Environmental tobacco smoke exposure and lung cancer: A systematic review

Table 6 Adjusted/corrected analyses: Husband smoking¹

Studies	n	Unadjusted for confoundingUncorrected for misclassificationRR (95%CI)	Adjusted for confounding2Uncorrected for misclassificationRR (95%CI)	Adjusted for confounding2Corrected for misclassification3RR (95%CI)
All	93	1.219 (1.138-1.305)	1.139 (1.062-1.221)	1.077 (0.999-1.162)
North America	29	1.074 (0.937-1.232)	1.004 (0.873-1.154)	0.898 (0.775-1.039)
Europe and New Zealand	20	1.174 (1.007-1.369)	1.092 (0.934-1.277)	1.062 (0.899-1.254)
China (including Hong Kong and study LIM)	27	1.321 (1.144-1.524)	1.239 (1.071-1.433)	1.175 (1.005-1.374)
Rest of Asia (including study ILCCO)	17	1.284 (1.187-1.389)	1.194 (1.103-1.291)	1.164 (1.072-1.262)
North America, Europe and New Zealand	49	1.112 (1.004-1.231)	1.037 (0.935-1.150)	0.959 (0.858-1.072)
Asia	44	1.314 (1.199-1.439)	1.229 (1.121-1.348)	1.181 (1.070-1.304)
Published in 1980s	26	1.361 (1.216-1.522)	1.267 (1.132-1.417)	1.194 (1.059-1.347)
Published in 1990s	27	1.152 (1.016-1.305)	1.077 (0.948-1.225)	1.005 (0.871-1.160)
Published in 2000s	26	1.240 (1.105-1.392)	1.163 (1.034-1.308)	1.115 (0.987-1.260)
Published in 2010s	14	1.139 (0.945-1.372)	1.059 (0.877-1.277)	1.026 (0.844-1.247)
< 100 cases	49	1.339 (1.178-1.521)	1.249 (1.098-1.422)	1.192 (1.038-1.370)
100-199 cases	22	1.117 (0.973-1.284)	1.042 (0.904-1.200)	0.978 (0.846-1.131)
200-399 cases	13	1.363 (1.190-1.561)	1.275 (1.114-1.460)	1.226 (1.051-1.429)
400+ cases	9	1.101 (0.973-1.247)	1.027 (0.905-1.166)	0.957 (0.826-1.108)
With dose-response data4	24	1.308 (1.181-1.449)	1.226 (1.105-1.359)	1.170 (1.052-1.302)
Without dose-response data	69	1.182 (1.088-1.286)	1.104 (1.014-1.201)	1.040 (0.948-1.141)
With age adjustment5	75	1.184 (1.100-1.274)	1.106 (1.027-1.191)	1.048 (0.966-1.136)
Without age adjustment	18	1.437 (1.194-1.728)	1.340 (1.110-1.618)	1.264 (1.026-1.556)
Case-control studies	77	1.226 (1.133-1.326)	1.144 (1.057-1.239)	1.080 (0.990-1.177)
Prospective studies	16	1.187 (1.043-1.350)	1.111 (0.977-1.264)	1.064 (0.928-1.220)

¹All analyses use random-effects models;

²Adjusted for confounding by fruit, vegetables and dietary fat consumption and by education;

³Using the Lee and Forey method[22] with an additive model and assuming a concordance ratio of 3 and misclassification rates of 2.5% for studies in North America and Europe and 10% for studies in Asia;

⁴Specifically for smoking by the husband;

⁵Or matching (within nonsmokers).