Diabetes in England: where are the hotspots?

According to GP practice data, around one in fifteen people aged 17+ in England had diabetes in 2016/17. That’s 3.1 million people diagnosed with diabetes, or 6.6% of everyone on a GP register aged 17 or older. Public Health England estimate that men are 26% more likely than women to have diabetes, and that 90% of cases are Type 2 diabetes.

The cost of medicines prescribed for diabetes was just under £1 billion in 2016 – the largest of any medicine category, and over 10% of the total cost of GP prescribing.

The prevalence of medical conditions is rarely the same across the country, and diabetes is no different – some areas of England have much higher rates than others. This blog post looks at which communities are most affected by diabetes, and why this might be.

Diabetes Hotspots

This table shows the local authority wards in England which we estimate have the highest rates of diagnosed diabetes. A map showing the whole of England is at the bottom of this page. The method for producing the estimates is described at the end of this post.

Table showing top 20 areas for diabetes prevalence in England

Like many other diseases, there is some association with areas that have poorer health, higher health deprivation, and older populations. Coastal communities in East Lincolnshire and West Norfolk are a familiar sight in rankings like these – Mablethorpe, for example, has the highest rates of medicine prescribing by GPs in England. So it is no surprise to see these areas listed here.

However, there are some differences. For most other diseases it would be unusual for areas of London, Leicester, Birmingham or Greater Manchester to be hotspots. This post will focus mainly on these areas which differ from typical patterns of disease prevalence.

Birmingham and Leicester

Some of the highest diabetes rates outside London are found in Birmingham and Leicester. In many areas this is likely to reflect differences in the ethnic composition of the population. Diabetes is nearly twice as common among Asian and Black ethnic groups as White, Mixed or other ethnic groups. Asian and Black people are also more likely to develop diabetes at a younger age. Ethnicity is not the only factor in diabetes, of course – risk is also related to age, family history, and excess weight for Type 2 diabetes.

Not all areas of Birmingham and Leicester have high diabetes rates. Areas in these cities with a high student population have low rates of diabetes, as we would expect given their younger age profile. This can also be seen in the area surrounding the Universities of Warwick (in Coventry) and Loughborough. Across England, the areas with lowest estimated prevalence of diabetes are those with high student populations.

Map of Birmingham showing diabetes prevalence by area

The darkest shaded areas on this map have diabetes prevalence above 11.7%, while the white-shaded areas have prevalence below 3.7%. A full colour scale is shown on the map at the bottom of the page. You’ll notice a grey area west of Birmingham – most GP practices in Dudley are not included in this data, so these areas are excluded.

London

A similar story is evident in the London area. The communities with the highest Black or Asian populations – e.g. parts of Ilford, Catford, northern Croydon, Hounslow, Southall, Wembley and Slough – also tend to be those with higher rates of diabetes.

Outside London, the picture changes somewhat. In Essex, Kent, and Sussex, diabetes prevalence is highest in coastal communities such as the Isle of Sheppey, East Kent, Romney Marsh, Bexhill, and Selsey in West Sussex. Most of these areas have a high proportion of people aged 65 or over, but diabetes prevalence in this region doesn’t directly track age structures.

Map showing diabetes prevalence in London area

North West England

Some of the trends seen above are also present in Greater Manchester and Merseyside, as shown in the map below. Parts of Oldham, Rochdale, Blackburn, Bolton and Ashton-under-Lyne have high estimated prevalence of diabetes, and a higher-than-average proportion of Black and Asian ethnic groups.

However, we also see higher rates in general. On average, diabetes prevalence in North West England is around 18% higher than in the South East England. This is similar for the East Midlands (19% higher than South East England), the North East (18% higher) and Yorkshire & the Humber (15% higher)

Map showing prevalence on diabetes in Manchester area

This blog only scratches the surface on variation in diabetes prevalence across England – we haven’t looked at the relationship with excess weight, for instance. Below you can download the data estimates for LSOAs, wards, and constituencies and explore for yourself.

 Map showing prevalenceof diabetes across England

How were these estimates calculated?

NHS Digital publishes an annual figure for the number of people aged 17+ on a register for diabetes at each GP practice in England. This data is collected through the Quality and Outcomes Framework. They also publish data on GP practice ‘footprints’ – e.g. the neighbourhoods that people who attend a given GP practice live in. Specifically, data shows, for each GP practice, the number of people attending that practice who live in each Lower Super Output Area (LSOA).

The estimates discussed here combine these two sources. An estimate for diabetes prevalence is made for each LSOA, based on the GP practices that its residents attend. So if all the residents of a particular LSOA attend a GP practice where diabetes prevalence is 7%, then we estimate that prevalence in that LSOA is 7%. If (as in most cases) the residents of an LSOA attend multiple GP practices, then the diabetes estimate is a weighted average of prevalence recorded at each practice. The ward-level data shown in the table above is based on aggregation from LSOAs.

There are limitations to this approach, since not all people attending a GP practice are alike – so some divergence between areas served by an individual GP practice is likely to be lost. Nevertheless, this is a useful approach for assigning GP data to local areas in a way that allows for some comparison, and is the most detailed estimate possible based on the data available.

As noted above, not all GP practices are included in the data this year. LSOAs with a data coverage of less than 60% are excluded from these maps – i.e. LSOAs where less than 60% of patients attend practices which are included.

While GP-level data for diabetes registrations is available for Scotland, Wales and Northern Ireland, there is no corresponding data on where GP patients live. As such, comparable estimates for small areas can only be produced for England.

Download the Diabetes-Prevalence-Data

Sources

Quality and Outcomes Framework 2016/17

Patients Registered at a GP Practice April 2017

2011 Census

Prescription Cost Analysis 2016