Correlates of undefined cause of injury coded mortality data in Australia

The objective of this research was to identify the level of detail regarding the external causes of death in Australia and ascertain problematic areas where data quality improvement efforts may be focused. The 2003 national mortality dataset of 12,591 deaths with an external cause of injury as the underlying cause of death (UCOD) or multiple cause of death (MCOD) based on ICD-10 code assignment from death certificate information was obtained. Logistic regression models were used to examine the precision of coded external cause of injury data. It was found that overall, accidents were the most poorly defined of all intent code blocks with over 30% of accidents being undefined, representing 2,314 deaths in 2003. More undefined codes were identified in MCOD data than for UCOD data. Deaths certified by doctors were more likely to use undefined codes than deaths certified by a coroner or government medical office. To improve the quality of external cause of injuries leading to or associated with death, certifiers need to be made aware of the importance of documenting all information pertaining to the cause of the injury and the intent behind the incident, either through education or more explicit instructions on the death certificate and accompanying instructional materials. It is important that researchers are aware of the validity of the data when they make interpretations as to the underlying causes of fatal injuries and causes of injury associated with deaths.