Statistical commentary: Dementia profile, March 2021 update

New in this update

The Clinical Commissioning Group (CCG) wider impacts of COVID-19 on health (WICH) dementia surveillance factsheets are published through the dementia profile to accompany the national WICH monitoring tool published by Public Health England (PHE). The indicators included in the dementia surveillance factsheets are the estimated dementia diagnosis rate, recorded prevalence, care plan reviews and the primary care prescribing of antipsychotic medication. The factsheets are now available with January 2021 data and will be updated monthly. To access the factsheets from the dementia profile, click ‘start’ and select ‘reports’ from the ‘data view’ menu.

The antipsychotic prescribing statistical factsheets have been developed to provide statistics on the prescription of antipsychotic medication to people with a formal diagnosis of dementia and also provide details of the general characteristics of this population. The factsheets contain CCG and primary care level data up to December 2020. To access the factsheets from the dementia profile, click ‘start’ and select ‘reports’ from the ‘data view’ menu.

The dementia profile was updated in February with new data for 36 indicators. A full list of the updated indicators and new time periods can be found in the ‘recent updates’ section (February 2021) of the profile. Indicators have been backdated 3 years and use the latest geographical boundaries.

Summary

This briefing provides an analysis of the dementia and Alzheimer’s disease national data (England) from the WICH monitoring tool with additional analysis at CCG level.

The outbreak of coronavirus (COVID-19) has led to unprecedented changes in the work and behaviour of general practices, therefore data relating to any primary care activity undertaken or recorded during the pandemic (March 2020 onwards) should be interpreted with caution. All analyses included in this briefing compare the latest available data (December 2020, taken during the coronavirus pandemic) to values from time periods before the pandemic.

The main points for this update are:

• since April 2020, there has been a consistent pattern of lower diagnosed prevalence rates for dementia in over 65 year olds compared to before the pandemic

• since January 2020, there has been a consistent pattern of lower proportions of dementia patients receiving a care plan or review compared to before the pandemic, with the gap widening as the year progressed

• the variation across CCGs in England of the proportion of patients receiving a care plan or review has increased significantly in December 2020 compared to before the pandemic

• since March 2020, there has been a consistent pattern of higher antipsychotic prescribing rates for dementia patients compared to before the pandemic

Findings

COVID-19 context for the data analysis

The context for the development of the PHE WICH monitoring tool is to allow users to explore the indirect effects of the COVID-19 pandemic on the population’s health and wellbeing. By the end of February 2021, 3.7 million people in England had received at least 1 positive COVID-19 test result, 380,000 people had been admitted to hospital and 108,000 deaths had occurred within 28 days of a positive COVID-19 test result. However, around 17.0 million people in England have now received their first vaccination for COVID-19 and a further 591,000 people have received their second vaccination.

Since March 2020, the COVID-19 pandemic and resulting restriction of activity have impacted on the provision of health and social services in England. The lack of access to these routine services are having a major impact on the quality of life for people living with dementia and their carers along with overall health outcomes.

Dementia and Alzheimer’s disease estimated diagnosis rates (aged 65+)

The aspiration of the challenge on dementia 2020 is that two-thirds of people with dementia and Alzheimer’s disease have a formal diagnosis for their condition. In December 2020 in England, the estimated dementia and Alzheimer’s diagnosis rate was 62.4% (95.0% confidence interval (CI) 56.3 to 67.6). This was a decrease of 5.4 percentage points compared to December 2019, but the decrease was not statistically significant.

Figure 1 shows that since April 2020, there has been a consistent pattern of lower diagnosis rates when comparing the same months for each reporting year, but none of these changes are statistically different. April 2020 corresponds with the peak of the first wave of the coronavirus pandemic.

Figure 1: Dementia and Alzheimer’s disease estimated diagnosis rates (aged 65+) by month, England 2019 and 2020

CCG level data

Figure 2 shows the distribution of the estimated dementia diagnosis rates at CCG level for December 2019 and December 2020. The median value decreased between these time periods from 68.6% to 63.1%. There was substantial variation in diagnosis rates across CCGs in both years, with values ranging from 56.4% to 88.5% in 2019 and from 50.8% to 79.3% in 2020. However, there was no change in variation across CCGs in England between these time periods (F statistic = 1.37, p value = 0.07).

Figure 2: Distribution of dementia and Alzheimer’s disease estimated diagnosis rates (aged 65+), for CCGs in England 2019 and 2020

Dementia and Alzheimer’s disease prevalence rates (aged 65+)

The recorded prevalence rate for England was 4.0% (CI 4.0 to 4.0) of the over 65 patient population in December 2020. This rate is now significantly lower than the December baseline (average between 2017 and 2019), when the rate was 4.3% (CI 4.3 to 4.3).

Since April 2020, there has been a consistent pattern of significantly lower prevalence rates when comparing to the baseline, as shown in figure 3 below.

Figure 3: Dementia and Alzheimer’s disease prevalence rates (aged 65+) by month, England 2017 to 2020

CCG level data

The box plots in figure 4 show the distribution of the prevalence rates at CCG level in December for the baseline and for 2020. The median value decreased between these time periods from 4.3% to 4.0%. There was substantial variation in prevalence rates in both time periods, with values ranging from 3.4% to 5.4% over the baseline period and from 3.2% to 5.1% in 2020. However, there was no change in the variation across CCGs in England between these time periods (F statistic = 1.25, p value = 0.20).

Figure 4: Distribution of dementia and Alzheimer’s disease prevalence rates (aged 65+), for CCGs in England 2017 to 2020

Percentage of patients with dementia and Alzheimer’s disease with a care plan or care plan review in the preceding 12 months (all ages)

The percentage of patients (of all ages) diagnosed with dementia and Alzheimer’s disease in England who had received a care plan or care plan review in the preceding 12 months was 46.8% (CI 46.6 to 46.9) in December 2020. This rate is significantly lower than the December baseline (average between 2018 and 2019), when the figure was 63.1% (CI 62.9 to 63.4).

Figure 5 shows that since January 2020, there has been a consistent pattern of significantly lower proportions of patients receiving a care plan or review when compared to the baseline, with the gap widening as the year progressed.

Figure 5: Percentage of patients with dementia and Alzheimer’s disease with a care plan or care plan review in the preceding 12 months (all ages), England 2018 to 2020

CCG level data

The box plots in figure 6 show the distribution of the CCG proportions of patients with care plans or care plan reviews in the preceding 12 months for the December baseline and for December 2020. The median value decreased between these time periods from 63.4% to 47.3%. The box plots also show the interquartile range has increased between the 2 time periods (5.2 and 8.2 percentage points for the baseline and 2020 respectively). This is a significant increase in the variation across CCGs in England (F statistic = 0.57, p value = 0.00).

Figure 6: Distribution of CCG proportions of patients with dementia and Alzheimer’s disease with care plan or care plan review in the preceding 12 months (all ages), England 2018 to 2020

Proportion of patients with Dementia and Alzheimer’s disease prescribed antipsychotic medication in the preceding 6 weeks (all ages)

The proportion of patients with dementia and Alzheimer’s disease in England who were prescribed antipsychotic medication in the preceding 6 weeks was 10.1% (CI 10.1 to 10.2) in December 2020. This rate is significantly higher than the December baseline (average between 2018 and 2019), when the figure was 9.4% (CI 9.3 to 9.5).

Since March 2020, there has been a consistent pattern of significantly higher prescribing rates when comparing to the baseline, as shown in figure 7.

Figure 7: Proportion of patients with dementia and Alzheimer’s disease prescribed antipsychotic medication in the preceding 6 weeks (all ages), England 2018 to 2020

CCG level data

The box plots in figure 8 show the distribution of these proportions at CCG level for the December baseline and for December 2020. The median value increased between these time periods from 9.1% to 9.5%. There was relatively low variation in both time periods (interquartile ranges of 2.7 and 3.0 percentage points for 2018 to 2019 and 2020 respectively) although there were a substantial number of outliers. However, there was no change to the variation across CCGs in England between the baseline and 2020 (F statistic = 0.83, p value = 0.29).

Figure 8: Distribution of CCG proportions of patients with dementia and Alzheimer’s disease prescribed antipsychotic medication in the preceding 6 weeks (all ages), England 2018 to 2020

Background and further information

Wider impact of COVID-19 on health (WICH)

The WICH monitoring tool is a national tool published by PHE. The tool is designed to allow users to explore the indirect effects of the COVID-19 pandemic on the population’s health and wellbeing. This tool presents a range of health and wellbeing metrics in interactive plots that can be broken down to show differences between groups. For example, you can explore grocery purchasing habits by region or social class.

The dementia related topics covered by the national tool are the estimated dementia diagnosis rate, memory clinic referrals, recorded prevalence, care plan reviews and the prescription of antipsychotic medication. This tool currently contains baseline data up to December 2019, with activity data up to December 2020. The data is refreshed monthly. The dementia section of the tool can be found by selecting the ‘access to care’ group link and then the ‘dementia and Alzheimer’s’ theme.

Changes in the primary care system

The data analysed in this publication are taken from the Quality and Outcomes Framework (QOF) in operation in primary care in England. The objective of QOF is to improve the quality of care patients receive by rewarding practices for desirable behaviours. GPs are awarded points according to their activity and payments are usually determined by the number of points accrued.

However, the approach to QOF has been revised during the pandemic to reflect the impact of COVID-19 on general practice. Some points will still be based on practice performance, but the majority will be based on historic performance without considering any activity or recording in the financial year 2020 to 2021. Data for dementia care plans fall into this latter category and this needs to be borne in mind when interpreting the data.

Interpreting the data

For the England level figures, value changes are considered significant if the 95% confidence intervals do not overlap with the confidence intervals for the comparison value.

Changes in variation between CCGs are confirmed by comparing the variances from each time period in a 2-tailed Fisher’s F test. The key results of this test are the F statistic (the ratio of the variances) and the p value (the probability of there being no difference between the variances). An F value close to one represents similar variances and a p value of less than 0.05 shows statistically different variances.

Box plots are designed to give a quick overview of the distribution of values within a dataset. The middle line represents the median average, the middle point of the data set when sorted in ascending order. Half the scores are greater than or equal to this value and half are less.

The lower and upper sides of the box are the lower and upper quartiles respectively. 25% of scores fall below the lower quartile value and 75% of the scores fall below the upper quartile value. Subtracting the lower quartile from the upper quartile gives the interquartile range, which can be used to assess the amount of variation in the values.

The lines coming out of the box are referred to as whiskers and represent any values that fall outside of the lower or upper quartiles but remain inside a limit of 1.5 times the interquartile range from those quartiles. If a value exceeds this limit, it is considered an extreme value or outlier and is represented in the chart by a dot.

Definition of dementia

Dementia is an umbrella term for a group of diseases which permanently damage the brain. The 3 most common forms of dementia are Alzheimer’s disease (60% to 70% of all dementias), followed by vascular dementia (15% to 20%) and mixed dementia (10% to 15%).

For datasets in the dementia profile that use the International Classification of Diseases coding structure, dementia is defined as:

• F00 – dementia in Alzheimer’s disease

• F01 – vascular dementia

• F02 – dementia in other diseases classified elsewhere

• F03 – unspecified dementia

• G30 – Alzheimer’s disease

• G31.0 – circumscribed brain atrophy

• G31.8 – other specified degenerative diseases of nervous system

For the datasets in the dementia profile that use the read code classification, dementia is defined using the QOF business rules.

Dementia profile

The dementia profile was first published in January 2016. The profile now contains a total of 43 indicators distributed across 6 domains. The structure of the profile reflects the Organisation for Economic Cooperation and Development dementia pathway and the NHS England well pathway for dementia. The 6 domains are:

• prevalence

• preventing well

• diagnosing well

• living well

• supporting well

• dying well

Indicator data is presented at sustainability and transformation partnership (STP), clinical commissioning group (CCG) and local authority (LA) geographies and gives local commissioners and providers the information they need to benchmark current practice against other CCGs, LA’s and England. Data is available online and as a downloadable document. Data sources and indicator methodologies are available within the definitions section of the online version of the profile.

Responsible statisticians: Michael Jackson, Emma Hodges, Katie Dowden.

Product Lead: Julia Verne.

For queries relating to this publication, please contact mhdnin@phe.gov.uk