Long time readers will have seen quite a few graphs like the one below over the years (for example here and here). They show the number of people admitted to hospital with heart attacks in a country. In this case, the country in England. I have previously used NHS hospital data to show that the English smoking ban had no effect on England's heart attack rate, contrary to a claim made by Anna "pants on fire" Gilmore. (In fact, the data in that graph came from her study; she just chose not to show it in a chart.)
You can see the non-effect of the ban (started July 2007) in the graph below. Clearly, there is a consistent, gradual downward trend, but no big dips. There are slight increases in the downward trend in 2005 and 2010, but these can hardly be attributed to a ban that started in 2007.
You knew this already, right? I only mention it again because this graph comes from a new study in the British Medical Journal which looks at the the heart attack rate in England between 2002 and 2010. So, just in case you think I've been making up the data these past two years, let this assure you that I have not.
The six page study does not mention the smoking ban at all and its data clearly do not support the notion that the ban had any observable effect on heart attack admissions. The big story is that deaths from heart attack have halved since the turn of the century. This is great news, but it has obviously been a steady process which has come about for a multitude of reasons.
If someone tells you that the heart attack rate fell after the smoking ban, they are not lying, but they are not being entirely truthful either. Pick any event of the last decade and the heart attack rate fell afterwards. Pathetic as this post hoc logic is, it has been the basis of one of the biggest scientific scams of recent years.