Largest-ever suicide-risk study identifies new prevention opportunity

TORONTO – Suicide prevention efforts have traditionally focused on the time period immediately following the first suicide attempt, but new research from The Hospital for Sick Children (SickKids), the Institute for Clinical Evaluative Sciences (ICES) and Sunnybrook Health Sciences Centre found that most suicide deaths occur well after the first attempt. The findings not only suggest the need for continued, long-term monitoring with individuals who have survived a suicide attempt, but also shine light on new prevention opportunities. The study is published in the April 1 online edition of JAMA Psychiatry.

The study, which includes more than 65,000 people who survived a self-poisoning episode – both children and adults – is the largest suicide-risk study to date. Researchers tracked every person who presented to an emergency department in Ontario for self-poisoning between April 2002 and December 2010.

The investigators found that the risk of suicide following non-fatal self-poisoning was 42 times higher than in the general population, and that the risk of death from accidents was 10 times higher following self-poisoning.  This suggests that the first episode of deliberate self-poisoning is a strong predictor for subsequent suicide and premature death.

“The durable risk of suicide long after the first self-poisoning episode suggests that to save lives we may need ongoing sustained initiatives. Most individuals who eventually died by suicide used more violent methods on subsequent attempts, and only 7 per cent of them reached hospital alive. The hope is that our findings can be used to target this high-risk group and that it may influence suicide-prevention strategies to include long-term follow-up and efforts,” says Dr. Yaron Finkelstein, lead author of the study and Staff Physician in Paediatric Emergency Medicine, and Clinical Pharmacology and Toxicology, and Associate Scientist at SickKids.

In Canada, suicide is the second leading cause of death in individuals aged 15 to 35 years, yet prevention efforts have remained a challenge, because the long-term outcomes following suicide attempts have not been well characterized. The present study also identified population-level suicide risk factors, which include being male, having engaged in multiple self-poisonings, higher socioeconomic status, a diagnosis of depression and psychiatric care in the year preceding the first self-poisoning episode.

“Previous research has largely focused on short-term studies of patients with known psychiatric conditions in individual health-care centres. However, no one has looked at the entire population including both patients with diagnosed mental health conditions as well as everyone else in the community. Additionally, this is the first study to focus exclusively on individuals with a first presentation for self-poisoning. More research is required, and our multidisciplinary team is working hard to dig deeper, and is focusing on the vulnerable group of teenagers, as well as subsequent self-harm behaviours,” adds Finkelstein, who is also Associate Professor of Paediatrics, Pharmacology and Toxicology at the University of Toronto.

“It’s surprising how little we know about long-term outcomes after a first self-poisoning episode,” said Dr. David Juurlink, a Senior Scientist at ICES, Head, Division of Clinical Pharmacology and Toxicology, Sunnybrook Health Sciences Centre and the study’s senior author. “By following a very large group of patients over a long period of time, this study demonstrates that the risk of suicide remains elevated long after a first attempt. The implication of this is that suicide prevention efforts in these patients must also be sustained.”

Numbers at a glance

• More than 130,000 individuals were tracked in this study, including 65,784 patients identified after first self-poisoning episode, compared with a similar number of individuals with no self-poisoning attempts
• 28 per cent (18,482) were teenagers (individuals younger than 20 years)
• Of the 65,784 patients discharged after a self-poisoning episode, 4,176 individuals died during the follow-up study period, 976 of them by suicide
• Average time from first self-poisoning episode to suicide was 585 days (1.6 years)
• Of the 976 suicide deaths, 107 were teens, with an average of 789 days (2.2 years) between the first self-poisoning episode and the suicide