Table 4

Physical work load according to internal JEM assessment and osteochondrosis or spondylosis of the lumbar spine

Variable		Referents				Osteochondrosis or spondylosis with chronic complaints, with or without disc herniation			“Pure” osteochondrosis or spondylosis with chronic complaints (cases with disc herniation excluded)
		Referents				Cases			Adjusted OR^4-150		95% CI	Cases		Adjusted OR^4-150	95% CI
		n	%			n	%		Adjusted OR^4-150		95% CI	n	%	Adjusted OR^4-150	95% CI
Sum of forces to the lumbar spine through lifting, carrying, or extreme forward bending, calculated on the basis of the means of the individual workload assessments performed by the referents within a given occupational group (Nh):
<3.0×10⁶	46	23.4		21	9.2	1.0	—	9	9.6	1.0	—
3.0–<6.0×10⁶	53	26.9		38	16.6	1.6	0.7 to 3.5	11	11.7	0.7	0.2 to 2.5
6.0–<10.5×10⁶	50	25.4		55	24.0	2.6	1.2 to 5.7	25	26.6	2.2	0.8 to 6.4
⩾10.0×10⁶	47	23.9		115	50.2	6.0	2.7 to 13.4	49	52.1	2.8	0.9 to 8.5
Unknown	1	0.5
p Value for trend^4-151						p<0.00005				p=0.01
Sum of forces to the lumbar spine through lifting, carrying, or extreme forward bending, calculated on the basis of the medians of the individual workload assessments performed by the referents within a given occupational group (Nh):
0	64	32.5		42	18.3	1.0	—	17	18.1	1.0	—
>0–<0.8×10⁶	42	21.3		42	18.3	1.7	0.9 to 3.4	19	20.2	2.6	1.0 to 6.6
0.8–<4.0×10⁶	46	23.4		46	20.1	1.8	0.9 to 3.4	19	20.2	1.9	0.8 to 4.8
⩾4.0×10⁶	44	22.3		99	43.2	3.7	2.0 to 6.8	39	41.5	2.9	1.2 to 6.9
Unknown	1	0.5
p Value for trend^4-151						p=0.0001				p=0.04

↵4-150 Adjusted for age, region, nationality, and other diseases of the lumbar spine.
↵4-151 Exposure score included as a continous variable in the logistic regression model.