Posts tagged as:

AMI

Two more heart attack studies

by Jacob Grier on November 3, 2011

As an addendum to the previous post, I should mention two more recent studies of smoking bans and heart attack rates. The first, from Brad Rodu, Nicholas Peiper and Philip Cole, published a couple months ago in Journal of Community Health, examines rates in six states and finds no effect:

The AMI mortality rate among persons age 45 + years (deaths per 100,000 persons, age-standardized to the 2000 US population) in the 3 years before adoption of the smoke-free ordinance (the expected rate) was compared with the rate observed in the first full year after the ban (the target year) in six US states. Target-year declines were also compared to those in states without smoking bans. Target-year declines in AMI mortality in California (2.0%), Utah (7.7%) and Delaware (8.1%) were not significantly different from the expected declines (P = 0.16, 0.43 and 0.89, respectively). In South Dakota AMI mortality increased 8.9% in the target year (P = 0.007). Both a 9% decline in Florida and a 12% decline in New York in the 2004 target year exceeded the expected declines (P = 0.04 and P < 0.0002, respectively) but were not significantly different (P = 0.55 and 0.08, respectively) from the 9.8% decline that year in the 44 states without bans. Smoke-free ordinances provide a healthy indoor environment, but their implementation in six states had little or no immediate measurable effect on AMI mortality.

The second unpublished study [pdf] looks at rates in 74 US cities that implemented smoking bans. It finds a decline of a mere 3% following implementation. Contrary to expectation, the effect disappears entirely when restricted to the 43 cities whose bans were meaningful. All things considered, it lends support to the idea that smoking bans have no short-term impact on heart attack rates.

[Thanks to Chris Snowdon and Michael McFadden for the links.]

Permalink - Share/Save - Comments (8)

A heart non-miracle

by Jacob Grier on June 16, 2010

Just when I thought I was out they pull me back in! Though living in Portland I can’t completely resist the lure of DC, so I’ve joined the blogging team at the Washington Examiner. It’s good to get back to the policy writing I’ve been neglecting lately and publishing there it will reach a larger audience. I’ll link to most of the things I write for the Examiner on this blog too. If you’d like to subscribe to all Opinion Zone blog posts the RSS feed is here.

My first post takes a look at how anti-smoking researchers spin this chart into proof that England’s smoking ban saves lives:

ami-england

The best they can come up with is to dubiously attribute a 2.4% decline in heart attacks to the smoking ban in the first year of its implementation. This is in stark contrast to the wild claims of 40, 27, and 18 percent in previous studies, which have been decisively revealed as junk science.

In the wake of this statistical drubbing you might think anti-smoking activists would learn not to attribute too much to secondhand smoke. Well, you would be wrong:

A new study published online ahead of print in the Archives of General Psychiatry concludes that secondhand smoke exposure is a cause of mental illness, including depression, psychoactive substance use, schizophrenia, delirium, and mental and behavioral disorder (see: Hamer M, Stamatakis E, Batty GD. Objectively assessed secondhand smoke exposure and mental health in adults.

Here we go again!

[Image courtesy of the always interesting Christopher Snowdon.]

Previously:
What really happened in Starkville?
An Oregon heart miracle?
Lazy reporting and the Pueblo ban study

Permalink - Share/Save - Comments (0)

About that meta-analysis…

by Jacob Grier on December 17, 2009

A few months ago newspapers eagerly picked up news of a meta-analysis of smoking ban studies finding that bans were associated with a 17% decline in heart attack rates in their first year. Will any of them report this whopper of a correction?

As it turns out, the study findings were due to a careless error. In the original study, the authors had inadvertently reported the Pueblo study has having reported a 70% reduction in heart attacks (a result that is completely implausible and clearly should have been noticed as having been in error). Instead, that study actually reported a 34% reduction in heart attacks. The meta-analysis authors published a correction in which they re-analyzed the correct data.

It turns out that the 11 studies did not find a 17% reduction in heart attacks, but only found an 8% reduction in heart attacks.

This level of decline in admissions for heart attacks is obviously not significantly different from the levels of decline in heart attacks that are being observed in the absence of smoking bans, which have varied between 5% and 10% per year in many communities.

That’s from Michael Siegel, of course, one of the few anti-smoking researchers defending scientific accuracy.

The shoddiness of the science behind the claims of rapid drops in AMI rates following smoking bans never ceases to amaze, nor does journalists’ willingness to report on it uncritically.

For more on the extremely flawed Pueblo study, see here.

Permalink - Share/Save - Comments (1)

A warning about Wales

by Jacob Grier on December 7, 2009

The Daily Post reports that new figures soon to be released by Wales’ Chief Medical Officer will show that heart rates have dropped in the region during the second year of its smoking ban. I look forward to seeing those figures, but the close of the article is particularly striking:

There was a 12.5% fall in the number of patients admitted to hospital with a heart attack between October and December last year, compared to the same period in 2006, before the ban on smoking in enclosed public spaces was introduced in Wales: some NHS trusts have seen the number of heart attacks fall by up to 40% in the same period.

See anything suspicious there? To my knowledge there isn’t anyone promoting the theory that smoking bans only reduce heart attacks in the final three months of the year. So why focus on just that time period?

The answer is that cherry-picking those 3 months supports ban proponents’ predetermined conclusion. As Christopher Snowdon has shown with the government’s own data, the rate of AMI actually rose slightly during the year the ban took effect and there were more heart attacks in the 5 months immediately following the ban than there were in those same months the year before. Overall there was practically no difference in the AMI rate between the two years, which is surprising since Wales’ rate of heart attacks had been on a downward trend. A fair reading of all the data is that the ban had no discernible effect, yet the story told by activists and mindlessly repeated by reporters is that the ban caused a reduction in heart attacks.

Such a weird statistic should have immediately raised flags for a journalist. A quick search on Google for the words “Wales,” “smoking ban,” and “heart attacks” would have revealed why the figure was selected. Unfortunately Post reporter Tom Bodden took it at face value, so readers don’t get the full story and the misleading statistic is propagated even more widely.

As Snowdon notes, the Welsh rate of AMI has been falling in recent years by as much as 10% per year. The fact that it didn’t fall in the year smoking was banned is an anomaly. My guess is that in the report about to be issued the rate will have resumed its previous decline and, in a classic case of conflating correlation with causation, researchers will credit the drop solely to the smoking ban.

It will be up the to journalists covering the report to treat it with skepticism, ask tough questions, and at the very least seek out a critical source before phoning in their stories. I’m not optimistic that they will.

Update 12/7/09: My prediction seems to be too optimistic. Chris decided to check the data again today and it turns out that the heart attack rate in Wales actually increased last year. So how will the upcoming report show that it declined? Well, that will be interesting to find out!

Update 12/9/09: Here’s the story and here’s Snowdon on why it’s just another example of junk science.

Previously:
More lazy tobacco reporting

Permalink - Share/Save - Comments (2)

Indy smoking ban increases heart attacks

by Jacob Grier on December 2, 2009

In Indianapolis, the smoking ban enacted in 2006 has unexpectedly caused an increase in heart attack deaths:

The ban, which affected all workplaces, including restaurants but excluding bars, went into effect on March 1, 2006. Had the smoking ban resulted in an immediate decline in heart attacks, as claimed by a number of anti-smoking groups and researchers and by a special Institute of Medicine committee, one would have expected the heart disease death rate in Marion County to have decreased in 2006, compared to 2005.

Data from the Marion County Health Department, however, show that the age-adjusted heart disease death rate for Marion County actually increased by 16% from 2005 to 2006, going from 171.0 to 197.6 deaths per 100,000 population.

This reversed a trend of declining heart disease death rates prior to the smoking ban. The rate had declined by 4.4% from 2002 to 2003, by 6.0% from 2003 to 2004, and by 5.8% from 2004 to 2005. Thus, the increase of 16% observed from 2005 to 2006 was a striking increase that coincided precisely with the implementation of the workplace and restaurant smoking ban.

Of course the ban didn’t actually cause the increase any more than bans in other cities caused the decreases so often hyped by anti-smoking advocates. And if the death rate can fluctuate this much in Indianapolis, a city of nearly 800,000, then the odds of getting meaningful data out of towns like Starkville, MS, Pueblo, CO, and Helena, MT are pretty damn low.* The fact that ban advocates cling so tightly to those success stories is an indication of just how the weak the association between bans and decreases in AMI really is.

*Those studies used overall rates of AMI rather than the rate of AMI deaths, but the two rates should move in tandem.

Previously:
What really happened in Starkville?
Lazy reporting and the Pueblo ban study

Permalink - Share/Save - Comments (6)

What really happened in Starkville?

by Jacob Grier on November 23, 2009

Last week I briefly commented on a study of heart attack (AMI) rates in Starkville, MS that found a 27% reduction in the AMI rate in the three years following the imposition of a smoking ban. Though I was initially dismissive, I decided to email the authors, Dr. Robert McMillen and Dr. Robert Collins, to ask for a copy of the study and to see the data. I expected to find the usual flaws, but what I found was even worse: In truth there is no completed study, the relevant data haven’t even been collected yet, and there are no grounds for concluding that the decline in heart attacks had anything to do with Starkville’s smoking ban.

Journalists covering the story reported that the results came from a study that had just been released. This is understandable, since that is what Mississippi State’s* press release claims:

A Mississippi State study released Monday [Nov. 9] shows a 27 percent decrease in heart attacks among Starkville residents since the city passed a smoking ban in 2006.

The “study” was actually just a two page preliminary report [PDF] that has not been published in a journal or subject to peer review. Nonetheless, in the press release and the report the authors express certainty that the decline is attributable to the smoking ban:

Without spending a dime, the community of Starkville has decreased heart attacks by more than 25% [...]

Current research shows that smoking bans in Starkville have contributed to a 27% reduction in the heart attacks of local residents [...]

There are two flaws that plague studies of heart attack reductions in small cities like Starkville. One is the size of the population, which makes wild fluctuations in the data possible. Starkville’s resident population is just a little over 20,000, so there’s nothing to be done about that. The other flaw is the lack of control groups. AMI rates could be declining for reasons unrelated to smoking bans, so it’s necessary to compare communities with smoking bans to similar communities without them.

Admirably, McMillen and Collins intend to collect data from other Mississippi cities to act as control groups. However they don’t have this data yet. When I wrote to them asking for a copy of the study, all I got was this email from Dr. McMillen:

The results that we released in our 2 page report are preliminary results form a larger study. The study examine AMI admissions from several communities that have passed smoke-free ordinances, as well as communities that have not. The latter will serve as controls for the purpose of comparison. The hospital in Starkville was the first to provide us with AMI admission data. When we have received data from the other communities in our study we will prepare a manuscript that compares AMI admissions before and after the smoke-free laws were enacted in communities with and without smoke-free laws.

Without the data from control groups there is no evidence that the decline was caused by the smoking ban. There’s absolutely no way to know whether the ban deserves complete, partial, or zero credit for the decline, and any statement to the contrary is pure speculation.

Michael Siegel has looked into Mississippi’s heart attack data and found that the AMI mortality rate has been trending downward throughout the state:

[...] from 2000-2002 to 2003-2005, there was a 19.3% decline in heart attack deaths in Mississippi. And from the period 2000-2002 to 2006-2008, there was a 29.2% decline in heart attack deaths in Mississippi.

From 2003 to 2008, heart attack deaths in Mississippi fell by 19.1%. From 2002 to 2008, they fell by 29.4%. And from 2000 to 2008, they fell by more than one-third: by 33.9%.

This demonstrates that heart attacks were declining substantially in the state of Mississippi anyway, even in the absence of a smoking ban. It suggests that if Starkville had not enacted a smoking ban, the study still would have found a very large decline in heart attacks from 2003-2005 to 2006-2008.

On Friday I wrote to McMillen and Collins to ask on what basis they reached their conclusion without having received the data from their control groups:

In the two page report you imply rather strongly that the decline in Starkville’s AMI rate is due to the smoking ban (”Without spending a dime, the community of Starkville has decreased heart attacks by more than 25%…”) (”Current research shows that smoking bans in Starkville have contributed to a 27% reduction in the heart attacks of local residents…”). I am curious to know how you have reached this conclusion without having received the data from control groups, as this seems to go far beyond what one could determine from your preliminary results.

I’ve yet to receive any response from them.

In two of my emails I requested to see the data from Starkville broken down year-by-year. If we are to believe the studies from Pueblo and Helena, the bulk of the decline should have occurred immediately after the ban took effect. It would be useful to know if the same pattern occurred in Starkville. They have yet to release this data.

Collins and McMillen have given their statements a veneer of scientific objectivity without providing the transparency needed to substantiate their claims. This hasn’t stopped them from using their results to push for a statewide smoking ban:

Data from the Mississippi State Department of Health and national figures indicates the state would save an estimated $125 million annually in health care expenses if a legislatively mandated smoking ban was enacted, [Collins] added.

“I plead with the Mississippi Legislature to ban smoking in public places,” Collins said. “Our data reflects the findings of every other community that has looked at what happened when smoking is banned in public venues.”

This is yet another example of what Siegel aptly calls “science by press release.” McMillen and Collins have no basis on which to rest their claims, have not published them in any journal, and haven’t even collected all of their data. Yet because they were critical of tobacco a willing press disseminated their conclusions far and wide without asking difficult questions or consulting critics.

When this study is completed it will be interesting to see what if finds. At that time its results could possibly be informative in the debate over a statewide smoking ban. But to go public with results now, before the data is even collected, is a corruption of science for the pursuit of political ends and unfortunately all too typical for today’s anti-smoking movement.

*Corrected.

Permalink - Share/Save - Comments (8)