Validity of diagnostic coding within the General Practice Research Database: a systematic review

The UK-based General Practice Research Database (GPRD) is a valuable source of longitudinal primary care records and is increasingly used for epidemiological research.

To conduct a systematic review of the literature on accuracy and completeness of diagnostic coding in the GPRD. DESIGN OF STUDY: Systematic review. METHOD: Six electronic databases were searched using search terms relating to the GPRD, in association with terms synonymous with validity, accuracy, concordance, and recording. A positive predictive value was calculated for each diagnosis that considered a comparison with a gold standard. Studies were also considered that compared the GPRD with other databases and national statistics.