This is probably the weakest test of OTC NRT for two reasons. all targets First, as mentioned above, quitlines may have given advice on use of NRT and thus did not differ substantially from prescription (Rx) NRT. Second, it is likely highly dependent smokers were not willing to call a quitline when no NRT was offered but decided to attend when they heard free NRT was available. Importantly, a few of the studies also reported not only just on the effectiveness of OTC NRT but also on the effectiveness of Rx medications and counseling (Fiore et al., 2000) and, thus, can be used to assess the specificity of any negative results. For example, assume OTC NRT users have quit rates similar to that in nonusers. If, in that same study, counseling was found effective, this would suggest a true negative result for OTC NRT.

If, on the other hand, counseling was also not found effective, then (if one believes quitlines are truly effective treatments) this result would suggest the study methods were insensitive to detect changes in quit rates due to use of treatment. Methods To locate studies, the first author searched PubMed and PsycInfo using the terms ��(replacement OR transdermal OR patch OR gum OR inhaler OR tablet OR lozenge) AND (quit* OR stop* OR cessation OR treat*) AND (tobacco OR smok* OR cigar*)�� and from 1990 to 2009 (only Switzerland had OTC NRT prior to this date). He also searched the Cochrane Database of Randomized Trials (http://www.cochrane.org) and his own set of articles. The first author located 769 articles whose titles suggested that they were applicable and read their abstracts.

This led to 71 articles that appeared to be applicable. Next, the first two authors independently screened these 71 for the following inclusion criteria: (a) examined abstinence rates among those trying to quit (one included study reported survival analyses, not abstinence; Gilpin, Messer, & Pierce, 2006) and (b) not an efficacy trial (see definition of efficacy above). Since we were interested in success from a given quit attempt, another inclusion criterion was available data on success among those who attempted to quit. Thus, our use of the term ��quit rate�� refers not to abstinence in the whole sample but to abstinence only among those who attempted to quit.

In addition, the study had to either compare abstinence between those using versus not using NRT when they tried to quit (retrospective cohort studies) or examined Batimastat quit rates before versus after NRT was available to those trying to quit (pre- vs. post-studies). A list of excluded studies and the reasons for exclusion can be found at http://www.uvm.edu/~hbpl/pdfs/Effectiveness.excluded.studies.pdf. The first two authors independently coded each study for how the participants were recruited, intent-to-treat (ITT) sample sizes, demographics and smoking history of the sample, whether other active treatments (e.g.