Survival, Hospitalization, and Acute-Care Costs of Very and Moderate Preterm Infants in the First 6 Years of Life: A Population-Based Study.

OBJECTIVES: To investigate survival, hospitalization, and acute-care costs of very (28-31 weeks' gestation) and moderate preterm (32-33 weeks' gestation) infants in the first 6 years of life and compare outcomes with the more widely studied extremely preterm infants (24-27 weeks' gestation) and to full term (low risk) infants (39-40 weeks' gestation). STUDY DESIGN: Birth data from all women residing in New South Wales, Australia, with gestational ages between 24-33 and 39-40 weeks in 2001-2011 were linked probabilistically to hospitalization and mortality data. Study outcomes were evaluated with the use of descriptive and multivariable analyses at birth (N = 559,532), discharge (N = 540,240), and at 1 (N = 487,447) and 6 years of age (N = 230,498). RESULTS: Mortality was greatest among extremely preterm infants (eg, 31.2% within 6 years) and decreased with increasing gestational age. Likewise, hospitalization within the first year of life increased with decreasing gestational age (aOR 5.5 [95% CI 4.7-6.4], 3.7 [3.4-4.0], and 2.6 [2.5-2.8] for birth at 24-27, 28-31, and 32-33 weeks' gestation, relative to 39-40 weeks' gestation). Hospitalization remained significantly increased with preterm birth at each year of age up to 6 years (aORs 1.3-1.6 at 6 years). Cumulative costs were significantly greater with preterm birth within the first year of life, and also between 1 and 6 years of age. CONCLUSIONS: The risks of adverse health outcomes were significantly greater in very and moderately preterm infants relative to full term infants but lower than extremely preterm infants. Crucially, preterm birth was associated with prolonged increased odds of hospitalization (up to age 6 years), contributing to greater resource use.

Risk factors and costs of hospital admissions in first year of life: a population-based study.

OBJECTIVE: To identify the maternal and infant risk factors associated with hospital admission in the first year and estimate the associated costs of infant hospitalization. STUDY DESIGN: Data from the Perinatal Data Collection for 599753 liveborn infants born in New South Wales, Australia, 2001-2007 were linked to hospital admission data. Logistic regression models were used to investigate the association between maternal and infant characteristics and admission to hospital once, and more than once in the first year; and average costs for total hospital admissions were calculated. RESULTS: Almost 15% of infants were admitted to hospital once and 4.6% had multiple admissions. Gestational age <37 weeks was most strongly associated with admission to hospital once, and severe neonatal morbidity was most strongly associated with multiple admissions (aOR 2.60; 95% CI 2.47-2.75). Infants born <39 weeks gestational age, to adolescent mothers, mothers who smoke, are not married, or had a planned delivery also have an increased risk of multiple admissions. Infants with severe neonatal morbidity contributed 27% of total infant hospital costs. With each increasing week of gestational age the mean annual cost decreased on average 10% and 27% for infants with and without neonatal morbidity respectively. CONCLUSIONS: Infants born with severe neonatal morbidity have increased hospitalizations in the first year; however, the majority of burden on health system is by infants without severe neonatal morbidity. Hospitalizations, and associated costs, increased with decreasing gestational age, even for infants born at 37-38 weeks. Targeted public health strategies may reduce the burden of infant hospitalizations.