TECHNICAL NOTE 2 CAUSES OF DEATH REVISIONS PROCESS


OVERVIEW

1 There have been two process improvements implemented by the ABS in recent years which have improved the quality of data, with the biggest improvements seen in the external cause chapter and for coroner certified deaths. These processes were both implemented for the 2008 reference year. The first was a revisions process outlined in Explanatory Notes 29-33 and the second was in relation to the use of additional information from the medical certificate cause of death and from information stored within reports on the NCIS, see Explanatory Notes 56-67 for further information. The following technical note outlines the impact of these two processes.

2 Previous publications of Causes of Death, Australia indicated that all coroner certified deaths registered after 1 January 2007 are now subject to a revisions process. Data are deemed preliminary when published for the first time, revised when published the following year and final when published two years after initial publication. In order to improve the quality of historical data, the 2006 reference year data has also been revised (see Technical Notes, Causes of Death Revisions, 2006 in the Causes of Death, Australia, 2010 release). Therefore in the current release 2006 to 2010 data are final, 2011 data are revised, and 2012 data are preliminary. The 2011 and 2012 data will be subject to further revisions. Data for the 2006 reference year has not been included for analysis in this technical note because the revisions process was different to that of the 2007-2011 reference years.


PRELIMINARY CODING

3 Table 1 illustrates preliminary, revised and final data for the 2010 reference year, for deaths certified by a coroner, by selected causes. Data are presented by the number of deaths allocated to codes which have no specificity of cause (R99), mechanism (X59, X84 and Y09) or intent (Y10-Y34) (whether the injury was inflicted purposefully or not). As indicated in Table 1, the number of deaths coded to these ill-defined causes decreases as they progress through the revisions process and are assigned more specific codes.

TABLE 1: SELECTED CAUSES OF DEATH, DEATHS CERTIFIED BY A CORONER - PRELIMINARY, REVISED AND FINAL DATA, AUSTRALIA, 2010
	2010 reference year			Change (prelim to final)
	P	R	F
Cause of death and ICD-10 code	no	no	no	no	%
R99	504	367	334	-170	-33.7%
X59, X84, Y09	93	89	54	-39	-41.9%
Y10-Y34	680	454	306	-374	-55.0%

IMPACT OF REVISIONS

4 Table 2 provides information on the impact of the revisions process for the 2010 reference year at the ICD-10 chapter level. As expected, the chapter to record the greatest change in the 2010 reference year is Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), which decreased by 160 deaths from preliminary to final coding. The cause of death codes in this chapter are considered to be 'ill-defined', such that deaths are coded to this chapter in the absence of information which would enable a more specific code to be applied. As the status of coroner cases moves from open to closed, and more information becomes available to the ABS for the coding of these deaths, R00-R99 deaths are able to be coded to more specific causes. The bulk of the 160 deaths from this chapter were re-coded to External causes of morbidity and mortality (V01-Y98) through the revisions process. This chapter increased by 106 deaths (1.2%) from preliminary to final coding for the 2010 reference year.

TABLE 2 - CAUSES OF DEATH REVISIONS , (PRELIMINARY, REVISED, FINAL) - by ICD-10 chapter - 2010 reference year
	2010 reference year			Change (prelim to final)
	P	R	F
Cause of death and ICD-10 code	no	no	no	no	%
Certain infectious and parasitic diseases (A00-B99)	2 148	2 150	2 153	5	0.2
Neoplasms (C00-D48)	43 298	43 310	43 310	12	0.0
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism D50-D89	408	410	410	2	0.5
Endocrine, nutritional and metabolic diseases (E00-E90)	5 704	5 710	5 714	10	0.2
Mental and behavioural disorders (F00-F99)	7 030	7 030	7 035	5	0.1
Diseases of the nervous system (G00-G99)	6 206	6 213	6 212	6	0.1
Diseases of the circulatory system (I00-I99)	45 499	45 520	45 501	2	0.0
Diseases of the respiratory system (J00-J99)	11 949	11 961	11 963	14	0.1
Diseases of the digestive system (K00-K93)	5 125	5 120	5 115	-10	-0.2
Diseases of the skin and subcutaneous tissue (L00-L99)	399	398	398	-1	-0.3
Diseases of the musculoskeletal system and connective tissue (MOO-M99)	1 180	1 179	1 181	1	0.1
Diseases of the genitourinary system (N00-N99)	3 399	3 400	3 399	0	0.0
Certain conditions originating in the perinatal period (P00-P96)	616	615	616	0	0.0
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)	605	610	610	5	0.8
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)	972	847	812	-160	-16.5
External causes of morbidity and mortality (V01-Y98)	8 918	8 981	9 024	106	1.2
Total(a)	143 473	143 473	143 473	0	0.0
(a) Includes deaths coded to H00-H59, H60-H95, and O00-O99.

5 Table 3 shows a comparison of change, from preliminary to final, for 2007 to 2010. As above, the largest change is seen in the number of deaths attributed to Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99). Over time there has been a gradual decline in the size of the percentage decrease in the change between preliminary and final data for this chapter, which indicates that more specific codes have been allocated in preliminary coding.

TABLE 3 - CAUSES OF DEATH REVISIONS, by selected ICD-10 chapter - changes from preliminary to final data: by percentage - 2007, 2008, 2009 and 2010
	2007	2008	2009	2010
Cause of death and ICD-10 code	%	%	%	%
Certain infectious and parasitic diseases (A00-B99)	-0.1	1.8	0.3	0.2
Neoplasms (C00-D48)	0.1	0.0	0.0	0.0
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism D50-D89	0.8	0.2	0.2	0.5
Endocrine, nutritional and metabolic diseases (E00-E90)	0.5	-0.2	0.3	0.2
Mental and behavioural disorders (F00-F99)	-0.4	-0.5	-0.1	0.1
Diseases of the nervous system (G00-G99)	0.3	0.4	0.1	0.1
Diseases of the circulatory system (I00-I99)	0.7	0.4	0.2	0.0
Diseases of the respiratory system (J00-J99)	0.4	0.1	0.0	0.1
Diseases of the digestive system (K00-K93)	0.9	0.6	0.1	-0.2
Diseases of the skin and subcutaneous tissue (L00-L99)	0.6	-0.5	0.8	-0.3
Diseases of the musculoskeletal system and connective tissue (MOO-M99)	1.3	-0.7	0.0	0.1
Diseases of the genitourinary system (N00-N99)	0.2	0.4	0.1	0.0
Certain conditions originating in the perinatal period (P00-P96)	1.6	0.2	-0.3	0.0
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)	3.7	0.8	0.9	0.8
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)	-46.4	-31.4	-29.9	-16.5
External causes of morbidity and mortality (V01-Y98)	4.3	1.1	2.1	1.2

6 While the revisions process has a minimal impact at the overall chapter level (with the exception of Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)), significant data improvements become more apparent when considering movements within individual chapters. Table 4 provides information on the impact of revisions on 2010 data at the sub-chapter level, mainly for the External causes of morbidity and mortality (V01-Y98) chapter. The following causes of death see notable reductions:

• Event of undetermined intent (Y10-Y34) (-374 deaths);
• Other ill-defined and unspecified causes of mortality (R99) (-170 deaths);
• Occupant of pick-up truck or van injured in transport accident (V50-V59) (-43 deaths) (see discussion below); and
• Other land transport accidents (V80-V89) (-31 deaths).

Notable increases include:

• Accidental poisoning by and exposure to noxious substances (X40-X49) (149 deaths);
• Car occupant injured in transport accident (V40-V49) (134 deaths);
• Intentional self-harm (X60-X84) (119 deaths);
• Falls (W00-W19) (43 deaths); and
• Assault (X85-Y09) (41 deaths).

The revisions process not only enables an improvement in the specificity of causes of death codes that can be applied to deaths, but also enables coding improvements to be applied to open cases. For example, Tables 3 and 4, below, show a decrease in the number of deaths due to Occupant of pick-up truck or van injured in transport accident (V50-V59) in the 2010 reference year. This cause decreased by 65.2% when comparing preliminary (66 deaths) and final (23 deaths) data for the 2010 reference year. This decrease is due to an improvement in quality assurance measures, which resulted in the more accurate coding of these transport accident deaths involving a utility vehicle to Car occupant injured in transport accident (V40-V49).

	2010			Change (preliminary to final)
	Preliminary	Revised	Final
Cause of death and ICD-10 code	no.	no.	no.	no	%
Sudden infant death syndrome (R95)	81	96	95	14	17.3
Other ill-defined and unspecified causes of mortality (R99)	567	430	397	-170	-30.0
Pedestrian injured in transport accident (V01-V09)	227	235	244	17	7.5
Pedal cyclist injured in transport accident (V10-V19)	39	40	39	0	0.0
Motorcycle rider injured in transport accident (V20-V29)	236	244	252	16	6.8
Car occupant injured in transport accident (V40-V49)	706	749	840	134	19.0
Occupant of pick-up truck or van injured in transport accident (V50-V59)	66	73	23	-43	-65.2
Occupant of heavy transport vehicle injured in transport accident (V60-V69)	28	31	32	4	14.3
Other land transport accidents (V80-V89)	108	95	77	-31	-28.7
Water transport accidents (V90-V94)	43	46	48	5	11.6
Air and space transport accidents (V95-V97)	24	26	26	2	8.3
Falls (W00-W19)	1 648	1 670	1 691	43	2.6
Exposure to inanimate mechanical forces (W20-W49)	88	95	88	0	0.0
Accidental drowning and submersion (W65-W74)	221	226	222	1	0.5
Other accidental threats to breathing (W75-W84)	213	212	214	1	0.5
Exposure to smoke, fire and flames (X00-X09)	58	67	71	13	22.4
Exposure to forces of nature (X30-X39)	44	44	46	2	4.5
Accidental poisoning by and exposure to noxious substances (X40-X49)	864	958	1 013	149	17.2
Accidental exposure to other and unspecified factors (X58-X59)	616	611	608	-8	-1.3
Intentional self-harm (X60-X84)(a)	2 359	2 418	2 478	119	5.0
Assault (X85-Y09)	217	244	258	41	18.9
Event of undetermined intent (Y10-Y34)	680	454	306	-374	-55.0
Drugs, medicaments and biological substances causing adverse effects in therapeutic use (Y40-Y59)	75	75	73	-2	-2.7
Surgical and other medical procedures as the cause of abnormal reaction of the patient, or of later complication, without mention of misadventure at the time of the procedure (Y83-Y84)	177	184	183	6	3.4
Sequelae of external causes of morbidity and mortality (Y85-Y89)	122	124	125	3	2.5
(a) Care needs to be taken in interpreting figures relating to suicide. See Explanatory Notes 92-94. 8 Table 5 shows the percentage change between preliminary and final data for 2007, 2008, 2009 and 2010 data at the sub-chapter level. Some notable changes due to the revisions process include: Deaths due to Intentional self-harm (X60-X84), which had the highest increase in deaths from preliminary to final coding for the 2007 reference year with an increase of 18.5% (347 deaths), to a smaller increase of 5.0% (119 deaths) from preliminary to final 2010 reference year coding. Deaths due to Assault (X85-Y09), which increased by 33.3% (54 deaths) from preliminary to final coding for the 2007 reference year. This cause increased by 18.9% (41 deaths) from preliminary to final coding for the 2010 reference year. As expected, ill-defined codes, such as Other ill-defined and unspecified causes of mortality (R99) and Event of undetermined intent (Y10-Y34) have seen the greatest percentage decrease from preliminary to final data for most reference years. TABLE 5 - Cause of Death Revisions, by ICD-10 selected causes - Percentage change between preliminary and final data - 2007, 2008, 2009 and 2010 Cause of death and ICD-10 code 2007 2008 2009 2010 Sudden infant death syndrome (R95) 15.5 30.5 21.8 17.3 Other ill-defined and unspecified causes of mortality (R99) -68.1 -46.5 -51.3 -30.0 Pedestrian injured in transport accident (V01-V09) 26.9 24.6 25.3 7.5 Pedal cyclist injured in transport accident (V10-V19) 32.4 16.7 5.7 0.0 Motorcycle rider injured in transport accident (V20-V29) 25.0 19.5 14.7 6.8 Car occupant injured in transport accident (V40-V49) 20.8 11.7 14.8 19.0 Occupant of pick-up truck or van injured in transport accident (V50-V59) 39.6 102.9 36.2 -65.2 Occupant of heavy transport vehicle injured in transport accident (V60-V69) 56.3 26.8 10.0 14.3 Other land transport accidents (V80-V89) 84.5 3.7 -34.6 -28.7 Water transport accidents (V90-V94) 16.1 15.6 37.1 11.6 Air and space transport accidents (V95-V97) 47.2 9.1 22.2 8.3 Falls (W00-W19) 12.4 8.4 5.8 2.6 Exposure to inanimate mechanical forces (W20-W49) 30.5 17.6 0.0 0.0 Accidental drowning and submersion (W65-W74) 4.4 15.7 9.9 0.5 Other accidental threats to breathing (W75-W84) 4.1 7.7 5.5 0.5 Exposure to smoke, fire and flames (X00-X09) 24.1 16.7 4.1 22.4 Exposure to forces of nature (X30-X39) 5.8 3.4 4.9 4.5 Accidental poisoning by and exposure to noxious substances (X40-X49) 32.7 40.8 25.7 17.2 Accidental exposure to other and unspecified factors (X58-X59) -18.2 -12.3 -1.1 -1.3 Intentional self-harm (X60-X84)(a) 18.5 6.8 9.6 5.0 Assault (X85-Y09) 33.3 23.6 29.5 18.9 Event of undetermined intent (Y10-Y34) -66.7 -57.7 -60.7 -55.0 Drugs, medicaments and biological substances causing adverse effects in therapeutic use (Y40-Y59) 1.7 6.3 -1.7 -2.7 Surgical and other medical procedures as the cause of abnormal reaction of the patient, or of later complication, without mention of misadventure at the time of the procedure (Y83-Y84) -2.1 -3.2 6.4 3.4 Sequelae of external causes of morbidity and mortality (Y85-Y89) 2.1 -1.9 -3.8 2.5 (a) Care needs to be taken in interpreting figures relating to suicide. See Explanatory Notes 92-94.