Impact of Alcohol Intoxication on Mortality and Emergency Department Resource Use in Suicidal Patients

In North America, suicide ranks among the top causes of death in individuals 15-60 years of age. In this study we aimed to determine whether an emergency department (ED) presentation for suicidal behaviors accompanied by acute alcohol intoxication was associated with increased six-month suicide or all-cause mortality compared to non-intoxicated presentations of suicidal behaviors.

We performed a retrospective cohort study of adults (≥ 18 years) presenting to 16 EDs in Alberta, Canada, between April 2011-March 2021. Suicidal attempt or self-harm was identified via International Classification of Diseases codes, 10th Rev, Canadian Enhancement (ICD-10-CA). Patients were classified as acutely intoxicated if they had relevant ICD-10-CA codes or a blood alcohol concentration ≥ 2 millimoles per liter (9.2 milligrams per deciliter). We excluded patients who died on arrival, were transferred, or were non-residents. The primary outcome was suicide-specific mortality at six months; secondary outcomes included all-cause mortality, use of involuntary holds, psychiatric consultations, admissions, and ED return visits. Median differences with 95% confidence intervals and unadjusted odds ratio (OR) with 95% CI were reported for continuous and categorical variables, respectively.

Among 58,051 suicidal or self-harm patients, 17,488 (30%) were classified as intoxicated. Six-month suicide mortality was similar between intoxicated and non-intoxicated groups (0.3% each; adjusted sub-distribution hazard ratio = 0.98 [95% CI, 0.73-1.38]), indicating no significant association between alcohol intoxication and suicide-specific death. Intoxicated patients were more often male (58% vs 52%; OR 1.26 [1.22-1.31]), arrived by ambulance (70% vs 50%; OR 2.32 [2.23-2.41]), and were more frequently placed on involuntary holds (26% vs 16%; OR 1.92 [1.83-2.00]). They had fewer hospital admissions (10.8% vs 15.4%; OR 0.63 [0.60-0.67]), longer ED stays (411 vs 277 minutes; median difference = 134 minutes [127.7-140.3]), and higher ED return rates at 30 days (19.8% vs 18.3%; OR 1.10 [1.05-1.15]) and six months (45.8% vs 42.1%; OR 1.16 [1.12-1.20]).

Acute alcohol intoxication among ED patients presenting with suicidal behaviors was not independently associated with higher six-month suicide mortality. Patients with acute alcohol intoxication had increased use of involuntary holds, longer lengths of stay, and more frequent ED return visits. Future work should explore other psychosocial and clinical factors, including substance use and psychiatric comorbidities, that may influence outcomes beyond the acute setting.