Missing diagnoses of congenital cytomegalovirus infection in electronic health records for infants with laboratory-confirmed infection

Congenital cytomegalovirus (CMV) is a leading cause of non-genetic sensorineural hearing loss and neurodevelopmental disabilities among US children. Studies using administrative healthcare databases have identified infants with congenital CMV using diagnostic codes from the International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification. Using Cerner Health Facts deidentified electronic health records, we assessed the sensitivity of CMV diagnostic codes among infants with laboratory confirmed congenital CMV infection (i.e. a positive CMV laboratory test–polymerase chain reaction, direct fluorescent antibody, or culture from urine, saliva, respiratory secretion or blood samples, or IgM serology–within 21 days of life). During 2010–2017, 668 congenital CMV cases were identified among 7,517,207 infants with encounters within 21 days of life, or 0.89 cases per 10,000 infants. The sensitivity of CMV diagnostic codes assigned within 21 and 90 days of life was 10.3% (95% CI: 8.2–12.9) and 11.1% (95% CI: 8.9–13.7), respectively.