Thursday 1 December 2016

Brazilian smoking ban miracle

This execrable study didn't get any media attention and when I saw it tweeted by Tobacco Control magazine I didn't even bother reading the abstract, so bored am I of fraudulent smoking ban miracles.

Anyone who's followed these scams over the last twelve years knows what to expect. Typically, the activist-researchers take heart attack figures from before and after a smoking ban, create a counterfactual that suits their purpose and then claim that there were fewer heart attacks than there would have been without a smoking ban. It helps if heart attacks are already in decline (they often are).

That's why I didn't read the study. I thought I'd seen it all before. But my interest was piqued by Michael Siegel who blogged about it yesterday. The authors attempted the method described above but were faced with the awkward fact that the heart attack rate absolutely skyrocketed after Sao Paolo introduced its smoking ban in early August 2009.

The authors helpfully provide all the numbers in the study - for this a crime carried out in plain sight - and I have graphed them below. The red line shows the date of the smoking ban.

You can see the number of deaths from myocardial infarction decline after September, but you can see the same seasonal trend in previous years with a fall at the end of the year and a rise at the start of the next. Early in 2010, it rises sharply - much more sharply than in previous years - and stays high for the rest of the period covered. Unless the population of Sao Paulo increased by half at the start of 2010, this is not a decline in the heart attack rate.

Before the ban, the number of deaths hardly ever exceeded 600 per month and was often below 500. Within a few months of the ban, there were never fewer than 700 deaths per month.

In the bizarro world of Tobacco Control, this shows that the 'mortality rate for myocardial infarction reduced following the smoking ban in Sao Paulo'.

Things are not much better if you look at hospital admissions for heart attacks. There is a year-on-year increase almost every month after the smoking ban...

These inconvenient facts would have deterred lesser mortals, but our intrepid researchers pressed on regardless, making so many unexplained adjustments to the data that they were able to conclude their study as follows:

Mortality rate and hospital admission rate for myocardial infarction decreased after the comprehensive smoking ban law in Sao Paulo city.

And so history is re-written. It can join the growing list of 'public health' facts that are not facts, such as 'minimum pricing reduced alcohol-related deaths in British Colombia by a third' or 'Rotten teeth in toddlers are at crisis level’ or 'Sugar tax reduced soda sales by 12 per cent in Mexico'. Or, indeed, 'Scottish smoking ban reduced heart attacks by 17 per cent'.

It's not that these guys have failed to prove cause and effect. There is no effect to find a cause for. The campaigners have created their own fantasy land where the facts are whatever they want them to be and words mean whatever they want them to mean.

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