Table 2

Factors assessed at baseline related to sick leave due to neck or back pain at the 18-month follow-up

Risk factors*	n	Cases†	Adjusted OR
Results from multivariate logistic regressions per variable set.
*In all the multivariate analyses, sex, age, neck and back pain during the past year were included together with all variables within each variable set with p⩽0.10 from univariate analyses.
†The number of participants reporting sick leave due to neck or back pain.
‡No ORs could be computed because no cases were available in this category.
§Higher score means more of the characteristics described. Range 1–5.
Background/demographic factors*
Employment grade
Blue-collar	1168	132	1.00
White-collar	404	16	0.34 (0.20 to 0.58)

Lifestyle factors*
No factors with p<0.05

Health-related and pain-related characteristics*
Sick leave during the previous year (all causes except neck or back pain)
No days	673	42	1.00
1–7 days	555	63	1.85 (1.22 to 2.80)
8–99 days	267	40	2.18 (1.35 to 3.53)
100–365 days	16	0	–‡

Back pain during the previous year
No	722	39	1.00
Yes, one time	219	25	2.00 (1.14 to 3.50)
Yes, several times	570	81	1.95 (1.24 to 3.06)

Perceived prognosis of own working ability in 2 years’ time
Almost certain	1397	119	1.00
Not certain about it	101	24	2.16 (1.24 to 3.78)
Probably not	13	2	0.67 (0.12 to 3.74)

Physical work characteristics*
Heavy lifting
Almost never	839	58	1.00
1–10 times per day	540	56	1.20 (0.78 to 1.89)
>10 times per day	194	34	2.03 (1.20 to 3.43)

Working with vibrating tools
Almost never	1122	81	1.00
5–30 min per day	245	32	1.62 (0.99 to 2.64)
31–60 min per day	73	11	2.16 (1.05 to 4.46)
>60 min per day	133	24	2.02 (1.15 to 3.55)

Psychosocial work characteristics*
Control of work pacing§
Lowest quartile (1) 1.00–2.34	346	53	1.00
(2) 2.35–3.00	357	36	0.70 (0.44 to 1.12)
(3) 3.01–3.75	409	34	0.58 (0.36 to 0.94)
(4) 3.76–5.00	446	26	0.44 (0.26 to 0.76)