Meta-Analysis of Smoking Ban and Heart Attack Studies

In the largest meta-analysis to date of studies examining the effect of smoking bans on heart attack admissions, a paper published this week in the journal Circulation concludes that smoking bans lead to an immediate 15% decline in heart attack admissions or deaths. I noted that the authors excluded from the analysis a study which found no effect of smoking bans on heart disease deaths in six states. After further examination of the reasons provided by the authors for the exclusion of that study, I have concluded that there was no valid reason for the study's exclusion and it appears to be motivated by a desire to exclude the negative findings than by a valid scientific justification.

To remind you, in that study (Rodu B, Peiper N, Cole P. Acute myocardial infarction mortality before and after state-wide smoking bans. J Community Health 2011), the authors examined age-adjusted rates of heart attack mortality during the 3 years before implementation of the smoking ban and during the first year after the smoking ban was implemented in the eight states that implemented smoking bans between 1995 and 2003. These trends were also compared with those in the 44 other states without smoking bans.

The results were that in four of the six states (California, Utah, Delaware, and South Dakota), the smoking bans were not associated with any significant short-term decline in heart attack mortality. In one of these states - South Dakota - there was an 8.9% increase in heart attack mortality during the first year of the smoking ban which was significantly different from the expected decline of 7.2%. These results certainly seem to refute the assertion that smoking bans lead to a dramatic, immediate decline in heart attacks.

The authors of the meta-analysis give two major reasons for excluding the Rodu study:

1. The study "did not report or present data that permitted estimating relative risk and confidence intervals."

2. "In addition, the analysis was based on a very small number of data points...".