Admissions for acute myocardial infarction during six month period (June to November) when smoking ban was enforced and equivalent months in years before and after ban, according to areas with (Helena) and without enforcement*


 Helena
 Not Helena
Ordinance year (2002)
24
18
Other years{dagger}
 40
12.4
Difference (95% CI)
–16 (–31.7 to –0.3)
5.6 (–5.2 to 16.4)
Helena difference-not Helena difference (95% CI)
–21.6 (–40.6 to –2.6)

* All comparisons done assuming Poisson distribution.

{dagger} Average number of admissions during six month period for years other than 2002.