Population-based neuropathological studies of dementia: design, methods and areas of investigation--a systematic review.
BACKGROUND
Prospective population-based neuropathological studies have a special place in dementia research which is under emphasised.


METHODS
A systematic review of the methods of population-based neuropathological studies of dementia was carried out. These studies were assessed in relation to their representativeness of underlying populations and the clinical, neuropsychological and neuropathological approaches adopted.


RESULTS
Six studies were found to be true population-based neuropathological studies of dementia in the older people: the Hisayama study (Japan); Vantaa 85+ study (Finland); CC75C study (Cambridge, UK); CFAS (multicentre, UK); Cache County study (Utah, USA); HAAS (Hawaï, USA). These differ in the core characteristics of their populations. The studies used standardised neuropathological methods which facilitate analyses on: clinicopathological associations and confirmation of diagnosis, assessing the validity of hierarchical models of neuropathological lesion burden; investigating the associations between neuropathological burden and risk factors including genetic factors. Examples of findings are given although there is too little overlap in the areas investigated amongst these studies to form the basis of a systematic review of the results.


CONCLUSIONS
Clinicopathological studies based on true population samples can provide unique insights in dementia. Individually they are limited in power and scope; together they represent a powerful source to translate findings from laboratory to populations.
Zaccai
Julia
J
Department of Public Health and Primary Care, University of Cambridge, Cambridge CB2 2SR, UK. jhz21@cam.ac.uk
Ince
Paul
P
Brayne
Carol
C
D000368:Aged; D000369:Aged, 80 and over; D001213:Asian; D001344:Autopsy / Q000706:statistics & numerical data; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D015140:Dementia, Vascular / Q000453:epidemiology / Q000473:pathology; D015340:Epidemiologic Research Design; D005260:Female; D005387:Finland / Q000453:epidemiology; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015337:Multicenter Studies as Topic; D011446:Prospective Studies; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology; D014589:Utah / Q000453:epidemiology