Toward Understanding the Difference Between Using Patients or Encounters in the Accounting of Emergency Department Utilization

EDs provide care to a relatively static population, with truly new patients composing only a minority of encounters. Although multiple encounters per patient are common, highly frequent use occurs for only a minority of ED patients, and then only for a discrete period. Encounters and patients are not equivalent units of analysis, and policymakers and researchers should determine which is most appropriate for their decisionmaking.