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].