Can mass media influence emergency department visits for stroke?

Background and Purpose - Television advertising has been associated with significant increases in the knowledge of the warning signs of stroke among Ontarians aged 45 and older. However, to date there has been little data on the relationship between knowledge of the warning signs of stroke and behavior. Methods - Data on presentation to regional and enhanced district stroke center emergency departments were obtained from the Registry of the Canadian Stroke Network for a 31-month period between mid 2003 and the beginning of 2006. Public opinion polling was used to track knowledge of the warning signs of stroke among Ontarians aged 45 and older. Results - The public's awareness of the warning signs of stroke increased during 2003 to 2005, decreasing in 2006 after a 5-month advertising blackout. There was a significant increase in the mean number of emergency department visits for stroke over the study period. A campaign effect independent of year was observed for total presentations, presentation within 5 hours of last seen normal, and presentation within 2.5 hours. For TIAs there was a strong campaign effect but no change in the number of presentations by year. Conclusions - Continuous advertising may be required to build and sustain public awareness of the warning signs of stroke. There are many factors that may influence presentation for stroke and awareness of the warning signs may be only one. However, results of this study suggest there may be an important correlation between the advertising and emergency department presentations with stroke, particularly for TIAs.