OBJECTIVE: The oldest old are the fastest growing segment of the US population, and accurate estimates of dementia incidence in this group are crucial for healthcare planning. Although dementia incidence doubles every 5 years from ages 65 to 90 years, it is unknown if this exponential increase continues past age 90 years. Here, we estimate age- and sex-specific incidence rates of all-cause dementia in people aged 90 years and older, including estimates for centenarians. METHODS: Participants are from The 90+ Study, a population-based longitudinal study of aging and dementia. Three hundred thirty nondemented participants aged 90 years and older at baseline were followed between January 2003 and December 2007. Age- and sex-specific incidence rates of all-cause dementia were estimated by person-years analysis. RESULTS: The overall incidence rate of all-cause dementia was 18.2% (95% confidence interval [CI], 15.3-21.5) per year and was similar for men and women (risk ratio, 0.94; 95% CI, 0.65-1.37). Rates increased exponentially with age from 12.7% per year in the 90-94-year age group, to 21.2% per year in the 95-99-year age group, to 40.7% per year in the 100+-year age group. The doubling time based on a Poisson regression was 5.5 years. INTERPRETATION: Incidence of all-cause dementia is very high in people aged 90 years and older and continues to increase exponentially with age in both men and women. Projections of the number of people with dementia should incorporate this continuing increase of dementia incidence after age 90 years. Our results foretell the growing public health burden of dementia in an increasingly aging population.
OBJECTIVE: The oldest old are the fastest growing segment of the US population, and accurate estimates of dementia incidence in this group are crucial for healthcare planning. Although dementia incidence doubles every 5 years from ages 65 to 90 years, it is unknown if this exponential increase continues past age 90 years. Here, we estimate age- and sex-specific incidence rates of all-cause dementia in people aged 90 years and older, including estimates for centenarians. METHODS:Participants are from The 90+ Study, a population-based longitudinal study of aging and dementia. Three hundred thirty nondemented participants aged 90 years and older at baseline were followed between January 2003 and December 2007. Age- and sex-specific incidence rates of all-cause dementia were estimated by person-years analysis. RESULTS: The overall incidence rate of all-cause dementia was 18.2% (95% confidence interval [CI], 15.3-21.5) per year and was similar for men and women (risk ratio, 0.94; 95% CI, 0.65-1.37). Rates increased exponentially with age from 12.7% per year in the 90-94-year age group, to 21.2% per year in the 95-99-year age group, to 40.7% per year in the 100+-year age group. The doubling time based on a Poisson regression was 5.5 years. INTERPRETATION: Incidence of all-cause dementia is very high in people aged 90 years and older and continues to increase exponentially with age in both men and women. Projections of the number of people with dementia should incorporate this continuing increase of dementia incidence after age 90 years. Our results foretell the growing public health burden of dementia in an increasingly aging population.
Authors: R Sulkava; K Kainulainen; A Verkkoniemi; L Niinistö; E Sobel; Z Davanipour; T Polvikoski; M Haltia; K Kontula Journal: Neurobiol Aging Date: 1996 May-Jun Impact factor: 4.673
Authors: L Letenneur; L J Launer; K Andersen; M E Dewey; A Ott; J R Copeland; J F Dartigues; P Kragh-Sorensen; M Baldereschi; C Brayne; A Lobo; J M Martinez-Lage; T Stijnen; A Hofman Journal: Am J Epidemiol Date: 2000-06-01 Impact factor: 4.897
Authors: L Fratiglioni; L J Launer; K Andersen; M M Breteler; J R Copeland; J F Dartigues; A Lobo; J Martinez-Lage; H Soininen; A Hofman Journal: Neurology Date: 2000 Impact factor: 9.910
Authors: L J Launer; K Andersen; M E Dewey; L Letenneur; A Ott; L A Amaducci; C Brayne; J R Copeland; J F Dartigues; P Kragh-Sorensen; A Lobo; J M Martinez-Lage; T Stijnen; A Hofman Journal: Neurology Date: 1999-01-01 Impact factor: 9.910
Authors: Wenna Duan; Parshant Sehrawat; Arvind Balachandrasekaran; Ashish B Bhumkar; Paresh B Boraste; James T Becker; Lewis H Kuller; Oscar L Lopez; H Michael Gach; Weiying Dai Journal: J Alzheimers Dis Date: 2020 Impact factor: 4.472
Authors: Michal Schnaider Beeri; Erin Moshier; James Schmeidler; James Godbold; Jaime Uribarri; Sarah Reddy; Mary Sano; Hillel T Grossman; Weijing Cai; Helen Vlassara; Jeremy M Silverman Journal: Mech Ageing Dev Date: 2011-11-03 Impact factor: 5.432
Authors: Szofia S Bullain; Maria M Corrada; Barbara Agee Shah; Farah H Mozaffar; Martina Panzenboeck; Claudia H Kawas Journal: JAMA Neurol Date: 2013-01 Impact factor: 18.302
Authors: Amy R Borenstein; Yougui Wu; James D Bowen; Wayne C McCormick; Jay Uomoto; Susan M McCurry; Gerard D Schellenberg; Eric B Larson Journal: Alzheimer Dis Assoc Disord Date: 2014 Jan-Mar Impact factor: 2.703