Dementia prevalence estimation among the main ethnic groups in New Zealand: a population-based descriptive study of routinely collected health data

Abstract

ObjectiveEstimates of dementia prevalence in New Zealand (NZ) have previously been extrapolated from limited Australasian studies, which may be neither accurate nor reflect NZ’s unique population and diverse ethnic groups. This study used routinely collected health data to estimate the 1-year period prevalence for diagnosed dementia for each of the 4 years between July 2016 and June 2020 in the age 60+ and age 80+ populations and for the four main ethnic groups.DesignA population-based descriptive study.SettingSeven national health data sets within the NZ Integrated Data Infrastructure (IDI) were linked. Diagnosed dementia prevalence for each year was calculated using the IDI age 60+ and age 80+ populations as the denominator and also age–sex standardised to allow comparison across ethnic groups.ParticipantsDiagnosed dementia individuals in the health datasets were identified by diagnostic or medication codes used in each of the data sets with deduplication of those who appeared in more than one data set.ResultsThe crude diagnosed dementia prevalence was 3.8%–4.0% in the age 60+ population and 13.7%–14.4% in the age 80+ population across the four study years. Dementia prevalence age–sex standardised to the IDI population in the last study period of 2019–2020 was 5.4% for Māori, 6.3% for Pacific Islander, 3.7% for European and 3.4% for Asian in the age 60+ population, and 17.5% for Māori, 22.2% for Pacific Islander, 13.6% for European and 13.5% for Asian in the age 80+ population.ConclusionsThis study provides the best estimate to date for dementia prevalence in NZ but is limited to those people who were identified as having dementia based on data from the seven included data sets. The findings suggest that diagnosed dementia prevalence is higher in Māori and Pacific Islanders. A nationwide NZ community-based dementia prevalence study is much needed to confirm the findings of this study.

Living with Dementia in Aotearoa (LiDiA): A Feasibility Study for a Dementia Prevalence Study in Māori and Non-Māori Living in New Zealand

“…Accurate community-based dementia prevalence information for Māori, Asian and Pacific peoples living in NZ is unavailable. The calculated dementia prevalence based on administrative data in 2019-2020 was 5.8% for Māori, 6.4% for Pacific, 3.7% for NZ European, and 3.4% for Asian in the age 60+ population; and 18.8% for Māori, 22.7% for Pacific, 13.6% for European, and 13.3% for Asian in the age 80+ population ( Cheung et al, 2022 ). These data are based on diagnostic coding and therefore do not include people with unidentified and/or undiagnosed dementia in these communities.…”

RANZCP Abstracts

“…Investment in SBE for psychiatric skills in medical students may have significant yields not only in psychiatric rotations but in developing interest in the specialty and patient interactions across settings. Objectives: To use routinely collected health data to estimate the 1-year period prevalence for diagnosed dementia and rates of anti-dementia medication use for each of the 4 years between 2016 and 2020 in the age <65 years and 60+ years populations and for the four main New Zealand ethnic groups (Chan et al, 2022;Cheung et al, 2022;Ryan et al, 2022).…”

“…Findings: Dementia prevalence age-sex standardised to the IDI population in the last study period of 2019-2020 was 231.6 for Māori, 183.5 for Pacific peoples, 126.5 for European and 87.0 for Asian per 100,000 age <65 years population (Ryan et al, 2022) and 5.4% for Māori, 6.3% for Pacific peoples, 3.7% for European, and 3.4% for Asian in the age 60+ population (Cheung et al, 2022). Overall, one-third of the dementia population received a funded anti-dementia medication (Chan et al, 2022).…”

Anti-dementia medication use in Aotearoa New Zealand: An exploratory study using health data from the Integrated Data Infrastructure (IDI)

“…In New Zealand, an estimated 1 in 50 people aged between 60 and 64 years have a diagnosis of dementia, rising to 1 in 8 of those aged between 80 and 84 years (Cheung et al, 2022; Ma’u et al, 2021b). Globally, it is estimated that there are currently more than 50 million people living with dementia, with these numbers projected to double in the next 20 years (Prince et al, 2015).…”

“…Recent New Zealand data suggest that risk factors with the greatest contribution to dementia prevalence differ by ethnicity (Ma’u et al, 2021a). There is also evidence to suggest that dementia prevalence is higher in Māori and Pacific peoples than other ethnicities (Cheung et al, 2022; Ma’u et al, 2021a). International data show similar trends, with people from minority ethnic groups (Cooper et al, 2010b) being less likely to receive anti-dementia medication (Cooper et al, 2015; Giebel et al, 2020; Jones et al, 2020; Matthews et al, 2007; Zhu et al, 2022).…”