. Author manuscript; available in PMC: 2015 Apr 1.

Published in final edited form as: J Immigr Minor Health. 2014 Apr;16(2):256–264. doi: 10.1007/s10903-012-9713-4

Table 3.

Changes in secondhand smoke measures at follow-up assessments

	Intervention participants		Control participants			All participants
	Response N	Mean change from baseline (SD) or percentage point change	Response N	Mean change from baseline (SD) or percentage point change	P-value, difference in change over time between groups	Response N	Mean change (SD) or N (%)
6-month follow-up
Child’s urine cotinine (ng/mL)	39	−0.13 (2.4)	33	+0.10 (3.0)	0.72	72	−0.02 (2.7)
Air nicotine concentration (g/m³)	83	+0.14 (2.6)	79	−0.23 (1.7)	0.29	162	−0.04 (2.2)
Hours of weekly household smoking	95	−7.4 (27.0)^*	88	−5.5 (22.3)^*	0.61	183	−6.5 (24.8)
Hours of child’s weekly exposure to SHS	102	−2.5 (8.2)^*	100	−4.0 (15.6)^*	0.38	202	−3.2 (12.4)
Household smoking ban	100	+17%^*	99	+16%^*	0.54	199	+16%
12-month follow-up
Hours of weekly household smoking	85	−11.1 (26.6)^*	80	−6.6 (19.9)^*	0.25	165	−9.0 (23.6)
Hours of child’s weekly exposure to SHS	90	−4.2 (10.9)^*	87	−5.5 (16.8)^*	0.53	177	−4.8 (14.0)
Number of household cigarettes smoked daily	87	−10.3 (14.0)^*	78	−10.8 (20.5)^*	0.85	165	−10.5 (17.3)
Household smoking ban	88	+25%^*	87	+30%^*	0.59	175	+28%

Intervention/control group differences were assessed using chi-square tests (household smoking ban) or two-sample t-tests on change variables (all other variables). Change over time within group was assessed using McNemar’s test (household smoking ban) or one-sample t-tests on change variables (all other variables).

Indicates change over time within group (intervention/control) is different from zero at p<0.05.