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

Table 5 Associations of knee pain patterns over 1 year with annual percentage cartilage volume loss and progression of radiographic knee osteoarthritis over 4 years in participants with 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	1.22 (0.06)		1.26 (0.06)^b
Fluctuating knee pain (pain at either time point)	1.52 (0.11)	0.001^c	1.47 (0.11)	0.03^c
Persistent knee pain (pain at both time points)	1.68 (0.12)		1.60 (0.12)^b
Trend		< 0.001		0.01
Annual percentage cartilage volume loss in lateral compartment
No knee pain at both baseline and 1 year	1.06 (0.05)		1.08 (0.05)^d,e
Fluctuating knee pain (pain at either time point)	1.41 (0.08)	< 0.001^c	1.38 (0.08)^d	< 0.001^c
Persistent knee pain (pain at both time points)	1.46 (0.09)		1.39 (0.09)^e
Trend		< 0.001		< 0.001
	Odds ratio (95% CI)	p Value	Odds ratio (95% CI)	p Value
Progression 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)	1.46 (1.04, 2.06)	0.03	1.34 (0.94, 1.89)	0.10
Persistent knee pain (pain at both time points)	2.13 (1.53, 2.97)	< 0.001	1.82 (1.28, 2.60)	0.001
Trend		< 0.001		0.001

*Adjusted for age, gender, body mass index and Kellgren-Lawrence grade
^bp = 0.02 for between-group difference
^c For difference in annual percentage cartilage volume loss in medial/lateral compartment among the three knee pain pattern groups
^dp = 0.001 for between-group difference
^ep = 0.002 for between-group difference