Table 4.
Unadjusted and adjusted HRs with 95% confidence intervals for mortality from Cox regression for baseline lung function Z-scores
| Unadjusted | Adjusteda | ||||
|---|---|---|---|---|---|
| n | HR (95% CI) | p | HR (95% CI) | p | |
| DLCO (Z) | |||||
| Normal (≥ − 1.64) | 697 | Reference | < 0.001 | Reference | < 0.001 |
| Mild (− 1.64 to − 3) | 270 | 2.47 (1.40, 4.35) | 1.86 (1.03, 3.34) | ||
| Moderate (− 3 to − 5) | 147 | 7.49 (4.48, 12.5) | 4.40 (2.51, 7.69) | ||
| Severe (< − 5) | 51 | 15.0 (8.45, 26.5) | 7.86 (3.84, 16.1) | ||
| KCO (Z) | |||||
| Normal (≥ − 1.64) | 901 | Reference | < 0.001 | Reference | < 0.001 |
| Mild (< − 1.64 to ≥ − 3) | 149 | 2.49 (1.47, 4.24) | 1.39 (0.79, 2.44) | ||
| Moderate (< − 3 to ≥ − 5) | 97 | 6.32 (3.99, 10.0) | 3.11 (1.82, 5.32) | ||
| Severe (< − 5) | 18 | 14.1 (7.31, 27.1) | 6.97 (3.08, 15.8) | ||
| VA (Z) | |||||
| Normal (≥ − 1.64) | 753 | Reference | 0.011 | Reference | 0.014 |
| Mild (< − 1.64 to ≥ − 3) | 324 | 1.49 (0.98, 2.26) | 1.59 (1.03, 2.45) | ||
| Moderate (< − 3 to ≥ − 5) | 84 | 2.40 (1.39, 4.16) | 2.09 (1.19, 3.66) | ||
| Severe (< − 5) | 4 | 2.81 (0.39, 20.4) | 5.75 (0.76, 43.6) | ||
| FEV1 (Z) | |||||
| Normal (≥ − 1.64) | 590 | Reference | < 0.001 | Reference | < 0.001 |
| Mild (< − 1.64 to ≥ − 3) | 364 | 1.83 (1.05, 2.84) | 1.68 (1.00, 2.83) | ||
| Moderate (< − 3 to ≥ − 5) | 200 | 4.07 (2.55, 6.50) | 2.98 (1.79, 4.96) | ||
| Severe (< − 5) | 11 | 2.90 (0.69, 12.2) | 3.46 (0.78, 15.4) | ||
| FVC (Z) | |||||
| Normal (≥ − 1.64) | 708 | Reference | < 0.001 | Reference | < 0.001 |
| Mild (< − 1.64 to ≥ − 3) | 341 | 2.04 (1.32, 3.16) | 2.10 (1.33, 3.30) | ||
| Moderate (< − 3 to ≥ − 5) | 111 | 3.68 (2.24, 6.05) | 4.00 (2.37, 6.76) | ||
| Severe (< − 5) | 5 | 2.34 (0.32, 17.1) | 3.40 (0.44, 26.3) | ||
| FEV1/FVC (Z) | |||||
| Normal (≥ − 1.64) | 802 | Reference | < 0.001 | Reference | 0.63 |
| Mild (< − 1.64 to ≥ − 3) | 199 | 1.33 (0.80, 2.24) | 1.00 (0.58, 1.69) | ||
| Moderate (< − 3 to ≥ − 5) | 151 | 2.55 (1.61, 4.04) | 1.22 (0.74, 2.02) | ||
| Severe (< − 5) | 13 | 4.55 (1.42, 14.6) | 2.01 (0.60, 6.79) | ||
Z-scores are derived from Global Lung Function Initiative reference values [20]
DLCO, diffusing capacity of the lung for carbon monoxide; KCO, transfer coefficient of the lung for carbon monoxide; VA alveolar volume; FEV1, forced expiratory volume in one second; FVC, forced vital capacity
aAdjusted for age, sex, smoking status, body mass index, First Nations status, and respiratory disease