Table 3.

Model Estimates: Parent-Reported Smoking, Child SHSe, and Cotinine

Variable	Estimate	Std Error	P-Value
Cigarettes Smoked
Intercept	4.133	0.635	<.001
Intervention and Time Effect
Time	−0.048	0.006	<.001
Splinea	0.017	0.007	0.025
Interventionb	0.022	0.297	0.940
Time*Interventionc	−0.151	0.009	<.001
Spline*Interventionc	0.210	0.012	<.001
Predictive Covariates
Two or More Smokers in Homeb	0.424	0.022	<.001
Race (White) b	0.688	0.347	0.050
Parent Age	−0.033	0.017	0.051
Child SHSe
Intercept	2.079	0.264	<.001
Intervention and Time Effect
Time	−0.154	0.009	<.001
Splinea	0.131	0.012	<.001
Interventionb	0.332	0.337	0.326
Time*Interventionc	−0.138	0.015	<.001
Spline*Interventionc	0.181	0.019	<.001
Predictive Covariates
Two or More Smokers in Homeb	0.228	0.034	<.001
Race (White) b	0.919	0.398	0.022
Log Cotinine
Intercept	1.829	0.215	<.001
Intervention and Time Effect
Time	0.014	0.008	0.076
Interventionb	0.126	0.197	0.523
Predictive Covariates
Two or More Smokers in Homeb	0.310	0.125	0.017
Smoking Status of Target Parent (Smoker) b	0.732	0.223	0.001
Location (On Campus)d	−0.237	0.056	<.001

Abbreviations: SHSe, secondhand smoke exposure; Std Error, standard error

^aIn the employed LMM/GLMM models, a Spline was used to indicate the slope change before and after the 3 month time points. The spline variable was constructed in the following way: if time ≤ 3 months, then spline = 0; if time > 3 months, then spline = time − 3.³⁴

^bFor the variables “Intervention,” “Two or More Smokers in Home,” “Race (White),” and “Smoking Status of Target Parent (Smoker),” the reference groups are “SCC (standard care control),” “0 or 1 smoker,” “Non-white,” and “Non-smoker,” respectively.

^cThe terms “Time*Intervention” and “Spline*Intervention” were used to indicate the interaction between time and/or spline and the intervention, respectively.

^d”Location (On Campus)” indicates the setting where the child spent the majority of time on the day preceding the urine collection (on the hospital campus vs. home or other residence).