A 5 year retrospective study of emergency department use in Northwest Ontario: a measure of mental health and addictions needs.

Objective: The main objective of this study was to understand the five-year trend in total emergency department (ED) visits, frequency of use, and diagnoses and disposition of patients. Since the region has experienced a profound increase in opioid use disorder since 2009, we were particularly interested in changes in the volume of mental health and addiction (MHA) ED presentations. Methods: Retrospective aggregate data analysis of ED visits to the Sioux Lookout Meno Ya Win Health Centre 2010-2014. Results: ED visit volume increased 29% over the five-year study period, while MHA ED visits increased 73%. The admission rate remained stable at 6.9% of ED visits. Five-year trends in clinically grouped diagnostic categories identified respiratory, MHA, and abdominal/pelvic complaints as the three most common ED presentations. In 2014, MHA presentations accounted for 10.3% of ED visits, 8.7% of admissions, and 20.0% of inter-hospital transfers. Conclusion: The dramatic increase in MHA ED visits mirrors the opioid epidemic the region is experiencing. MHA may soon become the commonest ED presentation. If reasons for ED visits serve as a proxy for unmet outpatient needs, increased efforts at developing community MHA services and addressing the related social determinants of health are required.