Injury prevention/original researchA Clinical Tool for Assessing Risk After Self-Harm
Introduction
The mean annual rate of people presenting to general hospitals in the United Kingdom after self-harm has increased in recent years, and the latest estimate is 170,000 per annum.1 In the United States, the number of presentations to emergency departments (EDs) after self-harm has been reported as more than 400,000 annually, with one third resulting in hospital admission.2 This number puts considerable pressure on medical and psychiatric services in hospitals.3 A number of guidelines have been published in the United Kingdom4, 5 on the management of self-harm. These have recommended that all patients treated in the ED after an episode of self-harm be given a psychosocial assessment before discharge by a member of staff trained for the task. There is no requirement for the assessment to be carried out by a mental health specialist. Even so, most hospitals fell short of these standards when surveyed.6 Many EDs lack sufficient psychiatric support to provide specialist psychosocial assessments on all patients.
Patients who present with self-harm are at high risk of further self-harm and suicide.7, 8 A quarter of patients who commit suicide have attended a general hospital because of self-harm in the preceding 12 months.3 The majority (up to 75%) of repeated episodes occur within 6 months of the index episode,9 and suicide risk is also highest during this period.10 A reduction in suicide is a key goal of mental health policy in England11 and was highlighted in the United States by the Surgeon General’s Call to Action to Prevent Suicide.12
The prediction of suicidal behavior is difficult because of the low specificity of identified risk factors.13 The initial assessment of self-harm patients is the responsibility of medical staff in the ED in most hospitals. Risk-stratification models have been used in ED settings in recent years to improve clinical care.14 These models prioritize sensitivity over specificity (ie, they identify most of the index cases but also pick up many nonindex cases). They enable clinicians to make informed choices about the appropriate treatment of patients. Methodologic standards for the development of clinical decision rules in emergency medicine have now been established to optimize the quality of novel clinical decision rules and to assist the emergency clinician in assessment(s).15 However, a recent US review concluded that there was limited evidence for the accuracy of screening tools in identifying suicide risk.16 A previous report by our group showed that the predictive value of global clinical assessments for self-harm was poor and could not be used as a basis for providing intervention.17
The aim was to develop a risk-stratification model for use by ED clinical staff in the assessment of patients attending with self-harm. Our goal was to derive a short (3- to 5-element) decision rule, first to correctly identify 95% or more of repetitions of self-harm and all suicides within 6 months and second to provide the best possible specificity. This rule was required to be simple and reliable enough to be used by ED clinical staff to help them discriminate between patients at higher and lower risk of repetition or subsequent suicide.
Section snippets
Study Design and Setting
The data were collected prospectively by using information from a citywide monitoring of self-harm known as the Manchester and Salford Self-Harm project.18 This project included 5 EDs in the neighboring cities of Manchester and Salford, which together serve a catchment population of 608,922 individuals. As part of routine clinical practice in all of the participating hospitals, after a presentation with self-harm, a standard psychosocial assessment form was completed by the emergency clinician;
Results
There were 11,819 episodes of self-harm treated in the study departments during the 3 ½-year study period (September 1, 1997, to February 28, 2001); 2,743 (22%) episodes were not included in the analysis because the patients had either refused treatment or left before assessment. Thus, 9,086 patient episodes were available for analysis. Of these, 6,933 episodes were in the derivation set and 2,153 episodes in the validation set, which is summarized in the recruitment diagram shown in Figure 1.
Limitations
This study has limitations. The accuracy of the model depends on the completeness of the database from which it was derived. Although we collected detailed psychosocial data on about 80% of possible self-harm episodes, patients using cutting as a method of harm may have been underrepresented in our study. The Manchester and Salford Self-Harm data set is based on self-harm episodes that are treated in EDs. Our findings may not be applicable to patients who do not wait for treatment or community
Discussion
We have derived the Manchester Self-Harm Rule that correctly identifies some 94% of patients who repeated self-harm in the next 6 months. Furthermore, there were no suicides missed by our rule within the 6-month follow-up period. The validation of the rule, in a set of patients treated in 2 EDs to those patients included in the derivation data set, produced similar results, suggesting that our rule is robust. The predictive value of the rule is superior to the predictive value of global
References (31)
- et al.
National study of US emergency department visits for attempted suicide and self-inflicted injury, 1997-2001
Ann Emerg Med
(2005) - et al.
Methodologic standards for the development of clinical decision rules in emergency medicine
Ann Emerg Med
(1999) - et al.
The Canadian CT Head Rule for patients with minor head injury
Lancet
(2001) - et al.
Deliberate self-harm patients who leave the accident and emergency department without a psychiatric assessment: a neglected population at risk of suicide
J Psychosom Res
(2001) - et al.
Management of deliberate self poisoning in adults in four teaching hospitals: descriptive study
BMJ
(1998) - et al.
Trends in deliberate self-harm in Oxford, 1985-1995: implications or clinical services and the prevention of suicide
Br J Psychiatry
(1997) Assessment Following Self-Harm in Adults: Council Report CR122
(2004)Self-Harm: The Short-Term Physical and Psychological Management and Secondary Prevention of Self-Harm in Primary and Secondary Care
(2004)- et al.
General hospital services for attempted suicide patients: a survey in one region
Health Trends
(1995) - et al.
High mortality by natural and unnatural causes: a 10 year follow-up study of patients admitted to a poisoning treatment centre after suicide attempts
BMJ
(1993)
Suicide and other causes of death, following attempted suicide
Br J Psychiatry
The early repetition of deliberate self-harm
J R Coll Physicians Lond
Suicide following deliberate self-harm: a 4 year cohort study
Am J Psychiatry
National Suicide Prevention Strategy for England
The Surgeon General’s Call to Action to Prevent Suicide
Cited by (0)
Supervising editor: Debra E. Houry, MD, MPH
Author contributions: JC and KM-J designed the original study, with help from EG and LA. JC collected the data, and JC, NK, and JD analyzed the data. JC, NK, JD, and KM-J contributed to writing the article, with help from EG and LA. All authors have seen and approved the final version. JC and LA secured funding for the project. JC takes responsibility for the paper as a whole.
Funding and support: The project was funded by Manchester Health Authority, South Manchester University Hospitals NHS Trust, Central Manchester and Manchester Childrens’ University Hospitals NHS Trust, Pennine Acute NHS Trust and the Mental Health Services of Salford NHS Trust.