The effect of a charted history of depression on emergency department triage and outcomes in patients with acute myocardial infarction

BACKGROUND: Patients with acute myocardial infarction may have worse outcomes if they also have a history of depression. The early management of acute myocardial infarction is known to influence outcomes, and patients with a coexisting history of depression may be treated differently in the emergency department than those without one. Our goal was to determine whether having a charted history of depression was associated with a lower-priority emergency department triage score and worse performance on quality-of-care indices. METHODS: We conducted a retrospective population-based cohort analysis involving patients with acute myocardial infarction admitted to 96 acute care hospitals in the province of Ontario from April 2004 to March 2005. We calculated the adjusted odds of low-priority triage (Canadian Emergency Department Triage and Acuity Scale score of 3, 4 or 5) for patients with acute myocardial infarction who had a charted history of depression. We compared these odds with those for patients having a charted history of asthma or chronic obstructive pulmonary disease (COPD). Secondary outcome measures were the odds of meeting benchmark door-to-electrocardiogram, door-to-needle and door-to-balloon times. RESULTS: Of 6784 patients with acute myocardial infarction, 680 (10.0%) had a past medical history of depression documented in their chart. Of these patients, 39.1% (95% confidence interval [CI] 35.3%-42.9%) were assigned a low-priority triage score, as compared with 32.7% (95% CI 31.5%-33.9%) of those without a charted history of depression. The adjusted odds of receiving a low-priority triage score with a charted history of depression were 1.26 (p = 0.01) versus 0.88 (p = 0.23) with asthma and 1.12 (p = 0.24) with COPD. For patients with a charted history of depression, the median door-to-electrocardiogram time was 20.0 minutes (v. 17.0 min for the rest of the cohort), median door-to-needle time was 53.0 (v. 37.0) minutes, and median door-to-balloon time was 251.0 (v. 110.0) minutes. The adjusted odds of missing the benchmark time with a charted history of depression were 1.39 (p < 0.001) for door-to-electrocardiogram time, 1.62 (p = 0.047) for door-to-needle time and 9.12 (p = 0.019) for door-to-balloon time. INTERPRETATION: Patients with acute myocardial infarction who had a charted history of depression were more likely to receive a low-priority emergency department triage score than those with other comorbidities and to have worse associated performance on quality indicators in acute myocardial infarction care.