In this cohort study of hospitalized patients with linked medical record data, we developed International Classification of Diseases (ICD) criteria that accurately identified laboratory-confirmed, severe influenza hospitalizations (positive predictive value [PPV] 80%, 95% confidence interval [CI] 71-87%), which we validated through medical record documentation. These criteria identify patients with clinically important influenza illness outcomes to inform evaluation of preventive and therapeutic interventions and public health policy recommendations.
Keywords: International Classification of Diseases; hospitalization; medical record extraction; severe influenza; validation.
© 2021 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.