5-YEAR INCIDENCE AND PREDICTION OF DEMENTIA AND COGNITIVE DECLINE IN A POPULATION-SAMPLE OF WOMEN AGED 70-79 AT BASE-LINE

Objective. To determine the incidence of dementia and cognitive declin e and their predictors in a population Sample. Settings. A rural geogr aphically defined population served by a single health centre. Sample. 75% of the 70-74-year-old, 100% of the 75-79-year-old women registere d with the practice. Method. Interview the total sample using an augme nted version of CAMDEX, including informant interview, and reaction ti mes at baseline and 5 years later. IQ was estimated at baseline only. Results: 365 women were interviewed at baseline, 237 at follow-up. Inc idence of dementia of all severities was 3.1% per annum (95% CI, 2.2-4 .3). CAMCOG declined by 12.6 points in those who became demented, MMSE by 3 points. Observed, self-reported and informant-reported cognitive difficulty at baseline all predicted later incidence of dementia. The additional use of estimated IQ and reaction times did not increase th e efficiency of either cross-sectional detection of dementia or predic tion of dementia at 5 years. Conclusions. The incidence of dementia wa s in the range reported by other studies; slight cognitive decline was noted in the total population, increasing with age and marked in inci dent dementia. Of clinical importance was the finding that both the in dividuals and the informants of those who subsequently demented were a ware of decline 5 years earlier. Simple and relatively easily administ ered cognitive tests were found to be the most efficient method of det ection of dementia. (C) 1997 John Wiley & Sons, Ltd.