Secular changes in dementia risk indices among 70-year-olds: a comparison of two Finnish cohorts born 20 years apart

AIMS: To compare dementia risk indices among two separate cohorts of 70-year-olds born 20 year apart. METHODS: Community-dwelling 70-year-old Finns were examined with similar examinations in 1991 (n = 1032) and in 2011 (n = 960). Dementia risk was assessed with the CAIDE Dementia Risk Score (CAIDE) (n = 1516), the Brief Dementia Risk Index (BDRI) (n = 1598) and the Dementia Screening Indicator (DSI) (n = 1462). RESULTS: The proportion of subjects with moderate or high risk for dementia was significantly higher in earlier than in later born cohort according to CAIDE (99% and 94%, respectively, p < 0.001) and BDRI (41% and 15%, p < 0.001), but not according to DSI (5% and 6%, p = 0.184). The total scores of the earlier born cohort were significantly higher than those of the later born cohort according to all three indices. CONCLUSIONS: According to dementia risk indices, it seems that dementia risk has decreased among community-dwelling 70-year-old subjects during the last decades in Finland.