According to the latest Samaritans Suicide Statistics Report (Scowcroft 2015), there were 6,708 suicides in the UK in 2013.

Research has shown that approximately 50-60% of people who die by suicide will have a history of self-harm, defined as intentional self-poisoning or self-injury; indicating that self-harm is a key risk factor for suicide (Foster et al., 1997).

Previous findings also imply that the episode of self-harm will often take place shortly before the individual takes his or her own life (Gairin et al., 2003). Moreover, in a study of hospital emergency department contact prior to suicide in mental health patients, Da Cruz et al. (2010) found that risk of suicide was significantly higher in frequent hospital attenders.

New research recently published in the Journal of Affective Disorders (Hawton et al 2015), has used data from the Multicentre Study of self-harm in England to estimate the risk of suicide following self-harm in individuals presenting to general hospital emergency departments (EDs) in Oxford, Manchester and Derby between 2000 and 2010, and followed up until 2012.

Methods

Demographic, clinical, and hospital management data were collected on all individuals who presented with non-fatal self-harm to EDs in each region between the 1 January 2000 and the 31 December 2010. The Data Linkage Service of the NHS, which traces and flags individuals using the Central Health Register Enquiry System, was used to supply mortality information on each individual. Individuals were followed up until the 31 December 2012, meaning that the minimum follow-up period for any individual was two years and the maximum was 13 years.

The authors defined suicide as “death where the underlying cause was intentional self-harm or undetermined intent”, reflecting the definition cited by the UK Office for National Statistics (ONS 2013).

Results

• 40,346 individuals presented with self-harm between 2000 and 2010, and could be traced with regard to mortality. Of these individuals, 23.3% were from Oxford, 49.1% were from Manchester, and 27.6% were from Derby. Individuals’ ages ranged from 7-97 years old.
• Of all deaths (N = 2,704) that occurred in the sample during the study follow-up period between 2000 and 2012, suicide was recorded as cause of death in 349 individuals and undetermined intent (probable suicide) was recorded in 164. Thus, 513 (1.3%) of the deaths during the study follow-up period were from suicide or probable suicide. 330 of these individuals were male (2.0%) and 183 (0.8%) were female.
• The absolute risk of suicide was greater in males than females throughout the study follow-up period, and the risk of suicide following self-harm increased substantially with age at the time of self-harm in both genders (apart from in females aged 55 years and over).
• While self-poisoning was the most frequent method of self-harm, hanging was the most common method used for suicide, particularly in males.
• The risk of suicide was highest during the first year of follow-up, especially during the first six months. Overall, 0.5% of individuals died by suicide within the first year following an initial episode of self-harm.
• The age-adjusted risk of suicide in the study population (for individuals aged 15 years and over) in the first year following self-harm was 49 (95% CI 43 to 57) times greater than the annual general population risk of suicide in England and Wales, based on mid-year population estimates averaged for 2001-2010. It was also greater in females (59, 95% CI 46 to 76) than males (46, 95% CI 38 to 54), although the difference was not statistically significant.
• There appeared to be a decrease in annual risk of suicide following self-harm during the first part of the study period, although overall there was no consistent trend.
• Deaths of a further 360 individuals were recorded as being the result of accidental causes, such as accidental poisoning involving painkillers. The risk of death in the first year following self-harm was considerably increased when deaths from accidental causes were included as suicides:
  • 57 (95% CI 51 to 65) times the risk in the general population
  • 68 (95% CI 54 to 86) times in females
  • 53 (95% CI 46 to 62) times in males.

Conclusions

This multicentre study estimated the risk of suicide following self-harm in a large sample of individuals across the UK using robust data collection techniques that allowed the authors to minimise the issue of sample attrition, which can be problematic in longitudinal studies.

The results of this study indicate that of all of the deaths that subsequently occurred in individuals who presented to EDs following self-harm between 2000 and 2010, followed up until 2012, nearly one in five (19.0%) was by suicide, which supports existing evidence that self-harm is a key risk factor for suicide.

The suicide rates reported in this study are somewhat lower than those reported in previous studies conducted in specific regions around the UK (e.g. Hawton et al., 2003). The authors suggest that this could be the result of the increase in deaths being recorded as accidental, in turn as a result of the greater use of narrative verdicts by coroners in England (Hill & Cook, 2011). Narrative verdicts record the facts surrounding the death in more detail than the traditional classification system (ONS, 2013). If the coroner does not provide any indication of suicidal intent then the international convention is that an undetermined cause or accidental cause code should be used (Linsley et al., 2001). From a comparison of the characteristics of these types of verdicts and suicide verdicts, Linsley et al. (2001) concluded that the majority of these verdicts, on the balance of probability, are suicides. The authors attempted to adjust for this to some degree by conducting a secondary analysis including deaths by accidental causes (N = 360), which yielded similar suicide rates to previous studies.

Limitations

• As the authors acknowledge, this study is restricted to self-harm patients presenting to general hospitals, meaning that it cannot tell us anything about the risk of suicide following self-harm that occurs in the community.
• The authors compared suicide risk in the study cohort with risk of suicide in the general population of England. The authors suggest that comparison with local suicide rates might have provided a different relative level of risk, but conclude that many of the study population would likely have moved away from the area over the study follow-up period. However, comparison with local rates could be important given that a comparatively large proportion of patients (49.1%) were from Manchester.
• Follow-up periods for individuals varied greatly (a minimum of two years and a maximum of 13 years), which could have resulted in an underestimation of suicide rates, e.g. some individuals would only have been followed up for two years compared to others who would have been followed up for up to 13 years.
• The authors did not present data on how many times the individuals in their sample presented to EDs with self-harm. Given the increased risk of suicide in frequent hospital attenders (Da Cruz et al., 2010), this information could also have been important to report.

Implications

The authors conclude that self-harm patients are clearly an important target group for suicide prevention initiatives (see van der Feltz-Cornelis et al., 2011, for a review). Moreover, the findings of this study imply that the initial period after a self-harm episode is a particularly pertinent time period for such interventions to be delivered.

The findings also indicate that individuals may often use one method to self-harm and another to take their own life. Thus, the authors further concluded that:

while clinicians should pay attention to potential access to methods used in a recent episode of self-harm, prevention of suicide in self-harm patients needs also to focus on broader aspects of prevention.

Finally, in terms of implications for future research in this area, the findings of this study indicate that:

in calculating estimates of suicide risk in self-harm patients, researchers need to be aware of current death classification issues that may influence the accuracy of findings.

Indeed, Linsley et al. (2001) have highlighted the importance of the development of a standardised assessment instrument to help decide which narrative verdicts should be coded as suicides, in order to enhance the reliability of epidemiological data on suicides.

If you need help

If you need help and support now and you live in the UK or the Republic of Ireland, please call the Samaritans on 116 123.

If you live elsewhere, we recommend finding a local Crisis Centre on the IASP website.

We also highly recommend that you visit the Connecting with People: Staying Safe resource.

Links

Primary paper

Hawton K, Bergen H, Cooper J, Turnbull P, Waters K, Ness J, Kapur N. (2015). Suicide following self-harm: Findings from the Multicentre Study of self-harm in England, 2000-2012. Journal of Affective Disorders, 175, 147 – 151. [PubMed abstract]

Other references

Scowcroft E. (2015). Suicide Statistics Report 2015 (PDF). The Samaritans.

Foster T, Gillespie K, McClelland R. (1997). Mental disorders and suicide in Northern Ireland. British Journal of Psychiatry, 170, 447-452. [PubMed abstract]

Gairin I, House A, Owens D. (2003). Attendance at the accident and emergency department in the year before suicide: Retrospective study. British Journal of Psychiatry, 183, 28-33.

Da Cruz D, Pearson A, Saini P, Miles C, While D, Swinson N, Kapur N. (2011). Emergency department contact prior to suicide in mental health patients. Emergency Medicine Journal, 28, 467-471. [Abstract]

Office For National Statistics (2013). Suicides in the United Kingdom, 2011 (PDF).

Hawton K, Zahl D, Weatherall R. (2003). Suicide following deliberate self-harm: long-term follow-up of patients who presented to a general hospital. British Journal of Psychiatry, 182, 537 – 542. [PubMed abstract]

Hill C, Cook L. (2011). Narrative verdicts and their impact on mortality statistics in England and Wales. Health Statistics Quarterly, 49, 81 – 100. [PubMed abstract]

Linsley KR, Schapira K, Kelly TP. (2001). Open verdict v. suicide – Importance to research. British Journal of Psychiatry, 178, 465 – 468. [PubMed abstract]

van der Feltz-Cornelis CM, Sarchiapone M, Postuvan V, Volker D, Roskar S, Grum AT, Hegerl U. (2011). Best practice elements of multilevel suicide prevention strategies: A review of systematic reviews. Crisis, 32, 319 – 333.

For help and support see Samaritans: http://www.samaritans.org/ or call on 08457 90 90 90