Tuesday, 15 August 2017

Teetotallers still dropping like flies

Another day, another large cohort study confirming the benefits of moderate drinking. This time it's a 14 year study involving 333,247 Americans which concludes:

Compared with lifetime abstainers, those who were light or moderate alcohol consumers were at a reduced risk of mortality for all causes (light—hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.76 to 0.82; moderate—HR: 0.78; 95% CI: 0.74 to 0.82) and CVD (light—HR: 0.74; 95% CI: 0.69 to 0.80; moderate—HR: 0.71; 95% CI: 0.64 to 0.78), respectively. In contrast, there was a significantly increased risk of mortality for all causes (HR: 1.11; 95% CI: 1.04 to 1.19) and cancer (HR: 1.27; 95% CI: 1.13 to 1.42) in adults with heavy alcohol consumption.

So that's a reduction in mortality risk of more than a fifth for both light and moderate drinkers compared to teetotallers. A similar magnitude of risk reduction was found in a BMJ study earlier this year. Numerous studies have been showing the same thing since the benefits of moderate drinking were first noticed (and covered up) 45 years ago.

The usual alcohol policy tweeps from the 'public health' lobby have been quiet today - perhaps because they are on holiday - and so the task of muddying he water has fallen to Buzzfeed. Its article, by Tom Chivers, mentions the usual excuse that non-drinkers are all terribly ill because they used to be alcoholics. Although Chivers acknowledges that this study only looked at lifetime abstainers, he implies that most studies of this kind do not. In fact, most studies conducted in the last fifteen year have only looked at lifetime abstainers. The 'sick quitter' hypothesis is a thoroughly debunked zombie argument that should have been dropped long ago.

With the sick quitters put to one side, he takes the fall back position of suggesting that there is something else about teetotallers that makes them less healthy:

But people who've never drunk in their lives are fairly unusual, in Western society, as well. So there may be some other factor that we haven't thought of.

There are several problems with this line of argument.

Firstly, saying 'teetotallers are less healthy because, er, reasons' isn't much of an argument to begin with.

Secondly, if it is an argument, it is an argument against all epidemiology. Different groups are usually different in several ways. That is why epidemiologists adjust for confounding factors. Of confounding factors, Chivers says: 'You can try to avoid these problems, but you can never do it perfectly.' This is trivially true, but there is a hint of the Nirvana fallacy about it. Perfection is impossible in observational epidemiology. The question is not whether it is perfect, but whether it is good enough. In this study, the researchers took account of a wide range of factors, including physical activity, smoking, race, body weight and education. They also adjusted for the prevalence of various diseases. The association between teetotalism and death remained.

Thirdly, it is not at all clear that teetotalism correlates with unhealthy behaviour. On the contrary, it often correlates with healthy behaviour (whereas heavy drinking correlates with unhealthy behaviour).

Fourthly, teetotallers are not 'fairly unusual' in the United States. A third of Americans are teetotal. Forty per cent of the people in this study did not drink and 23 per cent of them had never drunk. By contrast, only 5 per cent were heavy drinkers. It is therefore heavy drinking that is fairly unusual, but Chivers doesn't fault the evidence on alcohol harm from heavy drinking on the basis that there might be something weird about heavy drinkers.

A few other points are worth mentioning because they have been generally absent from the news reports about this study:

Firstly, the authors found a reduction in risk for cancer mortality among light drinkers, and no increase in cancer mortality risk for moderate drinkers. So much for there being 'no safe level'.

Secondly, they found no increased risk of heart disease mortality among heavy drinkers (but a large reduction among the other drinkers).

Thirdly, moderate drinking was defined as up to 14 drinks per week for men and up to 7 drinks a week for women. A 'drink' is not a unit, however. In this study, a drink is 14 grams of alcohol whereas a British unit is 8 grams of alcohol. The male moderate drinkers were therefore consuming up to 24.5 units and the female moderate drinkers were consuming up to 12.25 units.

The Buzzfeed piece claims that the statistician David Spiegelhalter 'says [the study is] a vindication for the new, low-risk NHS guidelines'. It's hard to see how. The authors clearly define moderate drinking differently to the NHS and there was a reduction in mortality in the group that included men who drink much more than the 14 units now recommended by the government. (NB. the only change to the guidelines was the reduction in the male limit.)

Spiegelhalter (who was on the guidelines committee) is quoted as saying: 'Once you get above the NHS guidelines of 14 units a week, that's when risk starts taking off.' Nothing in this study supports that statement. Is he getting confused between a US 'drink' and a UK 'unit'?

Fourthly, the health outcomes for light drinkers and moderate drinkers were virtually identical across the board, so there is no evidence for the claim that is sometimes made about the benefits of drinking only existing for people who drink tiny amounts.

Finally, an accompanying editorial notes that...

For most older persons, the overall benefits of light drinking, especially the reduced cardiovascular disease risk, clearly outweigh possible cancer risk.

Can we expect the 'public health' lobby to recommend that teetotallers start having a few drinks? Don't hold your breath.

Tuesday, 8 August 2017

Public Health England's shrinkflation

The British government's underhand manipulation of the food supply should be a major news story. So far it has been largely ignored so I was pleased to see Blair Spowart get to grips with it at Spectator Health today...

Don’t expect PHE to stop its interference when its targets are inevitably not met. It’s already tackling salt in much the same way as sugar. Next on their naughty list is saturated fat. Because PHE needs perpetual public health crises to justify its existence, it is always sure to find one – to the detriment of consumers. This wide-ranging food reformulation programme is all happening, moreover, without even the pretence of public consultation.

More needs to be done to show consumers who’s really ripping them off. The first step is moving beyond our kneejerk reaction to shrinkflation and related phenomena – ‘blame it on Brexit’ – and looking more closely at the subtle but powerful impact of our economically illiterate public health lobby.

Monday, 7 August 2017

The economic consequences of clean living

I'm pleased to announce the publication of the third part of the IEA's Public Purse trilogy looking at the net cost of bad habits to the nation's finances. We have previously looked at alcohol and obesity. We now turn our attention to smoking which is often said to impose a cost of £13.7 billion per annum on UK taxpayers. That figure comes from a risible Policy Exchange report from 2010 and is overwhelmingly made up of dubious lost productivity costs.

The question we ask in this series of reports is simple and important: what would be the impact on government revenues and spending if the 'public health' lobby won the war on drinking, smoking and obesity? Campaigners often claim, or strongly imply, that costs would fall but this is based on an economic calculation that exaggerates and misrepresents costs while ignoring savings.

Written with Mark Tovey (author of Obesity and the Public Purse), Smoking and the Public Purse takes a full account of the costs, savings and tax revenues associated with smoking and finds that the government would be spending £14.7 billion more per annum if nobody smoked.

In the absence of smoking, the government would spend an extra £9.8 billion annually in pension, healthcare and other benefit payments (less taxes forgone). Duty paid on tobacco products is £9.5 billion a year. In total, the gross financial benefit to the government from smoking therefore amounts to £19.3 billion. Subtracting the £4.6 billion of costs (above) produces an overall net benefit of £14.7 billion per annum.

The report also looks at the impact on the treasury if all three of the most discussed 'lifestyle factors' - obesity, alcohol and smoking - miraculously disappeared.

Alcohol and tobacco duty provide £10.7 billion and £9.5 billion to the government respectively, with an additional £4 billion of VAT charged on this duty. If, as expected, the forthcoming sugar levy raises £500 million per annum, the government will be in receipt of £24.7 billion of ‘sin tax’ revenue by 2018.

Taken together, the net benefit to the government from the three most hotly discussed ‘lifestyle factors’ - alcohol, obesity and smoking - is £22.8 billion.

You can download Smoking and the Public Purse here.

There is some news coverage here, here, here and here.

You can read my blog post for the IEA here.

And you can see Mark Littlewood talking about the findings on Sky News below:

Smoking and the Public Purse brings this series to an end. You can read all the relevant publications below. Nothing in them should be particularly controversial (see Death and Taxes for a review of the literature). It is obvious that a cost-benefit analysis requires benefits to be included alongside costs. Unfortunately, including benefits and savings doesn't suit single issue campaigners because it shrinks their estimates of the 'burden on taxpayers'. With the exception of obesity, which incurs a relatively small overall cost to the health service, doing the job properly turns a cost into a net saving.

I don't suppose this body of research will make much difference because it doesn't confirm what people want to believe (contrast that with the wafer-thin Policy Exchange document which has been cited hundreds of times in public debate), but I will keep banging this drum because it happens to be true.

 Alcohol and the Public Purse - Christopher Snowdon (2015)

Obesity and the Public Purse - Mark Tovey (2017)
Smoking and the Public Purse - Christopher Snowdon and Mark Tovey (2017)

Death and Taxes - Christopher Snowdon (2016)

Saturday, 5 August 2017

Chlorine, chickens and Brexit

I was on the Spiked podcast this week talking about the chlorinated chicken thing and why Remainers briefly became obsessed with it. Have a listen.

Thursday, 3 August 2017

Fast food, obesity and junk science

I was on the radio yesterday debating with some busybody from the NHS who wants to limit the number of takeaway shops in Britain's high streets. The feeble hook for this story was the news that the number of takeaway outlets in the country has increased by eight per cent in the last three years, according to a pearl-clutching Guardian analysis.

This would seem to reflect the resurgent economy and population growth but for the 'public health' lobby it is a crisis. Why? Because fast food causes obesity, dunnit?

But does it? Leaving aside the fact that takeaway food shops do not necessarily sell 'junk' or 'fast' food, the assumption that takeaways cause obesity has always been just that: an assumption.

What empirical basis does it have? A 2010 evidence review identified 12 studies looking at fast food outlet availability and obesity. Six found a positive association, five found no association and two found a negative association.

It also looked at six studies of fast food consumption and obesity. Three found an association, the other three didn't.

This is hardly compelling and I recommend reading this post by Mike Gibney in which he discusses some of the more recent evidence, starting with a 2017 study from the USA which concluded:

Our a priori prediction that FFRs [fast food restaurants] and FSRs [full service restaurants] would be positively linked to obesity prevalence was not supported

He also mentions a study of Europeans which found:

Our results suggest, contrary to normative views, that away from home food expenditures negatively affect BMI and that BMI is negatively related to the percentage of the food budget spent away from home.

And he mentions another recent study from the USA which found that...

Neighbourhood convenience stores and fast-food restaurants were not associated with BMI in any model.

The authors of that study argued that 'weak findings in the literature [which report an association between fast food and obesity] may be due to residual confounding'.

If you want to get an idea of how weak the evidence is for the fast food/obesity link, take a look at this study from the British Medical Journal. This is the one that campaigners like to cite because it concluded:

Exposure to takeaway food outlets in home, work, and commuting environments combined was associated with marginally higher consumption of takeaway food, greater body mass index, and greater odds of obesity.

The study looked at people's 'exposure' to takeaway food in Cambridgeshire and claimed that people who were heavily 'exposed' were 80 per cent more likely to be obese. The study concludes with a call for 'policies designed to improve diets through restricting takeaway food availability' which is a bit of a red flag for activist-driven research. This response from a statistician (which the authors never addressed) is devastating. It reveals that the finding was entirely dependent on adjustments to the data.

After reading the interesting article by Burgoine et al. I was at first irritated by the lack of a table to compare the characteristics (as shown in Table 1) of participants grouped according to quarters of take-away environment. Further, I missed a simple presentation of outcome variables (mean take-away consumption, mean BMI, percentage overweight and obese) grouped according to these same quarters. Usually one would expect such tables in order to assess the comparability of the groups with respect to possible confounders and for a direct, unadjusted comparison of outcomes, respectively.

Then I discovered this information in Web table 3 of the online appendix. Here, we see systematic differences between quarters with respect to education, smoking and car ownership. I think the authors should have presented these tables and drawn attention to these differences in the main printed article, even if the multiple linear regression models adjusted for the covariables concerned.

What surprised me even more in Web table 3 was the fact that mean take-away consumption was slightly inversely correlated with combined take-away availability, varying between 36.3 g/day in Q1 and 34.2 g/day in Q4. This contrasts completely with the results of the multivariate analysis (Fig. 1) in which a significant positive correlation between take-away availability and consumption was obtained. Moreover, In Web table 3 mean BMI is almost constant in all quarters of take-away availability, contrasting with the significant positive correlation between take-away availability and BMI derived from the multiple linear model (Fig. 2). While I accept that the multivariate analysis adjusting for potential confounders is the analysis of choice for such an observational study, the complete lack of agreement with the simple univariate analysis is worrying and should be presented and discussed.

A hint on the possible explanation for these inconsistencies is given under ‘sensitivity analyses’. ‘In models that omitted supermarket exposure as a covariate, the associations between combined take-away food outlet exposure, consumption of take-away food and body mass index were attenuated towards the null…’. These sensitivity results are given in Web figures 5 and 6. The expression ‘attenuated towards the null’ is an understatement: no association remains at all, in agreement with the simple univariate comparison.

If you look at the supplementary data, you can see that he is correct. There is no difference in average weight between those who have the greatest exposure to takeaways (4) and those who have the least (1). Moreover, the people who had the easiest access to takeaway food ate less of it than those who had the least access.

Your faith in the authors' conclusion therefore depends on how much faith you have in their numerous adjustments to the data. To my mind, it is junk science, but whatever you think of it, it is simply untrue to claim that the people in this study who were most 'exposed' to takeaways were fatter than other groups.

It brings to mind a study I wrote about five years ago which looked at fast food consumption among teenagers in Tower Hamlets. It concluded:

This study revealed a very high frequency of fast food consumption among the schoolchildren. Taste, quick access and peer influence were major contributing factors. These schoolchildren are exposed to an obesogenic environment, and it is not surprising that in this situation, many of these children are already overweight and will likely become obese as adults.

Notice how the authors beg the question. It is assumed that those who eat the most fast food will be most likely to be obese. They say that 'many of these children' are already overweight or obese but they do not say how many, nor do they compare obesity rates between those who eat a lot of it and those who do not.

You have to dig into the study to discover why they are so coy about this. It goes unmentioned in the text of the study, but we can see in Table 2 that there is an inverse relationship between frequency of takeaway consumption and body weight. The children who ate the most of it weighed the least and those who ate the least of it weighed the most.

This was clearly not what the authors were hoping to find so they ignored it and editorialised with a blatantly activist conclusion:

Clearly, actions need to be taken to either limit the ability of these children to access fast food outlets or to change the foods they purchased at these outlets (eg, less calorie dense, with more fruit and vegetables, with less fat and salt) and to have a ban on the sale of sweetened soft drinks at these outlets.

 Ever get the feeling you're being cheated?

Wednesday, 2 August 2017

Outdoor smoking bans and the dead hand of the state

Tobacco control involves an endless procession of idiotic and illiberal policies which have obvious unintended consequences. Those consequences are easy to predict, but the campaigners dispute their existence when the policy is being debated. Shortly thereafter, the negative impact becomes clear to see and the campaigners get a goverment grant to prove the existence of the bleeding obvious, and demand further legislation to address the problem - a problem they alone have created.

At the moment, for example, we are seeing the emergence of totally predictable - and widely predicted - riots in prisons in Britain as a total smoking ban is 'phased  in'. We are seeing tobacco companies quite predictably competing on price when no other mechanisms of competition are open to them. And we see businesses which are given the choice between allowing smoking and serving food make decisions that best suit their customers:

Smoking ban: Oakleigh traders ban meals to allow patrons to light up

Restaurant traders in Melbourne's south east are banning meals from their alfresco dining menus in favour of allowing punters to light up a cigarette.

On Monday, the state government of Victoria banned smoking in the outdoor dining areas of private businesses as part of its vendetta against smokers. The article quotes the owner of a Greek restaurant who would like to stay in business if it's all the same to the government.

He said that while most traders wanted to comply with the laws, some feared they would lose customers to other venues if they outlawed smoking all together in the fiercely competitive strip.

Between 9am and midday, Kentro Oakleigh no longer serves food outdoors.

Instead, its alfresco dining area has been morphed into coffee friendly, but meal-free, designated smoking zone.

Once the lunch rush hour hits, smokers are told to butt out.

"What a lot of people don't understand is that taking a cigarette away from an elderly Greek man is like taking away everything he's got," he said. "They come down each morning... they could stay five or six hours. It's their life, having a coffee, a cigarette, having some cake, socialising with their friends... that's the way it's always been."

We saw the hospitality industry deal with a similar ban in much the same way in New South Wales two years ago:

Inevitably, the hateful fanatics who supported this legislation are appalled that people are following the letter of their stupid law rather than its hateful spirit. Within hours of the ban coming into effect, they were portraying deliberate exemptions as 'loopholes'.

This bigot, Geoff Lake, has previously described the experience of walking through the Greek precinct of his town as 'like cleaning a chimney in Britain during the industrial revolution' so he is clearly no stranger to hysteria and exaggeration. He is quoted again in The Age today:

He said traders were "opportunistically" designating spaces as "non-eating" during particular times of the day allowing smoking to legally continue.

"It's a recipe for absolute chaos and disorder," Cr Lake said.

You can see from the photo he tweeted of people happily socialising just how much chaos and disorder have been created by people 'opportunistically' obeying the law, ie. none. The Age also provides a photo of the kind of miscreants Lake is talking about.

Chaos and disorder in Melbourne

He won't be happy until these people are banned from the premises altogether and the business is closed down. Even then, he won't really be happy because people like him never are.

Cr Lake said the mall was among the worst areas in Melbourne for passive smoke and it remained a critical public health issue.

People smoking outdoors has no impact on the health of others whatsoever. None. Some people might find it mildly irritating while they are eating, in which case they should go to a venue where people are not smoking. There is no justification for the government getting involved and it is laughable to describe it as a 'public health issue', let alone a 'critical' one.

He said council was seeking urgent legal advice on whether it could enact its own local laws to put a blanket ban on smoking in the area.

Of course he is. And, this being Australia where the concept of a 'fair go' does not exist for smokers, he will doubtless succeed.


This awful human being has now written a whole op-ed about the supposed 'loopholes' that allow a tiny sliver of choice. 

Thursday, 27 July 2017

Another study shows that vaping helps people quit smoking

A study published in the BMJ today will have the usual anti-vaping fanatics howling at the moon. It found that vapers were much more likely to attempt to quit smoking than those who don't vape, and that they are 73 per cent more likely to succeed in quitting smoking when they do. It also finds a significant increase in smoking cessation in the USA that coincides with the rise of vaping.

Anti-vaping throwbacks will no doubt say that correlation does not equal causation, but the authors examine two possible alternative explanations for the decline in the smoking rate and find them wanting...

First, in 2009 there was an increase in federal tobacco tax. The national cigarette tax increased by 158%, resulting in an immediate reduction in cigarette uptake among US adolescents. In our study we found a small but statistically significant increase in quit attempts among US adults, from 39.9% in 2006-07 to 41.4% in 2010-11 (fig 2, top panel). However, the total cessation rate did not change: 4.5% for both surveys (fig 2, bottom panel). Thus the effect of the 2009 federal tax on quitting by adult smokers, if there was an immediate one, was no longer detectable by 2010-11. This lack of change in smoking cessation under such a dramatic tax increase accentuates the difficulty in improving quit rates at the population level. 

Second, since 2012 there have been annual, national media campaigns aimed at increasing quit rates among adult smokers. The TIPS from Former Smokers campaign used evocative television spots showing the serious health consequences of tobacco use. This campaign, running from nine to 20 weeks in any given year, reached a large segment of the smoking population. A national survey after the first round of the campaign found that 78% of smokers saw at least one media spot. By 2015, there had been four rounds of the campaign. Surveys found a statistically significant increase in quit attempts, and the cessation rate of those who made a quit attempt was estimated to be between 5.7% and 6.1%.

In the present study we found statistically significant increases in both quit attempt and cessation rates from 2010-11 to 2014-15. This period coincided with the TIPS campaign and the dramatic increase in e-cigarette use.

Could TIPS alone explain the increase? Given the reach of the first TIPS campaign, after four rounds it was expected to reach most US smokers by 2014-15. However, the majority of smokers did not appear to change their quitting behavior: smokers who did not use e-cigarettes were the majority (77%) in 2014-15. Neither their attempt rate nor the annual cessation rate was statistically different from that of all smokers in 2010-11 (fig 1). It was e-cigarette users in 2014-15 who showed a dramatically higher quit attempt rate and a higher cessation rate. 

The authors caution against attributing all of the difference in cessation rates to vaping because it is possible that those who are most committed to quitting are more likely to use e-cigarettes. However, this study is hardly the first to find a significantly higher rate of quitting among vapers and randomised controlled trials have found the same thing. Indeed, the quit rate among vapers in this study is more modest than has been found in most other studies, but it's published in the BMJ so is getting more attention.

The authors are from California so it is brave of them to publish a study that not only shows that vaping works but that the favoured policies of the tobacco control cabal don't. As a final dig in the ribs they conclude their study by saying:

We found that e-cigarette use was associated with an increased smoking cessation rate at the level of subgroup analysis and at the overall population level. It is remarkable, considering that this is the kind of data pattern that has been predicted but not observed at the population level for cessation medication, such as nicotine replacement therapy and varenicline.

They'll probably never work again.