The Dementia Worldwide Cost Database (DWCD) (Wimo et al., 2017) estimates the amount of informal care time required based on dementia severity, depending on the level of assistance and oversight required. When weighted by New Zealand prevalence of the different dementia severities, each individual with dementia in the community receives on average 21.7hrs of informal care per week (Deloitte Access Economics, 2017).

In the absence of any NZ specific data, the Deloitte report (Deloitte Access Economics, 2017) used international data to estimate that ~92% of people with dementia in the community receive informal care from one or more carers.

References:

Deloitte Access Economics. (2017). Dementia Economic Impact Report 2016. Available from: https://www2.deloitte.com/nz/en/pages/economics/articles/dementia-economic-impact-report-2016.html.

Wimo A., Guerchet M., Ali G. C., Wu Y. T., Prina A. M., Winblad B., et al. (2017). The worldwide costs of dementia 2015 and comparisons with 2010. Alzheimers Dement. 13(1):1-7. https://doi.org/10.1016/j.jalz.2016.07.150.