Tomoyuki Ohara1, Jun Hata2, Daigo Yoshida2, Naoko Mukai2, Masaharu Nagata2, Toru Iwaki2, Takanari Kitazono2, Shigenobu Kanba2, Yutaka Kiyohara2, Toshiharu Ninomiya2. 1. From the Departments of Neuropsychiatry (T.O., S.K.), Epidemiology and Public Health (T.O., J.H., D.Y., N.M., M.N., T.N.), Neuropathology (T.I.), and Medicine and Clinical Science (J.H., N.M., M.N., T.K.), and Center for Cohort Studies (J.H., D.Y., N.M., T.K., T.N.), Graduate School of Medical Sciences, Kyushu University; and Hisayama Research Institute for Lifestyle Diseases (Y.K.), Fukuoka, Japan. ohara77@npsych.med.kyushu-u.ac.jp. 2. From the Departments of Neuropsychiatry (T.O., S.K.), Epidemiology and Public Health (T.O., J.H., D.Y., N.M., M.N., T.N.), Neuropathology (T.I.), and Medicine and Clinical Science (J.H., N.M., M.N., T.K.), and Center for Cohort Studies (J.H., D.Y., N.M., T.K., T.N.), Graduate School of Medical Sciences, Kyushu University; and Hisayama Research Institute for Lifestyle Diseases (Y.K.), Fukuoka, Japan.
Abstract
OBJECTIVE: To investigate secular trends in the prevalence, incidence, and survival rate of dementia in a Japanese elderly population in a comprehensive manner. METHODS: Five cross-sectional surveys of dementia were conducted among residents of a Japanese community, aged ≥65 years, in 1985, 1992, 1998, 2005, and 2012. We also established 2 cohorts consisting of the residents of this age group without dementia in 1988 (n = 803) and 2002 (n = 1,231), and each was followed for 10 years. RESULTS: The age-standardized prevalence of all-cause dementia and Alzheimer disease (AD) increased with time (for all-cause dementia: 6.8% in 1985, 4.6% in 1992, 5.3% in 1998, 8.4% in 2005, and 11.3% in 2012, p for trend <0.01; for AD: 1.5%, 1.4%, 2.4%, 3.9%, and 7.2%, respectively, p for trend <0.01), while no secular change was observed for vascular dementia (VaD) (2.4%, 1.6%, 1.5%, 2.4%, and 2.4%, respectively, p for trend = 0.59). The age- and sex-adjusted incidence of all-cause dementia and AD, but not VaD, increased from the 1988 cohort to the 2002 cohort (for all-cause dementia: adjusted hazard ratio [aHR] 1.68, 95% confidence interval [CI] 1.38-2.06; for AD: aHR 2.07, 95% CI 1.59-2.70; for VaD: aHR 1.18, 95% CI 0.83-1.69). The 5-year survival rate of all-cause dementia and AD improved from the 1988 cohort to the 2002 cohort (for all-cause dementia: 47.3% to 65.2%; for AD: 50.7% to 75.1%; all p < 0.01). CONCLUSIONS: The increased incidence and improved survival rate of AD could have resulted in the steep increase in AD prevalence in the Japanese elderly.
OBJECTIVE: To investigate secular trends in the prevalence, incidence, and survival rate of dementia in a Japanese elderly population in a comprehensive manner. METHODS: Five cross-sectional surveys of dementia were conducted among residents of a Japanese community, aged ≥65 years, in 1985, 1992, 1998, 2005, and 2012. We also established 2 cohorts consisting of the residents of this age group without dementia in 1988 (n = 803) and 2002 (n = 1,231), and each was followed for 10 years. RESULTS: The age-standardized prevalence of all-cause dementia and Alzheimer disease (AD) increased with time (for all-cause dementia: 6.8% in 1985, 4.6% in 1992, 5.3% in 1998, 8.4% in 2005, and 11.3% in 2012, p for trend <0.01; for AD: 1.5%, 1.4%, 2.4%, 3.9%, and 7.2%, respectively, p for trend <0.01), while no secular change was observed for vascular dementia (VaD) (2.4%, 1.6%, 1.5%, 2.4%, and 2.4%, respectively, p for trend = 0.59). The age- and sex-adjusted incidence of all-cause dementia and AD, but not VaD, increased from the 1988 cohort to the 2002 cohort (for all-cause dementia: adjusted hazard ratio [aHR] 1.68, 95% confidence interval [CI] 1.38-2.06; for AD: aHR 2.07, 95% CI 1.59-2.70; for VaD: aHR 1.18, 95% CI 0.83-1.69). The 5-year survival rate of all-cause dementia and AD improved from the 1988 cohort to the 2002 cohort (for all-cause dementia: 47.3% to 65.2%; for AD: 50.7% to 75.1%; all p < 0.01). CONCLUSIONS: The increased incidence and improved survival rate of AD could have resulted in the steep increase in AD prevalence in the Japanese elderly.
Authors: Sujuan Gao; Heather N Burney; Chris M Callahan; Christianna E Purnell; Hugh C Hendrie Journal: J Am Geriatr Soc Date: 2019-06-20 Impact factor: 5.562