Rates of JIA between ethnic groups in England
Graphical abstract of the study. Reproduced with permission. Full article available here

New research findings

Research published this week has shown that the number of children and young people diagnosed with Juvenile Idiopathic Arthritis (JIA) differs between ethnic groups. The study, undertaken by our Founder, Richard Beesley, as part of his PhD studying JIA at the University of Manchester has been published in Rheumatology Journal with co-authors Prof Kimme Hyrich and Dr Jenny Humphreys.


There is no central record of everyone with a diagnosis of JIA, so it can be hard to accurately estimate the number of children with the condition. In other studies, researchers have used a variety of different methods to try to estimate the number of children and young people with JIA. Because the studies have been run in different ways, and the information available is different in different countries, the estimates of the number of children with JIA also varies. So far, nobody else has tried to estimate if there is a difference in the number of children diagnosed with JIA between different ethnic groups. The researchers believe it is important to look at this, as it can help understand JIA and how families are impacted by it.

The study

In the UK, almost everyone has a GP (or family doctor). Every time you go to see your GP, they record information on your personal health record. In some cases in England, this information is anonymised and made available to researchers who can then study rare conditions such as JIA because they have information from a lot of different people. The information is held very securely and in a tightly controlled environment, and there is no way to identify individuals from it. Using this information, the researchers were able to identify which children in the sample had been diagnosed with JIA in England, and then look to see if there is a difference between ethnic groups. This isn't as simple as it could be because there are no codes for 'JIA', so a lot of work has to be done to start with to make sure every child with JIA on the system has been found.

What they found

The researchers found that the number of new cases of JIA (called incidence) between 2003 and 2018 was 5.4 per 100,000 children. This is similar to other recent studies. They also found that the total number of children with a diagnosis of JIA (known as prevalence) in 2018 was 59.4 per 100,000. This is also similar to other recent studies, but lower than previous work. It means around 1 in 1600 children are diagnosed with JIA (not 1 in 1000), although the 'official' figure is unlikely to change immediately.

More importantly, they found that both incidence (new cases of JIA) and prevalence (all cases of JIA) were different between ethnic groups. Both were higher amongst children from White ethnic groups. 

At the moment, we do not yet know why this is. It is likely to be a combination of genetic (your biology) and health equity factors. Health equity is about ensuring everyone is able to acess the right healthcare regardless of their background or circumstances.

What this means

Children and young people from Non-White ethnic groups in England are less likely to have a diagnosis of JIA. We don't yet know why. It might be that there is a biological difference meaning they are less likely to develop JIA; or it may be due to health inequity, meaning they are not able to get a diagnosis if they do have JIA.  Further research to understand the underlying cause of these differences is important to enable targeted interventions and appropriate service provision. 

Read the full paper

The full paper can be found at https://academic.oup.com/rheumatology/advance-article/doi/10.1093/rheumatology/kead700/7491604 

It is 'Open Access', meaning it is free to read online.

Our other published research

You can read more of our published research here. If you are a researcher and would like to partner with us, contact us about our JIA VIP Research Panel.