Dementia, stroke and Parkinson's disease in Spanish populations: a review of door-to-door prevalence surveys.

We identified 14 door-to-door prevalence surveys on dementia, parkinsonism or stroke in Spanish populations fulfilling specific criteria and combined selected age- and sex-specific data using logistic regression and taking Pamplona as a reference. The prevalence of dementia and of Alzheimer's disease varied significantly with space. However, the largest variation was seen for vascular dementia: odds ratio (OR) and 95% confidence interval (CI) for Gerona were 6.42 (3.23-12.3) in women and 2.30 (1.10-4.79) in men. Stroke was particularly frequent among Arevalo's women, with OR 2.10 and 95% CI 1.26-3.49. The prevalence of Parkinson's disease was twofold higher in Cantalejo. Although differences in methodology make the interpretation of results problematic, the prevalence of stroke and vascular dementia in Spain seems to vary spatially, indicating a space for prevention.