Adjusted and unadjusted results appeared similar. Finally, the major reason to doubt the efficacy of OTC NRT is hypothesized low compliance (Hughes, 2001; Walsh, 2008). Because compliance selleck chem with gum is lower than with patch, we examined whether the effectiveness of gum versus patch differed. The two studies that included both NRTs, each found effectiveness for patch but not for gum. Pre- and Post-Studies We located seven pre- and post-studies, three of which were also used in the retrospective cohort analyses (Table 3). Three studies used population-based samples and four used treatment samples. The three population-based studies examined abstinence rates among smokers who tried to quit before versus after NRT went OTC. The four treatment studies all examined abstinence rates before versus after the treatment provided free nicotine patches.

One study provided separate comparisons of gum, of patch, and of gum or patch; thus, we had a total of nine comparisons. Before describing the results, we describe the studies. Table 3. Methods of Pre- and Post-Studiesa Pre- Versus Post-Population�CBased Samples Hyland, Rezaishiraz, Giovino, Bauer, and Cummings (2005) examined data from the Community Intervention Trial for Smoking Cessation (COMMIT). Although this was not a true population-based sample, the sample was quite large, from several U.S. cities and approximated a random sample of smokers. The study tested policy interventions, which had only small effects. In 2001, the study asked participants about use of NRT over a long recall period, that is, the Rx period (1993�C1996) and the OTC period (1997�C2001).

It also reported on gum and patch users versus nonusers. This analysis was probably the most rigorous among the pre- versus post-studies. The analysis was unusual, in that it did not compare abstinence rates among all who attempted to quit pre- versus post-OTC change, but rather compared abstinence rates Carfilzomib only among NRT users during pre-OTC conditions versus among NRT users during OTC conditions. The OTC patch users were not less likely to abstain than the Rx patch users; OTC gum users were actually more, not less, likely to abstain than Rx gum users (see Table 4). When gum and patch use was combined, no difference in rates pre- versus post-OTC switch was found. Table 4. Outcomes of Pre- and Post-Studies The Pierce & Gilpin (2002) study was described among the retrospective cohort studies. When we estimated quit rates from its survival curve data, quit rates decreased in the post-OTC era. The Thorndike et al. (2002) study was also described among the cohort studies. When we calculated ORs using the data presented in these figures and text, quit rates increased with introduction of OTC NRT.