Estimated numbers of patients with liver disease related to hepatitis B or C virus infection based on the database reconstructed from medical claims from 2008 to 2010 in Japan.

Aim: To estimate the number of patients with liver-related diseases classified by hepatitis viruses (HBV, HCV) based on the information from re-coded medical claims including several diagnosed diseases. Methods: We analyzed reimbursement data provided by health insurance societies for 2.1 million individuals during 2008-2010. Database information of employees and their families aged under 65 years employees with hepatitis-related disease was extracted, the 1-year period prevalence was calculated, and then number of patients with liver disease related to HBV and HCV by sex and age groups, respectively, was estimated. Results: The estimated number of patients were almost equivalent during 2008-2010. As for HBV and HCV, the estimated numbers of patients with chronic hepatitis (CH) in a year ranged 192 641-226 601 and 282 438-306 877, respectively. Conclusion: In the 2008 Patient Survey in Japan, the number of patients was estimated by the main disease in one patient, even though the patient was diagnosed with several diseases. Based on the database with hepatitis-related diseases after evaluating several diagnosed diseases from medical claims, the estimation method and protocol may minimize the disadvantage of medical claim analysis, and is useful for patients, especially asymptomatic carriers and those with CH which had been underestimated in the 2008 Patient Survey.