Electronic cigarettes are widely promoted and used to help smokers quit traditional cigarettes, but a new analysis from UC San Francisco found that adult smokers who use e-cigarettes are actually 28 percent less likely to stop smoking cigarettes.The study — a systematic review and meta-analysis of published data — is the largest to quantify whether e-cigarettes assist smokers in quitting cigarettes.The findings will be published online January 14 in The Lancet Respiratory Medicine.“As currently being used, e-cigarettes are associated with significantly less quitting among smokers,” concluded first author Sara Kalkhoran, MD who was a clinical fellow at the UCSF School of Medicine when the research was conducted. She is now at Massachusetts General Hospital and Harvard Medical School.