Exposure to unspecified factor ICD-10-AM X59

Classifying injury by the external cause of injury aims to inform planning in injury prevention. The external code ICD-10 X59: code Exposure to unspecified factor is not helpful for this purpose. It is known as a ‘dump’ code (Henley G et al. 2007) and it is used in assessments of injury data quality (Lu et al. 2007).

Exposure to unspecified factor and death data

A high proportion of deaths coded to unspecified factor category have a fracture as an associated cause of death (also called: a contributing cause of death), and it is likely that a large number of these deaths are in fact due to falls (Henley et al, 2007). Including these records with fracture in the total fall count increases deaths due to falls in Australia by 90-80% (Henley G et al. 2007) (Henley et al. 2009).

The count in this indicator is based solely on the underlying cause of death and the records with X59 as the underlying cause of death are not re-distributed on the basis of the associated cause of death.

There are two indicators where associated causes of death are considered in addition to underlying cause of death. These indicators are covering deaths due to diabetes and death due to falls. The records with X59 as the underlying cause of death are included in the analysis of death from falls. They are not included in the analysis of death from diabetes, because X59 is an external cause of injury which does not refer to diabetes. In general, the deaths where the condition of interest is the underlying cause of death are clearly differentiated from the deaths where the condition is an associated cause of death and from the total to avoid confusion in relevant indicators.

See Methods: Injury and poisoning for further discussion of coding of injury- related deaths and Methods: Diabetes-related deaths.

Exposure to unspecified factor and hospitalisation data in NSW

Over the years Exposure to unspecified factor has been responsible for the second or third largest proportion of injury hospitalisations, just above or below motor vehicle transport. Falls have been the leading cause of injury hospitalisation.

Since 1998-99 the proportion of falls has been increasing in hospitalisation data in NSW (from around 34% to 42% in the ensuing 20 years), however the proportion of hospitalisations coded to Exposure to unspecified factor has not changed and remains around 10-11% of all records. This suggests that allocation of a more precise final code may not be easy to achieve.

Currently, almost a half of hospitalisations with Exposure to unspecified factor in external cause of injury code are day only admissions in NSW, which suggests time constraints as the main reason for the lack of better quality information. It is also possible that less attention is paid to recording details of less serious cases.

Exposure to unspecified factor has not been investigated in national injury hospitalisations yet and only the identifiable causes have been reported up to May 2011 (Kreisfeld et al. 2010).

In this report, hospitalisation records with X59 as the principal diagnosis are not re-distributed on the basis of additional diagnoses.

References

Henley G, Kreisfeld R, Harrison J. Injury deaths, Australia 2003-04. Canberra: 2007. Available at https://www.aihw.gov.au/getmedia/2daac948-ec7f-4a7d-bc22-889f5a54c8ab/injcat89.pdf.aspx?inline=true

Henley G, Harrison JE. Injury deaths, Australia 2004-05. Cat.no. INJCAT 127. Canberra: AIHW, 2009. Available at https://www.aihw.gov.au/getmedia/caa49268-97b8-404b-913b-f8e7ff9a830d/injcat-127-10777.pdf.aspx?inline=true

Kreisfeld R, Harrison JE. Hospital separations due to injury and poisoning 2005-06. Cat. no. INJCAT 131. Canberra: AIHW, 2010. Available at http://www.aihw.gov.au/publication-detail/?id=6442468389&tab=2

Lu TH, Walker S, Anderson RN, McKenzie K, Bjorkenstam C and Hou WH. "Proportion of injury deaths with unspecified external cause codes: a comparison of Australia, Sweden, Taiwan and the US". Injury Prevention 2007. Vol13 (4): 276-81.