The Prevalence and Incidence of Frontotemporal Dementia: a Systematic Review.
BACKGROUND
Population-based prevalence and incidence studies are essential for understanding the burden of frontotemporal dementia (FTD).


METHODS
The MEDLINE and EMBASE databases were searched to identify population-based publications from 1985 to 2012, addressing the incidence and/or prevalence of FTD. References of included articles and prior systematic reviews were searched for additional studies. Two reviewers screened all abstracts and full-text reviews, abstracted data and performed quality assessments.


RESULTS
Twenty-six studies were included. Methodological limitations led to wide ranges in the estimates for prevalence (point prevalence 0.01-4.6 per 1000 persons; period prevalence 0.16-31.04 per 1000 persons) and incidence (0.0-0.3 per 1000 person-years). FTD accounted for an average of 2.7% (range 0-9.1%) of all dementia cases among prevalence studies that included subjects 65 and older compared to 10.2% (range 2.8-15.7%) in studies restricted to those aged less than 65. The cumulative numbers of male (373 [52.5%]) and female (338 [47.5%]) cases from studies reporting this information were nearly equal (p=0.18). The behavioural variant FTD (bvFTD) was almost four times as common as the primary progressive aphasias.


CONCLUSIONS
Population-based estimates for the epidemiology of FTD varied widely in the included studies. Refinements in the diagnostic process, possibly by the use of validated biomarkers or limiting case ascertainment to specialty services, are needed to obtain more precise estimates of the prevalence and incidence of FTD.
1Brenda Strafford Chair in Geriatric Medicine,University of Calgary,Calgary,Alberta,Canada.
David B
DB
Hogan
2Hotchkiss Brain Institute,University of Calgary,Calgary,Alberta,Canada.
Nathalie
N
Jetté
2Hotchkiss Brain Institute,University of Calgary,Calgary,Alberta,Canada.
Kirsten M
KM
Fiest
2Hotchkiss Brain Institute,University of Calgary,Calgary,Alberta,Canada.
Jodie I
JI
Roberts
5Department of Clinical Neurosciences,University of Calgary,University of Calgary,Calgary,Alberta,Canada.
Dawn
D
Pearson
2Hotchkiss Brain Institute,University of Calgary,Calgary,Alberta,Canada.
Eric E
EE
Smith
4Department of Community Health Sciences,University of Calgary,University of Calgary,Calgary,Alberta,Canada.
Pamela
P
Roach
7Department of Medicine,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
Andrew
A
Kirk
2Hotchkiss Brain Institute,University of Calgary,Calgary,Alberta,Canada.
Tamara
T
Pringsheim
4Department of Community Health Sciences,University of Calgary,University of Calgary,Calgary,Alberta,Canada.
Colleen J
CJ
Maxwell
D005260:Female; D057180:Frontotemporal Dementia / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence
Alzheimer’s Disease; Dementia; Frontotemporal Dementia; Lewy Body Dementia; meta-analysis; systematic review