Abstract
PURPOSE: Pharmacoepidemiologic studies using electronic health record data could serve an important role in assessing safety and effectiveness of direct-acting antiviral therapy for chronic hepatitis C virus (HCV) infection, but the validity of these data needs to be determined. We evaluated the accuracy of pharmacy fill records in the national Veterans Health Administration (VA) Corporate Data Warehouse (CDW) as compared to facility-level electronic health record. METHODS: Patients prescribed a direct-acting antiviral regimen at five VA sites between 2014 and 2016 were randomly selected and reviewed. A random sample of patients with chronic HCV infection without evidence of HCV treatment during the study period also underwent chart review. We calculated positive predictive value and negative predictive value overall and by site. RESULTS: Of the 501 patients who received a total of 2416 prescriptions, 494 were validated using data extracted from CDW 6 months after the study period, yielding a positive predictive value of 98.6% (95% confidence interval, 97.6%-99.6%). Of the 100 patients with chronic HCV infection without prescriptions for HCV treatment, 99 were confirmed not to have received antiviral treatment (negative predictive value, 99.0%; 95% confidence interval, 97.1%-100%). CONCLUSIONS: These findings provide assurance to researchers who use national VA CDW data for retrospective cohort studies that the CDW contains accurate information on HCV therapies in the modern treatment era.