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

Examining the relationship between plasma pTau181 and cognitive decline, structural brain integrity, and biological ageing in midlife

INTRODUCTION

Although plasma pTau181 has been shown to accurately discriminate patients with Alzheimer's disease from healthy older adults, its utility as a preclinical biomarker in middle-aged community-based cohorts is unclear.

METHODS

Participants were members of the Dunedin Multidisciplinary Health and Development Study, a longitudinal study of 1037 people born in New Zealand in 1972-1973. Plasma pTau181, MRI-based brain structure, and DunedinPACE (an epigenetic biomarker of biological ageing) were measured at age 45; cognition was measured in childhood and age 45.

RESULTS

We observed a wide range of pTau181 concentrations in our same-aged sample (n=856; M=13.6pg/mL, SD=9.1pg/mL). Males had significantly higher pTau181 concentrations than females. No statistically significant associations were observed with cognitive decline, lower structural brain integrity, or accelerated biological ageing.

DISCUSSION

In this midlife cohort, wide variation in pTau181 concentrations was present by age 45, but was not associated with patterns of AD-risk in cognition, brain structure, or biological ageing.

Cultural Adaptation of Cognitive Stimulation Therapy for Māori with Dementia (CST-Māori)

Māori are the indigenous people of Aotearoa New Zealand. Cognitive Stimulation Therapy (CST) was initially developed in the UK, lacking in Māori cultural content and values. Cultural adaptation is needed to ensure Māori with dementia can benefit from this evidence-based treatment. This paper reports the outcome of a project aimed to adapt CST for Māori. We followed the five phases of international guidelines using the formative method for adapting CST to other cultures, including a critical cultural examination of the 18 CST principles. We piloted two CST-Māori programmes and collected pre- and post-outcome measures using the RUDAS and the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire. Written qualitative feedback was sought from participants and their family at the end of the CST-Māori programme. A total of 15 Māori (female: 53.3%) participated in the two programmes. Their mean age was 75.9 years (SD = 6.6) and mean baseline RUDAS scores was 17.7 (SD = 2.3). There was a statistically significant improvement in cognition (RUDAS: pre = 17.7, post = 19.4, p = 0.003) and in the WHOQOL subscales of physical (pre = 75.9, post = 88.5, p = 0.003), psychological (pre = 72.7, post = 81.3, p = 0.024) and environment (pre-80.6, post = 88.0, p = 0.006). Written feedback confirmed the acceptability of this culturally adapted programme by Māori living with dementia and their whanau (families). CST was successfully adapted for Māori with dementia. It is a culturally acceptable cognitive intervention and preliminary data confirmed the effectiveness of CST-Māori in improving cognition and quality of life.

Dementia prevalence and dementia risk in Indigenous Peoples: recent findings, current developments, and future directions

PURPOSE OF REVIEW

To highlight recent findings on the prevalence and risk and protective factors for dementia in Indigenous Peoples, who are disproportionately affected by health inequities driven by social determinants of health and historical injustices. With increasing numbers of Indigenous individuals entering older age, there is a growing need for research to better understand dementia and opportunities for prevention in Indigenous Peoples.

RECENT FINDINGS

Recent studies highlight a wide range of dementia prevalence across Indigenous Peoples, with estimates varying significantly by methodology, socio-cultural context, and region with stark gaps in regional representation. Studies suggested that Indigenous Peoples show distinct profiles of dementia risk factors, including higher rates of cardiovascular disease, lower educational attainment, and socioeconomic disadvantage. However, traditional lifestyles, strong social ties, and culturally grounded practices are suggested to offer protective effects against cognitive decline.

SUMMARY

Despite growing research attention, significant limitations remain in understanding dementia in Indigenous Peoples. The available evidence points to the need for culturally sensitive approaches in research and dementia prevention, as well as greater consideration of the social and environmental factors shaping brain health. Future research should aim to incorporate Indigenous knowledge systems and address the social determinants of dementia risk in Indigenous Peoples.

Prevalence of dementia among Indigenous populations of countries with a very high Human Development Index: a systematic review

Dementia is a health priority for Indigenous peoples. Here, we reviewed studies on the prevalence of dementia or cognitive impairment among Indigenous populations from countries with a very high Human Development Index (≥0·8). Quality was assessed using the Joanna Briggs Institute risk-of-bias tool and CONSolIDated critERia for strengthening the reporting of health research involving Indigenous peoples (CONSIDER), with oversight provided by an Indigenous Advisory Board. After screening, 23 studies were included in the Review. Relative to the respective non-Indigenous populations, greater age-standardised prevalence ratios were observed in the Australian Aboriginal and Torres Strait Islander (2·5-5·2), Aotearoa-New Zealand Māori (1·2-2·0), and Singaporean Malay (1·3-1·7) populations, and greater crude prevalence ratios were observed in the Canadian First Nation (1·3), Singaporean Malay (2·3), Malaysian Melanau (1·7-4·0), American Indian and Alaska Native (1·0-3·2), and Chamorro of Guam (1·2-2·0) populations. The prevalence ratios were greater across younger age groups, predominantly comprising those younger than 70 years. 14 studies presented a moderate risk of bias and few studies reported Indigenous involvement. Despite improved management of risk factors, a greater prevalence of dementia persists in Indigenous populations, overall and at younger ages than in non-Indigenous populations. Future epidemiological work involving Indigenous populations should uphold and prioritise Indigenous perspectives.

Estimating the incidence of dementia in New Zealand: a cohort study applying capture-recapture modelling to routinely collected linked health datasets

Background

Issues of under-diagnosis and under-coding of dementia in routinely collected health data limit their utility for estimating dementia prevalence and incidence in Aotearoa New Zealand (NZ). Capture-recapture techniques can be used to estimate the number of dementia cases missing from health datasets by modelling the relationships and interactions between linked data sources. The aim of this study was to apply this technique to routinely collected and linked health datasets and more accurately estimate the incidence of dementia in NZ.

Methods

All incident cases of dementia in the NZ 60+ population were identified in three linked national health data sets-interRAI, Public hospital discharges, and Pharmacy. Capture-recapture analysis fitted eight loglinear models to the data, with the best fitting model used to estimate the number of cases missing from all three datasets, and thereby estimate the 'true' incidence of dementia. Incidence rates were calculated by 5-year age bands, sex and ethnicity.

Findings

Modelled estimates indicate 36% of incident cases are not present in any of the datasets. Modelled incidence rates in the 60+ age group were 19.2 (95% CI 17.3-22.0)/1000py, with an incident rate ratio of 1.9 (95% CI 1.9-2.0) per 5-year age band. There was no difference in incidence rates between males and females. Incidence rates in Asian (p < 0.001) but not Māori (p = 0.974) or Pacific peoples (p = 0.110) were significantly lower compared to Europeans, even after inclusion of missing cases.

Interpretation

This is the first study to provide estimates of age 60+ dementia incidence in NZ and for the four main ethnic groups and suggests over a third of incident dementia cases are undiagnosed. This highlights the need for better access to dementia assessment and diagnosis so that appropriate supports and interventions can be put in place to improve outcomes for people living with dementia and their families.

Funding

Nil.

Incidence, Prevalence, and Risk for Urinary Incontinence for People with Dementia in the Community in Aotearoa New Zealand: An interRAI Study

OBJECTIVES

To identify 1-year period prevalence, 5-year incidence rate, and risks for urinary incontinence (UI) for people living with dementia.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Participants completed an International Residential Assessment Instrument Home Care (interRAI-HC) assessment in a 5-year period between August 1, 2016 and July 31, 2021 in Aotearoa New Zealand (N = 109,964).

METHODS

For prevalence analysis, a dementia cohort was selected for a 1-year period from August 1, 2020 to July 31, 2021 (n = 7775). For incidence analysis, participants in the dementia cohort were followed from the first dementia diagnosis during the 5-year period. Dementia was identified by combining diagnoses of "Alzheimer's disease" and "Dementia other than Alzheimer's disease." Participants were coded with UI if they were infrequently, occasionally, or frequently incontinent or if continence was managed with catheter/ostomy. Univariate and multivariate logistic regression analyses identified risk factors predicting UI onset. Cox regression analysis compared survival curves (months without UI) of the dementia and non-dementia cohorts, adjusting for variables significantly associated with incident UI in either cohort.

RESULTS

The 1-year period (August 1, 2020 to July 31, 2021) prevalence of UI was 50.1% among people with dementia. The 5-year incident UI rate was 30.2 per 100 person-years for the dementia cohort and 24.5 per 100 person-years for the non-dementia cohort. Parkinson's disease posed the greatest risk of UI in both cohorts [dementia cohort odds ratio (OR), 3.0; 95% CI, 2.1-4.2; non-dementia cohort OR, 1.7; 95% CI, 1.4-2.0]. Controlling for risk factors, the hazard ratio for UI was 1.4 for people with dementia.

CONCLUSIONS AND IMPLICATIONS

UI affects a significant proportion of people with dementia in Aotearoa New Zealand. Health professionals should directly ask about UI and consider living arrangements and comorbidities for people with dementia. Data-driven insights from interRAI-HC can guide resource allocation and service planning.

A scoping review of the unique landscape and challenges associated with dementia in the Western Pacific region

Dementia is a leading public health crisis that is projected to affect 152.8 million individuals by 2050, over half of whom will be living in the Western Pacific region. To determine the challenges and opportunities for capacity building in the region, this scoping review searched databases. Our findings reveal national and ethnoracial differences in the prevalence, literacy and genetic risk factors associated with dementia syndromes, underscoring the need to identify and mitigate relevant risk factors in this region. Importantly, ∼80% of research was derived from higher income countries, where the establishment of patient registries and biobanks reflect increased efforts and allocation of resources towards understanding the pathogenesis of dementia. We discuss the need for increased public awareness through culturally-relevant policies, the potential to support patients and caregivers through digital strategies and development of regional networks to mitigate the growing social impact and economic burden of dementia in this region.

Funding

FightMND Mid-Career Fellowship, NHMRC EL1 Fellowship, NHMRC Practitioner Fellowship (1156093), NHMRC Postgraduate scholarship (2022387).

Long-term impact of type 2 diabetes onset on dementia incidence rate among New Zealanders with impaired glucose tolerance: A tapered-matched landmark analysis over 25 years

INTRODUCTION

We aimed to investigate the association between the onset of type 2 diabetes (T2D) and dementia incidence rates (IR) in the population with impaired glucose tolerance (IGT) identified in primary care in New Zealand (NZ) over 25 years.

METHODS

Tapered matching and landmark analysis (accounting for immortal bias) were used to control for potential effects of known confounders. The association between T2D onset and 5- and 10-year IR of dementia was estimated by weighted Cox models.

RESULTS

The onset of T2D was significantly associated with the 10-year IR of dementia, especially in the socioeconomically deprived, those of non-NZ European ethnicity, those currently smoking, and patients with higher metabolic measures.

DISCUSSION

Our findings suggest that the onset of T2D is a significant risk factor for dementia in individuals with IGT. Dementia screening and structured diabetes prevention are vital in the population with IGT, particularly those from deprived or ethnic minority backgrounds.

HIGHLIGHTS

Increased dementia incidence rate links with T2D onset in people with IGT. Significant incidence varied by ethnicity, socioeconomic status, and health factors. Results emphasize the diabetes manage and socioeconomic factors on dementia risk. Secondary analysis highlights the key role of vascular health in dementia prevention.

Using interRAI Assessment for Research: Developing a National Research Agenda in Aotearoa New Zealand

interRAI provides a suite of standardized, validated instruments used to assess health and psychosocial well-being, and to inform person-centered care planning. Data obtained from these standardized tools can also be used at a population level for research and to inform policy, and interRAI is currently used in more than 40 countries globally. We present a brief overview of the use of interRAI internationally within research and policy settings, and then introduce how interRAI is used within the universal public health system in Aotearoa New Zealand (NZ), including considerations relating to Māori, the Indigenous people of NZ. In NZ, improvement in interRAI data utilization for research purposes was called for from aged care, health providers, and researchers, to better use these data for quality improvement and health advancement for New Zealanders. A national research network has been established, providing a medium for researchers to form relationships and collaborate on interRAI research with a goal of translating routinely collected interRAI data to improve clinical care, patient experience, service development, and quality improvement. In 2023, the network members met (hybrid: in-person and online) and identified research priorities. These were collated and developed into a national interRAI research agenda by the NZ interRAI Research Network Working Group. Research priorities included reviewing the interRAI assessment processes, improving methods for data linkage to national data sets, exploring how Indigenous Data Sovereignty can be upheld, as well as a variety of clinically focused research topics. Implications for Practice, Policy, and Research: This appears to be the first time national interRAI research priorities have been formally identified. Priorities identified have the potential to inform quality and clinical improvement activities and are likely of international relevance. The methodology described to cocreate the research priorities will also be of wider significance for those looking to do so in other countries.

Dementia among Minority Populations: A Scoping Review of Meaning, Language, and Translation

BACKGROUND

Dementia as a neurocognitive disorder is becoming increasingly common worldwide, and minority groups are more vulnerable than the general population. Many factors may contribute to their vulnerability such as misconceptions, language barriers, cultural factors, invalid assessment tools, lack of knowledge, or assigning spiritual beliefs to dementia symptoms. Therefore, this scoping literature review aimed to clarify how empirical studies reflect the meaning of dementia, language, and translation among minority ethnic groups.

SUMMARY

The PRISMA extension for the scoping review protocol was used. Thirty-eight studies published in English were reviewed and analysed. The findings revealed that lack of knowledge about dementia and attributing the disease to the normal ageing process were frequent among minority groups. Furthermore, their cultural-specific perspectives and worldviews of wellness and well-being can impact the way dementia is perceived, consequent help-seeking behaviours, or caregiving. Facilitating educational programs to enhance the knowledge and experiences of ethnic communities might be beneficial. Moreover, language is shown to be an important aspect in dementia assessment and participants' educational level could significantly impact their functional capacity when responding to cognitive measures. Even though there are some useful screening tests, diagnosis barriers might be eased by assessment tool development, modifications, and accurate translations for ethnic communities.

KEY MESSAGES

A promising pathway to support ethnically diverse communities regarding dementia can be raising awareness, providing ethnic-specific services, developing cultural-specific tools to assess dementia or any cognitive impairment by considering perceptions, language, and culture among ethnic groups. Cultural and spiritual considerations could also encourage engagement during assessment.

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

INTRODUCTION

Recent estimations have projected a threefold increase in dementia prevalence in Aotearoa New Zealand (NZ) by 2050, particularly in Maori and Pacific peoples. However, to date, there are no national data on dementia prevalence, and overseas data are used to estimate the NZ dementia statistics. The aim of this feasibility study was to prepare the groundwork for the first full-scale NZ dementia prevalence study that is representative of Māori, European, Pacific and Asian peoples living in NZ.

METHODS

The main feasibility issues were: (i) Sampling to ensure adequate community representation from the included ethnic groups, (ii) Preparing a workforce to conduct the fieldwork and developing quality control, (iii) Raising awareness of the study in the communities (iv) Maximizing recruitment by door-knocking, (v) Retaining those we have recruited to the study and (vi) Acceptability of study recruitment and assessment using adapted versions of the 10/66 dementia protocol in different ethnic groups living in South Auckland.

RESULTS

We found that a probability sampling strategy using NZ Census data was reasonably accurate and all ethnic groups were sampled effectively. We demonstrated that we were able to train up a multi-ethnic workforce consisting of lay interviewers who were able to administer the 10/66 dementia protocol in community settings. The response rate (224/297, 75.5%) at the door-knocking stage was good but attrition at subsequent stages was high and only 75/297 (25.2%) received the full interview.

CONCLUSIONS

Our study showed that it would be feasible to conduct a population-based dementia prevalence study using the 10/66 dementia protocol in Māori, European and Asian communities living in NZ, utilizing a qualified, skilled research team representative of the families participating in the study. The study has demonstrated that for recruitment and interviewing in Pacific communities a different but culturally appropriate approach is required.

Incidence of Young Onset Dementia in Waikato, New Zealand: A Population-Based Study

BACKGROUND

There is limited epidemiological research on the incidence of young onset dementia (YOD). Estimates of YOD incidence in New Zealand are extrapolated from international studies that do not reflect New Zealand's population and ethnic diversity.

OBJECTIVE

To determine the incidence of YOD in the geographical area served by the Waikato District Health BoardMethods: All new inpatient and outpatient in the age range 30-64 years with a documented diagnosis of dementia at Waikato Hospital between 1 January 2014 -31 December 2016 were identified. Incidence rates were calculated by 5-year age-band, sex, and ethnicity.

RESULTS

64 incident cases of YOD were included. Incidence rates for all cause YOD were 13.3 (95% CI 10.3-17.0) and 22.7 (95% CI 17.5-29.1) per 100,000 person-years in the age range 30-64 years and 45-64 years respectively. The incidence rate in Māori (20.0, 95% CI 11.4-32.4) was higher compared to non-Māori (12.0, 95% CI 8.9-15.9), but this difference was not statistically significant (p = 0.09).

CONCLUSION

The incidence of YOD in this study is similar to global estimates. Incidence may be higher in Māori compared to non-Māori, highlighting the need for culturally appropriate approaches to dementia prevention, intervention, and care.