The HCV National Register: towards informing the natural history of hepatitis C infection in the UK

The aim of this paper is to describe the development of a national hepatiti s C register and the completeness of the data it contains. This is a descri ptive report of the structure and function of the register, including case definitions, registration and follow-up procedures, and methods used to max imize data quality and to obtain comparative data sources. The register con tains data on HCV-infected individuals who acquired their infections on a k nown date and by a known route; to date all are transfusion recipients iden tified during the UK lookback exercise, who tested positive or indeterminat e for anti-HCV after receiving 'infected' blood issued before the introduct ion of routine testing of the blood supply for anti-HCV, By 31 December 199 9, 871 (87%) of 996 eligible transfusion recipients had been registered and 984 (99%) nagged in the NHS Central Registers. Registered patients had bee n infected for an average of 11.1 years (SEM 0.1): around half were being c ared for by clinicians with a specialist interest in liver disease. Except for the information on tobacco use, current alcohol use, and hepatitis B st atus, data were more than 80% complete, and for most variables, more than 9 0% complete. The consistency of data abstraction was found to be 98% (SEM 0 .5), In conclusion, the Register contains high quality anonymised data on o ne of the largest cohorts of individuals with HCV infections acquired on a known date and by a known route. It could serve as a model for other chroni c disease registers; developers may find the structure, design, and methodo logical issues addressed useful.