Validation of a proposed WOMAC short form for patients with hip osteoarthritis

Table 4 Correlation between the WOMAC short scales and SF-36 domains, and known-groups validity of the WOMAC short scales in cohort 1 (n = 788)

	WOMAC short scales
SF-36 domains	Pain ρ coefficient	Function ρ coefficient
Physical functioning	-0.44	-0.54
Role physical	-0.34	-0.36
Bodily pain	-0.48	-0.50
General health	-0.19	-0.17
Vitality	-0.32	-0.33
Social functioning	-0.38	-0.38
Role emotional	-0.17	-0.13
Mental health	-0.29	-0.25
Summary physical component	-0.34	-0.41
Summary mental component	-0.28	-0.25
	Pain Mean(SD)	Function Mean(SD)
Pain categorical scale
Minor (n = 32)^a	24.74 (12.96)^{b, c}	46.23 (17.56)^{b, c}
Moderate (n = 171)^b	43.68 (14.16)^{a, c}	57.97 (16.93)^{a, c}
Severe (n = 579)^c	61 (17.16)^{a, b}	72.67 (14.99)^{a, b}
P value	< 0.0001	< 0.0001
Functional limitation categorical scale
Minor (n = 79)^a	43.38 (16.63)^{b, c}	54.06 (17.48)^{b, c}
Moderate (n = 422)^b	51.70 (17.53)^{a, c}	65.38 (15.70)^{a, c}
Severe (n = 286)^c	64.94 (17.56)^{a, b}	76.68 (15.43)^{a, b}
P value	< 0.0001	< 0.0001

ρ: Spearman correlation coefficient.
Data are expressed as the Spearman correlation coefficient when studying the correlation between the WOMAC short scales and the SF-36 domains, and as the mean (SD) when comparing the WOMAC short scales according to the pain and functional limitation short categorical scales.
The scores for the WOMAC domains range from 0 to 100, with higher scores indicating worse health status. The scores for the SF-36 domains range from 0 to 100, with higher scores indicating better health status.
^abc Superscript letters indicated differences among the three subgroups by Scheffe's test for multiple comparisons at P< 0.05.

ISSN: 1477-7525