Thai SF-36 health survey: tests of data quality, scaling assumptions, reliability and validity in healthy men and women

Table 2 Tests of scaling assumptions

Scale	# items per scale, k	(a) Item internal consistency			(b) Item discriminant validity
		Range^a	Comparison^b	Success rate (%)	Range^c	Comparison^d	Success rate (%)
PF	10	0.48 – 0.68	10/10	100	0.10 – 0.31	70/70	100
RP	4	0.65 – 0.77	4/4	100	0.18 – 0.44	28/28	100
BP	2	0.83	2/2	100	0.22 – 0.46	14/14	100
GH	5	0.60 – 0.79	5/5	100	0.14 – 0.45	35/35	100
VT	4	0.64 – 0.75	4/4	100	0.16 – 0.59	28/28	100
SF	2	0.77	2/2	100	0.20 – 0.40	14/14	100
RE	3	0.67 – 0.84	3/3	100	0.18 – 0.44	21/21	100
MH	5	0.50 – 0.75	5/5	100	0.12 – 0.66	35/35	100

^a Correlations between items and hypothesized scale, corrected for overlap
^b Number of items out of k with correlation ≥ 0.40
^c Correlations between items and other scales
^d Number of items out of 7 × k where difference between the correlation of the item with its own scale and correlation with the other scales ≥ 2SE (= 0.0576)

ISSN: 1477-7525