Prevalence of dementia and major dementia subtypes in Spanish populations: a reanalysis of dementia prevalence surveys, 1990-2008.
BACKGROUND
This study describes the prevalence of dementia and major dementia subtypes in Spanish elderly.


METHODS
We identified screening surveys, both published and unpublished, in Spanish populations, which fulfilled specific quality criteria and targeted prevalence of dementia in populations aged 70 years and above. Surveys covering 13 geographically different populations were selected (prevalence period: 1990-2008). Authors of original surveys provided methodological details of their studies through a systematic questionnaire and also raw age-specific data. Prevalence data were compared using direct adjustment and logistic regression.


RESULTS
The reanalyzed study population (aged 70 year and above) was composed of Central and North-Eastern Spanish sub-populations obtained from 9 surveys and totaled 12,232 persons and 1,194 cases of dementia (707 of Alzheimer's disease, 238 of vascular dementia). Results showed high variation in age- and sex-specific prevalence across studies. The reanalyzed prevalence of dementia was significantly higher in women; increased with age, particularly for Alzheimer's disease; and displayed a significant geographical variation among men. Prevalence was lowest in surveys reporting participation below 85%, studies referred to urban-mixed populations and populations diagnosed by psychiatrists.


CONCLUSIONS
Prevalence of dementia and Alzheimer's disease in Central and North-Eastern Spain is higher in females, increases with age, and displays considerable geographic variation that may be method-related. People suffering from dementia and Alzheimer's disease in Spain may approach 600,000 and 400,000 respectively. However, existing studies may not be completely appropriate to infer prevalence of dementia and its subtypes in Spain until surveys in Southern Spain are conducted.
National Centre for Epidemiology, CIBERNED and Alzheimer' Disease Research Unit, Carlos III Institute of Public Health, Madrid, Spain. jpedro@isciii.es
Jesús
J
de Pedro-Cuesta
Javier
J
Virués-Ortega
Saturio
S
Vega
Manuel
M
Seijo-Martínez
Pedro
P
Saz
Fernanda
F
Rodríguez
Angel
A
Rodríguez-Laso
Ramón
R
Reñé
Susana Pérez
SP
de las Heras
Raimundo
R
Mateos
Pablo
P
Martínez-Martín
José María
JM
Manubens
Ignacio
I
Mahillo-Fernandez
Secundino
S
López-Pousa
Antonio
A
Lobo
Jordi Llinàs
JL
Reglà
Jordi
J
Gascón
Francisco José
FJ
García
Manuel
M
Fernández-Martínez
Raquel
R
Boix
Félix
F
Bermejo-Pareja
Alberto
A
Bergareche
Julián
J
Benito-León
Ana
A
de Arce
José Luis
JL
del Barrio
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D018579:Patient Selection; D015995:Prevalence; D012424:Rural Population; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014505:Urban Population