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

Respiratory Research

Table 6 Responsiveness: mean change of QOL in changed health status in anchor; significant changes of QOL confirm responsiveness

Improvement in the specific anchor
	FVC		DLCO		6MWD		SF-36 item		TDI		NYHA
n^a	9–11		10–11		14–17		10–15		15–16		18–19
	mean	sd	mean	sd	mean	sd	mean	sd	mean	sd	mean	sd
PSC	6.2*	6.5	−3.9	9.6	3.0	10.5	4.0	10.1	4.3*	11.1	1.8	9.4
MSC	−3.6	13.1	−1.8	10.5	−1.1	10.2	−0.7	9.0	−0.7	8.3	−1.4	7.3
PFI	15.3	24.0	−3.9	19.9	1.6	19.7	5.4*	11.7	5.5	18.9	−3.2	24.1
ROLEM	−16.7	72.4	0.0	64.8	−8.9	47.9	0.0	62.9	−6.3	42.5	−20.4*	36.4
ROLPH	17.5	39.2	−25.0	45.6	11.7	28.1	30.0	55.0	20.3	44.0	2.8	34.2
GHP	7.1	20.8	−11.9*	14.6	2.3	14.5	4.1	24.2	5.0	22.8	2.6	19.4
MHI	2.0	19.0	−4.2	10.2	3.2	11.7	−1.0	9.6	1.9	16.7	1.7	11.7
VITAL	4.5	12.8	−2.3	14.0	4.4	13.4	4.0	16.5	7.4	14.8	1.1	14.1
SOCIAL	1.1	30.8	−10.2*	9.4	0.0	15.3	1.8	18.9	3.1	23.0	6.6	21.0
PAIN	0.2	31.9	4.9	23.9	11.5	28.8	1.3	23.8	−0.3	36.1	6.9	29.6
deterioration in the specific anchor
	FVC		DLCO		6MWD		SF-36 item		TDI		NYHA
n^a	30–36		22–28		29–36		37–45		55–73		29–40
	mean	sd	mean	sd	mean	sd	mean	sd	mean	sd	mean	sd
PSC	−2.6	10.3	−5.0	10.4	−2.8*	8.5	−3.0*	9.5	−2.4	7.8	−1.1	9.0
MSC	−2.9	13.0	−2.8	10.0	0.1	9.6	−3.0*	9.5	−0.7	8.3	−1.0	11.0
PFI	−12.9*	23.8	−14.1*	25.0	−9.3*	21.4	−10.2*	22.3	−3.9	21.3	− 2.7	25.2
ROLEM	−7.3	62.1	−15.9	49.1	−3.1	44.3	−4.4	48.5	−1.7	37.9	2.2	57.7
ROLPH	−2.3	51.7	−15.0	36.8	−14.5*	33.0	−10.1	35.8	−9.0*	35.7	−4.9	39.6
GHP	−7.3*	17.1	−6.9	16.8	−2.3	17.4	−5.0	15.0	−4.8*	13.8	−6.7	17.1
MHI	−8.1	17.2	−4.4	17.3	−2.1	14.5	−5.8	17.3	−4.1*	13.5	−3.3	17.7
VITAL	−8.2*	18.8	−3.7	22.0	−3.0	15.7	−6.8*	15.0	−4.7*	15.8	−0.4	19.3
SOCIAL	−10.8*	29.6	−12.9*	25.6	−7.3	30.5	− 13.3*	24.8	−1.5	23.2	− 14.1*	32.2
PAIN	−3.1	32.6	−10.0	35.1	4.6	27.4	−3.3	37.9	−2.7	27.3	−8.1	31.0

a sample 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
SD standard deviation
*p < 0.05
**p < 0.001
Abbreviations: PCS Physical component score, MCS Mental component score, 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, sd standard deviation, FVC Forced vital capacity, DLCO Diffusing capacity of the lungs for carbon monoxide, 6MWD 6 min walking distance, SF-36 item indicating health status of the last year, TDI Transitional Dyspnoea Index, NYHA New York Heart Association

ISSN: 1465-993X