Cases of Dementia Projected to Increase Worldwide

Data presented at the Alzheimer's Association International Congress July 26-30, 2021 show that all types of dementia have been on the rise in recent years and are predicted to increase further. Rates of early-onset dementia are also increasing, and in the US, mortality from Alzheimer diseae (AD) has risen substantially.

In the US over the last 20 years, there has been an 88% increase in AD-related death from 16 to 30 per 100,000. These data, however, showed great disparity between urban and rural areas and among different regions of the US. In southeastern rural areas, the AD mortality rate was 274 per 100,000 people over age 65, whereas in the midAtlantic urban regions it was 86 per 100,000 over age 65. 

“Our work shows that there is an increasing discrepancy in AD mortality between urban and rural areas. This discrepancy could be related to, or might be the result of, other urban-rural health disparities, including access to primary care and other health services, socioeconomic level, time to diagnosis, and the rising proportion of older Americans living in these areas,” said Ambar Kulshreshtha, MD, PhD, from Emory University. “Identifying and understanding the reasons for these health disparities is critical for allocating key social and public health resources appropriately.”

In a global analysis of dementia incidence, cases are predicted to triple by 2030. In the analysis, it was estimated that the number of individuals with dementia would increase from 57.4 million (95% CI: 50.4, 65.1) in 2019 to 152.8 million (95% CI: 130.8, 175.6) in 2050. The increase is possibly caused by population growth and aging and is most prevalent in eastern subSaharan Africa and North Africa and the Middle East. This data can be used to determine policy changes about funding for research and public health planning efforts. With the expected increase in dementia cases, modifiable risk factors will need to be addressed by scaling up interventions.

In a systematic review and meta-analysis, age-standardized incidence rates of early onset dementia in individuals less than age 65 was 11/100,000 person-years. In those age 30 to 34, incidence was 0.15 per 100,000 person-years, whereas in those age 60 to 64, incidence was 4.83 per 100,000 person years. These data correlate to 360,000 new cases of early onset dementia per year globally, and suggest that while incidence remains age-dependent, the typical age at onset may be decreasing.