Table 2.

Associations of sex, age and occupational risk factors with new development and persistence of multi-site pain

Risk Factora	New onset of multi-site pain				Persistence of multi-site pain				Wald testd p- value
	No. at riskb	No. of cases	OR	(95% CI)	No. at riskc	No. of cases	OR	(95% CI)
Age (yrs)	165	27	1.0	0.9-1.0	350	217	1.0	1.0-1.1	0.12
Sex									0.91
Male	67	11	1		104	64	1
Female	101	16	0.8	0.3-2.5	246	153	1.3	0.7-2.3
Main occupation									0.80
Office worker	59	6	1		130	69	1
Postal clerk	46	8	2.3	0.6-9.0	71	49	2.0	1.0-4.1
Nurse	63	13	2.3	0.8-6.7	149	99	1.9	1.1-3.1
Hours worked per week
<40	45	2	1		83	49	1		0.04
≥40	123	25	5.0	(1.1-24.0)	266	167	1.0	(0.6-1.7)
Number of strenuous physical activities
0-1	35	7	1		35	15	1		0.29
2	35	4	0.5	(0.1-2.0)	67	34	1.2	(0.5-2.9)
3	47	6	0.5	(0.2-1.8)	127	78	2.0	(0.9-4.3)
4-7	51	10	0.9	(0.3-2.7)	121	90	3.2	(1.4-7.4)
Job satisfaction
High	150	23	1		266	161	1		0.88
Low	17	3	1	(0.3-4.0)	83	56	1.1	(0.6-1.9)
Job demands
Low	36	4	1		64	33	1		0.98
High	130	22	1.4	(0.4-4.8)	286	184	1.3	(0.8-2.5)
Job control
High	69	11	1		148	84	1
Low	99	16	0.7	(0.3-1.8)	202	133	1.2	(0.7-2.0)	0.54
Job support
High	139	20	1		286	176	1
Low	25	7	2.6	(0.8-8.3)	61	40	1	(0.5-1.8)	0.25
Job security
High	135	20	1		281	174	1
Low	31	7	1.4	(0.5-3.9)	69	43	1	(0.6-1.7)	0.49

^aEach risk factor was analysed in a separate logistic regression model, which also included sex, age (as a continuous variable) and occupation

^bSubjects who did not report pain at multiple sites in the year before baseline (information on some risk factors was missing for some participants)

^cSubjects who reported pain at multiple sites in the year before baseline (information on some risk factors was missing from some participants)

^dWald test for significance of differences between associations with new onset and persistence of multi-site pain