Excess Inpatient Cost Attributable to Neonatal Herpes Simplex Virus Diagnoses From Insurance Claims Data in the United States

Background:  Neonatal herpes simplex virus (nHSV) is a relatively rare infection that causes significant morbidity and mortality. Estimates of the cost associated with inpatient admissions for nHSV are limited. 

Objectives:  To estimate the excess cost incurred for newborns diagnosed with neonatal herpes virus using United States (US) health care claims data.

Methods:  We extracted inpatient information on singleton newborns from the MarketScan database for 2005-2009. We used the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes (single new born, V3000 and V3001; herpes simplex virus, 054.0-054.9 and length of stay > 7 days) to identify uninfected newborns and confirmed cases of nHSV diagnosis. We used a regression model that included the natural log of total cost as the dependent variable to estimate the additional cost due to nHSV. Covariates included gender, region, year of admission, employment status, prescription coverage, data source (i.e., employer or insurance company), health plan type and employment classification (such as salary or hourly). All costs were adjusted to 2009 US dollars.

Results:  Over the five-year period, we identified 73 cases that met our case definition for confirmed nHSV cases. We estimated that the adjusted average inpatient cost was $1,400 (unadjusted, $1,632) for normal uncomplicated births with no nHSV diagnosis and $41,532 (unadjusted, $55,433) for the nHSV cases. Thus, an additional cost of $40,132 was attributable to nHSV infection.

Conclusions: Our estimate reflects the cost paid by employee-sponsored health plans for inpatient care of those diagnosed with nHSV during the first year of admission. However, it is not representative of the inpatient cost of nHSV for the entire US population. Additionally, our estimate does not include the cost of long-term sequelae.

Implications for Programs, Policy, and Research:  Our estimate provides an important component for economic evaluation studies of nHSV as well as for estimating the economic burden of nHSV.