Univariable and multivariable Cox proportional regression analysis for time to all-cause, nonelective hospitalisation at 1 year
| Univariable analysis | Multivariable analysis: Model 1# | Multivariable analysis: Model 2# | ||||
| HR (95% CI) | p-value | HR (95% CI) | p-value | HR (95% CI) | p-value | |
| 4MGS m·s−1 | 0.03 (0.01–0.18) | <0.001 | 0.02 (0.01–0.14) | <0.001 | ||
| Slow 4MGS (reference: preserved 4MGS) | 3.97 (1.94–8.11) | <0.001 | 2.76 (1.16–6.58) | 0.02 | ||
| Age years | 1.03 (0.97–1.09) | 0.34 | ||||
| Sex (reference: female) | 2.19 (0.67–7.22) | 0.20 | 4.33 (1.10–17.09) | 0.04 | 3.76 (1.03–13.70) | 0.045 |
| Smoking status (reference: never-smoker) | 2.34 (0.96–5.69) | 0.06 | ||||
| FVC % pred | 0.98 (0.96–1.00) | 0.02 | ||||
| DLCO % pred | 0.96 (0.94–0.99) | 0.003 | 0.96 (0.93–0.99) | 0.005 | 0.96 (0.94–0.99) | 0.01 |
| 6MWD m | 0.99 (0.99–0.99) | <0.001 | 0.99 (0.99–1.00) | 0.09 | ||
| Prescribed antifibrotic medication during the study period (reference: no) | 0.82 (0.40–1.65) | 0.57 | ||||
| Respiratory hospital admissions in previous year n | 1.19 (1.01–1.41) | 0.04 | ||||
| Chest infections in previous year n | 1.10 (0.93–1.31) | 0.26 | 0.02 (0.01–0.14) | 0.15 | ||
4MGS: 4-m gait speed; FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; 6MWD: 6-min walk distance. Model 1: 4MGS (continuous format), age, sex, smoking status, FVC % pred, DLCO % pred, 6MWD, prescribed antifibrotic medication during the study period, number of hospital admissions in the previous year, number of chest infections in the previous year. Model 2: slow 4MGS (binary format), age, sex, smoking status, FVC % pred, DLCO % pred, 6MWD, prescribed antifibrotic medication during the study period, number of hospital admissions in the previous year, number of chest infections in the previous year. #: final model presented.