3303.0 - Causes of Death, Australia, 2015 Quality Declaration 
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 04/04/2017   
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YEAR OF OCCURRENCE

Year of occurrence versus year of registration

The Australian Bureau of Statistics generally present cause of death data on the basis of registration year. In Australia, most deaths are registered in the calendar year in which they occur, and so share the same year of registration and year of occurrence. However, a small proportion of deaths occur in a given calendar year which are not registered until subsequent years. Approximately 4% to 7% of deaths which occurred from 1997 onwards were registered in subsequent years, and as such will have a year of occurrence that is different to the year of registration.

Year of registration data offers a timely and stable dataset, which will not be altered over time. Conversely, a count of deaths by year of occurrence is more fluid. As deaths are registered and processed, the number of deaths on a year of occurrence basis may continue to rise, and may do so for many years. For example, there are nine currently known deaths which occurred in Australia between 1920 and 1950, which were not registered until 2000 or later. However, despite its fluidity, data presented on a year of occurrence basis has a number of benefits. These include:
  • offering a true reflection of the number of deaths that occurred in a given calendar year and enabling the examination of data that are free from administrative artefacts, such as registration and processing lags;
  • enabling analysis of seasonal patterns in causes of death;
  • facilitating international comparisons, as well as domestic inter-agency comparisons, which may report data based on year of occurrence.

Year of occurrence in time series data

Registration lags are more likely among those deaths which are referred to a coroner. These include many deaths due to external causes (such as suicides, transport accidents, and assaults). From 1997 onwards, between 6% and 13% of coroner-certified deaths experienced a registration lag, compared to 4% to 6% of deaths certified by a doctor. As the registration lags have more potential to impact time series for external cause deaths, the potential for year of occurrence data to smooth out these effects is also greater.

Figure 1 shows a time series for suicide deaths on a year of occurrence and year of registration basis. It illustrates the advantage that year of occurrence data has in smoothing the stepwise year on year changes that are noticeable in the year of registration data. In areas that are very closely monitored, such as counts of suicide deaths, this type of analysis can prevent over interpretation of year on year changes that are actually administrative artefacts rather than true changes in counts.

Graph Image for Year of registration vs year of occurrence patterns for suicide deaths, 2006-2014

Footnote(s): (a) The data by year of occurrence are based on the year in which the death occurred. A proportion of deaths occur in a given calendar year but are not registered until subsequent years. The year of death data presented in this table may increase in death counts over time, however any changes are likely to be minimal. (b) All causes of death data from the 2006 reference year 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: 2006-2013 (final) and 2014 (revised). See Explanatory Notes 52-55, A More Timely Annual Collection: Changes to ABS Processes (Technical Note) and Causes of Death Revisions, 2013 and 2014 (Technical Note) in this publication. (c) Intentional self-harm [suicide], includes ICD-10 codes X60-X84 and Y87.0. Care needs to be taken in interpreting figures relating to suicide. See Explanatory Notes 85-93.

Source(s): Year of registration vs year of occurrence patterns for suicide deaths, 2006-2014-Patterns in suicide deaths by year of occurrence and registration, 2006-2014



Seasonal patterns in causes of death

Considering deaths by occurrence date also offers a more accurate depiction of seasonal patterns in causes of death. One cause of death known to have a strong seasonal pattern is influenza. In 2014, there were 260 deaths in Australia that were due to influenza. Of these, 93 (35.8%) occurred in the month of August and a further 78 (30%) occurred in September. Figure 2 shows the monthly counts of deaths due to influenza by occurrence and by registration date. This clearly highlights that many of the deaths that occurred in August and September were registered in September and October, a month after the virus was at its most virulent.

During the colder months (May to October) the Department of Health releases Australian Influenza Activity Updates on a fortnightly basis, to monitor potential flu outbreaks. Monitoring of diseases is often focussed on quickly identifying epidemics, so identifying an unusually high prevalence of a disease is reliant on a good understanding of previous seasonal patterns. The timing of flu deaths on a month of death (as opposed to month of registration) basis, provides this more accurate depiction of previous seasonal patterns.

Graph Image for Deaths due to influenza, by 2014 month of occurrence and registration

Footnote(s): (a) The data by month of occurrence presented in this table may be affected by lagged registrations. There may be an increase in death counts over time, however any changes are likely to be minimal. (b) All causes of death data from the 2006 reference year onward are subject to a revisions process - once data for a reference year are 'final', they are no longer revised. The month of registration data presented in this table are revised.See Explanatory Notes 52-55, A More Timely Annual Collection: Changes to ABS Processes (Technical Note) and Causes of Death Revisions, 2013 and 2014 (Technical Note) in this publication.

Source(s): Deaths due to influenza, by 2014 month of occurrence and registration-Patterns in deaths due to influenza, by 2014 month of occurrence and registration




LAGGED REGISTRATIONS: VARIATIONS BY CAUSE OF DEATH AND INDIGENOUS STATUS

In Australia, the number of deaths which experience a registration lag is relatively low (currently 6.7% for deaths which occurred in 2014). It is very low when considering deaths registered two or more years after the occurrence of the death (around 0.1% to 0.2%). However, as previously shown, variations in the magnitude of registration lags can occur for particular causes of death and in certain subsets of the population.

The table below shows the number of deaths by cause that occurred in Australia in 2014, and which were registered in 2014 or 2015. The table indicates a higher proportion of lagged registrations for causes of death relating to the perinatal period (13.9%), causes not elsewhere classified (10.4%), congenital malformations, deformations and chromosomal abnormalities (9.2%) and external causes of death (9.1%). There are differences in the administrative processes that surround these deaths which are likely to influence the timeliness of death registration.

Among deaths of Aboriginal and Torres Strait Islander Australians, 12.2% experienced a lagged registration, compared to 5.4% for the non-Indigenous population. The proportion of deaths with a lagged registration was highest for Aboriginal and Torres Strait Islander persons who resided in very remote areas (21.4% of deaths had a lagged registration, compared with 7.8% for those in major cities). The higher proportion in very remote areas may be influenced by more limited access to services.

NB This data focuses on Aboriginal and Torres Strait Islander deaths for which the usual residence of the deceased was in New South Wales, Queensland, South Australia, Western Australia or the Northern Territory. Data for Victoria, Tasmania and the Australian Capital Territory have been excluded in line with national reporting guidelines (for information on issues with Aboriginal and Torres Strait Islander identification, see Explanatory Notes 56-66).



7.2 SELECTED CAUSES: 2014 Year of Occurrence(a)(b)(c)

Registered in 2014
Registered in 2015
Total as at 2015
Lagged Registrations
Cause of death and ICD-10 code
no.
no.
no.
%

ABORIGINAL AND TORRES STRAIT ISLANDER PEOPLE(d)(e)

All Causes
2 383
331
2 714
12.2

ALL PERSONS(g)

All Causes(e)
143 558
10 237
153 795
6.7
Certain infectious and parasitic diseases (A00-B99)
2 577
188
2 765
6.8
Neoplasms (C00-D48)
42 032
2 845
44 877
6.3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
499
27
526
5.1
Endocrine, nutritional and metabolic diseases (E00-E90)
5 815
450
6 265
7.2
Mental and behavioural disorders (F00-F99)
8 499
560
9 059
6.2
Diseases of the nervous system (G00-G99)
7 660
504
8 164
6.2
Diseases of the circulatory system (I00-I99)
42 179
2 876
45 055
6.4
Diseases of the respiratory system (J00-J99)
13 013
844
13 857
6.1
Diseases of the digestive system (K00-K93)
5 119
418
5 537
7.5
Diseases of the skin and subcutaneous tissue (L00-L99)
456
31
487
6.4
Diseases of the musculoskeletal system and connective tissue (M00-M99)
1 175
86
1 261
6.8
Diseases of the genitourinary system (N00-N99)
3 040
205
3 245
6.3
Certain conditions originating in the perinatal period (P00-P96)
477
77
554
13.9
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
545
55
600
9.2
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
1 426
166
1 592
10.4
External causes of morbidity and mortality (V01-Y98)
9 010
904
9 914
9.1

(a) The data presented in this table is based on deaths which occurred in 2014. A proportion of deaths occur in a given calendar year but are not registered until subsequent years. Care should be taken in interpreting the year of occurrence data presented in this table, as small increases may occur with further processing.
(b) All causes of death data from the 2006 registration year 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: 2014 (revised) and 2015 (preliminary). See Explanatory Notes 52-55, A More Timely Annual Collection: Changes to ABS Processes (Technical Note) and Causes of Death Revisions, 2013 and 2014 (Technical Note) in this publication.
(c) See Explanatory Notes 68-95 for further information on specific issues relating to time series and 2015 data.
(d) See Explanatory Notes 56-66 for further information on interpreting data relating to deaths of Aboriginal and Torres Strait Islander people.
(e) The deaths data for Aboriginal and Torres Strait Islander persons presented in this table is based on persons whose usual residence was in New South Wales, Queensland, South Australia, Western Australia or the Northern Territory. Data for Victoria, Tasmania and the Australian Capital Territory have been excluded, in line with national reporting guidelines. For further information on issues with Aboriginal and Torres Strait Islander identification, see Explanatory Notes 56-66).
(f) Includes deaths due to Diseases of the eye and adnexa (H00-H59), Diseases of the ear and mastoid processes (H60-H95) and Pregnancy, childbirth and the puerperium (O00-O99).
(g) Includes total deaths for Australia.