. Author manuscript; available in PMC: 2018 Apr 4.

Published in final edited form as: Pediatrics. 2016 Feb 26;137(3):e20152857. doi: 10.1542/peds.2015-2857

TABLE 1.

Study Populations

Measure	Level	Intervention, Enrolled, n = 374	Intervention, Not Enrolled, n = 493	Enrolled Versus Not Enrolled P^a	Control, n = 555	Enrolled Versus Control P^a
Gender, %	Male	67	65	.51	64	.43
Gender, %	Female	33	35		36
Age	Mean (SD)	13.0 (2.2)	13.4 (2.4)	.01	13.0 (2.2)	.97
	11–12	47	43	.06	48	.76
	13–15	35	32		33
	16–17	18	25		19
Race, %	White	48	47	.03	53	<.01
	Black	14	9		8
	Other	18	17		13
	Unknown	20	27		25
Hispanic, %	Yes	22	23	.01	26	.08
	No	70	62		63
	Unknown	9	15		12

χ² test of proportions used for comparisons between categories; Wilcoxon signed-rank test used for comparison between means.