Secular Trends in the Incidence of and Mortality Due to Alzheimer's Disease and Other Forms of Dementia in China From 1990 to 2019: An Age-Period-Cohort Study and Joinpoint Analysis.

Yongliang Gao,Xiaonan Liu

doi:10.3389/fnagi.2021.709156

Abstract

BackgroundThe number of individuals with dementia is increasing, which negatively affects families, communities, and health care systems worldwide. The changes in the incidence of and mortality due to Alzheimer’s disease and other forms of dementia at the national level in China have remained unknown over the past three decades.MethodsFollowing the general analytical strategy used in the Global Burden of Disease Study (GBD) 2019, the age- and sex-specific incidence and mortality rates for dementia in China were analyzed. Trends in the incidence of and mortality due to dementia from 1990 to 2019 were assessed by joinpoint regression analysis. The effects of age, period and cohort on the incidence of and mortality due to dementia were estimated by an age-period-cohort model.ResultsThe age-standardized incidence and mortality rates per 100,000 population were 103.83 (95% UI, 87.93–118.87) and 23.32 (95% UI, 5.66–61.31), respectively, for dementia in 2019. From 1990 to 2019, a significant average annual percentage change (AAPC) in the age-standardized incidence rate was observed in both males [0.49% (95% CI, 0.43–0.55%)] and females [0.31% (95% CI, 0.24–0.38%)], and the age-standardized mortality rate significantly increased in males [0.42% (95% CI, 0.31–0.53%)]. The population aged 55–59 years had the highest AAPC in the incidence of dementia [0.87% (95% CI, 0.81–0.93%)]. The age effect showed that the relative risks (RRs) of incident dementia and dementia-associated mortality increased with age among males and females, and individuals aged 60 years and older had significantly higher RRs. The RR of incident dementia increased with time, and the RR started to substantially increase in 2009. The cohort effect showed that the incidence decreased in successive birth cohorts.ConclusionAlzheimer’s disease and other forms of dementia continue to become more common among males and females in China, and the associated mortality rate in males significantly increased from 1990 to 2019. Early interventions should be implemented to reduce the burden of dementia on individuals at high risk in China.

Highlights

With the aging of the global population, Alzheimer’s disease and other forms of dementia have become major and increasingly severe global public health threats (GBD 2016 Disease and Injury Incidence and Prevalence Collaborators, 2017)
The sex-specific, age-standardized incidence and mortality rates for dementia fluctuated by calendar year
The age-standardized incidence rate has increased over the three decades

Summary

Introduction

With the aging of the global population, Alzheimer’s disease and other forms of dementia have become major and increasingly severe global public health threats (GBD 2016 Disease and Injury Incidence and Prevalence Collaborators, 2017). In 2016, the global numbers of prevalent cases and deaths due to dementia were 43.8 million and 2.4 million, respectively (GBD 2016 Disease and Injury Incidence and Prevalence Collaborators, 2017). Dementia is the fifth leading cause of death worldwide (GBD 2016 Disease and Injury Incidence and Prevalence Collaborators, 2017). The World Alzheimer Report 2019 estimated that the global prevalence will increase to 152 million by 2050 (Alzheimer’s Disease International, 2019). Dementia is a more serious public health problem in lowand middle-income countries (GBD 2016 Disease and Injury Incidence and Prevalence Collaborators, 2017). The number of individuals with dementia is increasing, which negatively affects families, communities, and health care systems worldwide. The changes in the incidence of and mortality due to Alzheimer’s disease and other forms of dementia at the national level in China have remained unknown over the past three decades

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