Table 7.

Analysis of the effects of demographic, lifestyle, and work factors on Number of awakenings

		Adjusted
		OR	95% CI			p
Age		1.00	0.98	–	1.01	0.73
Sex	(Ref: Male)	0.49	0.34	–	0.70	<0.01
Body mass index		1.06	1.01	–	1.12	0.02
Lifestyle habit
Longer sleeping hours on weekends than on weekdays	(Ref: No)	0.80	0.57	–	1.12	0.20
Nightcap	(Ref: No)	1.40	0.96	–	2.03	0.08
Smoking	(Ref: Former and never)	1.50	0.81	–	2.75	0.19
Exercise habits	(Ref: Once a week or less)	1.31	0.86	–	1.99	0.21
Smartphone use at bedtime	(Ref: No)	1.67	1.14	–	2.44	<0.01
TV watching in the bedroom	(Ref: No)	1.07	0.75	–	1.54	0.70
Water ingestion at bedtime	(Ref: No)	1.53	0.98	–	2.40	0.06
Ingestion of a caffeinated beverage
Coffee	(Ref: One cup per day or less)	0.98	0.68	–	1.41	0.91
Green tea	(Ref: One cup per day or less)	0.95	0.68	–	1.32	0.75
Tea	(Ref: One cup per day or less)	1.27	0.84	–	1.91	0.25
Energy drink	(Ref: One cup per day or less)	1.20	0.44	–	3.32	0.72
Shift worker	(Ref: No)	1.52	0.86	–	2.70	0.15
Commuting time (hours)		1.23	0.88	–	1.74	0.23
Brief Scale for Job Stress
Workload		0.75	0.57	–	0.98	0.04
Mental workload		1.46	1.10	–	1.94	<0.01
Problems in personal relationships		1.09	0.85	–	1.39	0.49
Job control		0.86	0.67	–	1.11	0.25
Reward from work		1.26	1.00	–	1.59	0.05
Support from colleagues and superiors		0.78	0.58	–	1.05	0.10

Statistical analyses were conducted using binomial logistic regression.

OR: odds ratio

CI: confidence interval

Logistic regression analysis, n = 693.