Cochrane Review
Smokers interested in quitting may have noticed a Cochrane Review report, "Nicobrevin for smoking cessation" by Stead, L.F., and Lancaster, T. 2006.
Pro-Health
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.

