Discussion
This overall aim of this study was to examine prescribing trends and
associated costs of anti-dementia drugs in primary care in England and
to investigate the impact of deprivation, regional demography and
disease prevalence on prescribing practices and patient access to these
drugs. This study demonstrates a three-fold rise in prescribing of
anti-dementia drugs in England in the last 10 years. The increase is
reflective of the policy emphases on the early and better diagnosis and
management of dementia in primary care in England. Alzheimer’s disease
and other dementias currently rank as the leading and second most common
cause of death amongst females and males in England respectively
[19]. In 2011 and 2014, there were updates to the coding framework
in primary care used to code the cause of death. These changes also
required dementia to be identified as the underlying cause of death
rather than ‘other health conditions’. An updated national strategy has
been launched in 2020 in England which aims to continue to emphasise
early diagnoses, treatment and support for investigation and provision
of newer therapies [20]. The prescription data analysed in this
study triangulates well with the increasing prevalence and mortality
data.
The number of prescription items for the NMDA receptor antagonist,
memantine, presented the largest percentage increase over the 10-year
period. This notable increase emerged in 2011 and may be causally linked
with an update to the NICE guidelines in the same year. Prior to 2011,
memantine was only recommended for use in clinical trials for patients
with moderate to severe AD [21]. However, following the update to
the NICE guidelines, memantine was recommended for patients with
moderate to severe AD who had a contraindication to AChE inhibitors
[22]. This increase in prescribing of memantine in 2011 is
concurrent with the trends observed in another study [23].
From 2009 to 2019, the cost per item of all anti-dementia drugs (BNF
Section 4.11) decreased by over 50%. Donepezil and memantine saw the
largest reduction in this value, decreasing by 98.8% and 92.9%
respectively. The observed reduction in costs coincides with
galantamine’s patent in January 2012, donepezil’s in February 2012 and
rivastigmine’s in July 2012. Memantine, the NMDA receptor antagonist,
lost exclusivity in April of 2014.
Analysis at Clinical Commissioning Group level found an inverse
relationship between deprivation and prescribing patterns. This is
concurrent with previous findings reporting that in English practices,
patients with dementia are 27% more likely to receive a dementia
prescription in the least deprived areas compared with those in the most
deprived areas [24]. Furthermore, these differences could be related
to factors affecting life expectancy based on deprivation considering
the late onset feature of dementia.
The variations in prescribing rates were higher in the most deprived
regions compared to the least deprived regions. Regional variations in
prescribing rates were also observed with no clear cut ‘North-South’
divide observed in the datasets. The data is suggestive of the presence
of pockets of ‘deprivation’ and ‘affluence’ in all regions [25, 26].
These differences need to be investigated further.
This study also shows that prescription of all antipsychotic medication
increased during the 10-year study period. The National Dementia
Strategy (NDS) published in 2009 aimed to reduce antipsychotic use among
people with dementia, however, the trends in prescribing of
antipsychotics from 2009 to 2019 has not reflected a change in
prescribing practices [4, 27]. Previous studies which has looked
into prescribing of antipsychotics following the launch of the NDS, also
suggested no notable change in prescribing rates 4 years following the
implementation of this strategy [6].