Retrospective claims analysis of the epidemiology and economic burden of diagnosed congenital cytomegalovirus in Japan.

Objective: Congenital cytomegalovirus (cCMV) is a leading infectious cause of birth defects; approximately 20%-25% of infants with cCMV develop long-term health complications including hearing loss, microcephaly, and developmental issues. This study assessed the epidemiology and burden of clinically diagnosed cCMV in Japan.

Methods: Insurance claims from the Japan Medical Data Center database (2011-2020) were analyzed retrospectively. Infants were included in the cCMV cohort if their first diagnosis (index date) of cCMV or CMV was within the birth/following month and had ≥24 months of continuous health plan enrollment post-index (study period). They were matched 1:1 to non-cCMV controls on sex, birth year, and index year. Birth prevalence was calculated annually through 2019. Healthcare resource utilization (HRU) and costs in 2023 Japanese Yen were summarized for the study period.

Results: Birth prevalence of diagnosed cCMV during 2011-2019 ranged from 6.88-22.56 per 100,000 births. 121 matched pairs were included in the burden analysis. The mean number of medical encounters was significantly greater for infants with cCMV than controls in year one post-index (14.6 vs. 11.3, p < 0.0001), driven by outpatient encounters. Infants with cCMV were more likely than controls to have an inpatient admission in the first two years of life. Mean medical costs were significantly greater for infants with cCMV than controls in year one (¥1.6 M vs. ¥378K) and year two (¥483K vs. ¥194K).

Conclusions: Infants diagnosed with cCMV in Japan had, on average, substantially higher HRU and healthcare cost burden than non-cCMV controls in the first two years of life.