Table 2.

Prognostic value of physical activity and established predictors of mortality in patients with IPF

	C statistic			Crude Cox regression of the raw predictors			Adjusted Cox regression of the standardized predictors
	AUROC	95% CI	p-value	HR	95% CI	p-value	HR	95% CI	p-value
Lung Function
FVC %pred.	0.79	0.65–0.92	0.001	0.96	0.94–0.99	0.001	0.36	0.20–0.66	0.001
DLCO %pred.	0.78	0.64–0.92	0.001	0.94	0.91–0.98	0.002	0.33	0.17–0.67	0.002
Exercise Capacity
6MWD	0.77	0.63–0.91	0.002	0.96a	0.93-0.98	0.003	0.56	0.37–0.87	0.009
Physical Activity
Steps per day	0.79	0.65–0.92	0.001	0.97b	0.96-0.99	0.002	0.46	0.26–0.82	0.008
Disease Severity
GAP Score	0.74	0.59–0.89	0.006	1.63	1.19–2.24	0.003	n/a	n/a	n/a

Adjustment was done for sex, age and antifibrotic therapy. For standardization, all continuous variables were divided by one standard deviation

Abbreviations: AUROC area under the receiver operating characteristics, HR hazard ratio, CI confidence interval, FVC forced vital capacity, DLCO diffusing capacity of the lung for carbon monoxide, 6MWD 6-min walking-distance, GAP Gender-Age-Physiology

^aCrude HR for 6MWD is reported per 10 m change. Therefore 6MWD results were divided by 10

^bCrude HR for SPD is reported per 100 steps change. Therefore SPD results were divided by 100