Emergency care may be failing to spot patients at risk of suicide, many of whom use these services in the year leading up to their death, suggests a small study published online in Emergency Medicine Journal.
Around 5000 people kill themselves in England and Wales every year, and previous research has indicated that the emergency department might be well placed to pick up patients vulnerable to suicide.
The researchers reviewed emergency department records in the North West of England for 286 people who committed suicide between 2003 and 2005 and who had been in contact with mental health services within 12 months of their death.
In all, emergency department data from 38 hospitals were assessed.
The suicides were identified from information submitted to the National Confidential Enquiry into Suicide and Homicide by People with Mental Illness.
The average age of the suicides was 47, ranging from 19 to 95. There were twice as many men as women.
The analysis showed that more than four out of 10 (43%; 124) of all 286 suicides had sought treatment at emergency care departments at least once in the year leading up to their death.
And of these, 35 (28%) had visited emergency care facilities more than three times in the last year of their lives. These "frequent attenders" died by suicide significantly soon after their last visit to emergency care than those who attended less often.
Over half (55%) of those who took their own lives were unemployed or on long term sick leave at the time of their death.
One in five cases had a primary diagnosis of schizophrenia and other delusional disorders; almost half (48%) had affective disorders, such as bipolar disorder or depression. Around one in 10 (9%) were dependent on alcohol and 3% were drug dependent.
The "frequent attenders" were significantly more likely to have a history of self harm and alcohol misuse. They were also more likely to be unemployed and to have sought help for psychological reasons, including self harm.
Best practice guidance recommends that self-harming patients who seek emergency care should be given a psychosocial assessment, but the researchers found little documented evidence to suggest this was happening.
"Although psychiatric services clearly have a prominent role in preventing suicide in mental health patients, emergency care departments may represent an important additional setting for suicide prevention," conclude the authors.
"Frequent attenders may represent a high risk group, and this should be recognised by emergency services," they add.