Table 4.

Current e-cigarette use^a among students in Orange County, CA: Odds ratios from multilevel logistic regression models

	Middle School (n=23,091)		High School (n=44,610)

	OR	95% CI	OR	95% CI

*School-level predictors*
Retailer presence (ref=none within 1/4 mile)^b	1.42	(0.82 – 2.46)	0.96	(0.71 – 1.28)
% eligible for free/reduced lunch program ^c	2.33	(1.53 – 3.54)	0.65	(0.48 – 0.88)
*Individual-level predictors*
Sociodemographic characteristics
Female (ref=Male)	0.99	(0.88 – 1.12)	0.84	(0.79 – 0.90)
Race-ethnicity (ref=non-Hispanic White)
Hispanic	1.57	(1.24 – 1.99)	0.96	(0.87 – 1.05)
Black	0.85	(0.46 – 1.54)	0.92	(0.70 – 1.20)
Asian	0.41	(0.29 – 0.60)	0.68	(0.59 – 0.78)
Other	1.14	(0.87 – 1.48)	1.04	(0.92 – 1.16)
Parent education (ref=College grad)
< College graduate	1.36	(1.13 – 1.63)	1.19	(1.10 – 1.29)
Missing/Don’t know	1.24	(1.03 – 1.50)	1.18	(1.06 – 1.32)
Behavioral risk factors
Tobacco use (ref=never used tobacco)	4.79	(4.01 – 5.72)	3.80	(3.53 – 4.09)
Alcohol use (ref= no alcohol in past 30 days)	5.04	(4.37 – 5.80)	4.49	(4.10 – 4.92)
Marijuana use (ref= no use in past 30 days)	4.53	(3.83 – 5.35)	3.31	(3.05 – 3.59)

Number of groups	123		83
Between-school variance (SE)	.211 (.049)		.096 (.023)
Intraclass correlation (SE)	.060 (.013)		.028 (.006)

Source: Authors’ calculations using California Healthy Kids Survey, 2013–2014 & OC E-cigarette Retailer Study

Notes: Odds ratios derivd from multilevel logistic regressions (full model shown). Middle school includes grade 7, high school includes grades 9 and 11.

Current use is defined as having used an e-cigarette in the past 30 days.

Retailer presence was defined as the presence of at least one e-cigarette retailer within 1/4 mile of school.

% of students within school eligible for free/reduced price lunch program (FRLP).