Knee pain as a predictor of structural progression over 4 years: data from the Osteoarthritis Initiative, a prospective cohort study

Table 4 Associations of knee pain patterns over 1 year with annual percentage cartilage volume loss and incidence of radiographic knee osteoarthritis over 4 years in participants without radiographic knee osteoarthritis at baseline

	Univariable analysis		Multivariable analysis^a
	Estimated marginal mean (SE)	p Value	Estimated marginal mean (SE)	p Value
Annual percentage cartilage volume loss in medial compartment
No knee pain at both baseline and 1 year	0.63 (0.03)		0.63 (0.03)^b,c
Fluctuating knee pain (pain at either time point)	0.80 (0.08)	0.01^d	0.81 (0.08)^b	0.01^d
Persistent knee pain (pain at both time points)	0.94 (0.12)		0.93 (0.12)^c
Trend		0.004		0.003
Annual percentage cartilage volume loss in lateral compartment
No knee pain at both baseline and 1 year	0.68 (0.03)		0.68 (0.03)^e,f
Fluctuating knee pain (pain at either time point)	0.88 (0.08)	0.008^d	0.89 (0.08)^e	0.005^d
Persistent knee pain (pain at both time points)	0.92 (0.11)		0.93 (0.11)^f
Trend		0.003		0.002
	OR (95% CI)	p Value	OR (95% CI)	p Value
Incidence of radiographic knee osteoarthritis
No knee pain at both baseline and 1 year	1.00		1.00
Fluctuating knee pain (pain at either time point)	1.96 (1.29, 2.99)	0.002	1.62 (1.04, 2.54)	0.03
Persistent knee pain (pain at both time points)	2.07 (1.16, 3.72)	0.01	1.57 (0.85, 2.90)	0.15
Trend		< 0.001		0.03

^aAdjusted for age, gender, body mass index and Kellgren-Lawrence grade
^bp = 0.04 for between-group difference
^cp = 0.02 for between-group difference
^dFor difference in annual percentage cartilage volume loss in medial/lateral compartment among the three knee pain pattern groups
^ep = 0.01 for between-group difference
^fp = 0.03 for between-group difference