These places are not exactly major conurbations, you may have noticed, and the numbers of heart attacks are so low—often single or double figures—that large fluctuations are common. When whole countries have been studied, advocates have been forced to resort to methodological jiggery-pokery (Scotland, 17%) and bald, unverifiable assertions (England, 2.4%).
Stanton Glantz has produced two meta-analyses in an attempt to shore up his hypothesis, claiming that heart attacks fall by 27%, and then 17%, after smoking bans are enacted.
But when the actual hospital admissions data are made available, they invariably fail to provide any evidence of an effect of smoking bans on the heart attack rate. The statistics from Denmark, Wales, Australia, England, Scotland, New Zealand and the United States have all failed to support the smoking ban/heart miracle hypothesis.
What should we trust? The evidence from places like Bowling Green, Ohio or the evidence from the entire USA? It has been obvious from the very beginning that anti-smoking campaigners have been mining the data to find big drops in heart attacks that roughly coincide with smoking bans. A study recently presented to an American Heart Association conference illustrates how easy this cherry-picking can be.
The study's finding are very interesting. The researchers looked at 74 US cities and found that the heart miracle effect has now fallen to just 3% (0.97 (0.95-99)). When the sample was limited to cities where the smokefree law was "meaningful"—ie. where there was a full smoking ban, rather than just restrictions—the effect disappeared entirely (0.99 (0.96-1.02). (Meaning that cities with lax smoking bans saw a bigger fall in heart attacks than those with "meaningful" smoking bans. Once again, the evidence fails to fit the theory.)
A drawback of the study is that there is no indication of how much the heart attack rate was falling before the ban, nor do the researchers compare rates to those in the cities which didn't have a smoking ban. When the study is published—if it is—hopefully the researchers will use a control group and look at the long-term trend.
What we do know is that rates of heart disease are falling in the USA, as they are in the UK and Europe. Even if one picks the more generous 3% figure, a modest decline of this order is likely to be in line with the secular trend. In other words: the smoking bans didn't make any difference.
If you look at the cities which brought in full smoking bans, you can see there is a great deal of variation in the heart attack rate with some going up, some going down and some going nowhere.
The variation is so great that no honest statistician would claim that there is any trend to be found amongst the data. But notice that four of the cities showed a statistically significant reduction in heart attacks and that the reduction was quite strong (at around 25%-30%). Now put yourself in the shoes of the tobacco control advocate who wants to show that smoking bans have a major effect on the heart attack rate. Which city would you choose to write your paper about? Evanston or Flagstaff?
The question, I think, answers itself. This is how they have been doing it. This is how we end up with 'news stories' like this from the BBC in 2003:
Town slashes heart attacksBanning smoking in public places could prevent hundreds of deaths from heart disease, according to a study in a small US town.
Heart attacks in Helena, Montana, fell dramatically when smoking in public places was banned for six months last year.
The number of admissions dropped to fewer than four a month - a fall of nearly 60%.
From "nearly 60%" to nearly zero in just 8 years. What a ridiculous fraud this whole thing has been and how pathetic that so many have fallen for it.
Thanks to Michael J. McFadden for the tip.