Table 3.

Associations between baseline characteristics and pain phenotypes at 24-month follow-up

Baseline characteristics	No Pain RR (95% CI)	Mild P-A RR (95% CI)	Mild P-R-A RR (95% CI)	Mod P-R-A RR (95% CI)
Age, yeara
< 60	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)
≥ 65	1.00 (reference)	1.01 (0.94, 1.08)	0.89 (0.80, 0.99)	0.68 (0.56, 0.82)
Genderb
Female	1.00 (reference)	1.11 (1.04, 1.20)	1.16 (1.05, 1.29)	1.89 (1.55, 2.31)
CES-D score	1.00 (reference)	1.01 (1.00, 1.01)	1.02 (1.02, 1.03)	1.04 (1.03, 1.14)
BMI, kg/m2
< 25	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)
25–29.9	1.00 (reference)	1.08 (0.98, 1.19)	1.43 (1.21, 1.68)	2.01 (1.46, 2.75)
≥ 30	1.00 (reference)	1.21 (1.10, 1.33)	1.81 (1.55, 2.13)	1.92 (1.40, 2.64)
Education
College or above	1.00 (reference)	0.96 (0.87, 1.06)	0.83 (0.75, 0.93)	0.80 (0.72, 0.88)
Race
Whites	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)
Non-whites	1.00 (reference)	1.04 (0.96, 1.14)	1.22 (1.11, 1.35)	2.08 (1.74, 2.49)
Injury	1.00 (reference)	1.18 (1.10, 1.27)	1.34 (1.22, 1.47)	1.30 (1.17, 1.44)
KL grade
0	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)
1	1.00 (reference)	1.28 (1.15, 1.43)	1.32 (1.10, 1.58)	1.45 (1.03, 2.05)
2	1.00 (reference)	1.63 (1.49, 1.79)	2.04 (1.76, 2.36)	3.08 (2.36, 4.02)
3	1.00 (reference)	1.84 (1.65, 2.06)	3.00 (2.58, 3.49)	3.88 (2.95, 5.10)
4	1.00 (reference)	2.63 (2.29, 3.01)	4.00 (3.45, 4.65)	5.42 (4.18, 7.03)

Mild P-A mild pain during activity, Mild P-R-A mild pain during both rest and activity, Mod P-R-A moderate pain during both rest and activity, RR relative risk, CI confidence interval, CES-D Center for Epidemiological Studies-Depression, BMI body mass index, KL Kellgren and Lawrence

^aAge and ^bgender were adjusted mutually

The rest factors were adjusted for all variables listed above