International Variations in Dementia and Alzheimer Disease Diagnosis and Certification Habits and Their Associations With Dementia and Alzheimer Disease Mortality: A Cross-Sectional Study of 38 Countries

Abstract

Objective: To examine international variations in national diagnosis and certification habits prefer recording dementia (D) versus Alzhiemer disease (AD) as the underlying cause of death (UCOD) and their associations with mortality rates of dementia and AD.

Methods: We calculated proportions of D/D+AD and AD/D+AD deaths as proxies of national diagnosis and certification habits. Pearson correlation coefficients (r) were estimated to assess the associations of proportions with the mortality rates of dementia or AD among adults aged 75 to 84 years across 38 countries.

Results: The countries with a high preference for recording dementia as the UCOD were Taiwan and Latvia with proportion of D/D+AD deaths of 92% and 88%, respectively, and those with a high preference for recording AD as the UCOD were Slovenia, Turkey, and Poland with proportion of AD/D+AD deaths of 100%, 99%, and 89%, respectively. The r values for the proportions and mortality rate for dementia and AD were 0.67 (95% CI: 0.44-0.81) and 0.46 (95% CI: 0.16-0.68), respectively.

Conclusion: We identified a small number of countries with obvious natonal diagnosis and certification habits preferring dementia or AD and had moderate effects on international variations in the mortality rates of dementia and AD.