Determining Time of Symptom Onset in Patients With Acute Coronary Syndromes

BACKGROUND: Prehospital delay, the time of symptom onset until the time of hospital arrival, for patients with symptoms of acute coronary syndrome (ACS) is frequently used to determine the course of care. Total ischemic time (time for symptom onset until the time of first coronary artery balloon inflation) is another criterion for quality of care for patients experiencing ST-segment elevation myocardial infarction. However, obtaining the exact time of symptom onset, the starting point of both time intervals, is challenging. Currently 2 methods are used to obtain the time of symptom onset: abstraction of data from the medical record and structured interviews done after the acute event. It is not clear whether these methods are equally accurate. PURPOSE: Using identified search terms, PubMed and the Cumulative Index to Nursing and Allied Health Literature were searched for articles published from 1990 to 2014 to identify studies that examined agreement between the 2 data sources to determine prehospital delay in patients with ACS. CONCLUSIONS: Five studies examined the accuracy and/or agreement of prehospital delay by medical record review and structured patient interviews. In these studies, the percentage of missing/incomplete data in the medical record was higher compared with interviews (14%-40% vs 12%-13%). Three of the 4 studies that compared the 2 data sources reported more than 50% disagreement, with the time of symptom onset starting sooner when obtained by interview compared with the time recorded in their medical record at hospital presentation. CLINICAL IMPLICATIONS: There is a need for a consistent, reliable method to assess the time of symptom onset in patients with ACS. To ensure the accuracy of data collected for the medical record, training of emergency and critical care clinicians should (1) emphasize the importance of assessing symptoms broadly, (2) provide tips on interviewing techniques to help patients pinpoint the time of symptom onset, and (3) instill the value of complete documentation.