Importance: Emergency departments (EDs) have the potential to play a pivotal role in suicide risk detection and prevention, yet little is known about the profile of risk of suicide after ED visits in the United States.
Objectives: To examine 1-year incidence of suicide and other mortality among ED patients who presented with nonfatal deliberate self-harm, suicidal ideation, or any other chief concern, and to examine sociodemographic and clinical factors associated with suicide mortality risk.
Design, setting, and participants: This retrospective cohort study included statewide, all-payer, longitudinally linked ED patient records and mortality data from all California residents who presented to a California-licensed ED at least 1 time from January 1, 2009, to December 31, 2011, with deliberate self-harm, suicidal ideation but not self-harm, or neither (a 5% random sample). Age-, sex-, and race/ethnicity-adjusted standardized mortality ratios (SMRs) for suicide and other manners or causes of death were determined for each patient group using statewide mortality data. Data were analyzed from January 10 to July 18, 2019.
Main outcomes and measures: Suicide and other manners or causes of death were ascertained using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes. Suicide rate and all mortality rates were measured per 100 000 person-years.
Results: Among 648 646 individuals (mean [SD] age, 43.8 [20.6] years; 350 687 [54.1%] women) who visited an ED in California from 2009 to 2011, the rates of suicide deaths per 100 000 person-years in the year after index ED presentation were 693.4 deaths among 83 507 individuals presenting with deliberate self-harm (SMR, 56.8; 95% CI, 52.1-61.4), 384.5 deaths among 67 379 individuals presenting with suicidal ideation but not self-harm (SMR, 31.4; 95% CI, 27.5-35.2), and 23.4 deaths among 497 760 reference patients (SMR, 1.9; 95% CI, 1.6-2.3). Compared with the demographically matched general population, the rates of nonsuicide external-cause mortality were also increased among patients with self-harm (SMR, 14.2; 95% CI, 12.9-15.5), patients with suicidal ideation (SMR, 11.8; 95% CI, 10.6-13.0), and reference patients (SMR, 2.2; 95% CI, 2.0-2.3). In all 3 groups, the rates of suicide mortality per 100 000 person-years were higher among men (deliberate self-harm: 1011.1 deaths; suicidal ideation: 539.8 deaths; reference: 36.6 deaths), people 65 years or older (deliberate self-harm: 1919.5 deaths; suicidal ideation: 691.2 deaths; reference: 28.6 deaths), and non-Hispanic white patients (deliberate self-harm: 914.1 deaths; suicidal ideation: 511.6 deaths; reference: 33.8 deaths) than among their respective referent groups. Other sociodemographic factors and clinical diagnoses were associated with striking differences in suicide rates, but these patterns were heterogeneous across patient groups.
Conclusions and relevance: These findings suggest that ED patients with deliberate self-harm or suicidal ideation are associated with substantially increased risk of suicide and other mortality during the year after ED presentation. The process of planning for ED discharge may present opportunities to help ensure safe transitions to continuing outpatient mental health care and to consider broader risk for unintentional injury and other causes of premature mortality.