Quality of life and Alzheimer's assessed

A decline in cognitive functions does not necessarily mean lower health-related quality of life for people diagnosed with mild to moderate Alzheimer's disease, new research suggests.

Undertaken by The University of Western Australia and Royal Perth Hospital, the 18-month longitudinal study is the first to investigate associations between quality of life and cognitive functions for people with Alzheimer's, as reported by patients and carers.

Surprisingly, researchers found that 26 of 47 participants with the disease showed stable or increased quality of life despite deterioration in their conditions.

Twenty of 47 family carers reported similar views.

Dr Pascalle Bosboom says this challenges current assumptions.

"The results raise questions regarding the assumption that improved memory scores associated with interventions will lead to improve health-related quality of life ratings," Dr Bosboom says.

"They may also suggest that as the disease progresses, the increasing severity of cognitive deficits is offset by decreasing awareness of impairment, and that this may override the impact of cognitive changes on the quality of life scores of people with the disease."

Dr Bosboom says the results indicate that interventions intended to improve quality of life might benefit from widening their focus from cognitive function to include areas such as anxiety and depression.

A large proportion of people with Alzheimer's disease are affected by behavioural and psychological symptoms of dementia (BPSD), which include agitation, aggression, depression, hallucinations, delusions and sleep disturbances.

Improving BPSD could help increase quality of life and perhaps even allow individuals to delay moving from their homes to residential care.

"If improving the quality of life of people with Alzheimer's disease is the ultimate aim of our interventions, then factors other than the increase of scores on cognitive tests should gain greater prominence in our treatment plans," Dr Bosboom says.

The study used the Quality of Life-AD scale, the Cambridge Cognitive Examination of the Elderly as well as a broad range of established neuropsychological tests to assess cognitive functions such as episodic memory, naming, language comprehension, word fluency, psychomotor speed, working memory, visuospatial skills and executive functions.

Demographic, lifestyle and medical background information were also collected at baseline and 18 months.

The researchers note that study participants were volunteers with mild to moderate dementia living in the community and that they may not represent those with more advanced illness living in residential care facilities.

They also concede the study's sample size as a limitation, and advocate for further testing of their findings.