by National Institutes of Health

A new study found that people who presented to California emergency departments with deliberate self-harm had a suicide rate in the year after their visit 56.8 times higher than those of demographically similar Californians. People who presented with suicidal ideation had suicide rates 31.4 times higher than those of demographically similar Californians in the year after discharge. The findings, published in JAMA Network Open, reinforce the importance of universal screening for suicide risk in emergency departments and the need for follow-up care. The study was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health.

More than 500,000 people present to emergency departments each year with deliberate self-harm or suicidal ideation—both major risk factors for suicide. However, little is known about what happens to these people in the year after they leave emergency care.

“Until now, we have had very little information on suicide risk among patients after they leave the emergency department because data that link emergency records to death records are rare in the United States. Understanding the characteristics and outcomes of people with suicide risk who visit emergency departments is important for helping researchers and practitioners improve treatment and outcomes,” said lead author Sidra Goldman-Mellor, Ph.D., an assistant professor of public health at the University of California, Merced.

Goldman-Mellor and colleagues sought to understand patterns of suicide and other mortality in the year after emergency department presentation—and patient characteristics associated with suicide death—by linking emergency department patient records from California residents who presented to a licensed emergency department between Jan. 1, 2009, to Dec. 31, 2011, with California mortality data.

The researchers divided individuals presenting to the emergency department into three groups: people with deliberate self-harm with or without co-occurring suicidal ideation (85,507 patients), people presenting with suicidal ideation but without deliberate self-harm (67,379 patients), and people without either self-harm or suicidal ideation, called “reference” patients (497,760 patients).

The researchers found that the probability of suicide in the first year after discharge from an emergency department was highest—almost 57 times that of demographically similar Californians overall—for people who had presented with deliberate self-harm. For those who presented with suicidal ideation, the suicide rate was approximately 31 times higher than among Californians overall. The suicide rate for the reference patients was the lowest amongst the studied groups, but still double the suicide rate among Californians overall.

The risk for death via unintentional injury (i.e., accidents) was also markedly elevated—16 times higher for the deliberate self-harm group and 13 times higher for the ideation group than for demographically similar Californians. Most deaths due to unintentional injury were found to be due to overdose—72% in the self-harm group and 61% in the ideation group—underscoring the overlap between suicide and overdose risk.

The researchers also examined if certain clinical or demographic characteristics measured at the emergency department visit were predictive of subsequent suicide death. For all three groups, men and those over the age of 65 had higher suicide rates than women and people 10-24 years of age. In all groups, suicide rates were higher for non-Hispanic white patients than for patients of other ethnicities. In addition, for all groups, those with Medicaid insurance had lower suicide rates than those with private- or other-payer insurance.

Comorbid diagnoses were also found to be associated with suicide risk, but differently for each of the three groups studied. For patients who had presented with deliberate self-harm, those with a comorbid diagnosis of bipolar disorder, anxiety disorder, or a psychotic disorder were more likely to die by suicide than those without these co-occurring diagnoses. For patients who presented with suicidal ideation, a comorbid diagnosis of depression was found to be associated with increased suicide risk. Among reference patients, patients with bipolar disorder, depression, or alcohol use disorder had an increased risk of suicide. Of note, patients in the deliberate self-harm group who presented to the emergency department with a firearm injury had a subsequent suicide rate in the following year of 4.4%, far higher rate than any other patient group in this study.

“We think our findings will be useful for guiding intervention and healthcare quality improvement efforts,” said Goldman-Mellor. “Our results also highlight the fact that patients with suicidal ideation or self-harming behaviors are at high risk not only for death by suicide, but also for death by accidents, homicide, and natural causes. We think this shows the importance of addressing the full spectrum of their health and social needs in follow-up care.”

Study co-author Michael Schoenbaum, Ph.D., a senior advisor for mental health services, epidemiology, and economics at NIMH added that this type of analysis should become routine, saying, “We improve what we measure. In cancer and heart surgery, we have tracked and reported patient survival for decades—and outcomes have steadily improved. We should do the same for people with suicide risk, to inform our prevention and treatment programs.”