Reusability of coded data in the primary care electronic medical record: A dynamic cohort study concerning cancer diagnoses

Re-users of coded routine primary care Electronic Medical Record data should be aware that 30% of cancer cases can be missed. Up to 130% of cancer cases found in the EMR data can be false-positive. The type of EMR system and the type of cancer influence the quality of coded diagnosis registry. While data quality can be improved (e.g. through improving system design and by training EMR system users), re-use should only be taken care of by appropriately trained experts.