dementia estimates and projections: australian states and territories

Dementia estimates and projections:Australian States and Territories1. BACKGROUNDAccess Economics (2003) provided estimates and projections to Alzheimer’s Australiain 2003 for the prevalence of dementia in Australia as a whole for the years 2002,2011, 2021, 2031, 2041 and 2051. These estimates were based on age specificprevalence rates derived from the Australian Bureau of Statistics (ABS) Survey ofDisability Ageing and Carers (DAC Survey) for the years 1998 and 1993, together withinternational epidemiological data. The international data provided the more robustestimates of total prevalence, while the DAC self-reported data (see ABS, 1999 forSurvey methodology) provided Australian age-gender splits, including for people agedunder 65 years.The main purpose of the 2003 Access Economics study was to provide the mostreliable projections of the time, with an emphasis on the burgeoning economic cost ofdementia due to demographic ageing, and the need for timely and cost-effectiveinterventions to improve the quality of life for Australians with dementia as part of anational strategy to improve awareness, prevention and treatment of this important andunder-recognised issue.Access Economics (2004) demonstrated that delays in the onset of Alzheimer’sdisease alone through prevention would produce substantial reductions in the futurenumber of cases and in the real costs of dementia. It was shown that if the onset ofAlzheimer’s disease could be delayed by 5 years, by mid-century there would be a49% reduction in the total number of cases projected.Professor Anthony Jorm and his colleagues at the Centre for Mental Health Research,Australian National University, have estimated new prevalence and incidence rates(Jorm et al, in press) based on the meta-analysis of European epidemiological studiesby Wancata et al (2003). In September 2004 the results of a more recent DAC Surveywere released (ABS, 2004), providing data collected June to November 2003, byseverity of disability and by care setting including residential aged care facilities. Inaddition, release in September 2003 of detailed 2001 Census data has enabled therecalculation of ABS Series B (mid-case) population projections by demographic groupand State/Territory; the fertility, mortality and migration assumptions are explained inABS (2003).Alzheimer’s Australia commissioned Access Economics to utilise the new data toestimate dementia prevalence and incidence for States and Territories, as well as a reestimationfor the whole of Australia. This report presents the findings of this newanalysis, details the methodology and explains variations between these and formeraggregate estimates for Australia from Access Economics (2003). Two companionreports for Alzheimer’s Australia Vic (Access Economics, 2005a) and for Alzheimer’sAustralia WA (Access Economics, 2005b) detail dementia prevalence and incidence forVictoria and Western Australia and their respective regions.1