Estimates of the Cost and Length of Stay Changes That Can Be Attributed to One-week Increases in Gestational Age for Premature Infants

Objective: To estimate the potential savings, both in terms of costs and lengths of stay, of one-week increases in gestational age for premature infants. The purpose is to provide population-based data that can be used to assess the potential savings of interventions that delay premature delivery.

Data: Cohort data for all births in California in 1998-2000 that linked vital records data with those from hospital discharge abstracts, including those of neonatal transport. All infants with a gestational age between 24 and 37 weeks were included. There were 193,167 infants in the sample after deleting cases with incomplete data or gestational age that was inconsistent with birth weight.

Methods: Hospital costs were estimated by adjusting charges by hospital-specific costs-to-charges ratios. Data were aggregated across transport into episodes of care. Mean and median potential savings were calculated for increasing gestational age, in one-week intervals. The 25th and 75th percentiles were used to estimate ranges.

Results: The results are presented in matrix format, for starting gestational ages of 24-34 weeks, with ending gestational ages of 25 to 37 weeks. Costs and lengths of stay decreased with gestational age from a median of $216,814 (92 days) at 24 weeks to $591 (2 days) at 37 weeks. The potential savings from delaying premature labor are quite large; the median savings for a 2 week increase in gestational age were between $28,870 and $64,021 for gestational ages below 33 weeks, with larger savings for longer delays in delivery. Delaying deliveries <29 weeks to term (37 weeks) resulted in savings of over $122,000 per case, with the savings being over $206,000 for deliveries <26 weeks.

Conclusions: These results provide population-based data that can be applied to clinical trials data to assess the impacts on costs and lengths of stay of interventions that delay premature labor. They show that the potential savings of delaying premature labor are quite large, especially for extremely premature deliveries.