[Emergency Department Use in Quebec for Patients with Mental Disorders, including Substance use Disorders]

Objectives This study investigated emergency department (ED) use, reasons for emergency visits, hospitalization rates, and duration of hospitalization in 2014-15 for a cohort of patients with mental disorders (MDs) including substance use disorders (SUDs), regarding sex, age and residential areas. Results were compared with data from patients without MDs for 2014-15, and with another cohort from 2000-01, which marked the beginning of primary care reform in Quebec and elsewhere, with the aim of measuring ED use over time. Methods Based on data from the Quebec Integrated Chronic Disease Surveillance System (QICDSS), participants included patients age 12 and over, diagnosed with at least one MD (or SUD) during an ED visit, hospitalization, or outpatient consultation in 2014-15 and 2000-01. Frequency distributions for ED visits and hospitalizations were produced, as well as for MDs or SUDs exclusively, or for co-occurring MDs-SUDs, and among high or very high ED users (4 to 11 visits/year, ≥12 visits/year), by gender, age (12-17, 18-24, 25-44, 45-64, and 65 and over) and residential area (Montreal, urban areas:>100,000, semi-urban areas: <100,000, and rural areas: <10,000). The age-standardized method based on the age structure of the 2014-15 population was used to compare data from 2014-15 to 2000-01. Frequency distributions for patients with and without MDs, and on ED and hospitalization rates were also produced for 2014-15. Results For the Quebec population, 12% had MDs including SUDs, of whom 39% had visited an ED, a decrease of 6% since 2000-01. Approximately twice as many patients with MDs had ED visits or hospitalizations, compared to patients without MDs. Nearly 17% of patients were high or very high ED users; and 34% were hospitalized. ED use was higher among patients 65 years and older, and those living in rural areas. Sixty-eight percent of ED visits for MDs exclusively were made by patients affected by anxiety-depression; whereas 51% of visits for SUDs exclusively were alcohol-related. Physical illnesses were the main reason for ED visits and hospitalizations; yet patients with severe MDs, co-occurring MDs and SUDs as well as those with more frequent ED visits tended to use EDs more for MD reasons. Conclusion This study demonstrated a very high volume of ED visits and hospitalizations among patients with MDs, including SUDs, compared to patients without MDs. Co-occurring disorders, especially physical conditions and multiple and severe MDs, contributed to frequent ED use and hospitalizations. Better care management, including more comprehensive personal care, for patients with MDs including SUDs and co-occurring disorders is needed, as well as the deployment of strategies that provide integrated mental health and medical care, particularly in Montreal where ED use by patients with predominantly severe and co-occurring MDs and physical illnesses, is more frequent.