Monday, March 29, 2010

UK Department of Health's New Tobacco Control Strategy Criticized for Lack of Evidence Base on Smoking Cessation Recommendations

On his new blog over at BMJ Group Blogs, Patrick Basham criticizes the UK Department of Health's new tobacco control strategy for lack of an evidence base in its smoking cessation recommendations.

Basham writes: "The strategy document says, “Those who are most successful in quitting use a combination of behavioural and medicinal support.” (p. 11) The only support for this rather extraordinary assertion is an unpublished report by West entitled, “The smoking pipe: a model of inflow and outflow of smokers in England.” But this source, which is a single page spreadsheet, provides little support for the claim about cessation. More troubling is that the DoH’s claim about the best way to quit smoking fails the most basic test of evidence-based medicine: it is contradicted by much of the published literature."

Basham then goes on to cite numerous published papers documenting that unassisted smoking cessation is more effective than quit attempts aided by pharmaceuticals and that unplanned quit attempts (i.e., cold turkey) is far more effective than planned quit attempts that typically rely upon pharmaceutical aids. Basham also cites evidence that on a population level, the majority of successful quit attempts do not involve pharmaceutical therapy, including the American Cancer Society's estimate that 90% of people who have quit smoking have done so without medicinal aids.

Basham concludes: "Despite the DoH and the pharmaceutical industry’s promotion of pharmaceutically-aided cessation, the evidence suggests that unassisted cessation, not behavioural and medicinal support, is the method used most often by those who quit smoking successfully. Perhaps, the only people who find this surprising or dismaying are those in the pharma-nicotine industry. Both physicians and their patients have an unqualified right to expect that the DoH provide scientifically accurate and objective information about smoking and tobacco control policy. The DoH has failed both the profession and the public in its claims about smoking cessation."

The Rest of the Story

I welcome Patrick Basham's blog, which promises to be a very important addition to the tobacco blogosphere. This inaugural column provides a concise, compelling, and poignant argument that the UK Department of Health's national tobacco control strategy fails the public in its recommendations concerning smoking cessation because it ignores the scientific evidence base and makes suggestions that are inconsistent with that evidence.

For example, the document asserts: "It is important to recognise that millions of smokers who want to quit – despite efforts to persuade them to seek support – will choose to go ‘cold turkey’, the least successful approach to quitting." This statement is inconsistent with the published literature, which demonstrates the exact opposite. The danger of relying upon such a claim is that it would lead to a dramatic reduction in smoking cessation if we discouraged cold turkey quit attempts and instead, tried to ensure that every smoker trying to quit goes through the government's pharmaceutical-based smoking cessation program.

The strategy document makes the unsupported claim that "Smokers who stop smoking with NHS support are up to four times more likely to stop successfully compared with smokers who stop without any form of support." No support is provided for this claim and I have been unable, on repeated attempts, to find any support for such a statement. As Basham concisely summarizes, the scientific literature demonstrates that the exact opposite is true: unaided cessation has been shown to be far more effective than drug-based cessation efforts.

How does the UK Department of Health support its statement that smokers using the NHS support were four times more likely to quit smoking? It cites a 2005 paper in Addiction which examines the 52-week prolonged abstinence rate for a cohort of subjects who utilized NHS support in a particular location (reference 48 in the report). That paper reports a 14.6% one-year prolonged abstinence rate among this cohort.

The problem? The study was not designed to compare the quitting rates for those who did and did not use the NHS support system. In fact, the study did not even measure the cessation rate for those who did not use NHS support. It was not a controlled study. There was simply an intervention group, but no comparison group. So how can the study possibly conclude that those who used the NHS support system were four times more likely to quit smoking?

Well, it doesn't. Nowhere in the paper is the assertion made that the NHS support yields smoking cessation rates that are four-times higher than cold turkey quitting. It seems that the Department of Health is citing a paper as supporting its conclusion when that paper does nothing of the sort. Perhaps they thought that nobody would actually take the time to read reference 48, but they were wrong. I guess they did not know about The Rest of the Story.

The rest of the story is that you can't simply compare the rates of quitting found in that study with published rates of overall quitting success because you're dealing with very different populations in terms of motivation to quit smoking. The only valid way to compare these rates would be to ensure that the two groups are equivalent in terms of motivation to quit smoking. Those who opt to use NHS support services are probably a more highly motivated group than the set of all smokers who make a quit attempt. To make the comparison that the Department of Health makes, one would have to do a study where you randomized subjects to either receive or not receive NHS support services. I'm aware of no such study.

We do, however, have an abundance of scientific evidence that refutes the claims made in this report.

When it comes down to it, I believe that cold turkey smoking cessation is the most effective way to quit and that is precisely what we should be aiming for. Smokers need to be highly motivated to quit and that level of motivation has to be high enough that the smoker just decides to go cold turkey and forgo a reliance on nicotine therapy or other drugs.

Others can certainly disagree with my conclusion, but to make unsupported claims that are not backed by the evidence base is, as Basham argues, a disservice to the public.

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