Patients consulting with Crohn's disease in primary care in England and Wales

Objective To determine annual incidence and prevalence for patients consult ing their GP because of Crohn's disease in England and Wales and compare de mographic details with matched controls. Design We used the fourth Morbidity Statistics in General Practice study (M SGP-4) which covered 468 042 person-years during a 12-month period in 1991- 92. Methods All GPs reporting a patient with Crohn's disease in MSGP-4 were sen t a questionnaire to confirm the diagnosis and obtain supportive details (s urgical, pathological, radiological and/or endoscopic). Data concerning eth nicity, social class, smoking status, living in an urban or rural environme nt and employment had been collected previously. Conditional logistic regre ssion models were used to analyse the data for cases and matched controls. Results Three hundred and fifteen patients were reported to have Crohn's di sease. Replies were obtained to 251 (80%) questionnaires. The diagnosis of Crohn's disease was confirmed in 184 cases (89%) and refuted in 23 cases (1 1%) - details were unavailable for 44 patients. The mean age of patients wa s 44 years, the female:male ratio was 1.46:1, and 108 (59%) patients had re quired surgery. Thirty-three of 178 (18.5%) patients were diagnosed within the study period. Hence, this study detected a prevalence for consulting Cr ohn's disease of 54.6-59.8/100 000 and an annual incidence of 10.1-11.1/100 ,000 in 1991-92. No significant differences were found between cases (n = 2 91) and controls (n = 1682) with regard to ethnicity, social class, smoking or living in an urban/rural environment, Patients with Crohn's disease had similar employment levels as controls, but were significantly more likely to be registered as permanently sick, odds ratio 4.01 (CI 2.21-7.29). Conclusions This national survey, including 1% of the population, suggests there are approximately 30 600 patients consulting their GP because of Croh n's disease in England and Wales, with 5700 new cases diagnosed per year. E ur J Gastroenterol Hepatol 10: 1007-1012 (C) 1998 Lippincott Williams & Wil kins.