Smokers interested in quitting may have noticed a Cochrane Review report, "Nicobrevin for smoking cessation" by Stead, L.F., and Lancaster, T. 2006.
Products, the distributors of Nicobrevin, contends that, contrary to the thrust
of the Cochrane Review report, the Dankwa and Schmidt trials mentioned in the
report provide cogent evidence of the efficacy of Nicobrevin. The reference in
the plain language summary of the report to a lack of evidence to assess
efficacy is misleading as the review's methodology only applied to long term smoking cessation.
Pro-Health also contends that the assumption by the authors that relapse rates may be relatively higher in actively treated groups after the end of treatment would apply equally to any form of smoking cessation therapy. Whilst past smokers do relapse from time to time the key to quitting is to commit to a smoking cessation therapy in the first place, and if unsuccessful, be determined to try again and break the habit.
The plain language summary of the Cochrane review concludes that "No randomised trials with long term follow up of smoking status were identified,so there was no evidence to assess efficacy".
This conclusion is misleading for the following reasons.
1. The objectives of the Cochrane Review were specifically designed to assess the effects of Nicobrevin on long term smoking cessation;
2. The selection criteria for the review only included those randomized trials comparing Nicobrevin to placebo or an alternative therapeutic control, which reported smoking cessation with at least six months follow up.
3. At "Description of Studies" the review report acknowledged that only two trials of Nicobrevin have been published and neither had long term follow up.One assessed patients at the end of four weeks treatment (Dankwa 1988) and the other after three months (Schmidt 1974);
4. The review therefore found no trials meeting the full inclusion criteria including long-term follow up;
5. The course of treatment with Nicobrevin is 28 days. The results of the Dankwa trial indicated substantial benefit from Nicobrevin in that the efficacy of Nicobrevin after a standard course of treatment was statistically significant;
6. At "Discussion" the Cochrane Review report discusses whether evidence of efficacy after long term follow up is necessary since smoking is a chronic condition and acknowledged that repeated quit attempts are generally needed;
7.The report's authors have taken the view that since the benefits of quitting are only likely to come from sustained cessation, products that have not been shown to increase long term quit rates cannot be recommended. They claim that it is possible that relapse rates may be relatively higher in actively treated groups after the end of treatment, so that the net benefit of treatment is eroded.