Use of administrative data for the identificationof laboratory-confirmed influenza infection: The validity ofinfluenza-specific ICD-9 codes
We used Pediatric Health Information System data and laboratory records from 3 children's hospitals to determine whether administrative data accurately identify children with laboratory-confirmed influenza. Among 23 282 inpatients, diagnosis codes for influenza detected 73% of laboratoryconfirmed influenza cases, whereas <1% of patients without a diagnosis code had laboratory-confirmed influenza. © The Author 2012. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society.