title: The efficacy and short-term effects of electronic cigarettes as a method for smoking cessation: a systematic review and a meta-analysis.
abstract: OBJECTIVE
  E-cigarettes are increasingly popular as smoking cessation aids. This review assessed the efficacy of e-cigarettes for smoking cessation as well as desire to smoke, withdrawal symptoms, and adverse events in adult smokers.
  
  
  METHODS
  A systematic review was conducted. Studies comparing e-cigarettes to other nicotine replacement therapies or placebo were included. Data were pooled using meta-analysis.
  
  
  RESULTS
  Of 569 articles, 5 were eligible. Study participants were more likely to stop smoking when using nicotine e-cigarettes (43/489, 9 %) versus placebo e-cigarettes (8/173, 5 %); however, this difference was not statistically significant (RR 2.02; 95 % CI 0.97, 4.22). The pooled effect estimates for the desire to smoke (RR -0.22; 95 % CI -0.80, 0.36), irritability (RR -0.03; 95% CI -0.38, 0.31), restlessness (RR -0.03; 95 % CI -0.42, 0.35), poor concentration (RR -0.01; 95 % CI -0.35, 0.32), depression (RR -0.01; 95 % CI -0.22, 0.20), hunger (RR -0.01; 95 % CI -0.32, 0.30), and average number of non-serious adverse events (RR -0.09; 95 % CI -0.28, 0.46) were not statistically significantly different. Only one study reported serious adverse events with no apparent association with e-cigarette use.
  
  
  CONCLUSIONS
  Limited low-quality evidence of a non-statistically significant trend toward smoking cessation in adults using nicotine e-cigarettes exists compared with other therapies or placebo. Larger, high-quality studies are needed to inform policy decisions.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada. khoudisv@mcmaster.ca.
authors.forename: S
authors.initials: S
authors.lastname: Khoudigian
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Devji
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Lytvyn
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|PATH Research Institute, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada.|Research Institute of St. Joseph's, Hamilton, ON, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Campbell
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|PATH Research Institute, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada.|Research Institute of St. Joseph's, Hamilton, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Hopkins
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|PATH Research Institute, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada.|Research Institute of St. Joseph's, Hamilton, ON, Canada.
authors.forename: D
authors.initials: D
authors.lastname: O'Reilly
mesh_terms: D066300:Electronic Nicotine Delivery Systems; D006801:Humans; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects; D016540:Smoking Cessation / Q000379:methods*; D013375:Substance Withdrawal Syndrome; D061485:Tobacco Use Cessation Devices
chemical_list: D009538:Nicotine
keywords: E-cigarettes; Meta-analysis; Public health; Smoking cessation; Withdrawal symptoms
references.citation: Lancet. 2013 Nov 16;382(9905):1629-37
references.pmid: 24029165
references.citation: Ther Adv Drug Saf. 2014 Apr;5(2):67-86
references.pmid: 25083263
references.citation: PLoS One. 2013 Jun 24;8(6):e66317
references.pmid: 23826093
references.citation: Expert Rev Respir Med. 2012 Feb;6(1):63-74
references.pmid: 22283580
references.citation: BMJ. 2003 Jan 25;326(7382):219
references.pmid: 12543843
references.citation: Cochrane Database Syst Rev. 2014;(12):CD010216
references.pmid: 25515689
references.citation: Addiction. 2011 Nov;106(11):2017-28
references.pmid: 21592253
references.citation: BMC Public Health. 2011 Oct 11;11:786
references.pmid: 21989407
references.citation: Circulation. 2014 May 13;129(19):1945-52
references.pmid: 24821825
references.citation: Tob Control. 2014 Sep;23(5):375-84
references.pmid: 24259045
references.citation: Int J Tuberc Lung Dis. 2014 Jan;18(1):5-7
references.pmid: 24365545
references.citation: Otolaryngol Head Neck Surg. 2014 Sep;151(3):381-93
references.pmid: 24898072
references.citation: BMJ. 2012 May 18;344:e2809
references.pmid: 22611167
references.citation: Psychopharmacology (Berl). 2013 Jun;227(3):377-84
references.pmid: 23344557
references.citation: Ann Pharmacother. 2014 Nov;48(11):1502-6
references.pmid: 25136064
references.citation: BMC Public Health. 2011 Jun 18;11:479
references.pmid: 21682915
references.citation: Intern Emerg Med. 2014 Aug;9(5):537-46
references.pmid: 23873169
references.citation: Addict Behav. 2012 Aug;37(8):970-3
references.pmid: 22503574
references.citation: Ann Intern Med. 2010 Nov 2;153(9):607-9
references.pmid: 21041581
references.citation: Addiction. 2004 Jan;99(1):29-38
references.pmid: 14678060
references.citation: Tob Control. 2010 Apr;19(2):98-103
references.pmid: 20378585
references.citation: Trends Pharmacol Sci. 2011 May;32(5):281-9
references.pmid: 21256603