TABLE 2.
SIGNIFICANT PREDICTORS IN MULTIVARIATE MORTALITY MODELS IN PATIENTS (N = 609) WITH SEVERE EMPHYSEMA
| Predictor | Hazard Ratio | 95% CI | P Value |
|---|---|---|---|
| Age, yr | |||
| 70–83 | 1.72 | 1.31–2.26 | <0.001 |
| 40–69 | Reference | ||
| Oxygen use (rest, exercise, or sleeping) | 1.40 | ||
| Yes | 1.40 | 0.98–2.01 | 0.07 |
| No | Reference | ||
| Hemoglobin, g/dL | |||
| 9.14–13.3 | 1.38 | 1.00–1.89 | 0.05 |
| 13.4–19.1 | Reference | ||
| Total lung capacity, % predicted | |||
| 140–203 | 0.69 | 0.47–1.01 | 0.06 |
| 95–139 | Reference | ||
| Residual volume, %predicted | |||
| 262–412 | 1.56 | 1.04–2.37 | 0.03 |
| 97–261 | Reference | ||
| DlCO | |||
| 6–21 | 1.36 | 1.01–1.84 | 0.04 |
| 22–68 | Reference | ||
| Maximal CPET workload, watts | |||
| Low* | 1.48 | 1.12–1.94 | 0.006 |
| High* | Reference | ||
| Difference in %emphysema (upper lung–lower lung) | 1.80 | 1.22–2.66 | 0.003 |
| −40.4 to −0.8 | 0.86 | Reference | 0.49 |
| −0.7 to 63.6 | 0.57–1.31 | ||
| Missing | |||
| Perfusion ratio | |||
| 0.00–0.14 | 1.53 | 1.11–2.12 | 0.01 |
| 0.15–3.13 | Reference | ||
| Modified BODE index† | |||
| 7–10 | 1.48 | 1.07–2.05 | 0.02 |
| 1–6 | Reference |
Definition of abbreviations: BMI = body mass index; CI = confidence interval; CPET = cardiopulmonary exercise testing; IC/TLC = ratio of inspiratory capacity to total lung capacity.
Adapted from Reference 35.
All variables listed in Table 2 were included in each model except as noted in the table; results are shown for those variables that were significant predictors at the P ≤ 0.05 level in either model.
Low exercise is defined as a maximal workload at or below the sex-specific 40th percentile (25 watts for females and 40 watts for males; high exercise is defined as a workload above this threshold.
Components of the modified BODE index are: BMI, FEV1, UCSD SOBQ score, and 6MWT distance. P for the four components for the modified BODE index = 0.12.