Evaluating the quality of data from the Japanese National Clinical Database 2011 via a comparison with regional government report data and medical charts

PurposeThe aim of this study was to examine the quality of data from the National Clinical Database (NCD) via a comparison with regional government report data and medical charts.MethodsA total of 1,165,790 surgical cases from 3007 hospitals were registered in the NCD in 2011. To evaluate the NCD's data coverage, we retrieved regional government report data for specified lung and esophageal surgeries and compared the number with registered cases in the NCD for corresponding procedures. We also randomly selected 21 sites for on-site data verification of eight demographic and surgical data components to assess the accuracy of data entry.ResultsThe numbers of patients registered in the NCD and regional government report were 46,143 and 48,716, respectively, for lung surgeries and 7494 and 8399, respectively, for esophageal surgeries, leading to estimated coverages of 94.7% for lung surgeries and 89.2% for esophageal surgeries. According to on-site verification of 609 cases at 18 sites, the overall agreement between the NCD data components and medical charts was 97.8%.ConclusionApproximately, 90-95% of the specified lung surgeries and esophageal surgeries performed in Japan were registered in the NCD in 2011. The NCD data were accurate relative to medical charts.