There’s an order to things: Item response theory as a way to make sense of functional decline in dementia

Sarah McGrory is a PhD Student at the Alzheimer Scotland Dementia Research Centre at the University of Edinburgh. She Tweets at @ alzscotdrcfunctional decline

Are some activities harder than others for people with dementia? In our research, recently reported in Age and Ageing, we looked at how people with dementia differed in their day to day activities. 202 people with mostly mild to moderate dementia in Scotland were asked about their activities

Activities (using the telephone, shopping, food preparation, housekeeping, laundry, travelling, taking medications, handling finances) can be measured using a questionnaire called the Lawton Instrumental Activities of Daily Living (IADL) scale. Usually scores on the individual tasks are added together to give a total score ranging from 0 to 8. This number can hide a lot of information about a patient’s functional ability. It assumes every functional activity is equally difficult, which is rarely the case. For example, being able to manage your finances is likely to be harder for most people than being able to eat. Continue reading