P3-046: Predicting dementia using instrumental activities of daily living in the development of screening guidelines and diagnostic criteria for predementia Alzheimer's disease study

Abstract

For diagnosing dementia, DSM-IV requires a decline from a previous level of functioning. This decline is generally measured with scales assessing instrumental activities of daily living (IADL). IADL are complex activities of daily living necessary for independent living, such as cooking and handling finances. Objective; The aim of this study is to evaluate the use of IADL in predicting dementia in people at risk for dementia. This study is part of the DESCRIPA (Development of Screening Guidelines and Diagnostic Criteria for Predementia Alzheimer's disease) study. This European cohort study consists of non-demented people aged 55 years and older attending a memory clinic. IADL was assessed using the Lawton & Brody IADL, Blessed DS, ADCS-ADL, Bayer ADL and Bristol ADL scale. To investigate whether IADL predicted dementia, baseline scores of the Blessed DS and Lawton & Brody IADL scale were compared with one year follow-up diagnosis of dementia using logistic regression. Explorative analyses were performed to compare item content of the different IADL scales, compose general IADL items and investigate whether these items could predict dementia. A total of 383 subjects were included in this study. The conversion rate to dementia (AD) was 12% at one year follow-up. The majority did not perceive problems in IADL at baseline. Lawton & Brody and Blessed DS total scores did not predict dementia (AUC=.59 and AUC=.52). Preliminary analysis showed that, when corrected for age and baseline MMSE, only one item of each scale remained in the best predictive model for dementia. For the Lawton & Brody, this item was ‘responsibility for own medication' and for the Blessed DS ‘the inability to interpret surroundings'. Currently used IADL scales are not helpful in predicting dementia at one year follow-up in a memory clinic setting. However, more up-to-date items are needed as these might predict dementia. This needs further investigation.