Nationwide validation study of diagnostic algorithms for inflammatory bowel disease in Korean National Health Insurance Service database

Chang Kyun Lee, Hyo Jung Ha, Shin Ju Oh, Jung Wook Kim, Jung Kuk Lee, Hyun Soo Kim, Soon Man Yoon, Sang Bum Kang, Eun Soo Kim, Tae Oh Kim, Soo Young Na, Jun Lee, Sang Wook Kim, Hoon Sup Koo, Byung Kyu Park, Han Hee Lee, Eun Sun Kim, Jae Jun Park, Min Seob Kwak, Jae Myung ChaByong Duk Ye, Chang Hwan Choi, Hyo Jong Kim

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Background and Aim: We conducted a nationwide validation study of diagnostic algorithms to identify cases of inflammatory bowel disease (IBD) within the Korea National Health Insurance System (NHIS) database. Method: Using the NHIS dataset, we developed 44 algorithms combining the International Classification of Diseases (ICD)-10 codes, codes for Rare and Intractable Diseases (RID) registration and claims data for health care encounters, and pharmaceutical prescriptions for IBD-specific drugs. For each algorithm, we compared the case identification results from electronic medical records data with the gold standard (chart-based diagnosis). A multiple sampling test verified the validation results from the entire study population. Results: A random nationwide sample of 1697 patients (848 potential cases and 849 negative control cases) from 17 hospitals were included for validation. A combination of the ICD-10 code, ≥ 1 claims for health care encounters, and ≥ 1 prescription claims (reference algorithm) achieved excellent performance (sensitivity, 93.1% [95% confidence interval 91–94.7]; specificity, 98.1% [96.9–98.8]; positive predictive value, 97.5% [96.1–98.5]; negative predictive value, 94.5% [92.8–95.8]) with the lowest error rate (4.2% [3.3–5.3]). The multiple sampling test confirmed that the reference algorithm achieves the best performance regarding IBD diagnosis. Algorithms including the RID registration codes exhibited poorer performance compared with that of the reference algorithm, particularly for the diagnosis of patients affiliated with secondary hospitals. The performance of the reference algorithm showed no statistical difference depending on the hospital volume or IBD type, with P-value < 0.05. Conclusions: We strongly recommend the reference algorithm as a uniform standard operational definition for future studies using the NHIS database.

Original languageEnglish
Pages (from-to)760-768
Number of pages9
JournalJournal of Gastroenterology and Hepatology (Australia)
Issue number5
Publication statusPublished - 2020 May 1

Bibliographical note

Publisher Copyright:
© 2019 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd

All Science Journal Classification (ASJC) codes

  • Hepatology
  • Gastroenterology


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