Laboratory testing and diagnostic coding for cytomegalovirus among privately insured infants in the United States: a retrospective study using administrative claims data

BACKGROUND Rates of laboratory testing and diagnostic practices for congenital CMV in the United States are unknown. We determined rates of CMV testing and diagnostic coding for CMV among insured infants in the United States using a national healthcare claims database. METHODS We analyzed medical claims from 2011 Truven Health MarketScan® Commercial databases for infants who were ≤30 days of age. We used ICD-9-CM codes to identify infants with CMV and CMV-associated conditions. We computed frequencies of infants with CPT codes for CMV testing. RESULTS A total of 368,266 infants met the study criteria. We identified 61 (0.02%) infants with a diagnostic code for CMV. Among the 368,266 infants, 229 (0.1%) infants had a code for CMV-specific testing, of which 43% had codes for CMV polymerase chain reaction (PCR) and/or CMV direct florescent antibody (DFA) testing, 44% for CMV serologic testing alone, and 13% for CMV serology and non-specific PCR and/or culture. Over 80% (187/229) with CMV testing had a code for ≥1 CMV-associated conditions. Although infrequently coded for, CMV testing was more common among infants with a code for a condition possibly associated with CMV than infants without these conditions (0.14% (187/ 136,857) vs. 0.02% (42/231,409)). CONCLUSIONS The low rates of CMV testing among infants with symptoms suggestive of congenital CMV infection and the substantial proportion of infants tested with only serologic assays instead of PCR or viral culture suggests gaps in awareness and knowledge of congenital CMV and its diagnosis among healthcare providers. Although claims databases presumably do not capture all diagnosed CMV cases or CMV-specific testing, healthcare claims are a potential source for surveillance and monitoring practices of CMV-specific testing and diagnostic coding for CMV among infants.