Eligible cases had biopsy-proven coeliac disease and fulfiled the updated European Society of Paediatric Gastroenterology and Nutrition (ESPGAN) criteria,20 were diagnosed after 1 January 1998, aged over 18 years at time of diagnosis, and registered with a general practice in south-east Wales. The 1 January 1998 was used as a cut-off date for diagnosis to increase the chances of completeness of GP clinical records studied during the 5 years prior to this date. Cases were identified at the coeliac clinic at Llandough Hospital, Cardiff. This is the main secondary care centre for coeliac disease for Cardiff and the Vale of Glamorgan and serves a total adult population of approximately 340 000. Referrals to this clinic arise from both primary and secondary care.
Five potential controls were matched to each case by sex, general practice, and date of birth (within 1-year bands) with the aim of recruiting two controls per case. Exclusion criteria for both cases and controls were unobtainable GP clinical records.
Cases were recruited following a formal diagnosis of coeliac disease and prior to a routine consultation at the hospital coeliac clinic. Once consent was obtained, the patients' GPs were contacted to obtain access to their general practice clinical records, and to enlist the GPs' help in recruiting controls. Potential controls were contacted via a letter from the GP, with an attached information sheet, and a consent form which would allow the research team to extract relevant data from their clinical records. A form indicating non-consent was also included to estimate the proportion that declined to participate. After 2 weeks if less than two control patients per case had consented, the practice was approached once more to identify five additional potential controls.
How this fits in
Earlier diagnosis of coeliac disease reduces morbidity and risk of complications. Diagnosis is often difficult as presenting features may not directly suggest gastrointestinal disease. Presentations in general practice during the 5 years prior to a diagnosis of coeliac disease were examined, and it was found that patients subsequently diagnosed with coeliac disease had an increased number of consultations compared with controls. Diarrhoea and anaemia were significantly predictive of an eventual diagnosis with coeliac disease. Increased awareness of the link between frequent consulting, diarrhoea, anaemia, and coeliac disease may assist GPs in achieving earlier diagnosis of this important and easily treatable condition.
