Wednesday, August 23, 2006

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

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

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

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

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

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

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

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

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

The Rest of the Story

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

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

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

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

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

That is one thing I am not.

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

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