TABLE 3—

Change in Weeknight Sleep Duration and Odds Ratios of Getting Adequate Sleep on Weeknights for Each Half-Hour Increase in School Start Time Among Boys, by Urbanicity Level: National Comorbidity Survey—Adolescent Supplement, United States, 2001–2004

	Sleep Duration		Adequate Sleep
Urbanicity and Start Time	Adjusted b (95% CI)	P	AOR (95% CI)	P
Major metropolitan county		< .001		.037
Before 8:01 am	33.76 (20.43, 47.09)		2.18 (1.22, 3.89)
8:01 am and later	−3.26 (−15.83, 9.31)		0.71 (0.44, 1.14)
Other urbanized county		< .001		.105
Before 8:01 am	11.86 (−1.85, 25.56)		1.48 (0.77, 2.85)
8:01 am and later	9.50 (−7.91, 26.92)		1.21 (0.71, 2.04)
Nonurban county		.024		.149
Before 8:01 am	−20.25 (−35.26, −5.23)		0.75 (0.49, 1.13)
8:01 am and later	11.26 (−2.07, 24.59)		0.89 (0.59, 1.35)

Note. AOR = adjusted odds ratio; CI = confidence interval. Adjusted estimates control for age, school level, and student employment. P values were determined by the Wald test of start time as a whole.