In the absence of any prevalence studies, the calculation of the average age of dementia onset is not possible.

Cullum et al., (2018) reported on 1106 referrals to a specialist memory service and calculated a mean age of onset of 74.6 years. They also showed that the onset of dementia in Māori and Pacific people referred to a specialist memory clinic was 8.5 years and 5 years earlier respectively, when compared to those of European/Pakeha ethnicity (table 41).

Table 41

Ethnicity	Age (yrs) (95% CI)
NZ European	79.1 (77.9 – 80.4)
Pacific People	73.9 (72.5 – 75.2)
Maori	70.6 (68.4 – 72.9)

 

References:

Cullum S., Mullin K., Zeng I., Yates S., Payman V., Fisher M., et al. (2018). Do community-dwelling Maori and Pacific peoples present with dementia at a younger age and at a later stage compared with NZ Europeans? Int J Geriatr Psychiatry. 33(8):1098-104. https://doi.org/10.1002/gps.4898.