 2 | 40.0% | 1 | 10.0% | 11 | 50.0% | 0.146 | 0.876 | ||||||||
| Female | 33 | 66.0% | 3 | 60.0% | 6 | 60.0% | 14 | 63.6% | 0.980 | 0.846 | ||||||||
| Age | 50 | 42.8 | 12.9 | 5 | 34.4 | 12.4 | 10 | 46.7 | 14.2 | 22 | 50.7 | 11.7 | 0.031 | 0.140 | ||||
| FEV1 % predicted | 50 | 110.0 | 15.6 | 5 | 118.6 | 10.2 | 10 | 117.9 | 17.1 | 22 | 117.8 | 15.4 | 0.344 | 0.142 | ||||
| FVC % predicted | 50 | 110.4 | 16.9 | 5 | 115.6 | 11.8 | 10 | 122.2 | 17.8 | 22 | 123.9 | 12.2 | 0.012 | 0.002 | ||||
| FEV1/FVC | 50 | 84.4 | 7.4 | 5 | 87.8 | 5.7 | 10 | 81.0 | 5.8 | 22 | 79.2 | 5.8 | 0.006 | 0.003 | ||||
| TLco % predicted | 27 | 92.0 | 21.8 | 2 | 89.1 | 21.5 | 3 | 76.0 | 13.8 | 15 | 80.2 | 21.7 | 0.315 | 0.145 | ||||
| Kco % predicted | 50 | 93.3 | 18.1 | 5 | 84.8 | 12.8 | 10 | 91.6 | 21.4 | 22 | 80.5 | 16.3 | 0.031 | 0.004 | ||||
| RV % predicted | 50 | 85.3 | 17.7 | 5 | 108.0 | 31.1 | 10 | 93.2 | 14.8 | 22 | 90.4 | 27.0 | 0.253 | 0.557 | ||||
| TLC % predicted | 50 | 104.0 | 12.7 | 5 | 115.5 | 19.7 | 10 | 111.8 | 13.0 | 21 | 109.2 | 13.4 | 0.126 | 0.107 | ||||
| RV/TLC | 50 | 26.2 | 6.7 | 5 | 26.8 | 8.9 | 10 | 27.4 | 6.4 | 21 | 30.5 | 12.6 | 0.543 | 0.153 | ||||
| FEV1 slope mL/year | 50 | −28.2 | 31.6 | 5 | −37.0 | 30.3 | 10 | −43.9 | 16.2 | 21 | −105.1 | 49.5 | N/A | N/A | ||||
| FEV1 % slope per year | 50 | 1.3 | 1.3 | 5 | −0.3 | 0.1 | 10 | −0.70 | 0.1 | 22 | −3.1 | 2.0 | N/A | N/A | ||||
| Kco % slope per year | 50 | −0.9 | 2.0 | 5 | −1.4 | 1.1 | 10 | −1.47 | 2.5 | 22 | −1.1 | 2.4 | 0.956 | 0.883 | ||||
| Distribution within Kco decline groups | ||||||||||||||||||
| Kco group 1 | 15 | 30.0% | 0 | 0.0% | 2 | 20.0% | 8 | 36.4% | 0.166 | 0.799 | ||||||||
| Kco group 2 | 2 | 4.0% | 2 | 40.0% | 1 | 10.0% | 1 | 4.5% | ||||||||||
| Kco group 3 | 9 | 18.0% | 0 | 0.0% | 2 | 20.0% | 2 | 9.1% | ||||||||||
| Kco group 4 | 24 | 48.0% | 3 | 60.0% | 5 | 50.0% | 11 | 50.0% | ||||||||||
Notes: TLco is overall gas transfer; Kco is gas transfer corrected for alveolar ventilation. % values indicate the proportion of each group with individual categorical characteristics. Significant P-values are given in bold.
Abbreviations: COPD, chronic obstructive pulmonary disease; FVC, forced vital capacity; FEV1, forced expired volume in 1 second; N/A, not available; SD, standard deviation; RV, residual volume; TLC, total lung capacity.