Changes in Platelet Counts and Thrombocytopenia Risk in Patients with Chronic Liver Disease with Different Etiologies Using Real-World Japanese Data

INTRODUCTION: Thrombocytopenia, a common complication of chronic liver disease (CLD), adversely affects the treatment in patients requiring invasive procedures. Multiple pathophysiological mechanisms contribute to the development of thrombocytopenia; thus, its incidence could differ among CLD etiologies. We investigated the risk of decline in platelet counts and developing thrombocytopenia across different CLDs in a real-world Japanese setting. METHODS: A Japanese claims database including 25 million patients (April 2008–August 2018) was used. Patients with at least one CLD diagnosis were classified into nine mutually exclusive categories: hepatitis B, hepatitis C, hepatitis B and C, unspecified viral hepatitis, autoimmune hepatitis, toxin/drug-induced hepatitis, alcoholic hepatitis, nonalcoholic steatohepatitis, and others. A random effects model was used to estimate the changes in platelet counts; proportional hazard analyses were used to examine factors associated with the incidence of thrombocytopenia based on the diagnosis. Patients with laboratory test data as variables were included in each analysis. RESULTS: The simulation included 68,536 patients. The mean values representing changes in the platelet count were significantly negative in the hepatitis C patients and negative, though non-significant, in the hepatitis B, toxin/drug-induced hepatitis, alcoholic hepatitis, and nonalcoholic steatohepatitis patients. In the proportional hazard analysis, 708 of 22,728 patients had thrombocytopenia. The hazard ratio (HR) was significantly high for patients with hepatitis B (HR, 2.879; p < 0.001), hepatitis C (HR, 1.876; p < 0.001), and hepatitis B and C (HR, 2.992; p < 0.001). CONCLUSION: A decreasing tendency in platelet counts was observed in most CLD etiologies, with hepatitis C showing a significant decrease. The incidence of thrombocytopenia was mostly associated with hepatitis B and/or C. Further research is warranted to elucidate the discrepancy between the decline in platelet counts and thrombocytopenia diagnosis, considering the factors relevant to the diagnosis, such as the frequency of outpatient visits and CLD treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12325-021-02008-x.