Validity and completeness of the General Practice Research Database for studies of inflammatory bowel disease

Abstract

Purpose: The objective of this study was to evaluate the validity and completeness of the General Practice Research Database (GPRD) as a tool for research into inflammatory bowel disease epidemiology. Methods: Patients diagnosed with inflammatory bowel disease were identified from GPRD. Mailed surveys were sent to the general practitioner caring for a stratified random sample of 170 of these patients and collected information on the diagnosis of inflammatory bowel disease and the most recent surgery and hospitalization. Results: Usable surveys were returned for 157 patients (92%). The inflammatory bowel disease diagnosis was highly probable or probable in 144 (92%, 95% CI 86 to 96%). Among the 53 patients with a potentially incident inflammatory bowel disease diagnosis, 33 (62%) had the first recorded diagnosis in GPRD within 30 days of the date reported in the survey (median difference −8 days; interquartile range 0 to −81days). Of 12 surgeries and 25 hospitalizations reported in the survey, 11 (92%) and 19 (76%) were identified in GPRD, respectively. Conclusions: The diagnosis of inflammatory bowel disease in GPRD appears reliable for most patients. Important medical events such as hospitalizations and surgery are recorded at a high rate, although algorithms to identify these events are complex. Copyright © 2002 John Wiley & Sons, Ltd.