The impact of certifying practices and statistical coding on the reporting of neurodevelopmental disabilities as the underlying cause of death in Australia

As neurodevelopmental disabilities emerge in early childhood, reporting them as the underlying cause of death in mortality statistics effectively establishes the cause of death at birth. This hampers efforts to address causes of premature mortality and improve life expectancy for this population.

To quantify the reporting of neurodevelopmental disabilities as the underlying cause of death in Australian data and determine whether it is due to death certification practices or statistical coding rules.

Our observational study analysed Australian death data (2007-2022). We identified ICD-10 codes for neurodevelopmental disabilities and determined whether these were documented on death certificates as a direct or contributing cause and whether, following statistical coding, they were reported as an underlying or associated cause of death.

ICD-10 codes for neurodevelopmental disabilities were present in 9878 deaths. For 40% of these, neurodevelopmental disability was reported as the underlying cause. This varied by disability type - from 8% for intellectual disability to 61% for Down syndrome. We found this was not always due to certifier practices. For 29% of deaths with a neurodevelopmental disability reported as the underlying cause, the corresponding condition was correctly recorded by the certifying practitioner as a contributing cause.

Neurodevelopmental disabilities are being reported as the underlying cause of death in Australian mortality statistics, due to both medical practitioners' assessments and statistical coding. To ensure mortality statistics better inform efforts to reduce premature mortality in people with neurodevelopmental disabilities, both education for certifying practitioners and a change to statistical coding rules are required.