Aims: Dementia cases in Aotearoa NZ are expected to triple over the next 30 years, yet accurate prevalence estimates remain limited. The IDEA project aims to determine dementia prevalence in Pākehā, Chinese, and Indian populations, enabling equity analyses with Māori and Pacific peoples.
Methods: A door‑knock survey is underway in randomly selected urban and rural meshblocks across two sites. Residents aged ≥65 years complete a doorstep cognitive screen administered by trained multilingual interviewers. A randomly selected subset receives full assessment using the 10/66 dementia protocol. Target sample sizes are 485 Pākehā, 410 Chinese, and 425 Indian/Fijian‑Indian participants (3% margin of error, 95% CI).
Results: In 20 months, >27,000 households were approached, 4,332 residents screened, and 1,653 completed full assessments; 31% declined interviews and 33.5% declined doorstep screening (updated results to mid‑2026 will be presented). Of 96 individuals meeting 10/66 criteria for dementia, 36 were aware of a diagnosis. Preliminary adjusted prevalence is 7.80% (95% CI: 5.92 - 9.69). When participants without an informant were included, with dementia status determined by clinical adjudication using available assessment data, adjusted prevalence was 10.17% (95% CI: 7.67–12.67). Prevalence increases sharply with age, from 4.6% at 65–74 years to 26% at ≥85 years.
Conclusions: The IDEA project provides the first robust, population‑specific dementia prevalence estimates for key ethnic groups in Aotearoa New Zealand. These data will support the design of culturally responsive dementia services.