Medical Utilization and Costs in Preterm Infants in the First 6 Years of Life After Discharge From Neonatal Intensive Care Unit: A Nationwide Population-Based Study in Korea

BACKGROUND: The improvement in the survival rate of preterm infants has paradoxically raised the risk of morbidities in childhood. Our objectives were to assess the medical utilization and costs in preterm infants following discharge from the neonatal intensive care unit in the first 6 years of life. METHODS: We conducted a population-based study using the National Health Information Database (2011–2017) provided by the Korean National Health Insurance Service (NHIS). A total of 361,190 children born in Korea between January 1 and December 31, 2011 were divided into four groups according to the gestational age at birth: extremely preterm (less than 28 weeks), very preterm (28–31 weeks), moderate to late preterm (32–36 weeks), and full term (37–41 weeks). The cumulative number of outpatient visits, cumulative length of hospital stay, rate of hospital and intensive care unit admissions, and cumulative medical costs for inpatients and outpatients were compared for each gestational age group. RESULTS: Earlier gestational age was significantly associated with an increased risk of the cumulative number of outpatient visits, cumulative length of hospital stay, and rate of hospital and intensive care unit admissions for the first 6 years of life. The mean cumulative inpatient and outpatient costs per child significantly decreased with increasing gestational age. When assessed based on population size, the total cumulative medical costs were highest for moderate to late preterm children. CONCLUSION: Earlier gestational age was strongly associated with increased healthcare resource utilization and medical costs. Our findings on the potential long-term socioeconomic impact on public health are expected to aid the development of future health care policies for preterm children.