Environmental tobacco smoke exposure and lung cancer: A systematic review

Table 5 Estimates used when adjusting for potential confounding effects¹

	Statistic	Fruit consumption	Vegetable consumption	Dietary fat consumption	Education
Lung cancer risk	N studies	14	16	6	12
	RR2	0.86	0.88	1.22	0.91
	(95%CI)	(0.78-0.96)8	(0.80-0.97)8	(1.09-1.36)8	(0.88-0.95)6
	per	SD	SD	SD	Year3
ETS exposure	N studies	11	16	12	13
at home	Difference24	-0.0737	-0.0568	0.1317	-0.5346
	(SE)	-0.02	-0.021	-0.032	-0.063
	unit	SD	SD	SD	Year3
Correlations5	Fruit consumption	1	+0.3147	-0.104NS	+0.143NS
	Vegetable consumption		1	-0.054NS	-0.1309
	Dietary fat consumption			1	-0.039NS
	Education				1

Note: P values are indicated by

⁶P < 0.001,

⁷P < 0.01,

⁸P < 0.05,

⁹P < 0.1, or

^NSP≥ 0.1. ¹All data are for lifelong non-smoking females;

²Based on random-effects meta-analysis;

³The SD for education was taken as 2.435 years based on six studies;

⁴Difference in level of confounder between those exposed and unexposed to ETS at home;

⁵Based on seven studies, using unweighted means.