Chronic hepatitis B in a large private hospital network in Türkiye: Clinical characteristics and electronic health record-data gaps

Background: Türkiye has intermediate hepatitis B virus (HBV) infection prevalence and an additional burden of hepatitis D virus (HDV). Large-scale real-world data describing adults with chronic HBV-infection and the completeness of routinely collected electronic health record (EHR) data for HBV monitoring and surveillance is not well characterized. Methods: A retrospective, cross-sectional study using EHR data from a multicenter private hospital network, including 18,284 adult patients with chronic HBV infection between 2017 and 2025 was conducted. The primary analysis included 17,927 adults with HBV monoinfection, defined as patients without a recorded ICD-10 B18.0 diagnosis code for chronic HBV with delta agent. We described demographic and clinical characteristics, liver disease outcomes, and the availability and consistency of key EHR variables relevant to HBV care, including ALT, HBV DNA, HBeAg, anti-HDV testing, B18.0 diagnosis coding, and structured treatment documentation. Results: Among adult patients with HBV monoinfection, 60.6% were male and the mean age was 53.5 years (SD 14.5). Cirrhosis and hepatocellular carcinoma (HCC) were recorded in 11.1% and 3.4% of patients, respectively, and were more common among men and older adults. Baseline ALT values were available for 45.5% of HBV monoinfected patients. Among patients without cirrhosis, HCC, or liver failure, both HBV DNA and HBeAg status were available for 1274 of 15,243 patients. Documented anti-HDV testing was available for 2213 of 18,284 patients (12.1%), while 357 patients (2.0%) had recorded B18.0 diagnosis code; only 76 of these 357 patients also had documented anti-HDV testing in available EHR field. Conclusions: In this large private-sector EHR cohort of adults with recorded chronic HBV infection, cirrhosis and HCC were common, particularly among older adults and men. The findings should not be interpreted as national HBV prevalence estimates, but they demonstrate the value of private-sector EHR data for characterizing diagnosed HBV care while highlighting gaps in laboratory monitoring, HDV documentation, and treatment data needed to support HBV surveillance and elimination efforts.