Associated causes of death in mortality

This article presents statistics on associated causes of death including psychosocial risk factors in the National Mortality Dataset

Released
23/10/2020

Associated causes of death in mortality

Interpreting associated causes of death

Circumstances relating to deaths from external causes are complex. Individual factors should not be considered in isolation.

Key statistics:

  • Associated causes of death were identified for 90.0% of suicides.
  • Mood disorders (including depression) were identified for 40.6% of suicides.
  • Problems with spousal relationship circumstances were the most common psychosocial risk factor, identified among 25.9% of suicides.

The national mortality dataset provides important information on underlying causes of death in Australia. It also provides in-depth details on associated causes of death. The term 'associated causes' is used when referring to conditions other than the underlying cause of death when using the International Classification of Diseases (ICD). Associated causes can include diseases that are part of the chain of events leading to death, risk factors and co-morbid conditions. 

For deaths that are referred to the coroner, the ABS codes causes of death from information contained on the National Coronial Information System (NCIS), including police, autopsy, toxicology and coroners reports. These reports provide a breadth of information relating to these deaths, much of which is highly important from a public health perspective. The coding of underlying and associated causes for coroner-referred deaths aims to capture all relevant details from these reports that sit within the framework of International Classification of Diseases (ICD). 
 
In 2017, the ABS undertook a pilot study to extend the range of information captured using the ICD. The main focus of this study was to incorporate codes relating to psychosocial risk factors in the coding of coroner-referred deaths. This work has since been extended through a collaboration between the ABS, the Australian Institute of Health and Welfare and the Department of Health as part of the Suicide and Self-Harm Monitoring Project. Data is now available for both 2018 and 2019. Engagement on the concepts underpinning this work is ongoing, resulting in small refinements to processes over time.

This report focusses on associated causes for coroner-referred deaths, particularly those due to suicide and accidental drug overdose. When examining these data, it is important to note that not one factor causes a person to die by suicide or other external cause of death. Risk factors should therefore not be considered in isolation. Instead they provide an insight into the complex interaction between biological, psychological and psychosocial factors which have contributed to these deaths. Demographic information such as age, sex and socioeconomic factors also provide additional context which can help guide public health responses to diseases and injuries.

It is important to note that the capture of information on associated causes of death (including psychosocial risk factors) is reliant on the documentation available for any given death. This in turn can be affected by the length of the coronial process for some types of death, the type of information available across different jurisdictions and administrative processes affecting report availability. As such, the information presented in this report reflects information contained within reports available on NCIS at the time of coding and does not necessarily reflect all causes associated with all deaths that have occurred.

Further data on associated causes of death can be found in the suicide datacube in downloads section of this publication. 

Associated causes for accidents, assaults and suicides

Deaths from external causes are grouped by intent, which includes accidents, assaults and suicides. Intent may also determine how a death is investigated and can therefore influence the type of information that can be captured and coded. High proportions of accidental drug overdoses and suicides have one or more associated causes. A much lower proportion of transport accidents have associated causes, as many risk factors for these deaths are environmental rather than health related and are therefore outside of the scope of ICD coding.  

The table below outlines the number of deaths by intent for coroner-certified deaths in 2019 with at least one contributing associated cause identified.

Deaths with one or more associated cause by intent type (a)(b)(c)(d)(e)(f)(g)(h)(i)(j)
Number of deaths with one or more associated causesProportion
Accidents (c)4,51975.8
Transport accidents (d)67845.5
Accidental drug overdose (e)1,19096.4
Suicide (f)(i)2,98590.0
Assault (g)15061.2
Other Intent (h)23178.3

(a) Causes of death data for 2019 are preliminary and subject to a revisions process. See the Data quality section of the methodology in this publication.
(b) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062).
(c) Accidents include ICD-10 codes V01-X59, Y85-Y86, Y89.9.
(d) Transport accidents ICD-10 codes V01-V99, Y85.
(e) Accidental drug overdose ICD-10 codes X40-X44.
(f) Suicide includes ICD-10 codes X60-X84, Y87.0.
(g) Assault includes ICD-10 codes X85-Y09, Y87.1.
(h) Other intent includes ICD-10 codes Y10-Y34, Y35-Y36, Y87.2, Y890-Y891. 
(i) Data presented for suicide is all certifier types.
(j) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue. 

Associated causes for suicides

Associated causes of death relating to suicide can be grouped into mental health conditions, chronic diseases and psychosocial risk factors. Each provide important insights that can help guide prevention and intervention activities.
 

Selected associated causes, proportion of total suicides, 2019 (a)(b)(c)(d)(e)(f)(g)(h)
Number of deathsProportion
Total suicides3,318100.0
Total suicides with reported mental and behavioural disorder (d)2,10963.6
Total Suicides with reported natural disease (e)1,78253.7
Total Suicides with reported psychosocial risk factors (f)2,12464.0
Total Suicides with any associated cause reported2,98590.0

(a)  Causes of death data for 2019 are preliminary and subject to a revisions process. See the Data quality section of the methodology in this publication.
(b) The data presented for intentional self-harm includes ICD-10 codes X60-X84 and Y87.0. Care needs to be taken in interpreting figures relating to intentional self-harm. See the Deaths due to intentional self-harm (suicide) section of the methodology in this publication.
(c) Data in this table indicates the number of deaths with each specified risk factor recorded. Risk factors may not be mutually exclusive, and therefore people with multiple psychosocial factors recorded will be counted in more than one category.
(d) Mental and behavioural disorder includes ICD-10 codes F00-F99
(e) Natural disease includes all disease and health related conditions with the exclusion of mental and behavioural disorders, injuries, and external causes. ICD-10 codes A00-E90 and G00-R99
(f) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062). 
(g) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue.  (h) Proportion is the number of deaths with selected associated cause divided by the total number of deaths in each cause grouping

Associated causes by sex

  • Mood disorders, including depression, were the most common co-morbidity, mentioned in 38.7% of male suicides and 46.3% of female suicides.
  • Substance use disorders (including intoxication) were reported in 30.6% of male suicides. Alcohol and other substances in blood were recorded in 22.3%.
  • Problems in spousal relationship circumstances was the most commonly mentioned psychosocial risk factor in deaths due to suicide.
  • Previous self-harm was reported in almost one-third (30.5%) of female suicides.
Top 10 associated causes, proportion of total suicides, by sex, 2019 (a)(b)(c)(d)(e)
MaleFemalePersons
Mood disorders (F30-F39)38.746.340.6
Mental and behavioural disorders due to psychoactive substance use (F10-F19)30.622.828.7
Problems in spousal relationship circumstances (Z630, Z635)27.022.425.9
Suicide ideation (R458)22.519.121.7
Findings of alcohol, drugs and other substances in blood (R78)22.316.520.9
Personal history of self-harm (Z915)17.530.520.7
Anxiety and stress-related disorders (F40-F48)16.125.618.4
Problems related to legal circumstances (Z650-Z654)11.45.49.9
Problems related to death of a family or primary support group member (Z634, Z818)8.49.28.6
Problems related to family circumstances (Z631-Z633, Z636-Z639)7.411.38.3

(a)  Causes of death data for 2019 are preliminary and subject to a revisions process. See the Data quality section of the methodology in this publication.
(b) The data presented for intentional self-harm includes ICD-10 codes X60-X84 and Y87.0. Care needs to be taken in interpreting figures relating to intentional self-harm. See the Deaths due to intentional self-harm (suicide) section of the methodology in this publication.
(c) Data in this table indicates the number of deaths with each specified risk factor recorded. Risk factors may not be mutually exclusive, and therefore people with multiple psychosocial factors recorded will be counted in more than one category. 
(d) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062). 
(e) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue.

Associated causes by age

The profile of associated causes in suicide varies when examined by age group. 

  • Problems related to substance use, such as harmful use and addiction, are more common among deaths due to suicide in younger cohorts.
  • Suicides in people aged 85 and over were most commonly associated with Limitation of activities due to illness and disability (Z736). 
  • Associated causes relating to chronic health conditions such as musculoskeletal disorders, cancer and heart disease, typically increase with increasing age.
  • Associated causes relating to economic and employment circumstances are most common among people aged 25-64.
Top 10 associated causes, proportion of total suicides, by age group, 2019 (a)(b)(c)(d)(e)(f)
 5-24 years25-44 years45-64 years65-84 years85+ yearsAll ages
Mood disorders (F30-F39)33.841.346.236.318.540.6
Mental and behavioural disorders due to psychoactive substance use (F10-F19)28.135.330.011.5np28.7
Problems in spousal relationship circumstances (Z630, Z635)29.632.924.58.15.425.9
Suicide ideation (R458)20.422.722.119.619.621.7
Findings of alcohol, drugs and other substances in blood (R78)22.326.019.610.55.420.9
Personal history of self-harm (Z915)25.422.321.012.77.620.7
Anxiety and stress-related disorders (F40-F48)15.220.419.715.27.618.4
Problems related to legal circumstances (Z650-Z654)8.111.510.96.49.9
Problems related to death of a family or primary support group member (Z634, Z818)10.47.38.89.68.78.6
Problems related to family circumstances (Z631-Z633, Z636-Z639)11.08.78.15.45.48.3
Problems related to employment and unemployment (Z56)5.69.210.01.57.7
Problems related to economic circumstances (Z594-Z598)2.76.210.95.67.0
Limitation of activities due to disability (Z736)np0.94.017.631.54.7
Diseases of the musculoskeletal system and connective tissue (M00-M99)np2.26.010.016.34.6
Malignant neoplasms  (C00-C97, D45-D46, D47.1, D47.3-D47.5)0.63.114.216.33.4
Ischaemic heart diseases (I20-I25)np0.73.210.816.33.1
Hypertensive diseases (I10-I15)0.63.08.112.02.6
Problems related to care-provider dependency (Z74)npnp2.212.00.8
(a)  Causes of death data for 2019 are preliminary and subject to a revisions process. See the Data quality section of the methodology in this publication.
(b) The data presented for intentional self-harm includes ICD-10 codes X60-X84 and Y87.0. Care needs to be taken in interpreting figures relating to intentional self-harm. See the Deaths due to intentional self-harm (suicide) section of the methodology in this publication.
(c) Data in this table indicates the number of deaths with each specified risk factor recorded. Risk factors may not be mutually exclusive, and therefore people with multiple psychosocial factors recorded will be counted in more than one category. 
(d) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062). 
(e) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue.
(f) The top ten multiple causes were captured for each age group then combined into one list, therefore the number of causes listed in the table is more than 10.

Associated causes for suicide by year

This section provides information on associated causes for suicide deaths for 2017, 2018 and 2019. These are the three reference periods for which expanded coding of associated causes has been undertaken. Over these three years, there have been small changes to the capture of information for specific codes, mostly those relating to psychosocial risk factors. As such, caution should be exercised when comparing changes between years. 

  • Mood disorders were the most common associated cause for suicide deaths across each of the three years (2017-19).
  • Likewise, substance use disorders were the second most common associated cause in each year.
  • Problems with spousal relationship circumstances (Z630, Z635) were the most common psychosocial risk factor identified each year and the third most common associated cause
     
Ranking of associated causes, number of deaths, 2017-2019 (a)(b)(c)(d)(e)
2017Rank2018Rank2019Rank
Mood disorders (F30-F39)1,54311,39211,3461
Mental and behavioural disorders due to psychoactive substance use (F10-F19)1,084293029522
Problems in spousal relationship circumstances (Z630, Z635)812378838583
Suicide ideation (R458)698668157204
Findings of alcohol, drugs and other substances in blood (R78)552767666935
Personal history of self-harm (Z915)781473446886
Anxiety and stress-related disorders (F40-F48)699557076117
Problems related to legal circumstances (Z650-Z654)31811258113288
Problems related to death of a family or primary support group member (Z634, Z818)3388271102849
Problems related to family circumstances (Z631-Z633, Z636-Z639)3289327827710

(a) All causes of death data from 2006 onward are subject to a revisions process - once data for a reference year are 'final', they are no longer revised. Affected data in this table are: 2017 (revised), 2018 and 2019 (preliminary). See the Data quality section of the methodology and Causes of Death Revisions, 2016 Final Data (Technical Note) and 2017 Revised Data (Technical Note) in Causes of Death, Australia, 2018 (cat. no. 3303.0).
(b) The data presented for intentional self-harm includes ICD-10 codes X60-X84 and Y87.0. Care needs to be taken in interpreting figures relating to intentional self-harm. See the Deaths due to intentional self-harm (suicide) section of the methodology in this publication.
(c) Data in this table indicates the number of deaths with each specified risk factor recorded. Risk factors may not be mutually exclusive, and therefore people with multiple psychosocial factors recorded will be counted in more than one category.
(d) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062). 
(e) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue. 

Associated causes for accidental drug poisonings

Associated causes of death also provide critical insights into deaths due to accidental drug poisonings.

  • Mental and behavioural disorders due to psychoactive substance use were recorded in over two-thirds of male deaths and over half of female deaths.
  • Ischaemic heart diseases and chronic lower respiratory diseases were recorded as associated causes for over 10% of drug overdose deaths. This indicates that these conditions were exacerbated by drug toxicity.
  • Problems related to legal circumstances (including recent release from prison) was recorded for 7.1% of accidental drug overdoses.
Most common associated causes, proportion of accidental drug poisoning, by sex, 2019 (a)(b)(c)(d)(e)
MaleFemalePersons
Mental and behavioural disorders due to psychoactive substance use (F10-F19)67.155.763.6
Mood disorders (F30-F39)26.032.528.0
Anxiety and stress-related disorders (F40-F48)16.523.518.6
Ischaemic heart diseases (I20-I25)16.19.514.1
Chronic lower respiratory diseases (J40-J47)9.714.011.0
Viral hepatitis (B15-B19)8.711.99.6
Diseases of the musculoskeletal system and connective tissue (M00-M99)7.212.78.8
Heart failure and other ill-defined heart diseases (I50-I51)8.46.37.8
Schizophrenia, schizotypal and delusional disorders (F20-F29)8.25.87.5
Pain (R52)6.010.67.4
Problems related to legal circumstances (Z650-Z654)8.24.57.1

(a) Causes of death data for 2019 are preliminary and subject to a revisions process. See the Data quality section of the methodology in this publication.
(b) Accidental drug overdose includes ICD-10 codes X40-X44.
(c) Data in this table indicates the number of deaths with each specified risk factor recorded. Risk factors may not be mutually exclusive, and therefore people with multiple psychosocial factors recorded will be counted in more than one category. 
(d) For a complete list of psychosocial risk factors, refer to explanatory note Annex listing: Psychosocial codes (exclusions and inclusions) in Psychosocial risk factors as they relate to coroner-referred deaths in Australia (cat. No. 1351.0.55.062). 
(e) Care needs to be taken when interpreting data derived from Victorian coroner-referred deaths including suicide. See Technical note: Victorian additional registrations and time series adjustments for detailed information on this issue.