Impact of Direct Mail Intervention on Knowledge, Attitudes, and Behavioral Intentions Regarding use of Emergency Medical Services for Symptoms of Acute Myocardial Infarction

Abstract

This study evaluated a direct mail intervention called the "Call Fast, Call 911" campaign designed to increase use of emergency medical services for symptoms of acute myocardial infarction. The campaign was targeted at individuals over the age of 50. Persons over 50 years of age (N = 130,000) in King County, Washington, were randomly assigned to intervention or control groups. Individuals in the intervention groups received six direct mail pieces over a 1-year period encouraging them to call 911 quickly in response to chest pain. A postintervention telephone survey of a random sample of households (N = 434) assessed the impact of the campaign on knowledge, attitudes, and behavioral intentions regarding use of emergency medical services for symptoms of acute myocardial infarction. The results showed no significant differences between intervention and control groups in terms of knowledge of AMI. However, there were significant differences in beliefs and behavioral intentions to call 911 in a cardiac emergency.