Table 4.
Multivariable Cox Proportional Hazards Models for Association of Baseline Clinical and High-Resolution Computed Tomography Variables with Disease Progression
| Visual Assessment C Statistic: 0.722 (95% CI = 0.639–0.804) |
AMFM Assessment C Statistic: 0.720 (95% CI = 0.637–0.802) |
|||||
|---|---|---|---|---|---|---|
| Predictor | HR (95% CI) | Standardized HR (95% CI) | P Value | HR (95% CI) | Standardized HR (95% CI) | P Value |
| Ground glass reticular | 1.98 (1.20–3.28) | 1.47 (1.11–1.96) | 0.008 | 1.36 (1.01–1.84) | 1.35 (1.01–1.76) | 0.04 |
| Former smoker | 0.77 (0.42–1.41) | — | 0.40 | 0.66 (0.36–1.22) | — | 0.18 |
| GAP stage | ||||||
| 1 | Ref. | — | Ref. | Ref. | — | Ref. |
| 2 | 1.49 (0.74–3.00) | — | 0.27 | 1.65 (0.83–3.29) | — | 0.15 |
| 3 | 3.96 (1.73–9.09) | — | 0.001 | 4.66 (2.10–10.31) | — | 0.0002 |
Definition of abbreviations: AMFM = adaptive multiple features method; CI = confidence interval; GAP = gender-age-physiology; HR = hazard ratio.
Analysis includes n = 156 patients. Of 159 subjects having baseline AMFM-scored high-resolution computed tomography (HRCT), n = 1 subject was missing smoking status and n = 2 missing diffusing capacity of the lung for carbon monoxide (DlCO) required for GAP stage calculation. Baseline characteristics for this subgroup, including number of events/outcomes, is shown in Table 1 column titled “Baseline HRCT.” Unstandardized HR is for each 10% increase in baseline total lung volume occupied by ground glass reticular. Standardized HR is for each standard deviation increase in ground glass reticular. The categorical variables were not standardized. The GAP stage (24) is a mortality prediction model incorporating age, sex, FVC, and DlCO, with higher GAP stages experiencing the worst outcomes. The outcome of interest is a composite FVC drop >10%, hospitalization, or mortality event.