What is the occurrence of clinically diagnosed coeliac disease and dermatitis herpetiformis in the UK today? A population based cohort study utilising electronically linked health records.

Date of ISAC Approval: 
21/06/2016
Lay Summary: 
To plan health services it is crucial to understand the number of people affected by diseases and identify areas where improvements could be made to reduce ill health and death. Therefore we previously carried out a study funded by Coeliac UK and Core charity, to estimate the number of people affected by coeliac disease and dermatitis herpetiformis (a skin condition associated with coeliac disease and gluten intolerance) in the UK. Our study showed a rise in the occurrence of coeliac disease over a 22-year period up to 2011, with wide variations by region. Whether the increase in incidence continued and whether the regional variation has reduced is important in understanding whether these disparities in diagnosis are improving. In another of our previous studies also, we highlighted that people with coeliac disease were given a prior diagnosis of inflammatory bowel disease, suggesting delayed diagnosis as an area for improvement. We do not know whether misdiagnosis is still a continuing issue and how common it is currently occurring. The study we propose which is funded by Coeliac UK aims to provide updated information on the occurrence and misdiagnosis of coeliac disease and dermatitis herpetiformis (DH). We will estimate the number of people with coeliac disease and dermatitis herpetiformis in the UK for the period between 2011 and 2015, and re-examine how often misdiagnosis of coeliac disease occurs.
Technical Summary: 
There is a consistent 1% serological prevalence of Coeliac disease across the UK that was not changing over time. However, our previous study up until 2011 found a rising incidence of the disease and a wide regional variation. We do not know whether the rise in incidence of clinical diagnosis has continued or whether the regional variation has improved. Moving to areas of improvement, our previously conducted case control study of prior diagnosis of Irritable Bowel Syndrome (IBS) in coeliac cases compared to controls, found an almost four fold excess of IBS diagnoses prior to a coeliac diagnosis compared to controls, suggesting a delay to the diagnosis of coeliac disease. Equally we do not know if diagnostic delay is an ongoing issue and how actively clinicians seek to avoid misdiagnosis. Using the most up to date data available, this study will update our previous work on trends and variations in the occurrence of coeliac disease and DH and re-assess whether misdiagnosis of Coeliac disease in the UK is continuing. We will first estimate the prevalence and incidence of coeliac disease and dermatitis herpetiformis in the UK from 2011 to 2015 inclusive. Secondly, we will determine the number of people with coeliac disease previously diagnosed with either irritable bowel syndrome (adults) or functional abdominal pain (children).
Health Outcomes to be Measured: 
Prevalence of incidence of coeliac disease Prevalence and incidence of dermatitis herpetiformis Number of people with coeliac disease that are previously misdiagnosed with irritable bowel syndrome or functional abdominal pain
Collaborators: 

Dr Colin Crooks - Chief Investigator - University Of Nottingham
Ms Harmony Otete - Researcher - University Of Nottingham
Professor Joe West - Researcher - University Of Nottingham

Linkages: 
Patient IMD;Practice IMD (Standard)