Table 3.

Concurrent validity of K-BILD

	SGRQ-I total	SGRQ-I impacts	SGRQ-I activities	SGRQ-I symptoms	SOBQ total	SF-36 PCS	SF-36 MCS	FVC%	DLCO%	6MWD (m)
K-BILD total	− 0.76	− 0.70	− 0.71	− 0.58	− 0.66	0.58	0.56	0.30	0.45	0.43
K-BILD psychological	−0.58	− 0.55	− 0.52	− 0.47	−0.45	0.33	0.60	0.24	0.34	0.31
K-BILD breathlessness and activities	−0.78	− 0.70	−0.76	− 0.57	−0.76	0.69	0.45	0.34	0.50	0.54
K-BILD chest symptoms	−0.69	− 0.66	−0.54	− 0.64	−0.57	0.54	0.44	0.24	0.32	0.30

All data are presented as Pearson’s correlation coefficients for all patients. All correlations had a p-value < 0.01 [16]. K-BILD King’s Brief Interstitial Lung Disease questionnaire, SGRQ-I IPF-specific version of St. George’s Respiratory Questionnaire, SOBQ University of California, San Diego Shortness of Breath Questionnaire, SF-36 Short Form-36, PCS Physical Component Score, MCS Mental Component Score, FVC Forced vital capacity, DLCO diffusion capacity of the lung for carbon monoxide, 6MWD Distance walked during the 6-min walk test