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.

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.

ANR Criteria Suggest that Helena and Piedmont Studies are Invalid

By criteria set out by Americans for Nonsmokers' Rights (ANR) to determine the validity of studies analyzing the impact of smoking bans, two studies being touted by ANR itself as demonstrating that smoke-free laws immediately and drastically reduce heart attacks are "illegitimate."

According to ANR:

"When handed a tobacco-related study - particularly if it claims that going smokefree hurts business - consider these factors to determine if it is a legitimate study or one funded and created by the tobacco industry. ...

Are sales figures analyzed for at least one year?

To identify underlying trends and fluctuations in the restaurant business cycle's yearly sales, was the study conducted over a sufficiently lengthy period to make the data meaningful? Economic impact studies should include restaurant sales data for several years before a law is enacted, as well as for all quarters after enactment. The economy changes for many reasons: inflation, seasonal variation, and fluctuations due to the weather and other superfluous events. Short-term observations cannot accurately evaluate economic impact. By collecting data for several years, it is possible to identify and quantify these trends and take them into account. An observed decrease in sales data for one or two quarters may simply be a typical downward trend in restaurant sales that occurs every year."

Despite the fact that restaurant sales would be expected to change more rapidly in response to a smoking ban than heart attacks, the Helena and Piedmont studies collected data for only 5-6 months after the implementation of smoking bans in those jurisdictions.

Thus, by ANR's own criteria, the Helena and Piedmont studies are not legitimate. Nevertheless, this hasn't stopped ANR from using those studies as the basis for its claim that smoking bans reduce heart attacks by 30-40%.

The Rest of the Story

Since the Piedmont study only examined heart attacks for 5 months following the implementation of Italy's smoking ban and the Helena study only examined heart attacks for 6 months after implementation of the smoking ban in Helena, neither of these studies comes close to meeting ANR's criterion of needing one year of data following a smoking ban before a legitimate conclusion can be drawn regarding the smoking ban's impact.

Therefore, I guess these studies are illegitimate.

What ANR pointed out about fluctuations in restaurant sales can also be said about heart attacks: "The rate of heart attacks changes for many reasons: medical treatments, seasonal variation, and fluctuations due to other superfluous events. Short-term observations cannot accurately evaluate heart attack trends. By collecting data for several years, it is possible to identify and quantify these trends and take them into account. An observed decrease in heart attacks for one or two quarters may simply be a typical downward trend in heart attack incidence."

Based on ANR's own argumentation, there is very real reason to suspect that the Helena et al. conclusions are invalid. At very least, there is strong reason for caution in interpreting the results of these studies.

However, ANR has gone so far as stating that any suggestion that the conclusions of these studies are premature is 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."

Yet we are to believe that ANR's attack against a slew of economic impact studies that found negative effects of smoking bans on restaurant sales is not hogwash.

I happen to think that ANR's criticism of these particular studies is valid, but if one is to have any consistency at all, then one must also acknowledge that the "opposition's" (I guess I am the opposition) questioning of the validity of the Helena et al. claims is also legitimate, if not valid.

ANR's statement to the public obviously fails to explain why I have criticized the Helena conclusions, since I support smoking bans and so am not "unfairly" attacking the Helena study because it "is powerful, and demonstrated the urgent need for smokefree laws to protect the public."

By the way, even if one accepted the Helena conclusions as the truth, they still do not demonstrate that "even a little exposure to secondhand smoke can be deadly." The study did not ascertain whether the heart attack admissions occurred among smokers or nonsmokers, so it can draw no conclusions on what the contribution of reduced secondhand smoke exposure was to the observed decline in heart attacks.

I take it that ANR would call me "painfully uneducated" since they link to an American Heart Association "fact sheet" that states that the argument that the observed decline in heart attacks in Helena may be due to random variation is painfully uneducated.

I also take it that ANR, and the American Heart Association for that matter are stating that by making my claims, I am "claiming that [I] alone [am] smart enough to draw a conclusion that none of the statisticians at the British Medical Journal and CDC agree with."

That, my friends, is hogwash. First of all, in claiming that there are alternative explanations for the observed findings in Helena, one is not making any claim about how smart one is. Instead, one is simply making a scientific argument. Second, it is wrong to imply that every statistician at the British Medical Journal and every statistician at CDC has agreed with the Helena conclusion.
The truth is that even the scientists at CDC who argued that 30 minutes of secondhand smoke might precipitate heart attacks questioned the validity of the Helena conclusions, pointing out a number of serious limitations of the study methodology that render any definitive conclusions premature:

"Although the results of the study by Sargent and colleagues are consistent with the literature on the risks of acute myocardial infarction associated with secondhand smoke, the study has some important limitations. Firstly, it contains no data on actual exposures to secondhand smoke among residents or cases, and thus no data on the changes in exposure to secondhand smoke that may have occurred after the policy was implemented. It might be reasonable to assume that levels of important smoke toxins within public places in Helena covered by the ordinance dropped dramatically. This effect has been observed in other locations where similar policies have been implemented, with air quality measurements showing 80-90% declines in public places. Even if such declines also occurred in Helena, some proportion of non-smokers would still have been exposed in their homes, cars, or other enclosed places not covered by the ordinance. Thus, without more data, the proportion of non-smokers in Helena among whom exposures were significantly reduced during the six months that the ordinance was in effect cannot be known.

A second concern is that the geographical isolation of the city, while making this type of study feasible, also resulted in a small number of admissions for acute myocardial infarction. As reported elsewhere, the typical number of acute myocardial infarction events per month before the ordinance was only about six or seven and was highly variable, with the actual number per month ranging from none to about 10-12. Although conservative statistical analyses were applied to these data, due to the small number of events and the lack of data on changes in active smoking, random variation and factors other than secondhand smoke exposure may have contributed to the findings.

Finally, the observed effect (a decline of an average of 16 admissions for acute myocardial infarction for a six month period) was substantially greater than what might be expected. With smokers accounting for 38% of the admissions, we can estimate that about 25 admissions (40*—0.62 = 24.8) were among former and never smokers during the equivalent six month period before the ordinance. Even assuming that the proportion of acute myocardial infarction cases among smokers was fairly constant across time, that all non-smokers were frequently exposed to secondhand smoke in public places, that virtually all this exposure was eliminated by the ordinance, and that all coronary heart disease risk related to this exposure was immediately reversed among non-smokers (that is, that risk dropped from 1.3 to 1.0), the maximum impact on admissions for acute myocardial infarction would be predicted to be about 18-19% (0.30*—24.8 = 7.44; 7.44/40 = 18.6%) during the six months that the ordinance was in effect. Taking all of the above assumptions and issues into consideration, a more conservative estimate of the predicted reduction in acute myocardial infarction events might be 10-15%."

According to ANR, therefore, these CDC scientists are part of the opposition which is attacking the Helena study because they despise smoking bans, and their arguments are unsubstantiated claims and pure hogwash.

I think I am finally beginning to understand ANR's logic here. If a study finds results favorable to the anti-smoking agenda, then it is a valid study and is not subject to any criticism. Any questioning of the results of that study must be based on opposition to smoking bans, and must be funded by or commissioned by the tobacco industry, probably through its front groups. Such criticism is hogwash.

If a study finds results unfavorable to the anti-smoking agenda, then it is junk science, probably funded by or commissioned by the tobacco industry through its front groups, and it needs to be countered, preferably by pointing out to the public that the science on the issue is "crystal clear," and thus not subject to any critique or opposing findings.

It's really too bad that I have been kicked out of the movement. I think I'm really beginning to understand the way that things work. I could have made a great career for myself in the movement, now that I really get it.

Who Wrote this Commentary on the Helena Study, Arguing that Using it to Conclude that Smoking Bans Reduce Heart Attacks is Wishful Thinking?

Today I offer a puzzle for Rest of the Story readers. Below is a commentary (unpublished) written by a scientist regarding the famous Helena study. The Helena study concluded that the smoking ban in that city immediately and dramatically reduced heart attack admissions (by 40%). That study has been widely cited throughout the world as demonstrating that smoking bans quickly and dramatically reduce heart attack rates.

The question is this: who wrote this commentary?

Writing to the Centers for Disease Control and Prevention (CDC) about a draft of its commentary that accompanied the Helena study, the scientist in question wrote:

"I would be very cautious with this and I think the first couple of paragraphs are far too strong for the data presented in the paper. I have seen earlier drafts of this paper with more complete descriptions of the data that were far less compelling. In your discussion of the limitations you seem to believe that the numbers presented are per month. That is not true, they are for the 6 month interval (i.e., 3-4 cases per month), and the difference is largely in the first couple of months in the earlier drafts. Small numbers or no, it would be useful to know the distribution of current, former, and never smokers for the different years (would you feel differently if 70% of the 24 AMI [acute myocardial infarctions] in Helena during 2002 were current smokers for example). The reluctance to produce these breakouts is concerning.

To validate this article with a CDC editorial ("the answer is yes") runs the risk of the writers of the editorial being associated with the over interpretation of the data presented in the article and you should think carefully about it. At best this is a provocative observation, but to suggest that it demonstrates that smoke free ordinances can lower AMI rates is wishful thinking."

The Rest of the Story

It was very interesting for me to read this commentary on the Helena study and its accompanying editorial, because it expresses exactly my scientific opinion regarding that study. At very best, the results of the Helena study are provocative. But the sample size is so small that the study cannot possibly conclude that the observed change in heart attacks is attributable to the smoking ban. To suggest that the Helena study demonstrates that smoke free ordinances can lower acute myocardial infarction rates is wishful thinking.

In addition, the commentary is interesting because it warns the CDC scientists not to put their own scientific integrity into question by blindly jumping on the Helena bandwagon. To argue that the Helena study supports the conclusion that smoke-free ordinances immediately decrease heart attacks or that the study demonstrates the positive benefits of a smoke-free ordinance would amount to over-interpretation of the data presented in the article.

While the CDC did tone down the article and included some limitations of the Helena study, it unfortunately did not alter its underlying conclusion that brief secondhand smoke exposure precipitates heart attacks among nonsmokers, and the headlines derived from the CDC commentary were wildly exaggerated and misleading.

Who do you think wrote this commentary, which expresses a scientific opinion which is virtually identical to that which I have expressed for many months on this blog?

National Anti-Smoking Groups Instructed Organizations to Use Helena Conclusions to Convince Public that Smoking Bans Immediately Reduce Heart Attacks

Three major anti-smoking organizations - the American Cancer Society, the International Union Against Cancer, and the Campaign for Tobacco-Free Kids - urged anti-smoking groups to increase the emotional appeal of the secondhand smoke health hazard message by communicating to the public that smoking bans can virtually instantly reduce heart attacks among both smokers and nonsmokers, based on a finding that there were 16 fewer heart attacks in Helena during the first six months of the city's smoking ban.

In a strategy document entitled "Building Public Awareness About Passive Smoking Hazards," the American Cancer Society and International Union Against Cancer offer suggestions to anti-smoking advocates about how to increase the emotional appeal of secondhand smoke health hazard claims. The Campaign for Tobacco-Free Kids appears to also have been a part of this strategy guide, although it is not listed as a primary author but instead, referred to in the document's introduction:

"On behalf of the American Cancer Society, The International Union Against Cancer, the Campaign for Tobacco-Free Kids, and the many wise and experienced colleagues who contributed to this lengthy project, we are deeply pleased to offer this series of guides, Tobacco Control Strategy Planning to the global tobacco control community."

The guide was designed "to help advocates develop practical strategies to overcome specific barriers to effective tobacco control policies."

In the document, anti-smoking groups were instructed to use the claim that 30 minutes of secondhand smoke exposure causes hardening of the arteries, blood clots, reduced blood flow to the heart, heart attacks, and strokes in order to increase the emotional appeal of their messages, a point I have discussed previously.

Here, I will discuss another instruction given to anti-smoking advocates: "Another message that may encourage the public to take action concerns a 2002 case study conducted in Helena, Montana (USA). Researchers found that, in the six months following the enactment of a new smoke-free workplace law, heart attack frequency declined significantly.

This message is effective for several reasons.

• It offers a positive indication of what can happen to public health when people stop smoking and breathing secondhand smoke in public places.
• It indicates that a ban on smoking in public places can reduce the incidence of heart attacks for smokers and nonsmokers alike.
• It demonstrates that the health benefits of clean indoor air ordinances are virtually immediate.
  
• It provides more scientific evidence that smoke-free workplace policies improve health and save lives, which should encourage communities around the world to take action to protect the health of their citizens."

The Rest of the Story

As I commented in my previous post, I don't believe that the observed findings in the Helena study support a conclusion that the smoking ban caused an immediate and dramatic drop in heart attacks. It simply isn't clear that the 16 fewer heart attacks that were observed in Helena during the first six months after the smoking ban was in effect were not simply random variation in the heart attack data for Helena. In such a small city, there is tremendous underlying variability in semi-annual heart attack admission rates, and that study does not allow a causal conclusion to be made.

Moreover, I have previously argued that it is scientifically implausible that the Helena smoking ban could have reduced heart attacks by 40% within six months. Even if all smoking were eliminated in Helena completely, one would no more than about a 40% decline in heart attacks. So how could a smoking ban in bars and restaurants have created such a large effect?

Thus, I find it unfortunate that we instructed tobacco control advocates to use the Helena conclusion to try to increase the emotional appeal of the secondhand smoke message. Since we are always accusing the tobacco industry of shoddy science, I think it's important that we not use the same shoddy science. So I think more scrutiny should have been given to this conclusion before we instructed advocates to use this shoddy science to promote our agenda.

A few elements of the document are particularly disturbing. First is the statement that this study demonstrates that "a ban on smoking in public places can reduce the incidence of heart attacks for smokers and nonsmokers alike." Even if the Helena conclusion was valid, it does not indicate at all whether the reduction in heart attacks was due to reduced secondhand smoke exposure, reduced smoking, or both. No information on smoking status was collected, no data on changes in secondhand smoke exposure were presented, and no data on changes in smoking prevalence were put forth.

Second is the statement that the study "demonstrates that the health benefits of clean indoor air ordinances are virtually immediate." There are immediate health benefits from clean indoor air ordinances, but the Helena study doesn't demonstrate that reducing heart attacks by 40% is one of them.

The Centers for Disease Control and Prevention, in its commentary on the Helena study (see: Pechacek TF, Babb S. How acute and reversible are the cardiovascular risks of secondhand smoke? BMJ 2004; 328: 980-983), which his been widely cited as supporting the contention that 30 minutes of secondhand smoke can cause heart attacks in nonsmokers, points out critical limitations of the study and makes it clear that these findings are not conclusive and that more research is necessary before any conclusions can be drawn:

"Although the results of the study by Sargent and colleagues are consistent with the literature on the risks of acute myocardial infarction associated with secondhand smoke, the study has some important limitations. Firstly, it contains no data on actual exposures to secondhand smoke among residents or cases, and thus no data on the changes in exposure to secondhand smoke that may have occurred after the policy was implemented. It might be reasonable to assume that levels of important smoke toxins within public places in Helena covered by the ordinance dropped dramatically. This effect has been observed in other locations where similar policies have been implemented, with air quality measurements showing 80-90% declines in public places. Even if such declines also occurred in Helena, some proportion of non-smokers would still have been exposed in their homes, cars, or other enclosed places not covered by the ordinance. Thus, without more data, the proportion of non-smokers in Helena among whom exposures were significantly reduced during the six months that the ordinance was in effect cannot be known.

A second concern is that the geographical isolation of the city, while making this type of study feasible, also resulted in a small number of admissions for acute myocardial infarction. As reported elsewhere, the typical number of acute myocardial infarction events per month before the ordinance was only about six or seven and was highly variable, with the actual number per month ranging from none to about 10-12. Although conservative statistical analyses were applied to these data, due to the small number of events and the lack of data on changes in active smoking, random variation and factors other than secondhand smoke exposure may have contributed to the findings.

Finally, the observed effect (a decline of an average of 16 admissions for acute myocardial infarction for a six month period) was substantially greater than what might be expected. With smokers accounting for 38% of the admissions, we can estimate that about 25 admissions (40x0.62 = 24.8) were among former and never smokers during the equivalent six month period before the ordinance. Even assuming that the proportion of acute myocardial infarction cases among smokers was fairly constant across time, that all non-smokers were frequently exposed to secondhand smoke in public places, that virtually all this exposure was eliminated by the ordinance, and that all coronary heart disease risk related to this exposure was immediately reversed among non-smokers (that is, that risk dropped from 1.3 to 1.0), the maximum impact on admissions for acute myocardial infarction would be predicted to be about 18-19% (0.30x24.8 = 7.44; 7.44/40 = 18.6%) during the six months that the ordinance was in effect. Taking all of the above assumptions and issues into consideration, a more conservative estimate of the predicted reduction in acute myocardial infarction events might be 10-15%."

The shame of the whole thing is that we didn't have to lower ourselves to this level, we didn't have to abandon our scientific integrity, in order to accomplish what this document wants to achieve.

There are immediate health benefits of smoking bans on the health of restaurant and bar workers, and plenty of them. And they have nothing to do with avoiding heart attacks. And there are immediate health benefits to smokers who quit because of these policies.

We didn't need to stretch the science in order to communicate these messages effectively and to promote our agenda. We could have just stuck with the science, and with the plain truth.

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.

TobaccoScam Fact Sheet Claims that Brief Exposure to Secondhand Smoke Caused 40% of Heart Attacks in Helena

The same "fact sheet" which claims that 30 minutes of secondhand smoke exposure clogs nonsmokers' arteries, gives them arteries with damage equivalent to that of a smoker, and puts them at increased risk of a heart attack or stroke also claims that brief exposure to secondhand smoke causes 40% of all heart attacks (or at least of all heart attacks in Helena, Montana).

According to the TobaccoScam fact sheet: "Breathing secondhand smoke for just twenty minutes has substantial, adverse effects on the heart, blood, and blood vessels. That's why making restaurants and bars (as well as workplaces) smokefree was associated with a 40% drop in hospital admissions for heart attacks when Helena, Montana, implemented a smokefree policy."

The Rest of the Story

What this fact sheet is claiming, then, is that brief exposure (20 minutes) to secondhand smoke causes a huge number of heart attacks. So huge, in fact, that when Helena banned smoking in bars and restaurants, the reduction in these brief exposures led to a 40% decrease in hospital admissions for heart attacks.

In other words, TobaccoScam is claiming that 40% of the heart attacks in Helena were attributable to brief exposures to secondhand smoke.

This claim seems implausible for three reasons:

First, it is scientifically unsound to conclude that the observed 40% decline in heart attack admissions in Helena over a six-month period was attributable to the smoking ban in the first place. It is highly likely that a substantial portion of this drop was due simply to random variation and that some of it was due to secular changes in heart attack admissions over time.

Second, even if the 40% decline in heart attack admissions were solely attributable to the smoking ban, it is scientifically unsound to conclude that these effects were due to reduced secondhand smoke exposure, rather than to lowered levels of active smoking (smoking cessation and reduced cigarette consumption). Certainly, it is not valid to conclude that all of the observed effect was due to reduced secondhand smoke exposure. The Helena study did not, in fact, measure the smoking status of those who suffered heart attacks, nor did it document changes in the smoking status or secondhand smoke exposure of city residents. So the study does not have the ability to determine whether any observed decline in heart attacks, even if due to the smoking ban, was due to changes in active smoking or changes in secondhand smoke exposure.

Third, it is implausible that a reduction in brief exposure to secondhand smoke could cause a 40% reduction in heart attacks. It has never been shown that brief exposure to secondhand smoke is a cause of heart attacks in the first place. Moreover, it is close to impossible that brief exposure to secondhand smoke explains 40% of all heart attacks. Smoking in its entirety is estimated to be responsible for only about 30% of heart attacks. So how could just brief exposure to secondhand smoke be responsible for 40%?

What I find most distressing about this claim is that it is unfounded. There is simply no evidence upon which to base an assertion that the 40% reduction in heart attacks in Helena was attributable solely to a reduction in secondhand smoke exposure, even if that reduction were indeed due to the smoking ban in the first place. The reduction, if due to the smoking ban, could just as easily (and probably more likely) be due to changes in active smoking. Recent evidence from New York City suggests that smoking bans can have substantial effects on active smoking rates and on cigarette consumption levels. These effects could just as easily explain any reductions in heart attacks. In fact, if I were forced to attribute any observed declines in their entirety to one factor or the other, I would choose active smoking reduction as an explanation long before I chose reduced secondhand smoke exposure resulting from the Helena smoking ban.

Readers unfamiliar with my latest commentary on the Helena-type studies may want to review it in order to understand why I do not believe any of these studies provide credible evidence that these smoking bans have resulted in drastic declines in heart attack admissions. In that post, I concluded that: "upon closer examination, the study which purports to demonstrate that a smoking ban in Bowling Green resulted in a massive decline in heart disease admissions demonstrated nothing of the sort, and possibly demonstrated that there was no significant decline in admissions attributable to the smoking ban. Like its predecessors (e.g., Helena and Pueblo), this is another example of shoddy science that apparently now passes as acceptable in tobacco control research."

Today's finding simply adds to the evidence I presented previously that the TobaccoScam fact sheet is misleading and needs to be corrected. In this case, it draws a conclusion that is not supported by any evidence and which is scientifically implausible anyway.

If public health officials in other cities that are enacting smoking bans are expecting to see immediate 40% reductions in heart attacks due to reduction in brief secondhand smoke exposures, I'm afraid they are going to be quite disappointed. There are undoubtedly health benefits to be realized from smoke-free laws; but this degree of an immediate reduction in heart attacks is probably not one of them.

As of now, the fact sheet remains unchanged. So I don't expect this particular point to be corrected, although I think it would be a great service to the public to do so. I'll report back later in the week on any changes on this site or the others I cited which are making exaggerated and deceptive claims about the acute cardiovascular effects of secondhand smoke.

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.

Trends in Heart Attacks in Lewis and Clark County Show Prematurity of Helena Study Conclusions

In a rapid response to the original BMJ study which concluded that a 40% decline in heart attack hospital admissions in Helena, Montana was attributable to the city's smoking ban, Drs. Brad Rodu and Philip Cole of the University of Alabama at Birmingham presented historical data on trends in the heart attack mortality rate for Lewis and Clark County (which includes Helena) for the years 1979-2001.

These data demonstrate that there is significant random variation in heart attack mortality trends (which suggests that there is also substantial random variation in heart attack incidence trends) in Helena, since 85% of the county population lives in Helena. This random variation is so marked that the observed heart attack mortality in several years is dramatically lower than, or higher than, the trend in preceding years.

As the authors point out: "The variability is most clearly illustrated by two periods: 1989-1993 and 1997-2001 (the bars for these periods are yellow). The latter period is notable because of the year 2000, in which the mortality rate was 110, about 50% higher than the mean for the other years in the period. The former period includes 1992, in which the mortality rate was 40% lower than the mean for the other years in the period. In addition, 1992 follows three years of increasing AMI mortality. In isolation, this period presents a picture very similar to that described by Sargent et al from 1998 to 2003."

The authors conclude that random variation cannot be ruled out as an explanation for the observed 40% decline in heart attack admissions in Helena coincident with the city's smoking ban.

In response, the authors of the original study wrote: "Rodu and Cole are following a well-established tobacco industry strategy of trying to shift the focus away from our actual observations."

The Rest of the Story

Rodu and Cole have, I think, convincingly illustrated the dangers in drawing a causal conclusion from an association between one specific factor and a single observed change in a complex phenomenon such as heart attack admissions, especially when there is tremendous baseline variation and substantial secular changes in that phenomenon and when one looks only at a small slice of the overall secular trend.

Using the same methodology as in the original Helena study, the authors could have concluded that there was a significant decline in heart attacks in Helena in 1992 (it seems quite obvious from the data that there was a drop in heart attacks in 1992 and if one was looking only at the period 1989-1992, one could easily conclude that something happened in 1992 to bring down the heart attack rate).

Does this mean that the 40% decline in heart attacks in 1992 was due to the absence of a smoking ban? Or to the election of Bill Clinton as president of the United States? Or to the Toronto Blue Jays having won the World Series? Or to the Pittsburgh Penguins winning the Stanley Cup?

Of course not. The point is that in order to truly have a picture of the underlying secular trend and random variation in a phenomenon as variable as heart attack admissions in a small city, one has to go back many years. Examining an isolated five-year period runs a huge risk of interpreting what is really random variation as being a significant annual change.

And this is precisely what I think is the fundamental flaw of the Sargent et al. analysis.

Given this serious flaw, I do not suggest that the paper does not provide any evidence that heart attack admissions may have fallen in response to the smoking ban. But I think the flaw is serious enough so that one cannot credibly conclude that the smoking ban was the cause of the observed reduction in heart attacks.

Perhaps most disturbing in this story, however, is the original authors' response to the very appropriate and enlightening analysis by Rodu and Cole. Instead of addressing the criticism on its scientific merits, the authors accuse Rodu and Cole of using some sort of tobacco industry strategy. And they accuse them of trying to shift the focus away from the observations, when in fact they are doing an excellent job of trying to spotlight the observations and show how they are within the overall range of random variation observed in heart attacks in Helena over time.

Sargent et al. seem to be following what is a common tobacco control strategy of failing to address the scientific merits of an argument by instead issuing an ad hominem attack on the messenger - in this case, accusing them of using tobacco industry tactics.

The rest of the story is that the underlying random variation in heart attacks in Helena seems to be high enough to fully explain the 40% drop in heart attacks observed in association with the implementation of a smoking ban. This doesn't mean that the observed decline could not be due to the smoking ban, but it does suggest, to me at least, that it is premature to conclude that the heart attack decline was caused by the smoking ban, as opposed to simply representing random variation.

More importantly, the rest of the story reveals the use of what I have recently come to learn is a common tobacco control strategy in responding to scientific criticism - deflecting the merits of that criticism by attacking its messenger.

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.

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)

Prominent Tobacco Control Researcher Cautions CDC that Helena Study Should Not Be Used to Conclude that Smoking Bans Immediately Reduce Heart Attacks

Despite a warning from a prominent tobacco control researcher, the Centers for Disease Control and Prevention used the evidence from the Helena study to widely disseminate to the public unsupported conclusions about the immediate effects of restaurant and bar smoking bans on heart attack rates.

Writing to the Centers for Disease Control and Prevention (CDC) about a draft of its commentary that accompanied the Helena study, this prominent tobacco control scientist wrote:

"I would be very cautious with this and I think the first couple of paragraphs are far too strong for the data presented in the paper. I have seen earlier drafts of this paper with more complete descriptions of the data that were far less compelling. In your discussion of the limitations you seem to believe that the numbers presented are per month. That is not true, they are for the 6 month interval (i.e., 3-4 cases per month), and the difference is largely in the first couple of months in the earlier drafts. Small numbers or no, it would be useful to know the distribution of current, former, and never smokers for the different years (would you feel differently if 70% of the 24 AMI [acute myocardial infarctions] in Helena during 2002 were current smokers for example). The reluctance to produce these breakouts is concerning.

To validate this article with a CDC editorial ("the answer is yes") runs the risk of the writers of the editorial being associated with the over interpretation of the data presented in the article and you should think carefully about it. At best this is a provocative observation, but to suggest that it demonstrates that smoke free ordinances can lower AMI rates is wishful thinking."

While the exact identity of the scientist who wrote this commentary is not known, I have narrowed it down to four possible individuals, each of whom is a highly-respected tobacco control researcher from within the anti-smoking movement. Each of these individuals has served as a frequent editor and reviewer of the Surgeon General's reports on smoking and health.

The Rest of the Story

The rest of the story is this: why is the opinion of this researcher, who clearly represents a substantial contingent within the anti-smoking movement, hidden upon secret documents that were only able to be obtained through a Freedom of Information Act request?

Why did this researcher, and others like him, who disagreed with the conclusions of the Helena study and the use of this study to argue that smoking bans immediately and dramatically reduce heart attacks, fail to make their concerns known more widely than just in this email?

If there are many others out there in the movement, who like me, believe that the Helena science is shoddy and that the findings have been over-inflated, then why have I been the only one willing to speak out?

And if my opinions are actually quite solid, as they appear to be from this highly respected researcher's commentary, then why have I been attacked viciously and consistently by the anti-smoking movement and accused of being an outsider and a traitor?

The answer is quite simple: because I went public with my comments. You aren't allowed to do that in tobacco control. If you dissent, you are allowed to write polite, personal, and private emails expressing your opinion, but you are not allowed to go public with your dissenting comments. You have to shut up and keep your opinion to yourself.

That is what many scientists in tobacco control did. And for good reason. If you go public, they will ruin your career. They will do everything they can to discredit you. You will be evicted from the movement. You will be accused of being a tobacco mole and a traitor.

What I want people to take away from this story, and the reason I think it is so vitally important, is that it demonstrates conclusively that my opinions regarding the shoddiness of the Helena study and the over-inflated conclusions from this study are shared by many other respected scientists within tobacco control. Many of my colleagues share precisely my views with regards to this area of research.

However, you will not find these views expressed publicly in any forum. To do so would be fatal to these researchers' careers in tobacco control.

Thus, the only views you will see from someone within the movement are my own. And the fact that I went public with these comments is what got me ex-communicated from the movement.

It is really a McCarthyist-like movement. You cannot express dissent publicly. You must tow the party line. You are allowed to disagree - privately. You are allowed to express your disagreement - privately. But you can't talk about it. You have to keep it to yourself. If you go public, that's it - you're ostracized, attacked, victimized. Thrown off the list-serves. Not allowed to present at conferences. Defamed behind your back.

The sad thing is that I was thrown out of the movement for expressing exactly the views expressed by this prominent, respected tobacco control researcher. He, like everyone else in tobacco control, knows that if he were to express these views publicly, he would be in the same boat as I am: sent away from the main ship to exile on a desert island. That's why it takes a Freedom of Information Act request to uncover these views of scientists from within the movement.

To interfere in any way with the movement's ability to promote smoke-free laws based on the most wild and exaggerated (and unsupported) claims is fatal to anyone's existence within the movement.

That more recent population-based studies do not support the Helena conclusion is of no consequence in this movement. Not because this evidence doesn't convince numerous scientists within the movement that the conclusions from Helena are wrong. But because there can be no public statement that anyone disagrees. The researchers have to keep it to themselves. They can discuss it amongst themselves, privately, in emails and at conferences. But they are not allowed to express it publicly. There can be no public debates about the established wisdom in tobacco control.

Helena Study Itself Reveals Implausibility of Conclusions

The study that is widely cited by anti-smoking groups as demonstrating that smoking bans in bars and restaurants immediately reduce heart attacks by 40% reveals, in its own discussion of the findings, the implausibility of the study's conclusions (see: Sargent RP, Shepard RM, Glantz SA. Reduced incidence of admissions for myocardial infarction associated with public smoking ban: before and after study. BMJ 2004).

Apparently realizing that readers of the article would likely question the plausibility of the conclusion that a mere smoking ban could result in such a drastic (40%) and immediate (within 6 months) reduction in heart attacks, the article analyzes the plausibility of its own conclusion:

"The effect associated with the smoke-free law may seem large but is consistent with the observed effects of secondhand smoke on cardiac disease. Secondhand smoke increases the risk of a myocardial infarction by about 30%; if all this effect were to occur immediately, we would expect a fall of -0.30x40.5=-12.2 in admissions during the six months the law was in effect, which is within the 95% confidence interval for the estimate of the effect (a drop of -32.2 to -0.3 admissions)."

The actual observed reduction in heart attacks in Helena was 16, so the prediction of a decrease in heart attacks by 12 is not too far off from the predicted reduction, under these assumptions.

The Rest of the Story

In essence, what the paper is arguing is that the conclusion of the Helena study is plausible because if one assumes that everyone who develops heart disease and suffers a heart attack from secondhand smoke gets heart disease and suffers that heart attack immediately (within 6 months), the observed decline in heart attacks in Helena is about what one would expect.

In other words, the paper makes the assumption that the effects of exposure to secondhand smoke on heart disease and myocardial infarction are immediate. There is no time necessary to elapse between exposure and suffering a heart attack.

What this means is that a person who is exposed to secondhand smoke acutely must immediately develop heart disease and be at risk of having a heart attack. The whole process of developing heart disease and suffering a heart attack must take place within 6 months in order for the Helena conclusions to be plausible.

The flaw here is that the paper attributes all of the observed increased risk of myocardial infarction among nonsmokers due to secondhand smoke to an immediate (within 6 months) effect of that exposure, and assumes that none of the effect requires more than 6 months of exposure. Thus, all of the effects of eliminating the increased risk in heart disease attributable to secondhand smoke would be realized within 6 months of a smoking ban.

This is clearly an impossible assumption. It cannot be true.

The evidence demonstrates that the effect of secondhand smoke on heart disease observed in the epidemiologic literature is a long-term effect, that results from chronic exposure to secondhand smoke over long periods of time.

Eliminating secondhand smoke (even if a complete ban on all smoking everywhere were implemented in Helena) would not result in an immediate 30% reduction in heart disease and myocardial infarction. It would take many years to see the effects of such an intervention - probably on the order of 10-20 years, if not more.

I am not taking issue with the assumption that based on the epidemiologic literature, a complete smoking ban would result in a 30% decline in heart disease (and heart attacks) over a 20-30 year period. But I am taking issue with the assumption that such a decline in heart attacks would be observed over a 6-month period. The epidemiologic literature simply does not support such an assumption.

Given that the assumption upon which the paper bases its defense of its plausibility is so preposterous, it basically is the case that the paper does not provide an adequate defense of its plausibility. In my view, the Helena conclusion remains a completely unfounded and implausible one, and it should not be widely disseminated by anti-smoking groups because it is not based on sound scientific reasoning (plausibility is, I think, one of the most important aspects of sound scientific reasoning).