3303.0 - Causes of Death, Australia, 2017 Quality Declaration 
Latest ISSUE Released at 11:30 AM (CANBERRA TIME) 26/03/2019   
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CAUSES OF DEATH REVISIONS, 2015 FINAL DATA
This note was released on 26 March, 2019.


OVERVIEW

1
Deaths that are referred to a coroner can take time to be fully investigated. To account for this, the ABS has implemented a revisions process for those deaths where coronial investigations remained open at the time a preliminary cause of death was assigned. Data are deemed preliminary when first published, revised when published the following year and final when published after a second year. This technical note focusses specifically on final data for 2015 coroner-certified deaths.

2
The revisions process has been applied to all reference periods from 2006 onwards. Revisions are one of two measures implemented to enable timely data to be released on coroner-certified deaths (see Explanatory Notes 52-60 for further information). The second measure, referred to as 'open coding', ensures that all available documentation is taken into account when assigning a cause of death to coronial cases that are yet to be finalised. The combination of these two measures, along with ongoing enhancements in the timeliness and completeness of documentation on the National Coronial Information System (NCIS), have resulted in significant improvements to the quality of preliminary Causes of Death data.

3
There are three main improvements to the Causes of Death data which are gained through the revisions process. Firstly, for deaths from natural causes a more specified condition may be identified. For example, a death may be coded to a condition such as cardiac arrest at preliminary coding, but with the later addition of an autopsy report, an underlying ischaemic heart condition could be identified. Secondly, for deaths from external causes (accidents, assaults and suicides) more information might be provided on mechanism. For example, a death coded to an unspecified accident with a fracture of hip, may later be found to have been caused by a fall down steps. Lastly, external causes may also have the intent of death updated through revisions. For example, a drug overdose where the intent of death was not determined at preliminary coding, may be updated to an intentional drug overdose when a coronial finding has been made.

CHANGES TO CAUSE OF DEATH PROCESSING AND REVISIONS

4 Up until the 2014 reference period, the ABS released the annual Causes of Death dataset 15 months after the end of each reference period (i.e. data for the 2014 reference period was published in March 2016). The 2015 release of Causes of Death, Australia was released six months earlier, representing a significant change in processing of the national mortality dataset.

5 Bringing forward the release of Causes of Death data meant that preliminary coding of coroner-certified deaths needed to occur approximately six months earlier than in previous years. Given that the timeliness of report availability on the NCIS is critical to the ABS's ability to assign specific cause of death codes, considerable analysis was undertaken to ensure the preliminary dataset would be of sufficient quality to be fit for purpose. See Technical Note 1 A More Timely Annual Collection: Changes to ABS Processes in the 2015 publication.

6 With earlier release of preliminary data, there is now a period of 30 months between the release of preliminary and final data. The table below shows the impact of this changed revisions process at the ICD-10 chapter level. As anticipated, the earlier release of data for the 2015 reference period resulted in more deaths assigned at preliminary coding to the Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (Symptoms and signs) (R00-R99) chapter. Consequently, a larger number of deaths have been reassigned from R00-R99 to other chapters over the 2015 revisions period compared to previous years (11.3% in 2014 and 34.3% in 2015). The redistribution of deaths to more specified ICD-10 codes is discussed in more detail below.

Causes of death revisions for 2011 to 2015 - percentage change from preliminary to final data, by selected ICD-10 chapter, all certified deaths (a)(b)(c)

2011
2012
2013
2014
2015
Cause of death and ICD-10 code
%
%
%
%
%

Certain infectious and parasitic diseases (A00-B99)
0.0
0.0
0.2
0.2
0.5
Neoplasms (C00-D48)
0.0
0.0
0.0
0.0
0.1
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
0.2
0.0
0.4
0.0
0.6
Endocrine, nutritional and metabolic diseases (E00-E90)
0.0
0.0
0.1
0.2
0.8
Mental and behavioural disorders (F00-F99)
0.1
-0.1
-0.1
0.0
0.1
Diseases of the nervous system (G00-G99)
0.0
0.2
0.2
0.2
0.6
Diseases of the circulatory system (I00-I99)
0.0
0.2
0.0
0.0
0.6
Diseases of the respiratory system (J00-J99)
-0.1
0.0
0.1
0.1
0.4
Diseases of the digestive system (K00-K93)
0.2
0.0
0.0
0.2
1.0
Diseases of the skin and subcutaneous tissue (L00-L99)
0.5
-0.3
0.0
0.2
0.8
Diseases of the musculoskeletal system and connective tissue (M00-M99)
0.2
-0.1
0.3
0.2
1.2
Diseases of the genitourinary system (N00-N99)
-0.1
0.0
-0.1
0.0
0.5
Certain conditions originating in the perinatal period (P00-P96)
-0.3
0.4
-0.5
0.6
0.5
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
0.7
0.4
0.3
1.0
1.4
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
-11.7
-11.2
-5.5
-11.3
-34.3
External causes of morbidity and mortality (V01-Y98)
0.9
0.7
0.4
0.9
0.8

(a) Excludes deaths coded to H00-H59, H60-H95, and O00-O99 as these causes account for a small number of deaths and few are reassigned over the revisions process.
(b) Since 2015 the release of Causes of Death, Australia has occurred 6 months earlier, representing a significant change in processing of the national mortality dataset. For further information regarding changes to ABS coding processes, see A More Timely Annual Collection: Changes to ABS Processes (Technical Note) in Causes of Death, Australia, 2015 (cat. no. 3303.0).
(c) This table includes both doctor and coroner-certified deaths.

7 The table below provides the counts of deaths by ICD-10 chapter for the 2015 reference period across the revisions process. Revisions are most likely to result in decreases in the number of deaths assigned to Symptoms and signs (R00-R99) with corresponding increases in other chapters.

8 Deaths which are originally coded to the Symptoms and signs (R00-R99) chapter can be reassigned to specific natural or external causes of death. The majority of those reassigned were found to be deaths from natural causes (67.8%), with Diseases of the circulatory system (I00-I99) being the most common natural cause. Of those reassigned to external causes of death, 17 were deaths due to intentional self-harm (suicide).


Causes of death revisions for 2015 - preliminary, revised and final, by selected ICD-10 chapter, all certified deaths (a)(b)

2015 reference year
Change (preliminary to final)
P
R
F
Cause of death and ICD-10 code
no
no
no
no
%

Certain infectious and parasitic diseases (A00-B99)
2,843
2,855
2,857
14
0.5
Neoplasms (C00-D48)
4,6551
46,574
46,595
44
0.1
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
522
525
525
3
0.6
Endocrine, nutritional and metabolic diseases (E00-E90)
6,638
6,677
6,689
51
0.8
Mental and behavioural disorders (F00-F99)
9,595
9,607
9,605
10
0.1
Diseases of the nervous system (G00-G99)
8,460
8,492
8,510
50
0.6
Diseases of the circulatory system (I00-I99)
45,392
45,605
45,642
250
0.6
Diseases of the respiratory system (J00-J99)
14,314
14,365
14,377
63
0.4
Diseases of the digestive system (K00-K93)
5,667
5,708
5,724
57
1.0
Diseases of the skin and subcutaneous tissue (L00-L99)
530
531
534
4
0.8
Diseases of the musculoskeletal system and connective tissue (MOO-M99)
1,302
1,306
1,318
16
1.2
Diseases of the genitourinary system (N00-N99)
3,535
3,544
3,554
19
0.5
Certain conditions originating in the perinatal period (P00-P96)
546
548
549
3
0.5
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
581
587
589
8
1.4
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
1,986
1,452
1,305
-681
-34.3
External causes of morbidity and mortality (V01-Y98)
10,573
10,659
10,662
89
0.8
Total(a)
159,052
159,052
159,052
na
na

na not applicable
(a) Includes deaths coded to H00-H59, H60-H95, and O00-O99.
(b) This table includes both doctor and coroner-certified deaths.

IMPACT OF REVISIONS - UNDERLYING CAUSE OF DEATH

9The expected outcome of the revisions process is to improve data quality. Enhancements to underlying cause of death data quality may include updates to either mechanism or intent or identifying an underlying cause where not previously possible. While the revisions process has a minimal impact at the chapter level (with the exception of R00-R99), data improvements become more apparent when considering movements within individual chapters.

10 The table below shows data for coroner-certified deaths only at the sub-chapter level. There were 61.5% of coroner-certified deaths with an unspecified mechanism reassigned through the full revisions process. The majority of these records had no change in intent, but were assigned a more specific mechanism. For example, a suicide death where the mechanism was unspecified at preliminary coding (Intentional self-harm by unspecified means (X84)) may be reassigned to a suicidal drowning (Intentional self-harm by drowning (X71)) during the revisions process when an autopsy becomes available for analysis.

11 The table below demonstrates that for deaths which were certified by a coroner, the number of cases assigned to Other ill-defined and unspecified causes of mortality (lll-defined causes of mortality) (R99) decreased by 49.4% over the full revisions process.


Causes of death revisions for 2015 - preliminary, revised and final, by selected causes of death, coroner-certified deaths (a)

2015 reference year
Change (preliminary to final)
P
R
F
Cause of death and ICD-10 code
no
no
no
no
%

Other ill-defined and unspecified causes of mortality (R99)
1,427
872
722
-705
-49.4
Unspecified mechanism (X59, X84, Y09)
387
204
149
-238
-61.5
Accidental exposure to other specified factors (X59)
302
164
132
-170
-56.3
Intentional self-harm by unspecified means (X84)
40
13
7
-33
-82.5
Assault by unspecified means (Y09)
45
27
10
-35
-77.8
Event of undetermined intent (Y10-Y34)
236
170
164
-72
-30.5

(a) This table includes coroner-certified deaths only.

12 The table below shows changes at the sub-chapter level for the 2015 reference period, with a focus on the External causes of morbidity and mortality (V01-Y98) chapter.

Notable increases in deaths due to external causes over the full revisions process include:
  • Falls (W00-W19) increased by 140 deaths. For many of the deaths reassigned to a fall, the type of injury was known at preliminary coding (e.g. broken hip), yet the mechanism was unknown (e.g. the broken hip was caused by an unspecified accident). Over the full revisions process, additional information about the nature of the mechanism became available allowing these records to be reassigned to a fall (e.g. the broken hip was identified to be due to a fall down stairs).
    • Accidental drug poisoning (X40-X44) increased by 102 deaths. Many of the deaths reassigned to an Accidental drug poisoning (X40-X44) were originally assigned to Ill-defined causes of mortality (R99). Drug-induced deaths require intensive investigations to accurately determine the cause and manner in which the death occurred. Over time, as investigations are finalised, more information on the NCIS becomes available allowing these deaths to be reassigned to Accidental drug poisonings (X40-X44).

    • Intentional self-harm (X60-X84, Y870) increased by 66 deaths. The majority of Intentional self-harm (X60-X84, Y870) deaths reassigned over the revisions process were originally assigned to deaths from an Undetermined intent (Y10-Y34) or Accidental drug poisoning (X40-X44).
    • Intentional drug poisoning (X60-X64) increased by 41 deaths. A large number of Intentional drug poisonings (X60-X64) were reassigned due to updated intent information becoming available (especially the final coronial finding). Most Intentional drug poisonings (X60-X64) were reassigned from Accidental drug poisoning (X40-X44).
    • Assault (X85-Y09) increased by 17 deaths. Most deaths were reassigned to Assault (X85-Y09) where updated intent information became available. The majority of deaths reassigned to Assault (X85-Y09) were originally assigned to Ill-defined causes of mortality (R99) or Exposure to unspecified factor causing other and unspecified injury (X599).


    Causes of death revisions for 2015 - preliminary, revised and final, by ICD-10 selected causes, all certified deaths (a)(b)(c)

    2015 reference year
    Change (preliminary to final)
    P
    R
    F
    Cause of death and ICD-10 code
    no
    no
    no
    no
    %

    Sudden infant death syndrome (R95)
    21
    40
    45
    24
    114.3
    Other ill-defined and unspecified causes of mortality (R99)
    1,480
    925
    775
    -705
    -47.6
    Transport accidents (V01-V99)
    1,383
    1,419
    1,437
    54
    3.9
    Car occupant injured in transport accident (V40-V49)
    712
    732
    762
    50
    7.0
    Other land transport accidents (V80-V89)
    110
    90
    66
    -44
    -40.0
    Other external causes of accidental injury (W00-X59)
    5,279
    5,354
    5,384
    105
    2.0
    Falls (W00-W19)
    2,474
    2,565
    2,614
    140
    5.7
    Accidental drug poisoning (X40-X44)
    1,095
    1,192
    1,197
    102
    9.3
    Exposure to unspecified factor (X59) (a)
    1,012
    877
    850
    -162
    -16.0
    Intentional self-harm (X60-X84, Y870) (b)
    3,027
    3,065
    3,093
    66
    2.2
    Intentional drug poisoning (X60-X64)
    430
    455
    471
    41
    9.5
    Intentional self-harm by hanging or suffocation (X70)
    1,705
    1,709
    1,712
    7
    0.4
    Intentional self-harm by drowning and submersion (X71)
    51
    55
    56
    5
    9.8
    Intentional self-harm by sharp object (X78)
    90
    97
    101
    11
    12.2
    Intentional self-harm by jumping from a high place (X80)
    129
    140
    143
    14
    10.9
    Intentional self-harm by jumping or lying before moving object (X81)
    101
    105
    108
    7
    6.9
    Intentional self-harm by crashing of motor vehicle (X82)
    35
    38
    41
    6
    17.1
    Intentional self-harm by unspecified means (X84)
    40
    13
    7
    -33
    -82.5
    Assault (X85-Y09)
    265
    274
    282
    17
    6.4
    Event of undetermined intent (Y10-Y34)
    237
    171
    165
    -72
    -30.4

    (a) Deaths assigned to Exposure to unspecified factor (X59) are more likely to be certified by a doctor. As such, % change shown in this table differs from the table presented above.
    (b) Care should be taken in interpreting figures relating to intentional self-harm. See Explanatory Notes 91-100.
    (c) This table includes both doctor and coroner-certified deaths. Figures presented in this table may show differences to the table above.

    13 Various improvements to the availability and timeliness of national mortality information have been undertaken over several years. One major improvement undertaken by the NCIS is the more timely upload of reports and information for open coroner cases. This information can then be used at an earlier point by the ABS to improve open coding data quality. Earlier availability of reports can reduce the number of deaths from Ill-defined causes of mortality (R99) present in the dataset at preliminary coding. The improved timeliness in report attachment on the NCIS was a key factor in enabling the ABS to bring forward the publication of annual causes of death data. A comparison of 2014 and 2015 final Ill-defined causes of mortality (R99) counts for coroner-certified deaths indicate a substantial reduction, from 956 in 2014 to 722 in 2015.

    14 There are some specific causes of death that may be more impacted by the changed revisions process. These include Accidental drug poisoning (X40-X44), Intentional drug poisoning (X60-X64) and Sudden Infant Death Syndrome (SIDS) (R95). Deaths from these causes require intensive investigations to accurately determine the cause and manner in which the death occurred. Therefore some key reports may not be available on the NCIS when preliminary coding of these deaths occur. These deaths are particularly sensitive to the revisions process in that more detailed information regarding the context of the death is often gained over time as information from investigations becomes available on the NCIS.

    15 The number of deaths assigned to SIDS (R95) increased by 24 deaths between preliminary and final coding. All were assigned to Ill-defined causes of mortality (R99) at preliminary. While revised data captures a significant proportion of SIDS deaths, the rules for classifying these deaths are influenced by specific terminology used in coronial findings. Data users should consider combining deaths coded to SIDS in conjunction with infant deaths coded to Ill-defined causes of mortality (R99) when seeking to understand how many sudden unexplained deaths in infants occur in total.

    16 Over the revisions process there was an increase of 136 drug poisoning deaths (includes all intents: Accidental (X40-X44), Intentional (X60-X64) and Undetermined (Y10-Y14)). Accidental drug poisoning (X40-X44) contributed the largest increase across intent types for drug poisonings over the 2015 revisions process, accounting for 75.0% of the increase.

    17 The process for determining that a death was caused by Accidental drug poisoning (X40-X44) is complex as multiple factors such as drug type, intent and presence of pre-existing natural disease need to be considered. Just over half (52.3%) of the deaths reassigned to an Accidental drug poisoning (X40-X44) were initially coded to Ill-defined causes of mortality (R99). These deaths typically did not have toxicology and/or pathology reports available on the NCIS at the time of preliminary coding. A further 21.9% of those reassigned to this category were initially coded to Undetermined drug poisoning (Y10-Y14) followed by Intentional drug poisoning (X60-X64) (6.5%).

    18 Determining deaths from Intentional drug poisoning (X60-X64) is similarly complex. One-third (33.3%) of deaths reassigned to an Intentional drug poisoning (X60-X64) were coded at preliminary as Accidental drug poisoning (X40-X44) deaths. These deaths typically had only an initial police report available at preliminary coding, where details on the intent of death can be unclear. A further 20.0% of reassigned Intentional drug poisoning (X60-X64) deaths were initially coded to Ill-defined causes of mortality (R99). These deaths typically did not have police, toxicology and/or pathology reports available on NCIS at the time of preliminary coding.

    IMPACT OF REVISIONS - ASSOCIATED CAUSES OF DEATH

    19 The revisions process has traditionally focussed on improving specificity of the underlying cause of death. More recently, there has been growing interest in associated cause statistics which can provide a more complete picture of the diseases and/or circumstances that contributed to a death. Associated causes include the type of injuries sustained by a deceased person, drug type in a drug-induced death (e.g. heroin, cannabis), chronic disease (e.g. cancer) and mental and behavioural disorders (e.g. depression, anxiety). The ABS has maximised the use of improved report attachment on the NCIS to enhance associated cause statistics through the revisions process. Analysis of associated causes of death can better enable targeted policy and prevention initiatives, especially for those deaths which are deemed preventable. For this reason, the revisions process typically focusses on associated cause of death enhancements for two key areas - drug specification in drug-induced deaths and mental and behavioural disorders implicated in deaths from external causes.

    Changes to drug types for drug-induced deaths

    20 There are multiple complex factors which need to be considered when a death is certified as drug-induced. The timing between the death and toxicology testing can influence the levels and types of drugs detected, making it difficult to determine the true level of a drug at the time of death. Individual tolerance levels may also vary considerably depending on multiple factors, including sex, body mass and a person’s previous exposure to a drug. Consideration of contextual factors around the death must also be considered such as pre-existing natural disease and reports from friends and families regarding the circumstances surrounding death. For these reasons, the certification of a death as being drug-induced can take significant time to complete, making these deaths particularly sensitive to the revisions process.

    21 Policies directed at reducing drug-induced deaths employ a variety of strategies depending on drug type. Information regarding the type of drug(s) in a drug-induced death can often depend on the availability of an autopsy, toxicology or coronial finding report. When these reports are not available, the drug type is unknown and coded to Other and unspecified drugs, medicaments and biological substances (Unspecified drug) (T509). Importantly, deaths coded with an Unspecified drug (T509) are still counted as a drug-induced death at preliminary output, but they may be enhanced with more specific information about drug type via the revisions process.

    22 From preliminary to final, the number of drug-induced deaths in 2015 where drug type was not specified (T509) decreased from 92 to five. As a result there was an increase in the number of specified drug types (see table below) with Benzodiazepines (T424) recording the largest increase (159 mentions) when analysed by single drug type. This was followed by Other opioids (T402) (96 mentions) and Other and unspecified antidepressants (T432) (89 mentions).


    Changes to associated cause drug types for 2015 - preliminary, revised and final, coroner-certified deaths (a)

    2015 reference year
    Change (preliminary to final)
    P
    R
    F
    Cause of death and ICD-10 code
    no
    no
    no
    no
    %

    Benzodiazepines (T424)
    544
    668
    703
    159
    29.2
    Other opioids (T402)
    492
    583
    588
    96
    19.5
    Other and unspecified antidepressants (T432)
    250
    312
    339
    89
    35.6
    Other and unspecified antipsychotics and neuroleptics (T435)
    115
    166
    182
    67
    58.3
    Psychostimulants with abuse potential (T436)
    232
    287
    289
    57
    24.6
    Tricyclic and tetracyclic antidepressants (T430)
    151
    198
    203
    52
    34.4
    4-Aminophenol derivatives (T391)
    131
    158
    177
    46
    35.1
    Other synthetic narcotics (T404)
    220
    257
    265
    45
    20.5
    Cannabis (derivatives) (T407)
    95
    129
    139
    44
    46.3
    Heroin (T401)
    266
    300
    308
    42
    15.8

    (a) This table includes coroner-certified deaths only.

    Changes to associated causes for intentional self-harm and accidental drug poisonings

    23 Associated causes of death may provide important contextual information for deaths due to Intentional self-harm (X60-X84, Y870). At preliminary coding, 71.6% of suicides in 2015 had associated causes mentioned as contributory factors to death. Through the revisions process, this proportion increased to 84.0%. The table below shows the top five increases for associated causes of death as they relate to Intentional self-harm (X60-X84, Y870). Mood disorders (F30-F39), which include depression and bipolar affective disorder, were the most common associated causes of death identified during the revisions process, followed by Suicide ideation (R458) and Mental and behavioural disorders due to psychoactive substance use (F10-F19).


    Changes to intentional self-harm associated causes for 2015 - preliminary, revised and final, coroner-certified deaths (a)

    2015 reference year
    Change (preliminary to final)
    P
    R
    F
    Cause of death and ICD-10 code
    no
    no
    no
    no
    %

    Mood disorders (F30-F39)
    1,039
    1,249
    1,353
    314
    30.2
    Suicide ideation (R458)
    504
    657
    752
    248
    49.2
    Mental and behavioural disorders due to psychoactive substance use (F10-F19)
    521
    680
    765
    244
    46.8
    Findings of drugs and other substances, not normally found in blood (R78)
    427
    544
    603
    176
    41.2
    Anxiety and stress-related disorders (F40-F48)
    278
    378
    449
    171
    61.5

    (a) This table includes coroner-certified deaths only.

    24 Associated causes of death may also provide critical insights into deaths due to Accidental drug poisoning (X40-X44). The table below shows the top five increases for associated causes of death as they relate to Accidental drug poisoning (X40-X44). As additional evidence and documentation was added to the NCIS there were 144 accidental drug overdoses where a Mental and behavioural disorders due to psychoactive substance use (F10-F19) such as addiction or chronic substance misuse was identified. Deaths in which Mood disorders (F30-F39) and Anxiety and stress-related disorders (F40-F48) were mentioned increased by 85 and 61 respectively.


    Changes to accidental drug poisoning associated causes for 2015 - preliminary, revised and final, coroner-certified deaths (a)

    2015 reference year
    Change (preliminary to final)
    P
    R
    F
    Cause of death and ICD-10 code
    no
    no
    no
    no
    %

    Mental and behavioural disorders due to psychoactive substance use (F10-F19)
    393
    497
    537
    144
    36.6
    Mood disorders (F30-F39)
    176
    236
    261
    85
    48.3
    Anxiety and stress-related disorders (F40-F48)
    81
    118
    142
    61
    75.3
    Schizophrenia, schizotypal and delusional disorders (F20-F29)
    53
    79
    86
    33
    62.3
    Disorders of adult personality and behaviour (F60-F69)
    11
    21
    33
    22
    200.0

    (a) This table includes coroner-certified deaths only.