evidence: The proportion of the very old in the Australian population is increasing: in 2016, there are 486,700 people aged 85 and over, representing 2.0% of the population. This number is projected to more than double by 2036, to 1.0 million (3.2% of the population) (ABS 2013). [...] The very old are under-represented in many health surveys, particularly frail or ill people who are cared for in settings such as hospitals and permanent residential aged care. As a result, the proportion of frail or ill people in the population may be under-estimated, and there is limited information on their experience of, and outcomes from, interactions with the health system. In addition, data regarding the very old is not consistently collected or reported—instead, broader 'old' age groups, such as people aged 65 and over, are often used instead. [...] - Proportions are not age-standardised, and in some instances higher prevalence may reflect the older age profiles in Inner regional and Outer regional/Remote areas.