Novo Nordisk

Investigating the prodrome of type 1 diabetes in childhood as it presents to Primary Care to predict earlier diagnosis and reduce ketoacidosis at presentation, using pseudoanonymised linked Primary and Secondary Care data.

Background

About 25% of children present in the life threatening condition of diabetic ketoacidosis when diagnosed with Type 1 diabetes. This rate has remained unchanged for 30 years. The symptoms of Type 1 diabetes can be attributed to other illnesses or key developmental periods in a child’s life. This study was commissioned to examine the 12 months period, in terms of contact with their GP, of children diagnosed with Type 1 diabetes in Wales over the last few years. This group of children would be matched with similar children, same gender, age and GP practice, to see if there is any difference in the number of visits, symptoms, diagnosis between the two.

This data will be made available by linking two data sets, the Brecon Group dataset (contains details of all children diagnosed with Type 1 diabetes) and the SAIL databank (contains details of GP visits).

Research aims

The aim of the research is to get a better understanding of the pathway to diagnosis of type 1 diabetes (T1D) in childhood. By exploring the number and reason for children’s appointments with their GP, prior to being diagnosed with T1D, we may be able to develop ways to aid earlier diagnosis which ultimately will help to reduce the number of children who are seriously unwell with diabetic ketoacidosis (DKA) at diagnosis. DKA is a life threatening condition and the most common cause of hospitalisation and death in children with T1D. Sadly, children continue to die at presentation of T1D including in South Wales, two within last four years. DKA also causes significant illness with impacts on financial and medical resources. It has also been shown that children who do not present in DKA at diagnosis are less likely to have long term diabetes-related complications. Currently, the rate of DKA is unacceptably high in the UK.

Prompt diagnosis of type 1 diabetes in children

Current literature suggests that there is a missed window for diagnosis and that 25% of children are still becoming very unwell, in DKA, at onset of T1D. Studies have found that almost 30% of newly diagnosed children had at least one visit with a medical practitioner prior to diagnosis and almost half had a delayed referral to secondary care. Risk factors for presenting in DKA at onset include delayed diagnosis. This study will build on these findings by undertaking an evaluation of the number of appointments, symptoms and diagnostic tests prior to diagnosis of approximately 400 children with T1D. By modelling these data with a cohort of matched children without T1D, it will be possible to ascertain any significant differences between the two cohorts and potentially identify strategies for earlier diagnoses and prevention of DKA.

The specific problem we are ultimately trying to address is ensuring that children with Type 1 diabetes are diagnosed promptly. By looking at patterns of visits, symptoms, diagnosis, prescriptions and any tests conducted, we might be able to design a system that alerts GPs to a potential case in the future.

Data linkage

Children diagnosed with T1D between 1st January 2010 and 31st December 2012 will be identified from the Brecon Group register. These data will be linked with the SAIL Databank. The SAIL analyst will anonymise the data so that no child can be identified e.g. date of birth will be removed and replaced with age at diagnosis. The SAIL analyst will also provide data from a group of children without T1D, at the ratio of 3:1, matched by age, gender and GP practice. The SAIL analyst will extract details of all of the visits that these children made to their GP over the previous 12 months. Therefore, the data will consist of a series of codes for symptom details, diagnoses, medications, tests undertaken and other illnesses or conditions. An exploration of any differences in GP consultations between those children who were in DKA at diagnosis and those who were not will also be undertaken.

Study design

This is the first time that this approach has been taken from data sets collected routinely.

Type 1 diabetes is a fairly rare condition, approximately 180 children are diagnosed with it a year in Wales, so we need large datasets of information to see if there are any significant differences between the two groups.

Involving the public and patients

Although the public have not been involved in this data linkage study directly, members of the public sit on the SAIL panel to determine whether the study should go ahead.