Table 3. Differences in Stages of Action for Air Nicotine Testing and Adopting a Smoke-Free Home Policy, Participants in Treatment (n = 257) and Control (n = 258) Groups by Participant Characteristics, Calculated by Linear Mixed Models, the FRESH Intervention,^a Central Kentucky, January 2013–August 2017.

Characteristic	Stage of Actionb
	Secondhand Smoke Testing (n = 499)		Adopting a Smoke-Free Home Policy (nc = 247)
	F	P Valued	F	P Valued
Age	1.53	.22	0.02	.89
Male	0.46	.50	0.09	.77
White/non-Hispanic	1.18	.28	0.15	.70
College education	0.64	.42	3.61	.058
Employed for wages	0.29	.59	0.36	.55
Years living in home	0.02	.88	0.24	.63
Family history of lung cancer	0.12	.72	0.81	.37
Smokers in the home	26.41	<.001	—	—
Self-efficacy	52.72	<.001	31.79	<.001
Lung cancer worry	1.06	.30	0.01	.92
Lung cancer risk	<0.01	.96	1.65	.20
Synergistic risk	2.00	.16	2.20	.14
Health-related self-concept	<0.01	.99	0.41	.52
Risk group	—	—	5.01	.007
Time	439.97e	<.001	29.33e	<.001
Treatment	126.78e	<.001	0.32e	.57
Treatment x time	63.01	<.001	3.14	.026

Abbreviation: —, not applicable; FRESH, Freedom from Radon Exposure and Smoking in the Home intervention.

^a FRESH was a randomized controlled trial to promote stage of action to reduce radon and air nicotine levels in the home.

^b Although the full sample size was 515, 16 participants missing 1 or more variables in the models could not be included in the multivariable analysis.

^c This model was restricted to those with smokers in the home (n = 256; 9 were omitted because of missing 1 or more variable values in the model).

^d P values calculated by type 3 tests of fixed effects in the mixed models.

^e Regressions modeling stage of action to test for secondhand smoke and adopt a smoke-free home ranging from 1 (unaware) to 5 (maintenance over time). Main effects not interpretable in either model given the presence of a significant interaction effect.