Psychometric properties and minimal important differences of SF-36 in Idiopathic Pulmonary Fibrosis

Respiratory Research

Table 3 Criterion validity analysed via correlation coefficiants

	n^c	PCS	MCS	PFI	ROLEM	ROLPH	GHP	MHI	VITAL	SOCIAL	PAIN
FVC % pred^a	232–257	0.35**	− 0.01	0.35**	0.11	0.35**	0.26**	< 0.01	0.20*	0.11	0.07
DLCO % pred^a	208–227	0.36**	0.05	0.39**	0.14*	0.37**	0.22*	0.04	0.20*	0.23*	0.02
6MWD^a	167-180	0.44**	0.17*	0.53**	0.18*	0.37**	0.29*	0.22*	0.32**	0.31**	0.17*
mMRC^b	180-196	−0.48**	− 0.11	−0.61**	− 0.14	−0.3**	− 0.32**	− 0.13	−0.37**	− 0.31**	− 0.16*
BDI^b	131-140	0.25*	− 0.05	0.38**	− 0.02	0.11	0.09	0.01	0.22*	0.14	0.14
NYHA^b	206–228	−0.33**	− 0.09	−0.41**	− 0.17*	− 0.37**	− 0.22*	− 0.13*	− 0.3**	− 0.18*	− 0.09

^aPearson correlation
^bSpearman correlation
^csample size varying depending on temporal relation of anchors and filled in SF-36, number of missing items within SF-36 and the possibility to calculate dimensions and summary scores
*p < 0.05
**p < 0.0001
bold at least moderate criterion validity (r ≥ 0.3)
Abbreviations: FVC pred forced vital capacity percent predicted, DLCO pred diffusing capacity of the lungs for carbon monoxide percent predicted, 6MWD 6 min walking distance, mMRC Modified Medical Research Council Dyspnea Scale, BDI Baseline Dyspnoea Index, NYHA New York Heart Association, GHP general health perceptions, PFI physical functioning, ROLPH physical role functioning, ROLEM emotional role functioning, SOCIAL social role functioning, MHI Mental health, PAIN bodily pain, VITAL Vitality

ISSN: 1465-993X