Persistence of morbidity and cost differences between late-preterm and term infants during the first year of life.

BACKGROUND: Late-preterm infants are known to have greater morbidity and costs compared with term infants during the neonatal period, but less is known about whether these differences continue beyond this period.
OBJECTIVE: The purpose of this study was to examine the most common causes and costs of rehospitalization and other health care use among late-preterm and term infants throughout the first year of life.
METHODS: We conducted a retrospective cohort study of late-preterm (33-36 weeks' gestation) and term infants born in 2004 with > or =1 year of enrollment in a large national US database of commercially insured members. All of the reported health care services and costs were examined from the birth hospitalization through the first year of life.
RESULTS: We evaluated 1683 late-preterm and 33 745 term infants. The average length of stay of the birth hospitalization for term infants was 2.2 days, and the average cost was $2061. Late-preterm infants had a substantially longer average stay of 8.8 days and average cost of $26 054. Total first-year costs after birth discharge were, on average, 3 times as high among late-preterm infants ($12 247) compared with term infants ($4069). Late-preterm infants were rehospitalized more often than term infants (15.2% vs 7.9%). A subset of late-preterm infants that were discharged late from their birth hospitalization had the highest rates of rehospitalization and total health care costs. Higher costs during rehospitalization of late-preterm infants, especially those with a late discharge, indicate their propensity to have more severe illness.
CONCLUSIONS: Late-preterm infants have greater morbidity and total health care costs than term infants, and these differences persist throughout the first year of life. Management strategies and guidelines to reduce morbidity and costs in late-preterm infants should be investigated.