Death by suicide

In 2016, the Office for National Statistics (ONS) definition of suicide was modified to include deaths from intentional self-harm in 10 to 14 years old children and deaths from intentional self-harm and events of undetermined intent in people aged 15 and over (John et. al., 2014, John, 2018). As such, suicide deaths should be identified through an algorithm that considers changes in coding practices over time and age-specific definitions defined below.

Related concepts

Deaths by suicide - Intentional self-harm

This includes deaths in people aged 10 and over with an underlying cause of death of 'intentional self-harm' (X60–X84).

Deaths by suicide - Undetermined intent

This includes deaths in people aged 15 and over with an underlying cause of death of 'event of undetermined intent' (Y10-Y34). The definition is divided in the following pre-2007 and 2007-onward definitions:

• Deaths by suicide - Undetermined intent (pre-2007): Prior to 2007, code Y33.9 included deaths with 'coroner's verdict pending' as well as 'open verdict', and is therefore excluded in this time period.

• Deaths by suicide - Undetermined intent (2007-onward): The Office for National Statistics is now coding deaths with 'verdict pending' as U50.9 for England & Wales, and we are therefore able to include Y33.9 ‘open verdict’ from 2007 onward.

Deaths by suicide - Accidental conclusions

There is evidence to suggest that a high proportion of deaths from poisoning and hanging that receive accidental conclusions are found, when subjected to clinical review, to be suicides (Gunnell et al, 2013). Such possible suicide deaths include ICD-10 codes relating to ‘accidental poisoning with prescribed drugs’ (X40–X41, X43–X49) and ‘accidental hanging’ (W75–W76), and may be used alongside ‘sequelae of external causes of morbidity and mortality’ (Y87, Y87.2, Y89, Y89.9). These codes are not included in the ONS definition and are, therefore, not used here to identify deaths by suicide. They may, nevertheless, be considered in people aged 16 and over during sensitivity analyses.

Deaths by suicide - Ill-defined / unknown cause

There is evidence to suggest that some deaths by suicide may be inappropriately registered as ‘other ill-defined and unspecified causes of mortality’ (R99) (Snowdon, 2021). The extent to which this occurs varies across countries, and in the United Kingdom, the rate of deaths coded as ill-defined is relatively low. R99 is not included in the ONS definition and are, therefore, not used here to identify deaths by suicide. These deaths may, nevertheless, be considered during sensitivity analyses.

How to use

To identify deaths by suicide, include all deaths with an underlying cause of death ICD-10 within Deaths by suicide - Intentional self-harm at age 10 years or older, or within Deaths by suicide - Undetermined intent (pre-2007) and 2007-onward at age 15 years or older prior to 2007 and from 2007 onward respectively.

References

Gunnell, D., Bennewith, O., Simkin, S., Cooper, J., Klineberg, E., Rodway, C., ... & Kapur, N. (2013). Time trends in coroners' use of different verdicts for possible suicides and their impact on officially reported incidence of suicide in England: 1990–2005. Psychological medicine, 43(7), 1415-1422.

John, A., Dennis, M., Kosnes, L., Gunnell, D., Scourfield, J., Ford, D. V., & Lloyd, K. (2014). Suicide Information Database-Cymru: a protocol for a population-based, routinely collected data linkage study to explore risks and patterns of healthcare contact prior to suicide to identify opportunities for intervention. BMJ open, 4(11), e006780.

John, A. (2018) “Midpoint review of the implementation of Talk to me 2: the Wales suicide and self-harm prevention action plan”. NHS Wales.