by Alzheimer's Research UK

The study, which also shows that these inequalities in England are not replicated in other parts of the UK, is published in the journal Age and Ageing.

Four drugs can be used to treat the symptoms of Alzheimer's disease, the most common cause of dementia: three 'cholinesterase inhibitors' (called donepezil, rivastigmine and galantamine) and a fourth drug called memantine. Cholinesterase inhibitors may also be helpful for some symptoms of dementia with Lewy bodies. Currently, there are no treatments available for other forms of dementia, such as vascular dementia or frontotemporal dementia.

In recent years, changes in the National Institute for Health and Clinical Excellence (NICE) guidelines have extended the use of these drugs to more patients – having previously restricted them for use in certain stages of Alzheimer's disease only. In addition, National Dementia Strategies in England, Scotland and Wales – launched in 2009 and 2010 – included an aim of helping all people with dementia access appropriate treatments. Researchers at UCL (University College London) set out to investigate whether these policy changes had affected prescribing rates for dementia treatments.

Using The Health Improvement Network – a database of patient records from more than 500 GP practices across the UK – the researchers examined the treatments given to 77,045 people over the age 50 between 2002 and 2013. All the patients had either been diagnosed with dementia, or had been prescribed at least one anti-dementia drug during this period. Within the group, 30% had a diagnosis of Alzheimer's disease or mixed dementia, while 47% had a diagnosis of dementia, but had not been diagnosed with a specific form of the condition.

A total of 28,337 people (37%) had been prescribed anti-dementia drugs during the study period. When the researchers analysed the results, they found that people living in the wealthiest areas of England were 27% more likely to have been prescribed these treatments compared to people living in the most deprived areas. However, in Scotland, Wales and Northern Ireland this disparity was not seen. The study did not investigate the reasons behind these differences, though the researchers put forward some possible suggestions, including a hypothesis that wealthier people may be more successful at pushing for treatments.

Hilary Evans, Chief Executive of Alzheimer's Research UK, the UK's leading dementia research charity, said:

"Existing treatments for dementia can help people cope with some of their symptoms, and although they don't work for everyone, it's vital that they should be offered to all those who could benefit. This research reveals a worrying disparity in the way treatments are prescribed, but the results don't tell us what may have caused this. Further work will be crucial to understand the factors behind this inequality and to help ensure everyone has the same access to treatments that could help them. It will also be important to determine whether this disparity exists for treatments for other conditions, or only for dementia treatments.

"It's important to note that NICE only recommends these drugs for use in certain types of dementia, but as nearly half the group did not have a specific diagnosis we can't be certain how many people could potentially have benefited from one of these treatments. This study further underlines the importance of an accurate diagnosis in helping people to access the appropriate treatments, and the need for research to improve diagnostic accuracy."

Why is there such a difference between prescribing rates?

At the moment, we can't be sure, as the study wasn't designed to investigate the underlying reasons behind any differences in prescribing rates. A number of factors could explain the results, but further research is necessary to understand what's driven this trend.

The researchers put forward a number of different theories. They suggest that more well-off people may be better able to push for an earlier diagnosis and for treatments, or that GPs may be less well-resourced in more deprived areas. Another theory is that more deprived areas may have a higher proportion of people with vascular dementia, for which there are currently no treatments available.

We don't yet have evidence to know whether any of these theories hold water, but the research does highlight a worrying trend that should be investigated further.

Journal information: Age and Ageing 

Provided by Alzheimer's Research UK