Comorbidity, limitations in activities and pain in patients with osteoarthritis of the hip or knee

Table 4 Results from the multivariate regression analyses: association between comorbidity (morbidity count (CIRS ≥ 1), morbidity count (CIRS ≥ 2), severity index) and limitations in activity (WOMAC, SF-36, timed walking test) and pain (VAS) ^Δ*

	Morbidity count	Morbidity count	Severity index
	(CIRS ≥ 1)	(CIRS ≥ 2)
WOMAC (physical functioning domain)	-0.208‡	-0.323‡	-0.322‡
	R² = 0.056	R² = 0.114	R² = 0.114
SF-36 (physical functioning domain)	-0.286‡	-0.350‡	-0.281‡
	R² = 0.114	R² = 0.152	R² = 0.113
Timed walking test
Age 50–60 **			0.148†
Age 61–71	0.169	0.184∫
Age 72–84	0.123	0.179∫
	0.262†	0.338‡
	R² = 0.139	R² = 0.185	R² = 0.097
VAS (pain)	0.167‡	0.233‡	0.230 ‡
	R² = 0.032	R² = 0.058	R² = 0.056

^Δ Standardized β's are presented *All multivariate associations are corrected for age and gender. Other corrections were found to be unnecessary. ** A significant interaction was found between morbidity count and age (age categories were chosen in order to have equal distribution of patients over the categories). ∫ 0.1 < p < 0.05; † p < 0.05; ‡ p < 0.01. WOMAC: Western Ontario and MacMaster universities osteoarthritis index; SF-36: MOS 36 item Short Form Health Survey; VAS: Visual Analogue Scale.

ISSN: 1471-2474