Table 4. Predictors of Household Air Nicotine Levels: Factors Influencing Adoption of and Adherence to Indoor Smoking Bans, Massachusetts, April 2010–September 2012.

Characteristic	Bivariate P	Multivariable Modela
		P	Mean (95% CI)
Living room
Total cigarettes smoked per week (all)	< .01
Total smokers in household (range = 0–3)	< .01
Home smoking rule	< .01
No ban			0.69 (0.22, 2.20)
Partial ban			0.12 (0.06, 0.23)
Complete ban			0.11 (0.06, 0.19)
Current smoker	< .01	< .01
No			0.12 (0.06, 0.23)
Yes			0.35 (0.19, 0.67)
Location of smoking	< .01	< .01
No smoking			0.07 (0.02, 0.23)
Outside only			0.20 (0.10, 0.41)
Indoors (with or without outdoor locations)			0.69 (0.44, 1.09)
Participant age, y	.16
Age of child, mo	.46
Household size	.09
Education levelb	.09
Race/ethnicityc	.05
Child had ≥ 1 health problem in past 6 mo (yes or no)	.24
Child's bedroom
Total cigarettes smoked per week (all)	< .01
Total smokers in household (range = 0–3)	< .01
Home smoking rule	< .01	< .01
No ban			0.38 (0.13, 1.10)
Partial ban			0.08 (0.04, 0.14)
Complete ban			0.08 (0.05, 0.13)
Current smoker	< .01	< .01
No			0.07 (0.04, 0.12)
Yes			0.27 (0.15, 0.48)
Location of smoking	< .01	< .01
No smoking			0.06 (0.02, 0.17)
Outside only			0.13 (0.07, 0.24)
Indoors (with or without outdoor locations)			0.32 (0.21, 0.48)
Participant age, y	.02
Age of child, mo	.04
Household size	.26
Education levelb	.13
Race/ethnicityc	.01
Child had ≥ 1 health problem in past 6 mo (yes or no)	.77

Note. CI = confidence interval; GED = general equivalency diploma.

^aFor the living room multivariable model, R² = 0.33; for the child's bedroom multivariable model, R² = 0.34.

^bEducational level (a proxy for socioeconomic position) was categorized as less than high school, high school or general equivalency diploma, some college, and undergraduate degree or higher.

^cRace/ethnicity was categorized as Hispanic, non-Hispanic White, non-Hispanic Black, or non-Hispanic other.