Table 5.

Association of chronic back pain with the Physical Composite Score and Mental Composite Score

	Physical Composite Score			Mental Composite Score
	Coef	95% CI		Coef.	95% CI
Chronic back pain status (ref: No pain)	−2.96	−3.13	−2.80	−1.25	−1.45	−1.05
Gender: female (ref: male)	−.54	−.71	−.37	−1.23	− 1.42	− 1.03
Age	−.08	−.08	−.07	−.02	−.03	−.01
Education (ref: no degree)
Middle school	1.00	.73	1.27	1.03	.70	1.36
High school	1.42	1.10	1.74	1.16	.78	1.54
Some college	1.50	1.17	1.84	1.28	.86	1.69
College degree	1.50	1.15	1.84	.97	.54	1.39
Occupation (ref: farmers)
Independent	.56	−.13	1.24	1.27	.43	2.11
Executive	.78	.15	1.41	.83	.04	1.62
Intermediary profession	.59	−.02	1.19	.94	.18	1.70
Employee	.19	−.41	.79	.92	.16	1.68
Blue collar worker	−.09	−.69	.52	.83	.07	1.59
Inactive	−.59	−1.21	.04	−.41	−1.21	.39
Relationship status: In a relationship (ref: single)	.16	.00	.31	1.36	1.16	1.55
Population density (ref: rural area)
< 20,000	.12	−.13	.37	−.14	−.44	.15
20,000 to 100,000	.19	−.06	.44	−.43	−.74	−.13
> 100,000	−.02	−.21	.17	−.45	−.68	−.22
Comorbidity
Any chronic pain (ref: absence)	−3.07	−3.23	−2.90	−1.59	−1.79	−1.40
Any other medical condition (ref:absence)	− 2.45	−2.62	− 2.27	−2.52	− 2.74	−2.30
R2	0.4302			0.1548

Note. Multivariable linear regression predicting physical and mental composite scores controlling for all socio-demographic variables presented in the table. Bold signifies statistically significant coefficients at p = .05 or greater