Incidence of dementia over a period of 20 years in a Norwegian population

• Published in: Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring
• Main Authors: Bente Johnsen, Ieva Martinaityte, Tom Wilsgaard, Henrik Schirmer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: dementia; incidence; Norway; prevalence; Neurology. Diseases of the nervous system; RC346-429; Geriatrics; RC952-954.6; Tromsø; North Norway
• Online Access: https://doi.org/10.1002/dad2.12479; https://doaj.org/article/ea45fb023c82461489748703c9955977

Abstract INTRODUCTION In Norway, the prevalence of dementia is higher than in demographically comparable, high income countries, but reliable incidence studies are lacking. This study calculated the incidence of age‐specific dementia from 2000 to 2019. METHODS Participants from The Tromsø Study (n = 44,214) were included. Participants with a dementia diagnosis (n = 2049 cases) were identified. Poisson regression was used to calculate age‐specific yearly and 5‐year incidence rates from 2000 to 2019. RESULTS The incidence of dementia has decreased from 2000 to 2019. The trend was highly significant for ages of 60–99 years, and was similar for both sexes. DISCUSSION The incidence of dementia in North Norway has decreased over the past two decades similar to that in Western countries, indicating that the total prevalence is increasing due to an aging population. This decrease of incidence could introduce a reduction in future estimation of dementia prevalence.