Exploring determinants predicting response to intra-articular hyaluronic acid treatment in symptomatic knee osteoarthritis: 9-year follow-up data from the Osteoarthritis Initiative

Table 2 Symptoms (WOMAC scores) at T0

	Total (n = 404)^a	Low,^b 0 < WOMAC pain^c < 4 (n = 118)	Moderate, 4 ≤ WOMAC pain^c ≤ 7 (n = 150)	High, WOMAC pain^c ≥ 8 (n = 136)	Low vs High p value^d	Moderate vs High p value^d
WOMAC at T0
	(n = 404)	(n = 118)	(n = 150)	(n = 136)
Pain (0–20)	6.13 ± 3.69	2.07 ± 0.80	5.37 ± 1.10	10.48 ± 2.19	< 0.001	< 0.001
	(n = 390)	(n = 116)	(n = 146)	(n = 128)
Function (0–68)	19.27 ± 11.63	8.61 ± 5.53	18.46 ± 8.23	29.87 ± 9.55	< 0.001	< 0.001
	(n = 404)	(n = 118)	(n = 150)	(n = 136)
Stiffness (0–8)	2.85 ± 1.68	1.84 ± 1.53	2.73 ± 1.38	3.85 ± 1.54	< 0.001	< 0.001
	(n = 390)	(n = 116)	(n = 146)	(n = 128)
Total (0–96)	28.17 ± 15.80	12.49 ± 6.76	26.56 ± 9.32	44.23 ± 11.71	< 0.001	< 0.001
WOMAC change (T0 to T1)	(n = 404)	(n = 118)	(n = 150)	(n = 136)
Pain	0.28 ± 3.90	1.90 ± 2.81	1.25 ± 3.72	−2.21 ± 3.71	< 0.001	< 0.001
Decrease ≥ 20% (responders)	31% (125)	19% (22)	27% (40)	46% (63)
0% < decrease < 20%	8% (31)	0% (0)	5% (7)	18% (24)
Stable = 0% (nonresponders)	14% (55)	14% (17)	14% (21)	13% (17)
Increase > 0% (nonresponders)	48% (193)	67% (79)	55% (82)	24% (32)	< 0.001 ^e	< 0.001 ^e
	(n = 390)	(n = 116)	(n = 146)	(n = 128)
Function	0.95 ± 12.50	5.35 ± 9.84	2.56 ± 11.60	−4.89 ± 13.50	< 0.001	< 0.001
	(n = 404)	(n = 118)	(n = 150)	(n = 136)
Stiffness	0.18 ± 1.84	0.43 ± 1.53	0.29 ± 1.77	−0.16 ± 2.10	0.010	0.032
	(n = 390)	(n = 116)	(n = 146)	(n = 128)
Total	1.35 ± 16.71	7.62 ± 13.02	4.12 ± 15.43	−7.50 ± 17.51	< 0.001	< 0.001

Results are shown as mean ± standard deviation or % and number (n) of participants’ IAHA injected knees. Bold data are significant at p < 0.05
T0 visit before IAHA treatment, T1 visit after IAHA treatment, IAHA intra-articular hyaluronic acid, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index
^aNumber of injected knees based on 310 participants
^bThe level of pain on WOMAC score was divided into three groups (Low, Moderate, and High) based on tertile analysis
^cWOMAC Likert 3.1 (scale 0–20) pain scores at T0. Participants with WOMAC pain score = 0 were excluded from analysis. A higher score indicates more pain/symptoms and greater function impairment
^dContinuous variables were compared using Student’s t test/Mann–Whitney test
^eProportions compared using the chi-squared test/Fisher’s exact test

ISSN: 1478-6362