BACKGROUND: 100 years after the first description, Alzheimer's disease is one of the most disabling and burdensome health conditions worldwide. We used the Delphi consensus method to determine dementia prevalence for each world region. METHODS: 12 international experts were provided with a systematic review of published studies on dementia and were asked to provide prevalence estimates for every WHO world region, for men and women combined, in 5-year age bands from 60 to 84 years, and for those aged 85 years and older. UN population estimates and projections were used to estimate numbers of people with dementia in 2001, 2020, and 2040. We estimated incidence rates from prevalence, remission, and mortality. FINDINGS: Evidence from well-planned, representative epidemiological surveys is scarce in many regions. We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year (one new case every 7 seconds). The number of people affected will double every 20 years to 81.1 million by 2040. Most people with dementia live in developing countries (60% in 2001, rising to 71% by 2040). Rates of increase are not uniform; numbers in developed countries are forecast to increase by 100% between 2001 and 2040, but by more than 300% in India, China, and their south Asian and western Pacific neighbours. INTERPRETATION: We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.
BACKGROUND: 100 years after the first description, Alzheimer's disease is one of the most disabling and burdensome health conditions worldwide. We used the Delphi consensus method to determine dementia prevalence for each world region. METHODS: 12 international experts were provided with a systematic review of published studies on dementia and were asked to provide prevalence estimates for every WHO world region, for men and women combined, in 5-year age bands from 60 to 84 years, and for those aged 85 years and older. UN population estimates and projections were used to estimate numbers of people with dementia in 2001, 2020, and 2040. We estimated incidence rates from prevalence, remission, and mortality. FINDINGS: Evidence from well-planned, representative epidemiological surveys is scarce in many regions. We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year (one new case every 7 seconds). The number of people affected will double every 20 years to 81.1 million by 2040. Most people with dementia live in developing countries (60% in 2001, rising to 71% by 2040). Rates of increase are not uniform; numbers in developed countries are forecast to increase by 100% between 2001 and 2040, but by more than 300% in India, China, and their south Asian and western Pacific neighbours. INTERPRETATION: We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.
Authors: K M Langa; M E Chernew; M U Kabeto; A R Herzog; M B Ofstedal; R J Willis; R B Wallace; L M Mucha; W L Straus; A M Fendrick Journal: J Gen Intern Med Date: 2001-11 Impact factor: 5.128
Authors: H C Hendrie; B O Osuntokun; K S Hall; A O Ogunniyi; S L Hui; F W Unverzagt; O Gureje; C A Rodenberg; O Baiyewu; B S Musick Journal: Am J Psychiatry Date: 1995-10 Impact factor: 18.112
Authors: Rajesh S Pandav; Vijay Chandra; Hiroko H Dodge; Steven T DeKosky; Mary Ganguli Journal: Am J Geriatr Psychiatry Date: 2004 Sep-Oct Impact factor: 4.105
Authors: K Érsek; T Kovács; A Wimo; K Kárpati; V Brodszky; M Péntek; L Jönsson; A Gustavsson; D McDaid; P A Kenigsberg; H Valtonen; L Gulácsi Journal: J Nutr Health Aging Date: 2010-10 Impact factor: 4.075
Authors: Joe Verghese; Mohan L Noone; Beena Johnson; Anne F Ambrose; Cuiling Wang; Herman Buschke; Vayyattu G Pradeep; Kizhakkaniyakath Abdul Salam; Kunnukatil S Shaji; Pavagada S Mathuranath Journal: J Am Geriatr Soc Date: 2012-10-05 Impact factor: 5.562
Authors: Thomas Polak; Martin J Herrmann; Laura D Müller; Julia B M Zeller; Andrea Katzorke; Matthias Fischer; Fabian Spielmann; Erik Weinmann; Leif Hommers; Martin Lauer; Andreas J Fallgatter; Jürgen Deckert Journal: J Neural Transm (Vienna) Date: 2017-09-01 Impact factor: 3.575
Authors: Annie Robitaille; Ardo van den Hout; Robson J M Machado; David A Bennett; Iva Čukić; Ian J Deary; Scott M Hofer; Emiel O Hoogendijk; Martijn Huisman; Boo Johansson; Andriy V Koval; Maaike van der Noordt; Andrea M Piccinin; Judith J M Rijnhart; Archana Singh-Manoux; Johan Skoog; Ingmar Skoog; John Starr; Lisa Vermunt; Sean Clouston; Graciela Muniz Terrera Journal: Alzheimers Dement Date: 2018-02-01 Impact factor: 21.566
Authors: Kieu T T Phung; Monique Chaaya; Gunhild Waldemar; Samir Atweh; Khalil Asmar; Husam Ghusn; Georges Karam; Raja Sawaya; Rose Mary Khoury; Ibrahim Zeinaty; Sandrine Salman; Salem Hammoud; Wael Radwan; Nazem Bassil; Martin Prince Journal: J Geriatr Psychiatry Neurol Date: 2014-04-25 Impact factor: 2.680