Longtime readers of my blog may remember the “heart miracle” studies of the previous decade. These studies purported to show that implementing smoking bans would bring about drastic and immediate reductions in the rate of heart attacks. I and several other writers expressed doubt for a variety of reasons, noting the small sample sizes and methodological oddities that seemed to point to a pre-determined conclusion. At the time, however, there weren’t many large scale studies being done that could settle the question.
Those large scale studies now exist, and as I write today at Slate, the evidence for the heart miracle hypothesis isn’t holding up:
[…] now that the evidence has had time to accumulate, it’s also become clear that the extravagant promises made by anti-smoking groups—that implementing bans would bring about extraordinary improvements in cardiac health—never materialized. Newer, better studies with much larger sample sizes have found little to no correlation between smoking bans and short-term incidence of heart attacks, and certainly nothing remotely close to the 60 percent reduction that was claimed in Helena. The updated science debunks the alarmist fantasies that were used to sell smoking bans to the public, allowing for a more sober analysis suggesting that current restrictions on smoking are extreme from a risk-reduction standpoint.
It’s a rather long piece and it covers a lot of ground, from the original heart miracle in Helena, Montana to the pervasive outdoor smoking bans that stigmatize smokers today. Read the whole thing.
During the editing of the article I also came across yet another new study from Japan. This one compares data from Hyogo Prefecture, one of the first regions in Japan to impose a smoking ban, to the control population of Gifu Prefecture. The time period is fairly long (one year before the ban, two years after) and the populations are large (5.58 million residents in Hyogo, 2.07 million in Gifu). One limitation of the study is that the Hyogo ban isn’t 100% comprehensive; businesses such as bars can allow smoking and some other businesses can have separate smoking rooms. Nonetheless, given the pervasiveness of smoking in Japan, even a partial ban would be expected to significantly reduce non-smokers’s exposure to secondhand smoke.
So what were the results? No trend in the number of acute coronary syndrome admissions appeared in either prefecture. “For the primary endpoint of this study, we did not observe a significant change from before to after the implementation of the partial smoking ban.”
The study did identify a small downward trend in Kobe City, which the authors attempt to spin as evidence that the smoking was in fact having the desired effect:
The reason why only Kobe City showed a significant decrease in the number of ACS admissions irrespective of subgroups is unclear. One possible reason is that the Hyogo Prefectural Capital Office is located in Kobe City, and social understanding of smoking legislation might have been accepted more widely. Indeed, questionnaires by Hyogo Prefectural Government Health & Welfare Department, distributed in the bars and restaurants larger than 100m2 in 2015, showed that the adherence rate to the smoking ban legislation was 97% in Kobe City and 88% in other Hyogo districts included in the present study. Therefore, compared with the other districts in Hyogo, the adherence rate to the smoking ban legislation was higher in Kobe City.
OK, maybe, but this seems like a stretch. One should always be skeptical of post-hoc attempts to explain why the effect one was looking for only appears in a certain subset of the data. It’s easy to come up with just-so stories that fit the expected narrative. There are myriad other factors that could be causing the decline, and chalking it up to slightly better adherence to an already partial smoking ban strikes me as a very unlikely (and very convenient!) candidate.
In any case, the bulk of high-quality research published in recent years weighs heavily against the idea that smoking bans will bring about miraculous health benefits. So as I argue in my Slate piece, let’s move on to a post-miraculous policy and make sensible accommodation for smokers’ preferences.