Monday 11 January 2010

Still no heart attack miracle in England

Today, Michael Siegel dissects another junk science study purporting to show that the introduction of a smoking ban led to a drop in heart attacks. And so it goes on in the world of tobacco control. 

Back in the real world, recently published NHS figures have shown us that, just as there was no big drop in heart attack admissions in the first year of England's smoking ban, so there was no drop in the second year of the ban.

This graph shows the number of emergency admissions for acute myocardial infarction (heart attacks) in English hospitals from April 1998 to March 2009:

Ho-hum. It's the same old story. The rate was falling gradually before the ban and it has fallen just as gradually since the ban. 

Whenever hospital data is publicly available, there is no sign of a heart miracle. Whenever the raw data is available only to a select group of epidemiologists, there is a 'dramatic' drop in heart attacks. When an epidemiologist announces a drop in heart attacks in a small town or region, it gets global news coverage. When evidence from an entire nation shows that a smoking ban had no effect on heart attacks, the news is confined to a handful of blogs.

The story is always the same, and I apologise for boring readers with one null study after another. But spare a thought for Dr Anna Gilmore, whose job it is to turn this mundane data into a newsworthy study showing that the smoking ban has saved thousands of lives. She may be working on it at this very moment. 

At some point this year, the media will be reporting a heart miracle in England, based on the very evidence I have shown above (or carefully selected parts of it). It sounds incredible, Orwellian even, but it will happen, and when it does none of the real figures will matter. None of the data carefully collected around the country and displayed on the HES England website will matter. The number of people who really got rushed to hospital with a heart attack in those years will be irrelevant.

If you want chapter and verse, I can tell you that the heart attack rate dropped by 3.84% and 3.79% before the ban, and by 3.75% and 2.61% after the ban. These figures are nowhere near big enough to guarantee news coverage. When the study appears it will probably show that heart attacks fell by at least 10%. We know this because that's what was reported before the study even began.

We live in post-evidential times. Whatever he who pays the fiddler wants to believe happened, is what happened. The real events are of no consequence. They are trees falling in an empty forest. 


Dick Puddlecote said...

So, if anything, the trend shows a slowing of the decrease in heart attacks. Or, some might argue, a very small increase in heart attacks in real terms.

Just being mischievous. ;-)

Anonymous said...


I think that you may be onto something:-)

Anonymous said...

I have just read Michael Siegels blog. He says that one major flaw in the study is that there is no comparsion group. One, major, flaw. How about THE major flaw. I wonder what happened to the concept of "control group"? This is not science, at least not any version that I am familiar with. I was taught that one of the most important questions to ask is "comapared to what?".
There is no science anymore, we are living in the age of - make it up as you go along - supported by clap your hands and the fairies will come - and underpinned by -tell the same lie often enough and it becomes the truth. It's depressing.

Outraged Englishwoman

Anonymous said...

Yesterday ASH UK reproduced an article about a CDC meta analysis which "proved" that smoking bans cause a drop in heart attacks. Let's all of us email ASH UK today, and provide them with the link to Chris's blog.

Anonymous said...

Given that smoking is supposedly a major cause of heart disease, I would be interested to see smoking trends charted against cardiovascular disease trends.