F3‐02‐03: MCI in Germany: Results from the AgCoDe and the LEILA75+ Study

Abstract

Mild Cognitive Impairment (MCI) is a condition of considerable clinical interest because it constitutes a pre-stage of dementia in many cases. Estimates of prevalence, age- and gender-specific incidence of MCI, risk factors for incident MCI in two samples (a population-based sample and a sample of GP patients) of cognitively healthy subjects aged 75 years and older. Furthermore data on progression to dementia are given and ways to improve prediction of dementia are searched. Data were derived from the primary-care-based German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe) with n = 3327 individuals 75+ at baseline and the population-based Leipzig Longitudinal Study of the Aged (LEILA75+) with n=1378 individuals 75+ at baseline. Study participants were assessed at 1.5year assessment intervals. Diagnosis were made using standardized criteria. Incidence rates were calculated according to the ‘person-years-at-risk’ method. Risk factors for MCI were analysed using multivariate logistic regression models and Cox proportional hazards models. The impact of MCI and IADL impairment on incident dementia was analysed using Receiver Operating Characteristic, Kaplan-Meier survival analyses and Cox proportional hazards models. MCI is a common condition with 15.4% (95% CI: 14.1-16.6) in the Age code and 19.3% (95% CI: 16.8-21.8) in the LEILA75+ study. The overall incidence rates of MCI for subjects aged 75 years and older was 76.5 (95%-PCI = 64.7-90.4) (LEILA 75+) and 56.5 (95% CI = 50.7-62.7) (Age code) per 1,000 person-years. The incidence rates were highest in age group 85+ years. Older age, vascular diseases, the APOE-e4 allele, subjective memory complaints, impairment in instrumental activities of daily living, and lower cognitive performance were identified as significant risk factors for future MCI. Predicting progression to dementia can be improved by considering impairment in instrumental activities of daily living (IADL). MCI and IADL impairment were found to be significantly associated with higher conversion to, shorter time to, and better predictive power for future dementia. MCI is a common condition. Subjective memory complaints in previously cognitively healthy individuals should be taken seriously as a possible pre-stage of MCI. Especially vascular risk factors provide the opportunity of preventive approaches. The inclusion of restrictions in instrumental activities of daily living in the criteria of MCI particularly might be useful to improve the prediction of dementia.