Lee PN, Fry JS, Forey BA, Hamling JS, Thornton AJ. Environmental tobacco smoke exposure and lung cancer: A systematic review. World J Meta-Anal 2016; 4(2): 10-43 [DOI: 10.13105/wjma.v4.i2.10]
Corresponding Author of This Article
Peter N Lee, MA, Director, P.N. Lee Statistics and Computing Ltd., 17 Cedar Road, Sutton, Surrey SM2 5DA, United Kingdom. peterlee@pnlee.co.uk
Research Domain of This Article
Allergy
Article-Type of This Article
Systematic Reviews
Open-Access Policy of This Article
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World J Meta-Anal. Apr 26, 2016; 4(2): 10-43 Published online Apr 26, 2016. doi: 10.13105/wjma.v4.i2.10
Environmental tobacco smoke exposure and lung cancer: A systematic review
Peter N Lee, John S Fry, Barbara A Forey, Jan S Hamling, Alison J Thornton
Peter N Lee, John S Fry, Barbara A Forey, Jan S Hamling, P.N. Lee Statistics and Computing Ltd., Sutton, Surrey SM2 5DA, United Kingdom
Alison J Thornton, Independent Consultant in Statistics, Okehampton EX20 1SG, United Kingdom
Author contributions: Lee PN, Fry JS and Forey BA planned the study; Hamling JS and Thornton AJ carried out the literature searches, assisted by Lee PN and Forey BA; Fry JS, Forey BA, Hamling JS and Thornton AJ carried out the data entry which was independently checked by one of these or Lee PN; Lee PN and Forey BA discussed any difficulties in interpreting published data or in the appropriate methods for derivation of RRs; Forey BA and Hamling JS conducted the main statistical analyses, and Fry JS the bias analyses along lines discussed and agreed with Lee PN; Lee PN drafted the paper, with the assistance of Thornton AJ, which was critically reviewed by the other authors.
Conflict-of-interest statement: Lee PN, Director of P.N. Lee Statistics and Computing Ltd., is an independent consultant in statistics and an advisor in the fields of epidemiology and toxicology to a number of tobacco, pharmaceutical and chemical companies including the sponsors of this study. Fry JS, Forey BA and Hamling JS are employees of, and Thornton AJ a consultant to, P.N. Lee Statistics and Computing Ltd.
Data sharing statement: Supplementary Files provide: (1) further information on the methods; (2) fuller description and results of the confounder/misclassification analyses; (3) description of reasons for rejection of some papers; and (4) fuller results of the main meta-analyses. Copies of the database files are available on request from the corresponding author at peterlee@pnlee.co.uk.
Correspondence to: Peter N Lee, MA, Director, P.N. Lee Statistics and Computing Ltd., 17 Cedar Road, Sutton, Surrey SM2 5DA, United Kingdom. peterlee@pnlee.co.uk
Telephone: +44-20-86428265 Fax: +44-20-86422135
Received: November 24, 2015 Peer-review started: November 25, 2015 First decision: December 28, 2015 Revised: January 19, 2016 Accepted: March 9, 2016 Article in press: March 14, 2016 Published online: April 26, 2016 Processing time: 141 Days and 4.8 Hours
Core Tip
Core tip: We present an up-to-date meta-analysis of the evidence relating non-smoker lung cancer to environmental tobacco smoke (ETS) exposure. We demonstrate a clear risk increase for spousal, at-home, workplace and total exposure, but not childhood exposure. For husband smoking, the relative risk (RR) is estimated as (RR = 1.22, 95%CI: 1.14-1.31). However, adjustment for confounding by education and dietary variables, and correction for misclassified wife’s smoking reduces it to (RR = 1.08, 95%CI: 0.999-1.16). Given the other data limitations and biases we discuss, one cannot reliably conclude that any true ETS effect on lung cancer risk exists. Our results suggest caution in drawing inferences from weak epidemiological associations where known biases exist.
