Table 3.

Mental health– and substance use–related behaviors in relation to sleep duration and wake-up time on school days

	Wake-up time				Sleep duration
	aORa	95% CI		P	aORa	95% CI		P
Feeling unhappy, sad, or depressedb	0.87	0.78	0.96	.006	0.72	0.68	0.75	<.0001
Trouble going to sleep or staying asleepb	0.97	0.92	1.02	.214	0.77	0.71	0.84	<.0001
Feel too tired to do thingsb	0.94	0.83	1.06	.308	0.68	0.67	0.70	<.0001
Feel hopeless about the futureb	0.85	0.78	0.92	<.0001	0.74	0.70	0.78	< .0001
Feel nervous or tenseb	0.79	0.68	0.93	.006	0.74	0.70	0.78	<.0001
Worry too much about thingsb	0.78	0.70	0.88	<.0001	0.72	0.69	0.76	<.0001
Does dangerous things without thinkingb	0.97	0.74	1.26	.800	0.76	0.67	0.86	<.0001
Has nightmares or bad dreamsb	0.84	0.72	0.98	.028	0.83	0.77	0.91	<.0001
Daily caffeinated drinksc	0.93	0.87	0.99	.030	0.77	0.73	0.82	<.0001
Tobacco used	1.37	1.03	1.81	.029	0.84	0.78	0.92	<.0001
Alcohol used	1.51	1.28	1.78	<.0001	0.92	0.87	0.98	.008
Drug used	1.45	1.24	1.70	<.0001	0.88	0.80	0.96	.006

AOR, adjusted odds ratio; CI, confidence interval.

^aOdds ratios for difference in risk of selected mental health– and substance use–related behaviors for each additional hour of delayed wake-up or sleep duration time, adjusted for grade level, sex, race, medication for learning disability, usual grades in school, and school-level free and reduced lunch eligibility proportion.

^bSeveral times or more vs twice or less during the past 2 weeks.

^cOnce a day or more vs less than once a day during the last 2 weeks.

^dOnce or twice a week or more vs never during the last 2 weeks.