Hospital utilization and costs among preterm infants by payer: Nationwide Inpatient Sample, 2009

Background

Preterm birth (<37 weeks gestation) and low birth weight (LBW, <2500 grams) are associated with increased infant mortality and neonatal and pediatric morbidity. In the U.S., Medicaid has borne a large share of the costs associated with all births during the past decade. Medicaid may cover an even larger proportion of births in the near future due to coverage under women’s preventive services and associated cost sharing. A clear understanding of current birth outcomes, prior to any major policy shifts, is warranted.

Methods

Mean length of stay (LOS) in days, secondary diagnoses for birth hospitalizations, primary diagnoses for rehospitalizations within 28 days of birth, and transfer status, and costs were described among preterm/LBW infants using the 2009 Nationwide Inpatient Sample (NIS), a database of discharge records from over 1,000 short-term, non-Federal hospitals.

Results

Of 4,167,900 inpatient stays, births among preterm/LBW infants represented 9.1% of stays but 43% of total costs for all infants. Nearly 6% were rehospitalized within 28 days of birth, accounting for an additional 23% of total costs. Similar patterns were observed across all payer types. Compared to commercially insured preterm/LBW infants (2.8%, 95% CI= 2.7-2.9), the incidence of rehospitalization was higher among preterm/LBW infants covered by Medicaid (3.7%, 95% CI= 3.6-3.8). Likewise, neonatal transfers were more common among preterm/LBW infants covered by Medicaid (7.3%, 95% CI= 7.2-7.5) than among commercially insured preterm/LBW infants (6.5%, 95% CI= 6.4-6.6).

Conclusions

LOS and diagnoses were similar across payer types, but Medicaid-covered infants were more likely to be rehospitalized and to be transferred.