Credibility of Helena/Pueblo Claims is Not Just a Theoretical Concern; Anti-Smoking Groups are Spewing Out this Propaganda Widely

I want to devote this post to emphasizing that my concern over the credibility of the Helena/Pueblo claims that smoking bans immediately and drastically reduce heart attacks by as much as 40% is not just a theoretical one regarding the science.

It is, instead, a practical concern that is made a critical one because this claim is being widely made by anti-smoking groups and advocates in national media campaigns as well as smoking ban battles throughout the country.

The point is: this is not a situation where we are making a lot out of a claim that simply appears in an isolated scientific paper or an isolated press release. We are dealing with a claim that has penetrated the tobacco control movement, and is becoming widely familiar among the media and the public.

The Rest of the Story

Here, therefore, is just a sample of public claims being made by public health and anti-smoking groups regarding the Helena and Pueblo studies:

• A Campaign for Tobacco-Free Kids press release states: "New Study Confirms Smoke-Free Laws Reduce Heart Attacks"
• A Pueblo City-County Health Department press release states: "The study validates previous scientific evidence that indoor smoke-free laws can dramatically reduce heart attacks and means that 108 fewer people had heart attacks in Pueblo in an 18-month period."
• An American Cancer Society press release quoted its CEO as stating about the Helena study: "There has never been better evidence in support of clean indoor air laws."”
• A UCSF press release stated: "In the first study of its kind, researchers have found that the number of heart attack victims admitted to a regional hospital dropped by nearly 60 percent during the first six months that a smoke-free ordinance was in effect in the area. The study's authors attribute much of the sharp decline in acute myocardial infarctions (AMI) to a near-elimination of the rapid and harmful effects of secondhand smoke on blood platelets and the arteries that supply blood to the heart."
• Americans for Nonsmokers' Rights not only states that the Helena study demonstrates the dramatic and immediate effects of smoking bans but also casts any criticism of the study as being hogwash: "The Helena Heart Study demonstrates that even a little exposure to secondhand smoke can be deadly. The study is powerful, and demonstrated the urgent need for smokefree laws to protect the public. So it comes as no surprise that the Helena Heart study has unfairly come under attack by the opposition. The opposition has used unsubstantiated claims to argue the validity of this study. These claims are hogwash."
• The Minnesota chapter of the American Heart Association not only touts the Helena study as being definitive, but accuses those who argue that the small numbers in the study make its results suspect as being "painfully uneducated" and urges the public to "believe the facts, not the fears": "Recently, opposition to the Freedom to Breathe Act in Minnesota has undertaken a concerned effort in legislative committees, meetings with legislators, and in public blogs to undermine the results of this landmark study. In particular, they have reported that the number of heart attacks in Helena dropped from seven to four, which is a statistically insignificant number...The opposition is very mistaken ... This statement is painfully uneducated. According to even the most conservative statistical analysis, there are less than five chances in 100 that the drop in heart attacks in Helena was a random drop."
• A Smoke Free Wisconsin brief argues, based on the Helena study, that: "Passing laws that have been proven to reduce the incidence of heart attacks will not only save lives, but will significantly reduce health care costs."
• According to the Smoke-Free Environments Law Project, the Helena study showed "that Helena, Montana smoke-free law had direct effect on decline in heart attack rate."
• A Jefferson County (Colorado) tobacco program press release boasted: "Pueblo Heart Study Confirms Smoke-free Laws Produce Immediate Reductions in Heart Attacks."
• A Larimer County (Colorado) health department press release more modestly claimed: "New Study Suggests Smoke-free Indoor Air Laws Reduce Heart Attacks."
• A SmokeFreeOhio web page states: "A study of emergency room patients in Helena, Montana, found that their 100% Clean Indoor Air Law reduced the city'’s rate of heart attacks by 40%."
  

It is quite clear, then, that the Helena/Pueblo claim, which is premature, if not invalid and implausible, has penetrated the tobacco control movement to a great extent, such that it is being widely bandied about in the effort to promote smoke-free legislation.

This is not only a disservice to the public, but I feel it greatly threatens the credibility of the entire movement.

The rest of the story demonstrates that this is not simply an academic issue. It is one that speaks to the integrity of the tobacco control movement and its responsibility to uphold the truth and the strength and quality of the scientific claims that it makes.

The movement's response to this problem will determine, to a large extent, its future credibility, and therefore, its future.

BMJ Letter Attributes Helena and Pueblo Heart Attack Declines to Random Variation

In a rapid response published on the BMJ online, Drs. Brad Rodu (Professor of Medicine at the University of Louisville) and Philip Cole have presented data which seems to confirm that the observed changes in heart attack admissions in Helena and Pueblo could be attributed to simply representing random variation in the underlying secular trend in that variable.

These authors used data on heart attack mortality in Lewis and Clark county in Montana (home of Helena) and Pueblo county in Colorado (home of Pueblo) to gauge trends in heart attack deaths over time (1979 to 2002) in these two cities.

First, the authors found that there was no decline in heart attack deaths from 2001 to 2002 (the year of the ban) in Helena, suggesting that whatever happened in Helena, fewer people did not die from heart attacks because of the smoking ban during its first six months.

Second, the authors found very high variability in year-to-year trends in heart attack mortality in both Pueblo and Helena, with several particularly striking variations, such that the single observed change in heart attack admissions from 2001 to 2002 in Helena and 2001-02 and 2003-04 in Pueblo could easily be attributed simply to random variation.

Demonstrating how much variability there was in these data, the authors point out that in Pueblo, there was a 28% decline in heart attack mortality between 2001 and 2002, even in the absence of a smoking ban. Had the smoking ban been implemented in 2001, the reasoning used by the Pueblo study authors could have concluded that 28% decline was caused by the smoking ban.

Moreover, these data demonstrate that there was a pre-existing decline in heart attack mortality in both Helena and Pueblo going into the time at which the smoking bans were implemented. So it would be expected that heart attack mortality would continue to decline.

The Rest of the Story

The bottom line is that I think Rodu and Cole have provided a compelling argument, backed up by convincing data, that there is tremendous variability in heart attack trends in Helena and Pueblo, large enough such that one cannot and should not make too much out of the simple observation of a change from one year to the next (or one 18-month period to the next) in this particular variable.

In other words, the observed changes in heart attack admissions in Helena and Pueblo could easily be attributed to random variation, rather than to an effect of the smoking ban.

Do these data prove that the heart attack decline was not due to the smoking ban? No. But they provide a plausible alternative explanation for the observed findings, and that is enough to render invalid the definitive causal conclusions that have been drawn from these studies.

Tobacco Control Movement Credibility Starting to Decline as Public Can't Differentiate Legitimate from Far-Fetched Claims

In what I think will be a harbinger of things to come, the first signs of erosion of the credibility of the tobacco control movement are starting to occur.

It takes the form of an apparent inability on the part of the public to differentiate between legitimate scientific claims of the tobacco control movement and those that are quite far-fetched. The first signs of this inability to differentiate the soundness of the claims is evidenced by an op-ed column in which the far-fetched Helena and Pueblo claims are being lumped together with claims related to the hazardous effects of secondhand smoke.

In an op-ed column published in Sunday's The Daily Camera (Boulder, Colorado), Jay Ambrose argues against the need for Colorado's recently enacted statewide smoking ban by questioning the evidence linking secondhand smoke to disease. In doing so, he lumps together claims by tobacco control advocates that secondhand smoke is harmful with claims that smoking bans in Helena and Pueblo resulted in as much as a 40% immediate decline in heart attacks.

Because the Helena and Pueblo claims have been "debunked," Ambrose argues, therefore the secondhand smoke health claims also must be invalid.

According to Ambrose: "The Helena study has been pretty thoroughly debunked by now. Its sample was tiny, the research effort was anorexic and the study didn't account for a similar decrease in a year prior to the ban. On the face of it, quick and substantial declines in heart attacks after a ban such as the one in Pueblo are much less likely to have a connection with the ban than to be a reflection of normal statistical ups and downs. This probability is brought home by a study of the heart-attack drops after smoking bans in states with a combined population of tens of millions, not in one community of tens of thousands. The finding? There was no overall drop."

The Rest of the Story

To be sure, the Helena and Pueblo studies have little to do with the health effects of secondhand smoke or the justification for smoking bans. Showing that smoking bans result in a decline in heart attacks is not a necessary criterion in order to adopt such policies. And demonstrating that these bans result in a decline in heart attacks is not necessary to conclude that secondhand smoke is a health hazard.

In short, the Helena and Pueblo studies really have little to do with the relevant issue: the alleged health hazards of secondhand smoke.

So why are these studies, which are not directly related to the health effects of secondhand smoke, being used to discredit the literature on the health effects of secondhand smoke?

The reason is that these studies call into question the credibility of the tobacco control movement and its scientific claims: the legitimate ones and the unreasonable ones equally.

The Helena and Pueblo claims are being viewed simply as claims of the anti-smoking movement, no different from any other scientific claims being made by the movement, including those related to the health effects of secondhand smoke. If the Helena and Pueblo claims are invalid, and have been debunked, then what reason is there for the public to believe the other claims being made by the same movement, even if those claims may happen to be substantially more solid scientifically?

Perhaps the most telling aspect of this story is that it puts someone like me in an awkward position in terms of trying to refute its central argument. Specifically, I am in the uncomfortable predicament of having to argue that although Ambrose is 100% accurate in his depiction of the validity of the Helena and Pueblo claims, he is not accurate in his depiction of the secondhand smoke health hazard claims.

This "subtlety" (which I'm sure it is to the public) is, I think, too fine to be generally appreciated by the media and the public. How am I to convince them that the tobacco control movement is completely stretching the science when it comes to Helena and Pueblo, but that when it comes to the dangers of secondhand smoke - well - here they are being sound in their scientific claims.

And my position becomes even more awkward when one considers the fallacious claims being made by a number of anti-smoking groups about secondhand smoke itself: I have to argue that although the anti-smoking movement is completely making up scientific claims about the health effects of secondhand smoke, they are actually correct about the health hazards of tobacco smoke exposure - just not these particular claims.

To a public and a media that are not scientists and that do not necessarily have the ability to discern legitimate from invalid claims, this is a difficult argument to make, and even more difficult to expect them to swallow!

This is precisely what I was trying to suggest when I wrote on March 13 (about shoddy scientific claims being made by anti-smoking groups) that:

"these actions are going to harm the credibility of the anti-smoking movement simply because they are so completely implausible and seemingly taken out of nowhere. The extrapolations being made are so extreme that they threaten to undermine the public's perception of the anti-smoking movement's ability to interpret and report the results of scientific studies at all, even when that reporting is appropriate.

The problem is - the public and policy makers will not necessarily know the difference. They will not be able to differentiate easily between when the claims we are making are legitimate and when they are extreme and errant extrapolations. They will just begin to question everything that we say."

And that is exactly what appears to be happening here.

While I acknowledge that this is just a small example - a single column in a small paper - I think it demonstrates precisely what the danger is to the credibility of the anti-smoking movement of anti-smoking groups that are making inaccurate, implausible, insufficiently documented, and even fallacious claims.

People may not know the difference - and it is going to be increasingly difficult to try to convince policy makers and the public that the movement is scientifically trustworthy, but just not with regards to Helena, Pueblo, the 20-minute heart attack claim, the 30-minute heart attack claim, etc.

I don't want to be in the position of having to say: "Well - if you set aside these 10 claims that we are making, we are most credible and trustworthy in what we're saying." Unfortunately, we're pretty much already there.

Invalid Studies Being Used to Promote Smoking Bans

According to an article in the Loveland Daily Reporter-Herald, two authors of the Helena and Pueblo studies (which purported to show that smoking bans in these cities reduced heart attack admissions by 40% and 27%, respectively) are using the conclusions from these studies to promote smoking bans throughout Colorado.

According to the article: "Controversial studies in Pueblo and Helena, Mont., link smoking ordinances to a decrease in heart attacks. Doctors involved with both studies spoke Wednesday afternoon at McKee Medical Center to kick off presentations around the state to promote smoking bans, whether on a local or state level. 'We'’ve been invited to a number of states to talk about the study. With the increased interest in Colorado, we decided to pair off the studies,' said Dr. Robert Shepard, medical director of New West Health Services in Helena, who oversaw the Helena study. ... Dr. Carl Bartecchi, a professor of clinical medicine at the University of Colorado School of Medicine ... used that study to promote a citywide indoor smoking ban in Pueblo, which took effect July 2003. ... 'The chances of this happening by chance are extremely thin,' Bartecchi said. ... Shepard added that most criticism comes from 'naysayers who just don'’t want to believe it.'"”

The Rest of the Story

Well I'm not a naysayer and I do want to believe it because it would be wonderful if smoking bans could decrease heart attacks by more than a complete ban on smoking would.

Unfortunately, an analysis of the plausibility of the Helena and Pueblo claims demonstrates that it is simply mathematically impossible for a smoking ban to result in a 40% decline in heart attacks when a complete ban on smoking would not likely result in that great a decline in heart attacks. Thus, in order to explain the Helena conclusion, the smoking ban would have had to cause every smoker in the city to quit smoking, and even then it's not clear there would have been a 40% decline in heart attacks. The purported effect of the smoking ban in Pueblo is equally implausible.

The Pueblo study is particularly unconvincing, and in my opinion, weak scientifically, because it compares two data points - one from the 18 months after the smoking ban and one from the 18 months prior to the smoking ban. There is simply not a long enough baseline period to establish what the baseline variability in heart attack admissions in Pueblo is and what the secular trend was in order to determine whether the observed 27% decline in hospital admissions was due to the smoking ban or to random variation in the underlying data.

It seems particularly unfortunate that the Pueblo study is being disseminated and used to promote smoking bans in Colorado, especially the fact that it is apparently being disseminated by the author himself, because the study is unpublished and is apparently under review by a scientific journal. Most journals frown upon the results of studies being disseminated while they are being peer reviewed and prior to publication.

And I find it unfortunate that the results and conclusions of this scientific study are apparently being disseminated and being used to promote policy prior to being published. In fact, it's not clear exactly what the point of seeking publication of these findings is, if they are going to be disseminated and used to promote policy prior to publication.

Usually, we wait until a scientific study is peer-reviewed and then published before disseminating the findings to the public and the media. There are of course some exceptions, but here it appears that the Pueblo findings are basically on tour.

I guess we can call this Winter Tour '06.

And it's really a shame because the Pueblo and Helena studies are not a reason to ban smoking in restaurants. In my opinion, there are other data to support smoke-free workplace policies. Therefore, I think it is a shame that the implausible and scientifically weak results from Pueblo and Helena are being used to promote these policies.

(In honor of smoking bans and Colorado: Here's the setlist from the Grateful Dead August 12, 1979 concert at Red Rocks)

Anti-Smoking Advocates Told How to Respond to Dissent about Pueblo Findings

In a message sent to hundreds of anti-smoking advocates, a prominent tobacco control researcher has apparently provided instruction for these advocates in how to respond to my questioning of the validity of the unpublished Pueblo study, which concluded that an observed 27% decline in heart attack admissions during the 18 months following implementation of a smoking ban (compared to the 18 months before the ban) was due to the smoking ban.

Advocates are apparently being told not to engage in discussion on the topic, and are referred to an electronic response comment on the published Helena study which essentially reiterates the findings of the two papers without directly addressing or even mentioning the specific criticisms rendered.

The message states: "We have received several enquiries from people on how to respond to criticisms on various smokers' rights websites and other blogs of ... study reporting that AMI's fell in Helena. We believe that the proper forum for such a scientific discussion is through the journal that published the paper... ." Readers are then referred to (link here).

Those comments essentially reiterate the findings of the studies, but do not address the specific alternative explanations I and others have offered:

"In thinking about possible alternative explanations for the findings in our and the Pueblo study, it is important to consider all the observations:

1. In both cities there was a substantial drop in AMI admissions when the smokefree laws went into effect.
2. There was no such drop in AMI admissions from people from the surrounding area (and, in the case of the Pueblo study, a nearby city) who were not covered by the ordinance.
   
3. There was a rebound in AMI admissions in Helena when enforcement of the law was suspended.
4. There was no change in the underlying pattern of AMI admissions in the surrounding area when enforcement of the Helena ordinance was suspended.

None of the individuals who have questioned either our or the Pueblo study have provided a plausible alternative explanation for these facts."

The Rest of the Story

This post is actually not about the scientific findings of the Pueblo study, but since I brought it up, I'll address the above comment first.

My suggested alternative explanation for the findings in the Pueblo study is that the results are due simply to chance. In other words, that there is a random variation in the annual (in this case, 18-month) trends in heart attack admissions in Pueblo and that with simply 2 data points, it is virtually impossible to establish what the underlying random variation in heart attack admission rates in Pueblo is; thus, it is impossible to attribute an observed 27% decline from one time period to the next to the smoking ban, rather than simply to random variation in the underlying data.

For the purposes of assessing the published argument, let's assume that this alternative hypothesis is correct. What would be the consequences for each of the 4 points made by the authors?

1. In both cities there was a substantial drop in AMI admissions when the smokefree laws went into effect.

If the observed drop in heart attack admissions in Pueblo was due to random variation in the overall trend, rather than due to the smoking ban, then one would expect to see a substantial drop in heart attack admissions when the smokefree law went into effect (this point is tautological, but I want to address each point directly).

2. There was no such drop in AMI admissions from people from the surrounding area (and, in the case of the Pueblo study, a nearby city) who were not covered by the ordinance.

If the observed drop in heart attack admissions in Pueblo was due to random variation in the overall trend, rather than due to the smoking ban, then one would expect to see no such drop in heart attack admissions in a nearby city because there is, by definition, no reason why the random variation pattern in Pueblo would also be followed exactly by the comparison city. If one looks at secular trends in heart attack admissions in Pueblo vs. Colorado City, one will not see that the patterns exactly mirror each other.

3. There was a rebound in AMI admissions in Helena when enforcement of the law was suspended.

If the observed drop in heart attack admissions in Pueblo was due to random variation in the overall trend, rather than due to the smoking ban, then one would expect to see a rebound in heart attack admissions in Helena in the precise time period when enforcement of the law was suspended. By definition, if the observed decline in hospital admissions for heart attacks were just a random variation, then one would expect to see those admissions rebound after the decline. Otherwise, it would not be a random variation but a true, sustained decline in heart attack admissions.

4. There was no change in the underlying pattern of AMI admissions in the surrounding area when enforcement of the Helena ordinance was suspended.

If the observed drop in heart attack admissions in Helena was due to random variation in the overall trend, rather than due to the smoking ban, then one would expect to see no change in the underlying pattern of heart attack admissions in the surrounding area. If the observed decline in Helena were due to random variation in those trends, then there is no reason to expect to see a particular change in heart attack admissions in the surrounding area. A corresponding decline in admissions in the surrounding area would signal a true secular decline in heart attack incidence, but that is not what is being posited in my argument. Instead, I'm simply positing that there is random variation in the Helena trends; one would not expect to see a similar "random" variation in the trends in the surrounding area.

In other words, each of the 4 pieces of evidence purported by the authors of this comment to be incompatible with my alternative explanation for the study findings is not only compatible with the study findings, but is, in fact, the precise finding that would be expected under my alternative hypothesis.

So my alternative hypothesis may well be wrong, but it is certainly not negated by the argument provided by this particular comment.

The Rest of the Rest of the Story

Now to the main point of this post.

There are actually two.

First, I think it is interesting to observe how this story is framed in terms of "how to respond" to my commentary, rather than on a discussion of the actual scientific issues involved. In other words, it appears that what the inquiring advocates wanted to know or what they were told was not the scientific validity of the comments in question, but instead, how to respond to these comments in order to dismiss them.

If someone from within the tobacco control movement wrote a critique of a study I had conducted, I doubt that I would send a message out to advocates telling them how to respond to that dissent from within the movement. I might well defend my study and my conclusions, but I am not in the business, nor do I think we should be in the business, of instructing people on how to respond.

Isn't there some room for advocates and organizations to analyze the scientific issues on their own and come up with an informed opinion on the issue? Do we not think for ourselves anymore? Are we simply automatons that merely follow directions rendered from above? Must we always assume that any conclusions suggested by a researcher that tend to support the anti-smoking agenda must automatically be correct and that any dissent from those opinions must be counteracted, rather than acknowledged as potentially credible?

Second, I think it is interesting to observe how this message sent to hundreds of anti-smoking advocates aims to stifle discussion on the issue, rather than promote it, by suggesting that any and all discussion of the issue must be done only in one form: through the British Medical Journal.

I didn't realize that the British Medical Journal was the great gatekeeper for all scientific discussion of tobacco control issues. Nor did I realize that it is simply inappropriate to discuss the rationale for tobacco control policies or the science behind these policies in any forum other than a medical journal. I didn't realize that scientific discussion of scientific findings relevant to policy issues in a public forum was simply inappropriate and not to be tolerated.

That's interesting, because in all the years I spent responding to criticisms of my own research showing the hazards of secondhand smoke for restaurant workers (and this is the science that actually, I believe, provides support for smoke-free policies, not the alleged effects on heart attack rates), I was never once told that it was inappropriate to discuss the issues outside of JAMA, the journal in which I published my findings. The only thing that seems to have changed is that I'm now on "the other side" of the issue, if one accepts that there is such thing as an established anti-smoking agenda that one can be on "the other side" of.

Actually, I think it is valuable to be able to engage a wide audience of people in a meaningful discussion of this scientific issue, and I don't see any reason why that discussion must or should be confined to the electronic response system of the British Medical Journal.

Moreover, if the premise of this message sent to advocates is correct, then the Pueblo study should never have been reported publicly, because it has not been published in any peer-reviewed, scientific journal. If scientific journals are the only appropriate forum for discussion of science, then there is no excuse for the press releases that were issued publicizing the results of the Pueblo study.

And furthermore, the Pueblo study was not published in any journal. So if it is true that the only appropriate forum to discuss the scientific issues raised by Pueblo is in the journal in which the study was published, then I guess I'm out of luck. There would simply be no way to express my views until (and if) the study finally appears in a journal (and there's no guarantee that it will even make it through the peer review process given its serious flaws).

Well perhaps that's the point. Perhaps the idea is that I shouldn't be expressing my opinion, since it apparently represents dissent from the "established" views of the anti-smoking movement.

OK - my bad.

New Data Show Decline in M.I. Admissions in Smoke-Free States is Lagging Behind Decline for Nation; Casts Doubt on Helena/Pueblo/Saskatoon Claims

Data recently released by HCUPnet, a service of the Agency for Healthcare Research and Quality (AHRQ), show that there was a substantial decline (8.2%) in heart attack hospital admissions in the United States between 2003 and 2004. This followed a smaller decline of 2.8% between 2002 and 2003. Overall, the decline in heart attack admissions in the U.S. between 2002 and 2004 was 11%.

These sharp declines in heart attack admissions suggest that the conclusion of recent studies that smoking bans caused declines in heart attacks in Helena, Pueblo, and Saskatoon are highly suspect, as these studies fail to control for the fact that during the same period of time as these smoking bans went into effect, a secular change in heart attack admissions was occurring.

An analysis of heart attack trends in states that implemented smoking bans in recent years (but prior to 2004, which is the most recent year for which heart attack data are available) reveals that there is no evidence that smoking bans led to a decline in heart attack admissions in these states.

In New York, a smoking ban in all bars and restaurants was implemented in July, 2003. A similar ban in New York City had been implemented in March of that year. If smoking bans caused a drastic and immediate decline in heart attacks (40% in 6 months was claimed by the Helena study), then one would certainly expect to have seen a substantial decline in heart attack admissions in New York State in 2003 and 2004.

However, heart attack admissions in New York State dropped by only 0.5% in 2003, and by 3.2% in 2004, compared with the national declines of 2.8% and 8.2%, respectively. Overall, the decline in heart attack admissions in New York State from 2002 to 2004 was only 2.7%, compared to a 10.7% drop in the nation as a whole.

In Florida, a smoking ban in all restaurants was implemented in July, 2003. If smoking bans caused a drastic and immediate decline in heart attacks on the order of 40% (as claimed in Helena) or 27% (as claimed in Pueblo), then one would certainly expect to have seen a substantial decline in heart attack admissions in Florida in 2003 and 2004.

However, heart attack admissions in Florida dropped by only 0.7% in 2003, and by 2.0% in 2004, compared with the national declines of 2.8% and 8.2%, respectively. Overall, the decline in heart attack admissions in Florida from 2002 to 2004 was only 2.7%, compared to a 10.7% drop in the nation as a whole.

During the period 2003-2004, the precise period when smoking bans were implemented in New York and Florida, these states lagged substantially behind the rest of the nation in their observed rates of decline in heart attack admissions. Instead of seeing a 40%, or even 27% decline in heart attack admissions in these states, there was less than a 3% decline over two years, and this was in the face of a nearly 11% decline in the nation as a whole during the same period.

The Rest of the Story

Obviously, I am not concluding from this analysis that smoking bans cause heart attacks. But it is perhaps worth noting that the same methodology used by the Helena, Pueblo, and Saskatoon studies would lead to such a preposterous conclusion. This is the problem with attributing any observed changes in a health outcome to one particular change (i.e., a smoking ban) and ignoring all other possible changes that occurred, including random changes in the health outcome itself.

The problem is particularly troublesome in very small samples, such as those in Helena, Pueblo, and Saskatoon.

The bottom line is that there simply is not evidence to support the conclusions being disseminated by a large number of anti-smoking groups that smoking bans lead to dramatic decreases in heart attacks. This is an unsubstantiated health claim if I've ever heard one.

But the lack of evidence to substantiate the claim, as well as the lack of plausibility of the claim, do not appear to be stopping anti-smoking groups from making the claim, and from using this as propaganda in their efforts to promote smoking bans.

If you are going to be a credible scientist, you have to be willing to look at the data. I have done that, and I conclude that there is not evidence to support a contention that smoking bans will dramatically reduce heart attacks. If anything, the evidence suggests that this is not the case. Unfortunately, it doesn't appear to me that many anti-smoking researchers and groups are willing to even look at this evidence. Instead, they simply attack those calling this to their attention as being tobacco industry sympathists.

That is one thing I am not.

However, I am starting to sympathize with those who are getting sick and tired of seeing anti-smoking groups continue to spout propaganda that is unsupported by the science. Yes, I'm starting to feel your pain.

ANR Calls Helena and Pueblo Junk Science Claims "Crystal Clear Science," While Decrying Economic Impact Studies with Same Methodology

In a press release, Americans for Nonsmokers' Rights (ANR) has concluded that a smoking ban in Pueblo resulted in a 27% decline in heart attacks, even though this decline could well be due to random variation as well as a secular decline in heart attacks that was occurring in Colorado in the absence of smoking bans. ANR called the conclusion that smoking bans in Helena and Pueblo resulted in 40% and 27% declines in heart attacks crystal clear science.

According to the press release: "The [Pueblo] study reaffirms the findings of the recent U.S. Surgeon General'’s Report, "“The Health Consequences of Involuntary Exposure to Tobacco Smoke,"” and the 2003 Helena Heart Study, published in the British Medical Journal, that comprehensive smokefree workplace laws have immediate improvements on community health. ... The Pueblo Heart Study is another report to add to the growing body of scientific evidence illustrating the tangible benefits of smokefree air in the workplace. The science is crystal clear. Smokefree air saves lives and saves money."

The Rest of the Story

I have already explained why I believe that the Helena, Pueblo, and Piedmont study conclusions are essentially junk science.

Briefly, these studies are seriously flawed because they are unable to rule out the reasonable and in fact likely possibility that the observed declines in heart attack admissions were due simply to random variation in the underlying data as well as to a secular trend in declining heart attack admissions during the study period. None of these studies ascertained heart attack admission rates long enough after the implementation of the smoking bans to be able to credibly assess whether it was actually the smoking ban that caused the observed decline in heart attacks or not.

In addition, the claims are scientifically implausible. There is no plausible way that a smoking ban could cause a 40% reduction in heart attacks in six months. Even if all smoking were eliminated completely, we wouldn't expect to observe a 40% decline in heart attacks in six months. So how could a simple smoking ban achieve such an effect?

What is strangely ironic about ANR's rhetoric is that at the same time it uses the Pueblo methodology to conclude that the smoking ban caused a 27% decline in heart attacks, it decries studies using the same methodology which conclude that smoking bans caused an adverse economic impact on restaurants and bars.

Apparently, ANR views the science as "crystal clear" when it supports its agenda, but as "junk science" when it opposes its agenda.

I'm so glad that I did make my exit from ANR, because I would be ashamed to be on the Board of the organization now with this kind of shoddy science coming out of the organization.

It's one thing to support smoking bans on solid scientific evidence of the hazards of secondhand smoke. It's another to widely disseminate shoddy scientific conclusions to the public and base a campaign to promote smoking bans on junk science claims that have no scientific validity.

One could argue that since these studies were published in journals, ANR is justified in touting these shoddy claims. But I would counter that as public health organizations, we have to be capable of evaluating the science ourselves, and of making our own judgments about the validity of the claims we are making.

What is striking to me is the deterioration of the quality of the science coming out of the anti-smoking movement (and I'm not singling out ANR here; it's just one example). Our science has become no better than that commissioned by the tobacco industry. And our standard for judging the quality of science has become whether or not it supports our agenda.

Steven Milloy's Critique of Helena and Pueblo Studies is Largely on the Mark

In an October 2003 column and a November 2005 commentary, Steven Milloy, founder and publisher of junkscience.com and adjunct scholar at the Cato Institute, attempts to debunk the scientific claim from the Helena and Pueblo studies that smoking bans resulted in a dramatic, immediate reduction of heart attack admissions by 40% and 27%, respectively.

About the Helena study, Milloy accepts that fewer heart attacks occurred during the six-month period that the smoking ban was in effect, but he argues that there is no basis upon which to attribute that decline to the smoking ban. He points out, for example, that a very similar decline in heart attacks occurred in 1998. He suggests that there is no credible explanation for "why the 1998 dip in heart attack rates was just an anomaly but the 2002 dip was definitely due to the smoking ban."

The 2002 decline in heart attacks, Milloy argues, appears to be simply part of a cyclical pattern. And there is not enough of a historical context (the study did not go back far enough in time), he argues, to determine that the observed decline was anything other than a reflection of the random variation in this statistic over time.

Milloy also criticizes the study for failing to study any of the pre-ban and post-ban patients (no information is available, for example, on the smoking status and reported secondhand smoke exposure of these patients). This, he argues, further weakens the credibility of drawing a causal conclusion from the study.

A similar criticism of the Pueblo study was offered by an associate professor of political science at the University of Colorado who teaches statistics and commented that: "I'd like to see data from the last 10 years. They just studied this for a year and a half, and the conclusions could be coincidental or caused by other factors."

The Rest of the Story

I have to admit that I find Milloy's comments on Helena and Pueblo to be largely on the mark. In fact, anyone who is familiar with my own commentaries of these studies will note a striking similarity between the main arguments that I have made and precisely what Milloy is arguing above.

While I don't similarly question the link between secondhand smoke and heart disease, on the particular question of whether the Helena and Pueblo studies provide solid evidence that smoking bans dramatically reduce heart attacks, I agree with Milloy, and for the precise reasoning that he provides in his own criticism of these studies.

If one looks at historical trends in heart attack rates in these relatively small localities like Helena and Pueblo, one will note that there are often large changes from year to year in heart attacks, and some of these changes are of a similar magnitude as the changes associated with the implementation of their smoking bans.

But there is simply no credible evidence that I am aware of that demonstrates that the observed changes are anything more than simply random variation in the underlying data. At very least, there is nothing to demonstrate that the magnitude of any effect on heart attack rates is 40% or even 27%, even if a small effect of these smoking bans on heart attacks did occur. In fact, as I have argued, it is not plausible or even mathematically possible that these declines were due to the smoking ban.

And I agree with the University of Colorado professor that one really needs to look at data further back in time, such as from the past 10 years, to adequately understand what the baseline level of variation in these data is, and that is essential before when could conclude that the observed changes in these particular years is attributable to the smoking ban rather than to random variation.

I also should add that Milloy makes one other point that is worthy of highlighting. He discusses the fact that the Helena results were widely disseminated to the media and the public before the study was ever published or available for public scrutiny and he criticizes this "science-by-press conference" approach to releasing results by anti-smoking advocates "because they know their immediate audience likely will not be able to ask probing questions -- a tough thing to do when only sketchy details are hurriedly presented to people with no familiarity of the research conducted."

I completely agree. I would add that the release and dissemination of the Pueblo study followed the same pattern (science by press release - there is no actual study available for the public to review and so there is no way that anyone can scrutinizes the study methodology and results adequately). And I would add that it is not just the immediate audience that will not be able to ask probing questions, but the remote audience (the thousands of people who read news articles about the study) as well.

This is inappropriate, because it seems contrary to the integrity of science to present and widely disseminate research findings without making the details of the research available for public scrutiny. There are limited exceptions to this, I think, such as studies with dramatic clinical relevance for which a delay in sharing the results could affect the medical treatment of patients. But for the most part, if you're not willing or able to share your research, you probably shouldn't be releasing the results of that research via press release.

For many reasons, I am seriously concerned about the implications of this story for the credibility of the tobacco control movement. The public's interest and that of the movement itself, will certainly not be best served if the integrity of our science degrades into the realm of "junk science."

Helena Findings Defy Common Sense; Strongest Argument Yet For Prematurity of Study Conclusions

While I have presented several lines of reasoning (line 1 line 2 line 3) to explain why I think the conclusions from the Helena and Pueblo studies are premature (these studies concluded that there was a 40% and 27% reduction, respectively, in heart attack admissions within 6-18 months after a bar and restaurant smoking ban was implemented), I have yet to present what I think is the strongest evidence to date that the conclusions being widely disseminated regarding these studies are unwarranted and far too premature.

First, let's stipulate, for the purposes of this argument, that the smoking ban in Helena was so effective that it immediately resulted in the complete elimination of both smoking and secondhand smoke in Helena.

The question is: by what percentage would the number of observed heart attacks in Helena fall in six months?

I think the maximum possible proportion by which heart attacks could drop due to the complete elimination of all smoking is about 50% (and this is being liberal).

Consider the following:

1. After one year of quitting smoking, the risk of heart attacks in the most susceptible smokers (those who have already had a heart attack) drops by 50%.

2. It is estimated that among all people under 50, the proportion of heart attacks attributable to smoking is 50%. The proportion would be lower if the entire population were considered.

3. Smoking is estimated to cause approximately 170,000 heart attacks each year, out of a total of about 865,000 heart attacks, or a proportion of 20%. Even assuming that secondhand smoke causes a whopping additional 30% of all heart attacks, the proportion of heart attacks caused by smoking and secondhand smoke is not higher than about 50%.

I think it is relatively safe to say that if all smoking were eliminated, and therefore all secondhand smoke as well, we could at best expect to see a 50% decline in heart attacks.

Never have I seen any data that suggests that the majority of heart attacks are due to smoking and secondhand smoke. I think the highest plausible figure is about 50%.

The Rest of the Story

OK then. If the Helena smoking ban resulted in the complete and immediate elimination of all smoking, then at most, we would expect to see a 50% reduction in heart attacks.

So how can it possibly be the case that just banning smoking in bars and restaurants in Helena resulted in a 40% reduction in heart attacks?

Not only is the claim not supported by sufficient data that rules out the possibility that the observed decline in heart attacks was largely attributable to random variation in the data, but the claim flies in the face of common sense and plausibility.

I simply don't see any way that the elimination of secondhand smoke in bars and restaurants in Helena and any effect this had on reducing cigarette consumption could possibly have reduced heart attacks by 40% when the complete and total elimination of smoking and secondhand smoke exposure in Helena would at most reduce heart attacks by 50%.

Common sense (or more technically, plausibility) is one of the most important criteria that we use to judge the validity of scientific conclusions. In this case, it is simply not plausible, even under the most extreme of potential assumptions, that the smoking ban in Helena could have resulted in a 40% decline in heart attacks.

In other words, it is not plausible that 40% of the heart attacks that were occurring in Helena were attributable to either secondhand smoke exposure in bars and restaurants in the city or to smoking that was reduced or eliminated after the smoking ban.

There is really only one way in which this plausibility problem could be overcome. If the study (or a study) were to document some sort of unprecedented and unbelievable drop in smoking rates in Helena due to the smoking ban, then it would become plausible to observe this magnitude of an effect. For example, if it turned out that 75% of smokers in Helena quit smoking after the smoking ban, then the observed findings would become believable. Even if 50% quit, I think it would be believable.

But I am not aware that the study or any other study has indeed documented such drastic reductions in population smoking rates in Helena (or anywhere else that a smoking ban was implemented). In fact, I'm not aware of any data that has documented that there was any reduction in smoking in Helena following the smoking ban.

The lack of plausibility of the Helena claim is, I want to emphasize, not the only reason why I believe it is premature, if not completely invalid. Rather, it is the combination of the lack of plausibility with the plausible alternative explanations that have been offered to account for the findings in light of the severe limitations in the study design, in particular, the possibility that the observed finding was simply reflecting random variation in the heart attack trends.

Finally, I want to re-iterate that I am a proponent of smoking bans, and I do not opine that the invalidity of the Helena and Pueblo conclusions means that smoking bans are not justified. In fact, I don't think it has anything to do with that question, because I wouldn't expect to see a dramatic decline in heart attacks in association with any smoking ban (for the reasons outlined above).

The reason I think this is important is because it goes to the very credibility of the tobacco control movement. If we continue to go around spouting out these claims, eventually the public is going to catch wind of the fact that we are blowing a bunch of wind, especially in light of the common sense conclusion that there is no way a smoking ban could reduce heart attacks by 40%. As a result, our credibility will be hurt.

And the problem is that in the future, I'm afraid the public is not going to be able to discern whether it is the case that we are making exaggerated claims or solid ones. Once we lose our credibility, there may not be an easy way to regain it. And that will jeopardize and undermine our future efforts to promote smoking bans because no one will believe any of the claims we make, even the ones that are indeed justified and well-supported by the scientific evidence.

Drastic Declines in Heart Attack Admissions in Nebraska and South Carolina in 2004: Cut in Anti-Smoking Programs May be the Reason

According to data from the Healthcare Cost and Utilization Project (HCUP) database, there was a dramatic decline in heart attack hospital admissions in Nebraska in 2004 and a sharp decline in heart attack admissions in South Carolina during the same year. These declines in heart attacks coincide precisely with sharp cuts in funding for anti-smoking programs in each of these states.

In Nebraska, heart attack admissions fell by 28.5% from 2003 to 2004. This is in marked contrast to the existing trend in heart attacks in the state. Heart attack admissions were increasing by an average of 2.3% per year during the period 2001-2003 in Nebraska.

In South Carolina, heart attack admissions fell by 12.5% from 2003 to 2004. This is also in marked contrast to the existing trend in heart attacks in that state. Heart attack admissions were increasing by an average of 3.0% per year during the period 2001-2003 in South Carolina.

These declines in heart attacks are much greater than what would have been expected based on trends in other states. In all other states for which data are available, heart attack admissions fell by 5.1% from 2003 to 2004.

The dramatic decline in heart attack admissions in Nebraska coincides with a dramatic cut in funding for the state's tobacco control programs. According to the state: "The Nebraska legislature did away with the funding for this [state tobacco control] program in the spring of 2003. Tobacco Free Nebraska's $21 million ($7 million in each of three years) was cut. Third year funding for Tobacco Free Nebraska was eliminated and the TFN staff resources must rely on state general funds and CDC funds to sustain a skeletal program. Local coalition funding was virtually eliminated as well. ... Tobacco Free Nebraska has launched a $700,000 media campaign to air radio and television commercials with anti-smoking themes. ... This effort has been eliminated by the historic legislative cut of the spring 2003."

It appears, then, that the historic legislative cut in anti-smoking programs in 2003 resulted in the greatest decline in heart attack admissions observed in Nebraska and in the successful reversal of the increasing trend in heart attacks in the state.

The huge decline in heart attack admissions in South Carolina, which reversed that states trend of increasing heart attack admissions during the previous two years, coincided with the complete elimination of what had been a successful anti-smoking program conducted during the previous four years.

These declines in heart attacks, which buck the national trend, occurred in states which have enacted no statewide smoking bans, few if any local smoking bans, and which both received grades of F in 2004 from the American Lung Association for the category of Smokefree Air in its State of Tobacco Control 2004 Report Card.

The Rest of the Story

Of course the observed declines in heart attacks in Nebraska and South Carolina in 2004 were not due to the cuts in anti-smoking programs. But this demonstrates the danger of using data from one year after an event to draw conclusions regarding the effect of that event on the phenomenon of interest, especially when the sample is small and there is great baseline variation.

This is why the claims being made from Helena, Pueblo, and Saskatoon are so suspect. In these studies, data from one year (6-18 months) after a smoking ban was implemented are being used to suggest that the smoking ban resulted in that single year's observed decline in heart attack admissions. Essentially, you have a single data point that is being used not only to assume that a definite trend is present but to ascertain the cause of the change in the statistic for that single year.

The reasoning used here is exactly the same as that used in the Helena, Pueblo, and Saskatoon studies. Baseline trends in heart attack admissions for a period of roughly four years prior to the event of interest were studied to establish the baseline trend in heart attack admissions. Then the heart attack data for the first year following implementation of the event of interest were used to assess the effect of the event on heart attack admissions. A dramatic decline in heart attacks was observed that coincided perfectly with the event in question. No similar decline (to the same extent) was observed in a number of control states that did not have the event of interest. Using the same reasoning as in Helena, Pueblo, or Saskatoon, one would conclude that the cut in anti-smoking programs resulted in the dramatic 28.5% decline in heart attack admissions in Nebraska in 2004 and in the large 12.5% decline in heart attack admissions in South Carolina in 2004.

This is shoddy science. It's shoddy because there is simply too much underlying variability in the data to establish a definite trend from one year's data point and to eliminate the possibility that the single year change that is being observed is simply due to random variation, rather than to an effect of the smoking ban.

And here, the sample sizes are huge compared to any of the studies that are being relied upon to claim that smoking bans dramatically and immediately reduce heart attack rates. In Nebraska, there were about 1800 heart attack admissions per year, compared to only about 80 in Helena. The Helena conclusion was based on a reduction of about 16 heart attacks, while the Nebraska "conclusion" is based on a reduction of about 540.

In fact, an examination of the HCUP data reveal that the variation in heart attacks is rather strongly related to the sample size. In states with very large populations, there is little variability. For example, in the two largest states in the database (Florida and California), there was no year-to-year variation of greater than 5.5%. But in the smallest state (Hawaii), there was as much as a 15% year-to-year variation in heart attack admissions.

With small populations, it is going to take more than just five years of data to adequately establish baseline trends and to estimate the random variability in heart attack admissions. And it is going to take more than one year to establish that a definite change in the trend has occurred, rather than simply random variation.

Massachusetts is a great example of this. There was a 12.0% decline in heart attacks in Massachusetts in 2004. This is in sharp contrast to the average 9.2% increase in heart attacks in Massachusetts during the period 2001-2003. Does this mean that something which occurred in late 2003 or early 2004 caused the sharp decline?

We can't really tell yet. First of all, we would need to know the underlying variation in the data. Do we observe changes from year-to-year in Massachusetts of this magnitude?

Well, from 2001 to 2002, heart attack admissions in the state increased by 18.3%, but admissions were essentially stable from 2002 to 2003. Is this just random variation, or is there a real trend? You need to go back further than 2001 and farther ahead than 2004 to find out. After all, there were more heart attacks in Massachusetts in 2004 than in 2000. That certainly doesn't sound like a trend of declining heart attacks. The 2005 data point may help to clarify this. If heart attacks continue to fall, then it appears there may be a real trend. But if they are up a little, it will make it appear that there is just a fair amount of variability occurring.

The bottom line is that even in a large population with many heart attacks occurring, we cannot draw causal conclusions regarding the effect of smoking bans based on these data. It is hard to imagine drawing sweeping causal conclusions from similar data in a population that is exceedingly smaller. It's hard to believe that a change in heart attack admissions from 40 to 24 is being used as the basis of a national campaign to convince the public that acute secondhand smoke exposure causes heart attacks.

The rest of the story is that shoddy science is being used to promote smoking bans and the science is shoddy because one cannot validly conclude that the observed year-to-year change in one data point in the rather small populations of Helena, Pueblo, and Saskatoon were due to the smoking ban, rather than to baseline variation, secular changes, or some other factors.

New Study Casts Doubt on Claim that Smoking Bans Substantially Reduce Heart Attack Admissions

A new study released yesterday on the Smoker's Club, Inc. web site, questions the claim that smoking bans cause a 40% (as observed in Helena, Montana) or 27% (as observed in Pueblo, Colorado) drop in hospital admissions for myocardial infarctions (heart attacks).

The authors, David W. Kuneman and Michael J. McFadden, analyzed data on hospital admissions for acute myocardial infarction from the HCUP project (Healthcare Cost and Utilization Project), which is "a family of health care databases and related software tools and products developed through a Federal-State-Industry partnership and sponsored by the Agency for Healthcare Research and Quality. HCUP is based on statewide data collected by individual data organizations across the United States and provided to AHRQ through the HCUP partnership. ... HCUP data are used for research on hospital utilization, access, charges, quality and outcomes. ... Researchers and policymakers use HCUP data to identify, track, analyze and compare hospital statistics at the national, regional and State levels."

Specifically, the authors examined the total number of hospital admissions for acute myocardial infarction in the year prior to and after a smoking ban in each of four states which enacted some form of smoking ban in restaurants and/or bars during the period for which data from HCUP are available (1997-2003): California, New York, Florida, and Oregon.

For California, a complete ban on smoking in bars was implemented in January 1998. Heart attack admissions increased from 40,608 in the year preceding the bar smoking ban (1997) to 43,044 during the year following the smoking ban (1998), an increase of 6.0%.

For New York, a complete ban on smoking in bars and restaurants was implemented in July 2003. Heart attack admissions increased from 31,728 in the year preceding the bar smoking ban (2002) to 31,888 during the year in which the smoking ban was implemented (2003), an increase of 0.4%.

For Florida, a ban on smoking in restaurants (free-standing bars excluded) was implemented in July 2003. Heart attack admissions decreased from 40,077 in the year preceding the bar smoking ban (2002) to 39,783 during the year in which the smoking ban was implemented (2003), a decrease of 0.7%.

For Oregon, a ban on smoking in restaurants which allow children was implemented in July 2001. Heart attack admissions increased from 4,957 in the year preceding the ban (2000) to 5,125 in the year following the ban (2002), an increase of 0.4%, and there was almost no change in heart attack admissions during 2001 -- the year in which the ban was implemented (4,927, 0.1% decrease from 2000).

The authors point out that none of these findings provides any suggestion that the statewide smoking bans had any immediate and substantial effect on heart attack admissions.

The authors point out that while the total number of heart attacks studied in Helena and Pueblo totaled 315, the total number of heart attacks in this study was over 315,000, or 1,000 times higher. They suggest that this larger sample size as well as the examination of state-wide data rather than just data in isolated cities makes the conclusions from this study more stable than from the existing studies on this topic.

The paper concludes: "Statistically this larger population base makes for a far more stable statistical environment and the data from this population would provide a far sounder scientific basis for decisions about smoking bans that will affect the lives and livelihoods of millions of people."

The Rest of the Story

In addition to confirming Kuneman and McFadden's findings, I extended their analysis by:

• examining trends going back in time as far as 1997, the earliest available online data (in order to have a more stable baseline period to establish secular patterns); and
  
• examining trends in heart attack admissions in all the other states in the online database without smoking bans that included data for the entire study period 1997-2003 (a total of 8 states - New Jersey, South Carolina, Utah, Washington, Arizona, Colorado, Hawaii, and Iowa; Massachusetts was not included because of the extensive local smoking bans) (in order to have a comparison group).
  

For California, I compared heart attack admission trends during the period 1997-2002 for California versus the 8 non-ban states in the HCUP online database and versus the nation as a whole. Trend lines were essentially parallel throughout the period. From 1997 to 1998, heart attack admissions in California increased by 6.0%, compared to a 3.8% increase in the comparison states and a 6.2% increase in the remainder of the nation. From 1997 to 1999, heart attack admissions increased by 9.9% in California, compared to 4.8% in the comparison states and 4.3% in the remainder of the nation.

For New York, overall trends were similar to those in the comparison states and to the nation as a whole, except that New York did not experience the slight decline in heart attack admissions during 2003 that was observed elsewhere. In New York, admissions for heart attacks increased by 0.4% from 2002 to 2003, while heart attacks decreased by 3.1% in the comparison states and by 2.8% nationally during the same time period.

For Florida, heart attack admissions increased slightly faster than in the comparison states between 1997 and 2000, but the patterns were similar from 2000-2003. There was a slight decrease in heart attacks between 2002 and 2003 in Florida (0.7%), the comparison states (3.1%), and the nation as a whole (2.8%).

For Oregon, there was a 0.4% increase in heart attack admissions from 2000 to 2002, while admissions in the comparison states dropped by 0.7% during the same period, and admissions nationally increased by 4.3%.

Commentary and Conclusions

I think Kuneman and McFadden are to be congratulated for having made an important contribution to the analysis of this research question. I think that their analysis, along with my extension of that analysis, provides compelling evidence that brings into question the conclusion that smoking bans have an immediate and drastic effect on heart attack incidence.

In fact, these analyses demonstrate that on a state-wide level, there is no suggestion of any large-scale effect on heart attack admissions associated with the implementation of statewide bans on smoking in child-friendly restaurants, all restaurants, bars, or bars and restaurants.

If there were a true 27% or 40% decrease in heart attack admissions due to smoking bans that occurred almost immediately (within six months, as claimed), one would have expected to see a demonstrable decline in such admissions in states that implemented such bans.

An effect of such smoking bans can certainly not be ruled out, especially because the 2004 data for New York and Florida are not yet available (so only the first six months post-ban could be examined). However, it does seem quite clear that if there is an effect, it is not nearly as immediate or as dramatic as suggested in press releases. (see also Pueblo release and Bowling Green press release and Greeley news article)

My honest appraisal of what is going on here is that anti-smoking groups have been too quick to go to the media with definitive claims of a drastic and immediate effect of smoking bans on heart attacks when the scientific evidence is simply not sufficient to support such claims. What is happening, I believe, is that the anti-smoking agenda is driving the interpretation of the science. As I stated before, it is an agenda which, in this case, I wholeheartedly support (I have been lobbying for workplace smoking bans, especially those in bars and restaurants for 21 years). However, I don't think the importance of the ultimate objective justifies the use of shoddy science to support that objective.

At this point, I must make 3 critical points:

First, I am not suggesting that there was anything wrong with the studies that were done in Helena and Pueblo or that the authors did anything wrong in stating their conclusions within the Helena paper. What I am suggesting, instead, is that drawing definitive, generalized conclusions based on these two small studies, and sending out press releases to the media with these definitive conclusions (before the Pueblo study has even been published) is irresponsible and undermines the scientific credibility of the tobacco control movement.

Within themselves, it may be that the Helena and Pueblo studies are quite solid (I have argued not with respect to the Pueblo study, but there is room for differing interpretations of the evidence); however, that doesn't mean that the evidence is sufficient to support a general conclusion that smoking bans reduce heart attacks by 27-40%. The fact that population-wide studies with much larger sample sizes do not seem to bear out these findings is exactly the reason why one has to be careful in concluding an effect with a small and select sample (and especially, in the face of huge random variations in secular trends in a small geographical area).

Second, I am not suggesting that this is a reason not to support smoke-free restaurant and bar laws. In fact, one of the things that I think tobacco control groups have been doing wrong is using data such as this to support such ordinances. I think the reason for these laws is that secondhand smoke is a substantial workplace hazard for bar and restaurant workers. That's it. Whether the laws end up reducing heart attacks (probably by virtue of smokers quitting or cutting down) or not is not relevant in my mind to the issue of whether we should protect workers from a substantial and preventable occupational hazard.

I think by harping on these data, anti-smoking groups have set themselves up for failure, and therefore done a disservice to the overall effort to protect workers from secondhand smoke. Because now that valid scientific doubt is being cast on this exaggerated claim, it may well hurt the effort to protect these workers.

This is what I meant when I suggested that the credibility of the movement is being threatened by the tactics being used. If the focus of the debate shifts to the validity of the heart attack reduction claim rather than the need to protect workers from a severe and preventable occupational hazard, then we may well lose the debate. I fear this is now going to happen now that the "cat is out of the bag."

Third, and finally, I am not concluding here that smoking bans do not reduce heart attacks. I am not even concluding that smoking bans did not reduce heart attacks in Helena or Pueblo. What I am concluding is that the overall evidence does not support the conclusion that the observed declines in heart attack admissions in Helena or Pueblo (or Bowling Green or Greeley) are in fact: (1) real, rather than simply chance variations; (2) attributable to the smoking ban, rather than some other factor; and (3) widely generalizable to other communities.

It is possible, for example, that local smoking bans may have an effect that state-wide smoking bans do not have. Perhaps all the local media attention focuses public attention on the matter and results in publicity that ends up changing smoking behavior. And perhaps that doesn't happen as effectively at a state level. But I think a lot more research is needed before we can conclude that the reason why we don't observe a substantial reduction in heart attack admissions associated with smoking bans on a state-level is that the effect only holds at a local level.

Moreover, I would point out that in my analysis of trends in heart attacks in Massachusetts, where there was a huge proliferation of smoke-free bar and restaurant regulations between 2000 and 2003, I found that heart attack admissions increased in Massachusetts by 31.8% during this time period, compared to a 2.4% decline in the comparison states, and a 1.5% increase nationally.

In short, what I am concluding is that it is far too premature to conclude that smoking bans reduce heart attacks substantially and in a short period of time. And that as much as anti-smoking groups are doing important work by promoting smoke-free bar and restaurant laws, it simply is not responsible (nor wise strategically, I think) to be using shoddy science to support this cause. In the long run, it is our credibility (and ultimately therefore, the health of the public) that is going to lose out.

Massachusetts Study Shows Lower Smoking Prevalence Associated with Reduced Heart Attack Rates, But Doesn't Show Any Immediate Effect of Smoking Bans

After careful examination of the study released last week by the Massachusetts Department of Public Health, it is clear that the study fails to show any immediate decline in heart attacks following passage of the statewide smoking ban. The study does demonstrate, however, that declining smoking prevalence is closely tied to declines in heart attack rates. Thus, while the study documents that interventions - such as smoking bans - which reduce smoking prevalence will eventually result in declines in heart attacks, it does not provide any evidence that smoking bans will immediately reduce heart attacks. This study refutes, rather than supports the conclusion of studies from Helena, Pueblo, Bowling Green, and several other sites.

The Rest of the Story

The study was designed primarily to examine whether the statewide smoking ban, implemented on July 5, 2004, resulted in an immediate drop in heart attack deaths. In the first year after the smoking ban was implemented, there was no significant decline in heart attack deaths in the state. Moreover, there was no decline in heart attack deaths even among just those residents living in towns that did not previously have smoking bans. Thus, this study refutes the conclusions from Helena, Pueblo, Bowling Green, etc. that smoking bans immediately reduce heart attacks by decreasing secondhand smoke exposure.

The study did find a decline in heart attack rates from the first to second year after the statewide smoke-free law was implemented, but it turns out that the magnitude of this decline was not significantly different in towns with or without smoking bans prior to the state law. Thus, the study provides no evidence that the statewide smoking ban was associated with any significant decline in heart attacks, even up to two years after its implementation.

While not the primary purpose of the study, it did incidentally find that heart attack death rates were significantly lower, over the long-term period of 1999-2006, among residents of towns with smoking bans compared to residents living in towns without such bans. The mean smoking prevalence in these towns was substantially lower in these towns (17.6% vs. 20.1%). These data provide evidence that smoking prevalence is (not unexpectedly) closely related to heart attack death rates. From this, one can conclude that the observed declines in heart attack rates over time is due, in part, to the observed declines in smoking prevalence. It should be emphasized, however, that these are long-term effects that occur over a long period of time, not the six months to one year that were touted in the Helena et al. studies.

The rest of the story, then, is that the Massachusetts study provides no evidence that smoking bans are associated with an immediate decline in heart attacks and that it in fact refutes the conclusions of previous studies that heart attack rates decline within the first six months to one year following implementation of smoking bans. The study does, however, demonstrate that declines in smoking prevalence will, over time, result in declines in heart attack deaths.

The lack of solid scientific data that smoking bans lead to immediate reductions in heart attacks is not stopping anti-smoking advocates from making such a claim. In a press release from the Henry Ford Health System, the lead author of a new study on this very topic stated: "If Michigan were to implement a comprehensive smoking ban tomorrow, we would see a 12 percent drop in heart attack admissions after the first year."

Note that this study is simply a review of the previous flawed literature (Helena et al.). It provides no new evidence. Unfortunately, the statement by this researcher is unsupported by the scientific evidence. But as I have noted recently, anti-smoking advocates are now holding themselves to very low scientific standards. What now passes for science is what in the past we would have called an interesting anecdote.

One final point deserves emphasis. The release of the Massachusetts study represents yet another example of "science by press release." I do not understand why the researchers didn't wait until the study was accepted for publication and then release the results when the article was published, which is the usual practice. Since the study has been submitted for publication, it would have made sense to wait until publication to release the findings. In fact, many journals will not allow researchers to release a study to the public while it is under review.

If the study was not being submitted for publication, it would be a different matter (assuming that the full study was made available for public review). But because the study is under review at a journal, it cannot be released publicly. Thus, there is no opportunity for scrutiny and review of the study conclusions.

It is very interesting to me that it is always these heart attack and smoking ban studies that are released prior to scientific review. It almost makes one think that the researchers are subconsciously aware that the conclusions are shoddy and that they want to get press coverage of their hoped-for conclusions before the results are actually held up to high scientific standards. I have to admit that it's a great strategy, because once the results are disseminated through the media, it is too late to retract or clarify them later.

Response to Questioning the Plausibility of Helena Findings from a Study Author

I received the following response, written by one of the authors of the original Helena study, to my questioning of the plausibility of the claim that the Helena smoking ban reduced heart attack admissions by 40% within six months.

How to Protect the Credibility of Secondhand Smoke Science from the Threats Posed by Michael Siegel's Ill Informed Criticisms of Helena/Pueblo

Michael Siegel has put out another blog expressing concern that the media is questioning the credibility of the evidence that there are rapid drops in heart attacks when smokefree laws go into force. He is, of course, one of the main reasons for this questioning. The two main sources of criticism are Michael Siegel and Jacob Sullum from the Reason Foundation (which has a history of tobacco industry funding). While Siegel and Sullum (and, to a lesser extent, Ken Warner, who agrees that there is an effect, but thinks thinks that the OBSERVED changes are too big to be "mathematically possible") have all said they don't believe the evidence, none has presented a plausible alternative explanation for the observed evidence.

The fact that there was a 13% drop in heart attacks in New York City also provides more evidence for a large immediate effect of eliminating exposure to SHS. (One would expect a smaller change in NYC than in isolated places like Helena or Pueblo because not all people covered by the ordinance would be hospitalized in NYC and vice versa. In addition, there were some earlier ordinances in some surrounding jurisdictions, which would "smear out" the effect in time.)

We have addressed these issues (except the NYC information, which came later) at http://bmj.bmjjournals.com/cgi/eletters/328/7446/977#124711 .

The Rest of the Story

This is an interesting response, because rather than address the specific criticism, which is that the Helena claim of a 40% drop in heart attacks due to 6 months of a smoking ban is implausible (given that if all smoking were eliminated completely, there could be, at most, a 50% reduction in heart attacks based on the epidemiologic data), the response instead tries to discredit the messenger, first by suggesting that he is ignorant of something without mentioning what it is that he is ignorant of, and second by trying to associate him, through a chain of links, to the tobacco industry.

The only possible response that would adequately address my commentary is one which explained why a 40% drop in heart attacks due to a smoking ban is plausible, in light of the epidemiologic data which suggest that no more than a 50% reduction in heart attacks is possible even if all smoking and secondhand smoke were to be completely eliminated.

In other words, what I am suggesting is that it is mathematically impossible for the smoking ban to have caused a 40% reduction in heart attacks.

The way to deal with such an argument would be to provide some rationale, or some reason, why it is not in fact mathematically impossible, which the response (as well as the eletters) fails to do.

As far as offering a plausible alternative explanation for the observed findings - I have already offered one. I believe that the findings could well be due to random variation in the heart attack trend. I have already explained why this alternative explanation is entirely consistent with all of the data and findings that have been presented.

But it is important also to recognize that if the problem is that the study findings are implausible, then the burden is not on the reviewer to supply an alternative explanation for the findings; the burden is on the one making the claims to explain why the results are plausible.

It's kind of like suggesting that if I question the claim that the flying spaghetti monster is responsible for the creation of the universe because I don't think that it's plausible that a flying spaghetti monster created the universe, I must supply an alternative explanation for the creation of the universe or my criticism of the flying spaghetti monster theory is not valid. Hardly.

Let me reiterate that I'm not questioning the premise that a smoking ban will reduce heart disease, including incidence of heart attacks. I'm just pointing out that a 40% drop in heart attacks due to a smoking ban is completely implausible, and mathematically impossible.