The fag end of advocacy research
On closer inspection, claims that England's smoking ban has led to a steep fall in heart attacks quickly turn to ash.
Here, Patrick Basham and John Luik argue that claims about a steep decline in heart attacks following England’s smoking ban are an illusion; further below, Rob Lyons questions a widely reported story about how many lives the ban has saved.
Even though it is a bit early for the season of miracles, readers of the UK Daily Mail were treated to one last month when the paper reported, just in time for the one-year anniversary of England’s public smoking ban, that the smoking ban had ‘cut the number of heart attacks by more than 40 per cent at some hospitals’.
What the Mail was claiming, of course, was that there was a decline of 40 per cent in the numbers of people admitted to some hospitals suffering from heart attacks due to the fact that smoking was no longer allowed in public places in England.
The real miracle here is that such a scientifically illiterate story would be (a) written, and (b) make it past the editors of (c) even the sensationalist Daily Mail. There are so many problems with this claim that we shall confine ourselves to the three most glaring.
First, the story is based on starkly incomplete data since it fails to cover all of the hospitals in England. And even the hospitals that it does cover present a misleading statistical picture. For instance, one NHS trust – Shrewsbury and Telford, which had a supposed 41 per cent drop in heart attack admissions – accounts for almost a third of the total reduction in heart attack admissions for the entire country, according to Brian Bond writing on Michael Siegel’s The Rest of the Story blog (16 June 2008). Yet this same hospital accounts for only one per cent of the total patients in the country. This alone raises significant suspicions about the accuracy of not just this Trust’s data but of the entire statistical analysis being presented.
Second, even allowing for the selectivity of the data, the scale of the reduction in heart attack admissions is nowhere near 40 per cent across the country. Indeed, the overall reduction in heart attacks was only three per cent, and this figure needs to be put into context in the sense that heart attack figures vary substantially from year to year. For instance, heart attack admissions increased by over five per cent from 2001/2002 to 2002/2003, but then fell by that amount in 2003/2004 (1). A further bit of context suggests that heart attack rates have been declining all across Europe for about the past decade. So a three per cent decline in one year is nothing unusual.
Third – and here things become very interesting – there is absolutely no evidence that the already small and statistically non-signficiant reduction in heart attacks was due to the smoking ban. Simply because there was a reduction in heart attack admissions during the same period that there was a smoking ban does not mean that the one was the cause of the other.
The Mail presented no data about whether those admitted to hospital with heart attacks were smokers or ex-smokers, or whether they had ever been exposed to second-hand smoke, or most crucially, how much they had been exposed to. In other words, the crucial component of science – warranting that you have accurately measured something – is completely absent here. And, of course, the entire idea that such a short period without public smoking can lead to a startling reduction in cardiac admissions is itself biologically implausible given that the alleged damage from second-hand smoke would not be so quickly undone. In fact, the best epidemiological evidence suggests that there is not a statistically significant link between heart disease and second-hand smoke in healthy non-smokers.
One can be somewhat forgiving about all of this scientific illiteracy since, after all, we are talking about the Daily Mail. What is much less acceptable, however, is the fact that the British Heart Foundation and the British Cardiovascular Society, both organisations that presumably claim scientific foundations, could spout such nonsense. The British Heart Foundation said these results ‘proved’ that the public smoking ban was ‘the most significant public health initiative this century’ – which suggests that these folks have as weak a grasp on the history of public health as they do on science.
Similarly dubious claims were made about the Scottish smoking ban – which preceded England’s – in September 2007, where a 17 per cent decline in hospital admissions for heart attacks was similarly put down to the ban. That claim was based on statistics from just nine hospitals (1). Anyone spot a ban-justifying pattern here?
So here’s where we are in terms of public discussion about smoking and smoking policy in the UK today: a tabloid paper can produce a dramatic and scientifically untrue claim about the effects of a ‘smoking policy’, trumpet that claim and have it endorsed by two scientific societies, who know, or at least should know, that it is false, while the rest of the press, along with the government, look on either with approval or in silence.
Patrick Basham and John Luik are authors of a forthcoming book, Up to Snuff, to be published by the Social Affairs Unit, examining the negative consequences of the ban on smokeless tobacco in the European Union.
by Rob Lyons
‘Smoking ban has saved 40,000 lives’, proclaimed the UK Independent among many others earlier this week, suggesting that England’s smoking ban has had a dramatic effect on public health. The reports were based on a survey led by Professor Robert West, director of tobacco studies at the Health Behaviour Research Unit, University College London. West told the Independent: ‘These figures show the largest fall in the number of smokers on record. The effect has been as large in all social groups – poor as well as rich. I never expected such a dramatic impact.’
A smoking ban would be expected to focus minds – but surely it is too early yet to make firm claims about long-term health effects? The figures sound impressive, but hundreds of thousands of people quit smoking each year regardless of smoking bans. In a report published on Tuesday, Smokefree England – One Year On, the UK Department of Health estimated that 234,060 quit between April and December 2007 using their smoker’s helpline, ‘a 22 per cent increase in the number of successful quitters’. So, the ban – and the debate around it – may have encouraged more people to try to give up smoking, but the increase is not as dramatic as headlines would have us believe.
Smokers also tend to ‘fall off the wagon’. So it’s better to look at overall smoking rates in the medium term before judging the merits of the ban. We can’t do that yet for England. But in Ireland, which introduced a ban in 2004, smoking rates have actually gone up. The Irish Times noted in April 2008 that the ‘number of people who said they were smokers fell from 33 per cent in 1998 to 27 per cent in 2002 but increased to 29 per cent last year’.
Rob Lyons accused UK health campaigners of smoking smokers out of polite society. Ken McLaughlin described the smoking ban in psychiatric institutions as madness. spiked writers around the world reported on the global crusade against the ‘evil weed’. Nathalie Rothschild reported on a rare protest against the English smoking ban. Mick Hume reflected on what the ban says about today’s society. Or read more at spiked issue Smoking.
(1) Further discussion of this point can be found at Veritas Vincit Pro Libertate
(2) Smoking ban brings big cut in heart attacks in Scotland, study finds, Guardian, 11 September 2007
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