Table 3– A comparison of mortality and progression-free survival in relation to technetium-99m-labelled DTPA clearance in ILD of SSc and IPF patients

DTPA clearance variable	Mortality				Progressive-free survival
	SSc-ILD		IPF		SSc-ILD		IPF
	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value
Increasing rapid total clearance^# min	1.02 (1.00–1.03)	0.02	1.01 (0.99–1.02)	0.28	1.01 (1.00–1.02)	0.006	1.00 (0.98–1.01)	0.58
Patients with an abnormal clearance^# min	1.21 (0.69–2.12)	0.51	1.56 (0.82–2.96)	0.18	1.59 (1.06–2.38)	0.02	0.93 (0.49–1.77)	0.83
Increasing rapid fast clearance^¶ min	1.01 (0.91–1.13)	0.81	1.01 (0.96–1.07)	0.71	1.10 (1.01–1.19)	0.03	1.00 (0.94–1.06)	0.95
Increasing %FC^¶	1.02 (1.00–1.04)	0.06	1.00 (0.99–1.02)	0.66	1.01 (0.99–1.02)	0.30	1.00 (0.98–1.01)	0.78
Increasing delayed slow clearance^¶ min	1.00 (0.98–1.01)	0.60	1.00 (0.99–1.01)	0.38	1.00 (0.99–1.01)	0.61	1.01 (1.00–1.02)	0.01

DTPA: diethylene triamine pentacetate; ILD: interstitial lung disease; SSc: systemic sclerosis; IPF: idiopathic pulmonary fibrosis; HR: hazard ratio; %FC: % DTPA cleared by the fast component. ^#: 168 SSc-ILD patients and 97 IPF patients; ^¶: 126 SSc-ILD patients and 81 IPF patients.