Predicting the risk of repetition after self harm: cohort study
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《英国医生杂志》
1 Centre for Suicide Prevention, Department of Psychiatry and Behavioural Sciences, University of Manchester, Manchester M13 9PL, 2 Department of Psychiatry and Behavioural Sciences, Manchester Royal Infirmary, Manchester M13 9WL, 3 Department of Emergency Medicine, Manchester Royal Infirmary
Correspondence to: N Kapur nav.kapur@manchester.ac.uk
Introduction
The predictive value of risk assessments after self harm was low. Emergency department staff were more cautious in their assessment of risk, rating more people as at high risk of repetition. Consequently, they identified a greater proportion of people who repeated (higher sensitivity), but fewer of those assessed as at high risk actually went on to repeat (lower positive predictive value). This may reflect different processes of assessment but could also be due to the consequences of making a high risk assessment. For emergency department staff such an assessment may necessitate a referral to psychiatric services. For psychiatric staff it generally means attempting to access relatively scarce interventions (such as psychiatric admission).
What is already known on this topic
Identification of those who are at risk of repetition is considered a key objective of assessment after self harm, but it is unclear how good emergency department and mental health staff are at predicting risk
What this study adds
Emergency department staff may be more cautious in their assessment than specialist staff, rating more people as at high risk of repetition
Exclusively high risk approaches to intervention are unlikely to succeed because of the large numbers of repeaters in the low and moderate risk groups
Risk assessments may have influenced subsequent management. This is unlikely to have had a serious effect on our findings because only a few people receive specialist follow up or admission after self harm,4 and the effect of even quite intensive interventions on repetition is small.5 Although case ascertainment for the database is good (about 80%), men and those who did not wait for treatment were under-represented in our sample. This study investigated clinical assessment but actuarial risk assessment tools are unlikely to be much better at identifying those who go on to repeat self harm.2
Exclusively high risk approaches to management after self harm are unlikely to be worth while. Restricting intervention to people identified as at high risk, even assuming a completely effective intervention, would prevent fewer than one fifth of repeat episodes. Also, we need further work to improve our understanding of the factors (both individual and organisational) that influence the assessment of risk after self harm.
This article was posted on bmj.com on 26 January 2005: http:bmj.com/cgi/doi/10.1136/bmj.38337.584225.82
We thank the staff from the MASSH project for data collection and the clinicians at the participating hospitals for completing the assessment forms. We would also like to thank Roger Webb for statistical advice and Paul Corcoran and Tim Cole for their comments on the manuscript.
Contributors: The initial idea for the study arose from discussions between NK, JC, EG, and KM-J. NK designed the study with input from all authors. JC supervised data collection. CR, JK, and NK did the final data preparation and analyses. NK produced the initial draft of the paper, and all authors commented on drafts. NK is guarantor.
Funding: Manchester Mental Health and Social Care Trust.
Competing interests: None declared.
Ethical approval: Not needed.
References
Owens D, Horrocks J, House A. Fatal and non-fatal repetition of self-harm. Systematic review. Br J Psychiatry 2002;181: 193-9.
National Collaborating Centre for Mental Health. Self-harm: the short term physical and psychological management and secondary prevention of self-harm in primary and secondary care (full guideline). National Clinical Practice Guideline 16. Leicester and London: British Psychological Society and Royal College of Psychiatrists, 2004.
Taylor C, Cooper J, Appleby L. Is suicide risk taken seriously in heavy drinkers who harm themselves? Acta Psychiatr Scand 1999;100: 309-11.
Hawton K, Townsend E, Arensman E, Gunnell D, Hazell P, House A, et al. Psychosocial and pharmacological treatments for deliberate self harm. Cochrane Database Syst Rev 1999;(4): CD001764.
Kapur N, House A, May C, Creed F. Service provision and outcome for deliberate self-poisoning in adults: results from a six centre descriptive study. Soc Psychiatry Psychiatr Epidemiol 2003;38: 390-5.(Navneet Kapur, senior lecturer1, Jayne C)
Correspondence to: N Kapur nav.kapur@manchester.ac.uk
Introduction
The predictive value of risk assessments after self harm was low. Emergency department staff were more cautious in their assessment of risk, rating more people as at high risk of repetition. Consequently, they identified a greater proportion of people who repeated (higher sensitivity), but fewer of those assessed as at high risk actually went on to repeat (lower positive predictive value). This may reflect different processes of assessment but could also be due to the consequences of making a high risk assessment. For emergency department staff such an assessment may necessitate a referral to psychiatric services. For psychiatric staff it generally means attempting to access relatively scarce interventions (such as psychiatric admission).
What is already known on this topic
Identification of those who are at risk of repetition is considered a key objective of assessment after self harm, but it is unclear how good emergency department and mental health staff are at predicting risk
What this study adds
Emergency department staff may be more cautious in their assessment than specialist staff, rating more people as at high risk of repetition
Exclusively high risk approaches to intervention are unlikely to succeed because of the large numbers of repeaters in the low and moderate risk groups
Risk assessments may have influenced subsequent management. This is unlikely to have had a serious effect on our findings because only a few people receive specialist follow up or admission after self harm,4 and the effect of even quite intensive interventions on repetition is small.5 Although case ascertainment for the database is good (about 80%), men and those who did not wait for treatment were under-represented in our sample. This study investigated clinical assessment but actuarial risk assessment tools are unlikely to be much better at identifying those who go on to repeat self harm.2
Exclusively high risk approaches to management after self harm are unlikely to be worth while. Restricting intervention to people identified as at high risk, even assuming a completely effective intervention, would prevent fewer than one fifth of repeat episodes. Also, we need further work to improve our understanding of the factors (both individual and organisational) that influence the assessment of risk after self harm.
This article was posted on bmj.com on 26 January 2005: http:bmj.com/cgi/doi/10.1136/bmj.38337.584225.82
We thank the staff from the MASSH project for data collection and the clinicians at the participating hospitals for completing the assessment forms. We would also like to thank Roger Webb for statistical advice and Paul Corcoran and Tim Cole for their comments on the manuscript.
Contributors: The initial idea for the study arose from discussions between NK, JC, EG, and KM-J. NK designed the study with input from all authors. JC supervised data collection. CR, JK, and NK did the final data preparation and analyses. NK produced the initial draft of the paper, and all authors commented on drafts. NK is guarantor.
Funding: Manchester Mental Health and Social Care Trust.
Competing interests: None declared.
Ethical approval: Not needed.
References
Owens D, Horrocks J, House A. Fatal and non-fatal repetition of self-harm. Systematic review. Br J Psychiatry 2002;181: 193-9.
National Collaborating Centre for Mental Health. Self-harm: the short term physical and psychological management and secondary prevention of self-harm in primary and secondary care (full guideline). National Clinical Practice Guideline 16. Leicester and London: British Psychological Society and Royal College of Psychiatrists, 2004.
Taylor C, Cooper J, Appleby L. Is suicide risk taken seriously in heavy drinkers who harm themselves? Acta Psychiatr Scand 1999;100: 309-11.
Hawton K, Townsend E, Arensman E, Gunnell D, Hazell P, House A, et al. Psychosocial and pharmacological treatments for deliberate self harm. Cochrane Database Syst Rev 1999;(4): CD001764.
Kapur N, House A, May C, Creed F. Service provision and outcome for deliberate self-poisoning in adults: results from a six centre descriptive study. Soc Psychiatry Psychiatr Epidemiol 2003;38: 390-5.(Navneet Kapur, senior lecturer1, Jayne C)