Letters to the Editor The journal publishes both invited and unsolicited letters. EFFECTIVENESS OF NICOTINE REPLACEMENT THERAPY—A REBUTTAL In a press release about their recent case–control study [1], Alpert et al. concluded that the study showed that ‘NRT is no more effective in helping people stop smoking cigarettes in the long-term than trying to quit on one’s own’. We believe this conclusion is unwarranted for several reasons. We cite three of these below. Briefly, the Alpert et al. study found that smokers who had used nicotine replacement therapies (NRTs) in the previous 2 years and were abstinent at the time of the survey were not less likely to relapse during a subsequent follow-up period than were ex-smokers who had not used NRT. First, the study tests whether the use of NRT in the distant past (up to 2 years prior to the survey) prevents relapse during a subsequent period years after use of NRT. Studies have found that the therapeutic effect of NRT is concentrated during the weeks it is being used, and after this the rate of relapse is similar between NRT and control conditions [2,3]. Thus, NRT does increase long-term abstinence, primarily by increasing the initial number of quitters [2,3]. By the nature of its method, the Alpert study was blind to this effect on early quit- ting. Testing the effect of NRT on relapse that occurs years after its use is not an appropriate evaluation of NRT effectiveness nor, for that matter, of most tobacco control activities. For example, we doubt that exposure to media advertisements on cessation would decrease the rate of relapse years after they were seen, but they may still be effective, even over the long term, because they stimulated quit attempts while the advertisements were airing. Secondly, the paper fails to cite important relevant lit- erature. It cites three population-based case–control studies that failed to find an effect of NRT; however, it fails to cite 12 similar effectiveness studies [4], many of which found that NRT was effective. It also fails to cite random- ized, controlled trials of NRT conducted in very real- world settings; e.g. smokers visiting a store and obtaining NRT without any advice [5], which showed greater quit- ting with NRT use. Thirdly, the study evaluates outcomes between groups that are not comparable. It is well known that smokers who choose to use NRT are more vulnerable to failure in the first place [6]—which is why they seek extra help. Such vulnerable smokers are biased to show high relapse rates, independent of what treatment they use.Therefore, comparing them to smokers who felt they did not need help to quit is not an appropriate comparison. The Cochrane [7] and United States Public Health Service (USPHS) [8] meta-analyses and the USPHS guide- lines [8] have concluded that NRTs ‘increase the rate of quitting by 50–70%, regardless of setting’ [5], based on outcomes from more than 100 RCTs. We do not believe that the results of the Alpert et al. study provide reason to doubt their well-established conclusion. Declarations of interest JH has received consulting fees and research grants from companies that develop or market medications or services for smoking cessation (including NRT) and companies/organizations that engage in tobacco control activities. In the past KMS has received consulting fees and research grants from companies that develop or market medications or services for smoking cessation (including NRT) and companies/organizations that engage in tobacco control activities. JF undertakes research and consultancy for companies that develop and manufacture medicines to aid smoking cessation. Through Pinney Associates, SS consults exclusively to GlaxoSmithKline, maker of NRT products, regarding smoking cessation. SS also has a share of a patent for a novel nicotine replacement product. RW undertakes research and consultancy for companies that develop and manufacture medicines to aid smoking cessation. He also has a share of a patent on a novel nicotine delivery device. Endnote All letters to the editor are subject to review within Addic- tion’s peer review process. Because Robert West, current Editor-in-Chief of Addiction, is one of the contributors to this letter, it was processed by the Regional Office for the Americas to provide an independent evaluation of its suitability for publication. A response prepared by Alpert et al. to other comments about their original paper can be found at: (http://tobaccocontrol.bmj.com/content/early/ 2012/03/22/tobaccocontrol-2011-050129.short/reply #tobaccocontrol_el_3882). (Archived by WebCite® at http://www.webcitation.org/67gOyjbkcc). Keywords: Effectiveness, nicotine, nicotine replace- ment therapy, relapse, smoking cessation, tobacco. © 2012 Society for the Study of Addiction Addiction, 107, 1527–1529