The Use of the International Classification of Diseases, Ninth Revision (ICD-9) Coding in Identifying Chronic Hepatitis B Virus Infection in Health System Data: Implications for Surveillance

Reena Mahajan, Anne C. Moorman, Stephen J. Liu, Loralee Rupp, Monina Klevens, (CHeCS) for the Chronic Hepatitis Cohort Investigators


We evaluated sensitivity, specificity, and predictive values of the ICD-9 coding system for surveillance of chronic hepatitis B virus infection (HBV) using data from an observational cohort study. All HBV cases were validated by chart review. Of 1,652,055 adult patients, 2,202 (0.1%) were included in the cohort based upon laboratory data or hepatitis B ICD-9 codes. Use of one ICD-9 code had a sensitivity of 83.9%, positive predictive value of 61.0%, and specificity and negative predictive values > 99%. Our findings suggest that use of one or two hepatitis B ICD 9 codes can identify cases with chronic HBV infection.

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Online Journal of Public Health Informatics * ISSN 1947-2579 *