. 2014 Nov 17;11(11):11879–11897. doi: 10.3390/ijerph111111879

Table 4.

Test of Balance across Propensity Score Strata (N = 914).

Peer Alcohol Consumption	Stratum 1			Stratum 2			Stratum 3			Stratum 4			Stratum 5
	Mean		p-Value ^a	Mean		p-Value ^a	Mean		p-Value ^a	Mean		p-Value ^a	Mean		p-Value ^a
	Yes (n = 38)	No (n = 70)	p-Value ^a	Yes (n = 84)	No (n = 96)	p-Value ^a	Yes (n = 80)	No (n = 56)	p-Value ^a	Yes (n = 129)	No (n = 31)	p-Value ^a	Yes (n = 300)	No (n = 30)	p-Value ^a
Youth
Male	0.68	0.56	0.20	0.54	0.52	0.84	0.54	0.66	0.15	0.42	0.48	0.51	0.48	0.43	0.60
Age	12.35	12.40	0.59	13.27	13.22	0.65	13.93	13.85	0.34	14.35	14.43	0.45	15.95	15.21	0.00
Family Context
Monthly income (unit: 100 Chilean pesos)	2.52	2.78	0.26	3.02	3.22	0.41	3.10	2.94	0.50	3.22	2.46	0.02	3.34	3.28	0.85
Less than middle school	0.05	0.03	0.53	0.13	0.03	0.01	0.04	0.11	0.11	0.06	0.06	0.96	0.04	0.13	0.03
Middle school to less than high school	0.53	0.63	0.30	0.37	0.40	0.71	0.40	0.34	0.47	0.34	0.48	0.14	0.31	0.23	0.38
High school	0.39	0.31	0.40	0.48	0.53	0.46	0.53	0.50	0.77	0.56	0.45	0.29	0.61	0.60	0.94
Some college or more	0.03	0.03	0.95	0.02	0.04	0.51	0.04	0.05	0.65	0.04	0.00	0.27	0.04	0.03	0.86
Married	0.76	0.81	0.53	0.73	0.72	0.91	0.63	0.61	0.83	0.68	0.58	0.28	0.60	0.70	0.29
Number of drinks consumed in the past 30 days	19.68	10.60	0.06	22.08	17.00	0.52	10.31	19.75	0.11	11.60	7.65	0.43	18.21	19.47	0.90
Social Context
Neighborhood danger and drugs	2.48	2.40	0.71	2.75	2.78	0.82	2.80	2.93	0.51	3.03	2.95	0.68	3.41	3.13	0.16
Advertisement on newspapers/magazines (low exposure)	0.37	0.57	0.04	0.45	0.35	0.18	0.25	0.18	0.32	0.22	0.19	0.77	0.14	0.30	0.02
Advertisement on newspapers/magazines (moderate exposure)	0.37	0.24	0.17	0.31	0.34	0.63	0.36	0.45	0.33	0.37	0.42	0.63	0.43	0.33	0.32
Advertisement on newspapers/magazines (high exposure)	0.26	0.19	0.35	0.24	0.30	0.34	0.39	0.38	0.88	0.41	0.39	0.81	0.43	0.37	0.48
Advertisement on television (low exposure)	0.34	0.43	0.38	0.26	0.32	0.37	0.16	0.21	0.44	0.24	0.10	0.08	0.12	0.13	0.83
Advertisement on television (moderate exposure)	0.24	0.27	0.70	0.39	0.30	0.20	0.36	0.36	0.95	0.26	0.29	0.76	0.31	0.37	0.55
Advertisement on television (high exposure)	0.42	0.30	0.21	0.35	0.38	0.68	0.48	0.43	0.59	0.50	0.61	0.24	0.57	0.50	0.48
Observations (n)	38	70	--	84	96	--	80	56	--	129	31	--	300	30	--

^a: p-value of t-test for continuous variables and chi-square test for categorical variables.