title: Reassessing the evidence relating smoking bans to heart disease.
abstract: Recent studies have compared rates of acute myocardial infarction before and after introducing smoking bans. Some meta-analyses report post-ban reductions up to 19%, implausibly large considering likely changes in smoking habits and passive smoke exposure. Our literature reassessment demonstrates major weaknesses in many studies and meta-analyses, including failure to consider data from control areas or existing trends in acute myocardial infarction rates, incorrect estimation of variability, and use in some meta-analyses of results for population subsets or estimates apparently unrelated to the data reported. We report meta-analyses using a consistent approach to derive estimates of the ban effect, taking account of time trends and control data, which indicate a much smaller reduction. Preferring national to regional estimates where available, we estimate a 5% reduction (95% CI 3-8%). Omitting estimates where trend adjustment was impossible, this becomes 2.7% (2.1-3.4%), consistent with reported declines of 2-3% in large national populations (England, France, Italy, USA). We discuss some limitations of these estimates. Further evidence is needed, possibly by analyzing national mortality data. Our findings highlight the need for a valid approach when estimating the effect of bans, and demonstrate major weaknesses in many previous publications.
authors.affiliation: P.N. Lee Statistics and Computing Ltd., 17 Cedar Road, Sutton, Surrey SM25DA, UK. PeterLee@pnlee.co.uk
authors.forename: Peter N
authors.initials: PN
authors.lastname: Lee
authors.forename: John S
authors.initials: JS
authors.lastname: Fry
mesh_terms: D002170:Canada; D005060:Europe; D006331:Heart Diseases / Q000453:epidemiology*; D006801:Humans; D009520:New Zealand; D012306:Risk; D012907:Smoking / Q000453:epidemiology*; D014028:Tobacco Smoke Pollution / Q000517:prevention & control*; D014481:United States
chemical_list: D014028:Tobacco Smoke Pollution