Risk score for the prediction of dementia risk in 20 years among middle aged people: a longitudinal, population-based study

BACKGROUND Several vascular risk factors are associated with dementia. We sought to develop a simple method for the prediction of the risk of late-life dementia in people of middle age on the basis of their risk profiles. METHODS Data were used from the population-based CAIDE study, which included 1409 individuals who were studied in midlife and re-examined 20 years later for signs of dementia. Several midlife vascular risk factors were studied to create the scoring tool. The score values were estimated on the basis of beta coefficients and the dementia risk score was the sum of these individual scores (range 0-15). FINDINGS Occurrence of dementia during the 20 years of follow-up was 4%. Future dementia was significantly predicted by high age (> or = 47 years), low education (< 10 years), hypertension, hypercholesterolaemia, and obesity. The dementia risk score predicted dementia well (area under curve 0.77; 95% CI 0.71-0.83). The risk of dementia according to the categories of the dementia risk score was 1.0% for those with a score of 0-5, 1.9% for a score of 6-7, 4.2% for a score of 8-9, 7.4% for a score of 10-11, and 16.4% for a score of 12-15. When the cut-off of 9 points or more was applied the sensitivity was 0.77, the specificity was 0.63, and the negative predictive value was 0.98. INTERPRETATION The dementia risk score is a novel approach for the prediction of dementia risk, but should be validated and further improved to increase its predictive value. This approach highlights the role of vascular factors in the development of dementia and could help to identify individuals who might benefit from intensive lifestyle consultations and pharmacological interventions.