Impact of extended drinking hours in Ontario on motor-vehicle collision and non-motor-vehicle collision injuries.

Objective: On May 1, 1996, Ontario, Canada, amended the Liquor Licence Act to extend the hours of alcohol sales and service in licensed establishments from 1 am to 2 am. The purpose of this study was to evaluate the impact of extended drinking hours in Ontario on motor-vehicle collision (MVC) and other injuries admitted to regional trauma units based on Ontario Trauma Registry data.
Method: A quasi-experimental design using interrupted time series was used to assess changes in admissions to Ontario trauma units. The analyzed data sets were monthly data on number of admissions from MVC and other causes of injury during the 11 pm-12 am, 12-1 am, 1-2 am, and 2-3 am time windows for 4 years before and 3 years after the policy change (May 1992-April 1999).
Results: For MVC injuries, no significant pre-post increases were found for the 2-3 am period commensurate with the introduction of the extended drinking hours, but decreases were found for the 11 pm-12 am and 1-2 am periods. For non-MVC injuries, a significant increase was found for the 2-3 am period.
Conclusions: The data sets suggest that increased availability of alcohol as a result of extension of closing hours had an impact on non-MVC injuries presenting to Ontario trauma units, but road safety initiatives may have mediated the effects of the extension on MVC injuries. These observations are consistent with those of other studies of small changes in alcohol availability.