Table 4. Multiple logistic regression analysis to determine the factors identifying participants with short sleep duration.

	Model 1 (n = 9,611)			Model 2 (n = 8,589)			Model 3 (n = 9,098)
	odds ratio	95% CI	P	odds ratio	95% CI	p	odds ratio	95% CI	p
Male	0.71	0.63–0.80	<0.01	0.69	0.61–0.79	<0.01	0.70	0.62–0.80	<0.01
Age (y)	1.00	0.99–1.00	0.15	1.00	0.99–1.01	0.39	1.00	0.99–1.01	0.12
Body mass index (kg/m2)	1.02	1.00–1.03	0.01	1.02	1.00–1.03	0.04	1.02	1.01–1.04	<0.01
Current smoker	0.91	0.79–1.05	0.20	0.89	0.76–1.04	0.15	0.91	0.79–1.05	0.21
Frequent alcohol drinker	0.95	0.84–1.08	0.44	1.00	0.88–1.14	0.99	0.94	0.83–1.07	0.33
Irregular sleep schedule	2.24	1.95–2.56	<0.01	-	-	-	2.28	1.98–2.63	<0.01
Hypnotic drugs	1.60	1.32–1.93	<0.01	1.70	1.39–2.08	<0.01	-	-	-
Analgesics	1.11	0.87–1.41	0.41	1.06	0.81–1.37	0.66	1.15	0.88–1.49	0.30
Gastroesophageal reflux disease	1.16	1.04–1.29	<0.01	1.16	1.03–1.30	0.01	1.18	1.06–1.32	<0.01
No. unfavorable dietary behaviors	1.19	1.12–1.25	<0.01	1.19	1.13–1.26	<0.01	1.20	1.13–1.26	<0.01
Knee pain	1.19	1.07–1.32	<0.01	1.18	1.05–1.32	<0.01	1.17	1.05–1.30	<0.01
Low back pain	1.13	1.02–1.24	0.01	1.12	1.02–1.24	0.02	1.11	1.00–1.22	0.04

Model 1: Analysis including all subjects.

Model 2: Analysis including only participants without irregular sleep schedule.

Model 3: Analysis including only participants who did not take hypnotics drugs.