Spatial Disparity and Factors Associated with Dementia Mortality: A Cross-Sectional Study in Zhejiang Province, China

Abstract BackgroundThere is evidence of spatial disparity in mortality from Alzheimer’s disease and other forms of dementia in China. Regional factors of physical and social features may be influencing this spatial disparity. However, there are few reports on dementia mortality in China, and the true extent of spatial disparity in dementia mortality across small regional localities is unclear. The majority of people who die from dementia are over 60 years old. This study aims to explore the geographical variations in dementia mortality, estimate the relative risk and identify districts at higher risk for intervention and further study.Methods We used surveillance data on deaths from Alzheimer’s disease and other forms of dementia in Zhejiang province from 2015–2019 to estimate the spatial risk of death from dementia using a Bayesian spatial model. We mapped predicted relative risk to visualize the risk of death from Alzheimer’s disease and other forms of dementia and to identify risk factors associated with dementia.ResultsA total of 30,398 deaths attributable to dementia as the underlying or related cause (multiple causes) were reported in 2015–2019. Counties and districts located in the southeast and west of Zhejiang province had significantly higher standard mortality ratios than others. The predicted mean relative risk was 0.98, with a range of 0.14 ~ 4.37. Counties and districts with a smaller proportion of residents aged 60 years or older, poorer economic status, inferior health resources and worse pollution had a higher risk of dementia death.ConclusionsThere is spatial disparity in dementia mortality across different districts in Zhejiang. Our study adds new evidence on the association between social and environmental factors and the risk of dementia death. Appropriate preventive health strategies can be developed to reduce such spatial disparity in the risk of dementia mortality.