Saturday, 12 March 2011

Not bad science, but awful logic

In today's soar-away Guardian, Ben Goldacre has taken on the subject of plain-packaging:

This week our government committed itself to the removal, albeit slowly, of cigarette displays in shops. But plain packaging on cigarettes has been delayed for further consultation.

The Unite union is unimpressed. It represents 6,000 people in tobacco production and distribution, and put out a statement: "Switching to plain packaging will make it easier to sell illicit and unregulated products, especially to young people." This, the union added, "may increase long-term health problems".

Tory MP Philip Davies said: "Plain packaging for cigarettes would be gesture politics … it would have no basis in evidence."

Everyone is entitled to their own opinions, but not, sadly, their own facts.

Strong words, from which we must assume that Goldacre has found the "facts" to show that plain packaging will not help the illicit trade and does have basis in evidence.

But if he has, there's no trace of them in this article. What we get instead is a mildly interesting précis of surveys showing that some smokers believe that low tar cigarettes are less hazardous. This, says Goldacre rather hyperbolically, is "one of the most important con tricks of all time: people base real decisions on it, even though low-tar cigarettes are just as bad for you as normal cigarettes, as we have known for decades."

The collected data from a million people shows that those who smoke low-tar and "ultra-light" cigarettes get lung cancer at the same rate as people who smoke normal cigarettes. They are also, paradoxically, less likely to give up smoking.

The study he links to is Harris, 2004, which found that smokers of low-tar cigarettes have a similar lung cancer risk to those who smoke what Goldacre calls "normal" cigarettes. But the study also shows that smokers of high tar cigarettes (+22mg tar) have a statistically significant 44% increase in risk compared to those smoking lower tar cigarettes. To be fair, Goldacre's decision not to mention this latter finding could be justified on the basis that cigarettes of this strength are no longer legal in the EU. But when they were available (1930s to 1990s), there is plenty of epidemiological evidence to show that low tar cigarettes reduced risks somewhat.

As late as the 1960s, cigarettes regularly had tar yields of 40mg and over. Reducing tar yields to a quarter of this level does seem to have made them less hazardous in many respects—that is why the EU has made cigarettes progressively weaker. So it is not quite true to say that people believe light cigarettes are less hazardous purely because of the tobacco industry "con trick". For many years, they really were.

The EU's limit is now just 10mg of tar, which means that, by earlier standards, all cigarettes smoked today are ultra-light. The difference between a modern 5mg 'light' cigarette and a 'strong' 10mg cigarette is pretty negligible and the corresponding effect on health is likely to be similarly negligible. For the sake of argument, let's assume that modern lights are indeed no better than modern full-strengths.

What is not true is that smokers of low tar cigarettes are "paradoxically, less likely to give up smoking." The study Goldacre cites does not support that. In fact, it says the exact opposite:

We observed the smoking habits of all participants only at enrolment in 1982. However, based on a 13% subsample of participants who were re-enrolled in the CPS-II nutrition cohort, we found that men and women who smoked very low tar and low tar cigarettes in 1982 were more likely to have quit smoking by 1992.

But what does any of this have to do with plain-packaging? The answer is not very much at all. Goldacre does a pretty good job of debunking an argument that nobody is making, but does a poor job of rebutting what Unite and Philip Davies are saying. He implicitly assumes that by stopping the industry using colours to show which products are low tar, the myth of safer cigarettes will disappear and this will benefit public health. But that's just a hope and a prayer. Low tar cigarettes will still be available under plain packaging and smokers will still know that Marlboro Lights are on sale, regardless of what they are called or what they look like.

And even if low tar cigarettes disappeared altogether, there is no reason to think that people who smoke them will quit rather than simply switch to "normal cigarettes". Some of them might quit, of course, but that is mere supposition and we're supposed to be dealing only in facts here.

The truth is that there is very little evidence on either side of this debate because, if we go through with this scheme, we will be the first country on earth to try it. It is fatuous to pretend that there is any proof that it will work; likewise, there's no solid evidence that it will make things worse. Goldacre finds it plausible that banning colours will remove the illusion of reduced risk and lead people to quit (campaigners said the same when they banned the word 'light', but as Goldacre points out, it made no real difference).

Other people—including Unite—find it plausible that plain packaging will make it easier for the illicit trade to make counterfeit cigarettes and will draw smokers to the black market by turning the white market grey. (And we do know from chemical analyses that counterfeit cigarettes are more hazardous than official brands, if that's our concern.)

There are what-ifs on both sides of the argument, and neither side should claim that they are dealing with "facts" while their opponents deal only in "opinion".

At the end of the day, there can be no evidence for something that has never been tried. It is, therefore, factually accurate for Philip Davies to say that the policy "has no basis in evidence" and wrong for Goldacre to portray his hopes as facts.

11 comments:

Anonymous said...

There is a potential lowest risk of all cigarette been invented called the e-cig that is nothing but flavoured steam, yet everyone has run away from considering pushing for that alternative in the long run for fear their benefactors from pharmaceuticals and tobacco won't continue benefacting them. The political arguments are mostly based on concocted lies or arguments where none existed to push some agenda over another. Yet long run real solutions to real problems get ignored in the process. One has to wonder in the longer term stretch of time then looking back what the historical comment will be about the policy makers these days in the area of tobacco and other evil long-used products of nature, including alcohol, food, sugar, salt and beverages.

Richard White said...

Nicely done Chris. This reminds me of a comment left in the CATCH debate about how cigarettes have changed since the 60s, with them being far lower in tar content and also how smoking patterns have changed e.g. the 100 a day smoker largely no longer existing. Perhaps the 'safer cigarette' that has been mentioned for all this time is already here in the shape of 'regular' cigarettes.
It makes me curious though, that these lower tar initiatives have been here since the 1990s and the rhetoric about cigarettes hasn't, despite the fact that we simply won't know if and how the reduction to 10mg as 'full strength' has made a difference for a few more decades.

Xopher said...

"Gesture Politics"
Simply defined as 2 fingers to the millions that disagree.

Snowdon said...

Rich,

Low tars have been around since the 'tar derby' of the 1930s. Lower yields and filters are the only things that have made smoking somewhat less hazardous in 100 years of trying (the charcoal filter seems to have been particularly effective but it never really caught on), but the scale of improvement is open to question (all the usual caveats about low-risk epidemiology apply). It's certainly fair to say that an unfiltered Gauloise is worse for you than a Silk Cut ultra. As Harris mentions in his study, ultra-lows have not been around for long enough to see what, if any, benefit smokers who used them exclusively experience.

The focus has been on lung cancer, naturally, and there has been a shift from large cell to adenocarcinoma, because - as Goldacre rightly says - people do tend to inhale more deeply. The National Cancer Institute's monograph about this recognised that the epidemiology was fairly consistent in showing reduced risk but wasn't sure that it was borne out by national lung cancer rates. Although there is a reduction in risk for lung cancer of around 25% (taking all studies together), the effect on other diseases is less clear and it's definitely an exaggeration to say that the safer cigarette has arrived in any sense. That said, the idea that all cigarettes are equally bad (including counterfeit ones, as some fanatics claim) is a dangerous delusion. Some time soon I'll be blogging about the people who propose banning filters on this basis.

Richard White said...

Chris,

True about the tar derby, although i was referring specifically to our 10mg limit. Do you know if they went that low in the 1930s or after?

It's a bloggling premise that ALL cigarettes are as bad as each other - i fail to see how someone who believes inhaling smoke can cause lung cancer can refute that something to reduce the amount of smoke/particles makes no difference. I wasn't aware people were advocating banning filters. If anything, i'd say the filters could do with more work to be 'safer'. I'm not sure how much of a risk there is from inhaling the particles that make up the filter, but it certainly does happen, and the regular Swan filters make me cough. Here in the States the filters have an outer 'casing' that has completely removed my cough. So do the charcoal filters back in the UK.

Richard White said...

(by '1930s' of after i mean 1930s and the period following, not 'was it the 1930s, or just another decade?')

Dick Puddlecote said...

Goldacre's 'Bad Science' site is a particularly poorly named one. It should be titled 'Science which disagrees with me' instead.

Ann W. said...

more unintended consequence from anti tobacco

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/03/10/BAFU1I8I51.DTL&tsp=1

A San Francisco jury has awarded $1.36 million to a terminally ill man who smoked filter-tipped Kent cigarettes in the 1950s that contained asbestos.

Medical groups' concerns about tobacco in the early 1950s prompted companies to start selling filtered cigarettes. Kent's ads promoted the Micronite filters as "the greatest health protection in cigarette history" and said they removed seven times as much tar and nicotine as other leading filters. The company removed asbestos from the filters in 1957.

Anonymous said...

My understanding (somewhere in my bookmarks, but Firefox seems so sluggish in recent versions, with more than a dozen or two tabs open, that trying to find it stalls everything!) is that it was a health body (Canadian?) that first pushed for lower tar cigarettes, on 'evidence', and the tobacco industries did their best to comply...

As for 'addictiveness', have a look in Google Books for "A Critique of Nicotine Addiction" - using different search terms will get you different views; it's an expensive book; but the authors as well as going against the "established" view on addiction, suggest that "compensation" is also misunderstood; people regulate high nicotine tobacco intake downward.

Then there's the recent insanity of "U.S. Presses Tobacco Firms to Admit to Falsehoods About Light Cigarettes and Nicotine Addiction"

IMHO they were quite right to assert that it's not addictive, and (if they were indeed pressured to come up with "low tar" cigarettes, following best advice at the time from health authorities), hardly deceitful about "light" & "mild" either!

- Ross

timbone said...

The first 'low tar' cigarette I am aware of (although it was not 'low tar' but mild) was Benson and Hedges Silk Cut in the 1960s. This was a cigarette aimed at women, and was basically a B&H with teeny weeny holes in the filter.

It is ironic that in the 1970s, cigarette packets contained a little advice slip from HM Government, which included, "Take fewer puffs", "Remove from mouthb between puffs", "Leaver a longer stub", and , wait for it, "TRY CHANGING TO A LOWER TAR BRAND".

To reduce the tar yield in, to coin a phrase, a 'normal' cigarette, (one without holes in the filter), manufacturers have had to replace tobacco with other materials. I believe this includes tree bark. As a smoker of both roll ups and factory made cigarettes, I am certainly aware that the factory made cigarettes can make me more chesty - too much wood smoke?

I did unknowingly buy 200 counterfiet B&H once. I could not smoke them all, I don't know what was in them, but I could feel it.

ftumch said...

A little OT..., but this just in:

http://www.bbc.co.uk/news/health-12728629

14 March 2011 Last updated at 02:35

"Six leading health groups have dealt the government a blow by refusing to sign up to its new "responsibility deal" on alcohol in England.

The deal covers voluntary agreements with the drinks industry on issues such as promotions and labelling, aimed at tackling alcohol abuse.

But the organisations, including Alcohol Concern, accused ministers of not being tough enough on the industry."

And the groups concerned?

"The full list of organisations which are refusing to sign up is: Alcohol Concern, the British Association for the Study of the Liver, the British Liver Trust, the British Medical Association, the Institute of Alcohol Studies and the Royal College of Physicians."

We live in the age of Rule By Experts. Only those who are qualified to tell us how to live need apply... and they wonder why the low turn-out come election time?