TABLE 4.

Summary of meaningful change thresholds of King's Brief Interstitial Lung Disease (K-BILD) questionnaire total score

Method of analysis	Anchor	Change in K-BILD total score		Thresholds
Anchor-based methods				Threshold for stabilisation
Mean change#		Stable	Minimal-to-moderate decline
	Global QoL¶	0.6	–3.9	–1.7§
	Global physical health¶	0.5	–3.3	–1.4§
		Stable	Minimal decline
	Global QoL¶	0.6	–3.7	–1.6§
	Global physical health¶	0.5	–2.6	–1.1§
eCDF analysis		Stable	Minimal-to-moderate decline
	Global QoL+	0.7	–3.3	–1.3§
	Global physical health+	0.0	–3.8	–1.9§
Youden index cut-point
	Global QoL			–1.5
	Global physical health			–1.5
Distribution-based method				Threshold for deterioration
sem				–3.2
0.2 sd				–2.5
0.5 sd				–6.3

QoL: quality of life; eCDF: empirical cumulative distribution function. ^#: threshold analyses were conducted to determine the meaningful cut-point in K-BILD mean change score that lies half-way between the group means for stable patients (no change) and patients with minimal-to-moderate decline (−1 to −2 units) according to the anchor categories. Post hoc analyses using the mean change method were also conducted based on the stable patients (no change) and in patients with minimal decline (−1 unit). ^¶: mean. ⁺: median. ^§: half-way cut-point=(stable group+declinegroup)/2.