Validity of Diagnoses of Aortic Dissection and Pulmonary Embolism in Hospitalized Patients Using the Japanese DPC Database.

Acute aortic dissection (AD) and pulmonary thromboembolism (PE) are life-threatening conditions requiring timely diagnosis. In Japan, large-scale validation studies of administrative data for these diagnoses are limited. It is required to validate the accuracy of International Classification of Diseases, 10th Revision (ICD-10) codes for acute AD and PE in the Diagnosis Procedure Combination (DPC) database using medical chart review as the reference standard.We reviewed DPC data from the University of Tokyo Hospital (April 2018-March 2024). Patients with I710 (AD) or I260/I269 (PE) listed in key diagnosis fields were identified. Chart reviews confirmed diagnoses, and 199 randomly selected patients without AD/PE codes served as negative controls. Sensitivity, specificity, and positive predictive value (PPV) were calculated.Among 10,483 records, 54 had DPC-coded AD and 71 had PE. Chart review confirmed 47 cases of acute AD and 48 of acute PE. No false negatives were found among controls. For acute AD, sensitivity was 100.0% (95% CI: 92.5-100.0), specificity 96.6% (93.1-98.6), and PPV 87.0% (75.1-94.6). For acute PE, sensitivity was 100.0% (92.6-100.0), specificity 89.6% (84.9-93.3), and PPV 67.6% (55.5-78.2).ICD-10 codes in the DPC database accurately identify acute AD and PE, with particularly high sensitivity. While PPV for acute PE is lower, likely due to inclusion of chronic conditions, DPC data can be cautiously used for research and surveillance in academic hospital settings. Multicenter validation is needed to ensure broader generalizability.