Geographic clustering of emergency department presentations for acute coronary syndromes and heart failure in Alberta: a population-based study

CMAJ Open. 2017 May 18;5(2):E402-E410. doi: 10.9778/cmajo.20160155.

Abstract

Background: Collectively, the most common acute cardiac presentations to emergency departments are acute coronary syndromes (ACSs) and heart failure. We examined geographic variation and clustering in emergency department presentations by adults for ACS or heart failure in Alberta in 2010/11.

Methods: All emergency department presentations for ACS or heart failure made by Alberta residents aged 35 years or more during 2010/11 were extracted from 5 linked population-based Alberta administrative health databases. Data extracted included demographic characteristics, hospital admissions and physician claims. Spatial scan tests and logistic regression analyses were performed.

Results: There were 6342 patients with ACS (mean age 65.9 yr, 63.1% male) and 4780 patients with heart failure (mean age 76.6 yr, 49.9% male). For both ACS and heart failure, a primary cluster and 2 secondary clusters were identified. Different clusters were identified for the 2 conditions. For both conditions, patients living in the clusters had more primary care physician claims, prior emergency department visits and prior hospital admissions than did patients living outside the clusters. However, they were less likely to have had a specialist claim in the prior 2 years (odds ratio 0.64 [95% confidence interval 0.56-0.73] for ACS and 0.51 [95% confidence interval 0.43-0.61] for heart failure).

Interpretation: Geographic areas were identified with higher numbers than expected of patients presenting to the emergency department for ACS or heart failure. Lower specialist access in these areas was associated with increased emergency department use.