Toronto has had a ban on smoking since 1996 (phased in gradually) and has seen massive declines in hospitalisation for smoking relatedillnessses since that time.

Areas where the smoking ban was not in force did not see similar drops.

article here

"Hospitalization for cardiovascular conditions dropped 39 per cent, including a 17.4 per cent decrease in heart attacks, while hospital visits for respiratory conditions fell by 33 per cent.
The 10-year study looked at hospital admissions data in Toronto from January 1996 — three years before the first phase of the city’s smoking ban — to March 2006 — two years after the last phase was in place.

The ban was rolled out in three phases: workplaces and public buildings in October 1999, restaurants in June 2001 and bars in June 2004.

As control areas, the authors used Durham Region and Thunder Bay — where smoking bans were not in place until after 2004 — and found no change in hospitalization rates for the conditions under study. Researchers also found no decline in hospitalization rates in Toronto for conditions not influenced by smoking or secondhand smoke."

 

good to see the use of a control group.

 

So, Nz has had a ban for, what, about 3-4 years now?  It will be interesting to see if a similar study can be done here too.