Trends in prehospital delay time and use of emergency medical services for acute myocardial infarction: Experience in 4 US communities from 1987-2000

Background: Prolonged delay in seeking care for acute myocardial infarction (AMI) is associated with decreased use of time-dependent treatments and increased mortality and morbidity. Methods: Time from symptom onset to arrival at hospital and emergency medical service use were abstracted from medical records of 18 928 patients hospitalized for AMI and captured in the community surveillance component of the ARIC study from 1987 to 2000. A cut point of 4 hours was used to assess clinically relevant delay time recommendations for treatment with current therapies. Results: In 2000, the overall proportion of persons with delays from symptom onset to hospital arrival of ≥4 hours was 49.5%. Blacks and women consistently delayed longer than whites and men. Between 1987 and 2000, there was no statistically significant change in the proportion of patients delaying ≥4 hours (relative change +0.6% in men, -7.4% in women, -2.3% in whites, -8.9% in blacks, -7.9% in persons with diabetes, and -0.8% in persons without diabetes); however, there is a noticeable narrowing of gaps between sex, race, and diabetes status over the study period. The percentage of those who used emergency medical services increased significantly over the study period (1987 37.1%, 2000 44.5%, P ≤ .0001). Conclusions: Many patients continue to experience prolonged delays from onset of symptoms to hospital arrival. Delay time for hospitalized AMI changed little in the ARIC communities from 1987 to 2000. New public health strategies should be developed to facilitate rapid access to acute care for AMI.