Tag Archives: ageing

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. Reblogged from the British Geriatrics Society blog.functional 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.

Our research used a statistical technique called item response theory (IRT) to get more information from a questionnaire about function. IRT allows the different activities to be ranked according to their difficulty. This can be especially useful for assessing progression of cognitive impairment. Knowing the expected order of decline can help to monitor progression, so any changes from the usual course, or changes in rates of decline, can be identified and studied. IRT can help to identify key tasks in a scale, and can also show in what order tasks might become more difficult as dementia progresses.  To do this, though, clinicians and researchers have to record answers to every task on a scale, not just to the total number.

We found that the tasks included in the scale could be ordered by increasing difficulty from being able to use the telephone (easiest) to the ability to shop (most difficult). This means a person may be having problems shopping independently may showing the first sign of functional difficulties related to cognitive impairment. Problems with this task should alert doctors as a possible early symptom of cognitive decline. Recognising these early stages is very important and can help people live independently for as long as possible with the help of medications, family education and counselling.  Looking at the individual tasks within a scale instead of relying on the total score can help us to understand more about dementia progression and help us to identify care requirements for patients.


Chronic Disease begins in Childhood

dis_childThis blog was posted with the kind permission of the BGS Blog Team and
is an extract of a conference report from the British Geriatrics Society Spring 2013 Meeting in Belfast, by Liz Gill, Freelance Journalist.

Research is increasingly suggesting that old age is influenced by conditions and events in early life, a concept supported by data from The Irish Longitudinal Study on Ageing, TILDA, which has studied 8,500 people aged 50 and over for the past ten years. behaviour, family background and use of health care. They were then revisited every two years providing a rich set of data involving almost one in every 140 people in Ireland.

The study is already shedding light on the biology of ageing as well as allowing for the rapid transfer of findings into policy. For example, it has unearthed a huge discrepancy between reported health and objective health in conditions such as atrial fibrillation, hypertension, osteoporosis and the risk of polypharmacy,  prompting new awareness campaigns.

One of its most interesting findings is the influence of the early years, as Dr Cathal McCrory, TILDA research fellow, explains. “Poor health in childhood increases the risk of cardiovascular disease, arthritis, cancer, lung disease and psychiatric disorders. The lower the social class in childhood the higher the blood pressure and body mass index in adulthood. Parental illness, family dysfunction, neglect, abuse and poverty which probably means poor nutrition and overcrowding, all chip away at physical and mental health. They may even influence the foetus: developing systems may be particularly vulnerable to adversity.”

What happens is that stress hormones are released as a fight or flight reaction to perceived threats increasing blood pressure and heart rate. A young body can cope over a short period but chronic activation can lead to long term problems. “Childhood really is a critical period. The more challenges a child faces the more likelihood he or she is to develop disease later in life.”