Table 3. Spinal diseases and symptoms predicted by chronotype.^a .

Chronotype	Odds ratio	95% confidence limit
		Lower	Upper
Spinal disease diagnosed or treated by doctor in the past 12 months
Model 1(N = 6063, No N = 5133, Yes N = 930)
Evening-types	1.1	0.9	1.4
Intermediate-types	0.9	0.8	1.1
Model 2 (N = 6063, No N = 5133, Yes N = 930)
Evening-types	1.5	1.2	1.9***
Intermediate-types	1.1	0.9	1.2
Model 3 (N = 5945, No N = 5035, Yes N = 910)
Evening-types	1.6	1.2	2.0***
Intermediate-types	1.1	0.9	1.3
Backache past month
Model 1(N = 6070, No N = 3417, Yes N = 2653)
Evening-types	1.5	1.3	1.8***
Intermediate-types	1.2	1.1	1.3****
Model 2 (N = 6070, No N = 3417, Yes N = 2653)
Evening-types	1.5	1.3	1.8****
Intermediate-types	1.2	1.1	1.4***
Model 3 (N = 5951, No N = 3351, Yes N = 2600)
Evening-types	1.5	1.3	1.8***
Intermediate-types	1.2	1.1	1.4****

^a Model 1 crude (univariate); model 2 controlled for gender and age; model 3 controlled for gender, age, education level, civil status, physical activity, alcohol consumption, and current smoking. Morning-types as the reference category. ^* p<0.05; ^** p<0.01; ^*** p<0.001; ^**** p<0.0001.