Background Mass media campaigns for stroke awareness encourage the public to recognise stroke symptoms and respond to stroke in a timely manner. However, there is little evidence to suggest that media messages can influence behaviour after stroke onset. The F.A.S.T. (Face Arm Speech Time) test is a common stroke recognition tool used in public education campaigns.

Objective To assess the impact of the F.A.S.T. campaign on health service use in Ireland, which has had no previous exposure to a F.A.S.T. media campaign.

Methods An interrupted time series design was used to detect behaviour change after the introduction of the first Irish F.A.S.T. campaign in presentations of patients with suspected stroke to two emergency departments (EDs), serving a population of about 580 000.

Results There was a significant change in ED attendance of patients with reported stroke symptoms after the introduction of the F.A.S.T. campaign (β=0.84, 95% CI 0.43 to 1.24; p<0.001), although this was not sustained. ED presentation within 3.5 h was associated with emergency medical services activation (OR=3.1, p<0.001) and self-referral to the ED (OR=2.67, p<0.001).

Conclusions This first Irish F.A.S.T. campaign had an initial impact on ED attendance of patients with stroke symptoms. However, the campaign effects were not sustained in the long term. Results indicate that prehospital delay in accessing acute stroke services is a complex process with involvement of factors other than stroke knowledge and intention to call 911.