Assessing Concordance of Cancer Registry Data and Electronic Health Record Data in Metastatic Cancer: a Cohort Study of Patients with Colorectal Liver Metastasis in a U.S. Integrated Health System

Rates of metastatic cancer are increasing, but our knowledge of the accuracy of metastatic diagnoses within real world data is limited. In this brief report, to evaluate the accuracy of various data sources, we assessed concordance between cancer registry diagnoses and electronic health record (EHR) International Classification of Diseases diagnoses for the presence of colorectal liver metastases (CRLM) for patients within a single academic health care system. 1025 patients diagnosed with CRLM were evaluated. Concordance between cancer registry data and EHR data for the diagnosis of synchronous CRLM was low (k = 0.66). Additional data quality issues identified included (1) a 9 % rate of false positives in cancer registry data for the diagnosis of CRLM and (2) discordant data between the metastatic diagnosis and cancer registry stage affecting 16 % of cases. These results highlight important limitations of real world databases in the identification and study of patients with metastatic cancer.