Background: National evidence suggests that there is considerable variation between regions in emergency department utilization for routine health care needs. Many emergency departments are poorly equipped to manage the needs of patients with mental health or substance misuse diagnoses, who could often be more effectively managed in other settings. We sought to quantify differences in the frequency of mental health and substance misuse-related emergency department encounters across urban counties in North Carolina.
Methods: Data from the 2010 North Carolina State Emergency Department and Inpatient Databases were analyzed with descriptive, bivariate, and multivariate statistics. Primary discharge diagnoses were classified using the International Classification of Disease, Ninth Revision, Clinical Modification codes included with the databases.
Results: The overall rate of mental health and substance misuse encounters in urban counties was 19.1 encounters per 1,000 people (4.5% of all emergency department encounters). This rate ranged from 6.4 encounters per 1,000 people (2.4% of encounters) in Wake County to 30.1 encounters per 1,000 people (6.4%) in Orange County.
Limitations: There is a possibility of nondifferential classification error in the state databases, as coding practices and coding errors may vary between facilities. We were unable to confirm diagnoses through additional clinical information or Diagnostic and Statistical Manual criteria.
Conclusion: Mental health and substance misuse-related encounters constitute a small percentage of emergency department encounters in North Carolina's urban counties, with significant variation between counties. Diverting some of these encounters to community-based mental health and substance misuse health care providers could reduce emergency department utilization while improving the quality of care delivered to this vulnerable patient population.
©2016 by the North Carolina Institute of Medicine and The Duke Endowment. All rights reserved.