Differences in the potential for dementia prevention between major ethnic groups within one country: A cross sectional analysis of population attributable fraction of potentially modifiable risk factors in New Zealand

Abstract

Background: Twelve potentially modifiable risk factors (less education, hypertension, obesity, alcohol, traumatic brain injury (TBI), hearing loss, smoking, depression, physical inactivity, social isolation, diabetes, air pollution) account for an estimated 40% of worldwide dementia cases. We aimed to calculate population attributable fractions (PAFs) for dementia for the four largest New Zealand ethnic groups (European, M āori, Asian, and Pacific peoples) to identify whether optimal dementia prevention targets differed by ethnicity.Methods: We calculated risk factor prevalence for 10 risk factors using the New Zealand Health Survey 2018/19 and published reports for hearing loss and TBI prevalences. We calculated the PAF for each risk factor using calculated prevalence and relative risk estimates from previous meta-analyses. To account for risk factor overlap, we calculated communality of risk factors and a weighted PAF.Findings: The weighted PAF for dementia was 47 • 7% overall in New Zealand, 47 • 6% for Europeans, 51 • 4% for M āori, 50 • 8% for Pacific peoples, and 40 • 8% for Asians. Highest PAFs for Europeans were hearing loss (8%) and social isolation (5 • 7%), and for Asians hearing loss (7 • 3%) and physical inactivity (5 • 5%). For M āori and Pacific peoples, highest PAFs were for obesity (7 • 3% and 8 • 9% respectively) and hearing loss (6 • 5% and 6 • 6%). Interpretation: New Zealand has higher dementia prevention potential than worldwide estimates with high prevalences of untreated hearing loss and obesity. The relative contribution of individual risk factors PAFs varies by ethnic group. Public health strategies for dementia prevention need to be tailored to these differences.

Potentially preventable dementia in a First Nations population in the Torres Strait and Northern Peninsula Area of North Queensland, Australia: A cross sectional analysis using population attributable fractions

“… 3 The total PAF% was also higher than estimates for China (39·5%) and India (41%), which used nine risk factors, although lower than six Latin American countries (55·8%). 7 Our results were consistent with previous estimates from New Zealand using 12 risk factors (47·7%), 5 especially for the Māori population (51·4%). First Nations populations globally experience higher potentially modifiable risk factors for dementia, 32 often related to the consequences of colonization and the erosion of traditional lifestyles.…”

“…Air pollution, the 12 th risk, was excluded as the study population resides in a remote region, where atmospheric pollution is an unlikely risk. 5 For the 13 people who participated in both the DPS and the ZKHP, the recency and completeness of their data from both surveys were reviewed to determine if they had a dementia risk factor. Table 1 summarises the definitions of dementia risk factors in the two surveys, and the harmonization of these risks is described below.…”

“…The Lancet Commission on Dementia Prevention, Intervention, and Care ( The Lancet Commission ) estimates that 40% of dementias worldwide are due to 12 potentially modifiable risks; obesity, physical inactivity, smoking, low education, diabetes mellitus, hypertension, depression, hearing impairment, alcohol consumption, social isolation, traumatic brain injury (TBI), and air pollution. 3 Similar work has been conducted to estimate the proportion of potentially preventable dementia in Australia, 4 New Zealand, 5 Canada, 6 India, China, and several Latin American countries. 7 These estimates are based on population attributable fractions (PAF%), which quantify how much a set of risk factors contributes to the burden of dementia in a population.…”

Variation in Population Attributable Fraction of Dementia Associated With Potentially Modifiable Risk Factors by Race and Ethnicity in the US

“… 5 , 6 However, this approach may disguise intranational heterogeneity, as has been shown among ethnic groups in New Zealand. 12 There are stark disparities in dementia rates across groups in the US. 13 , 14 Compared with prevalence among non-Hispanic White individuals, the prevalence of dementia is twice as high among non-Hispanic Black and 1.5 times as high among Hispanic individuals.…”

Air pollution and mental health: associations, mechanisms and methods

“…Presently almost all studies estimate exposure based on disclosed residential address, without factoring in time spent elsewhere, and individual-level protective or exacerbating factors including air filtration devices or mask-wearing are included as mediators in few studies [33 ]. Without readily available air pollutant assessments, some models -which inform policymakers and steer intervention approach -resort to proxy measures, like binary assessments of urban residence, which are unlikely to capture the complexity or ubiquity of exposure [116]. WHO Global Air Quality Guidelines offer general advice on improving methodological quality [1 && ].…”