Regionalization and local hospital closure in Norwegian maternity care: the effect on neonatal and infant mortality

Objective. To study whether neonatal and infant mortality, after adjustments for differences in case-mix, were independent of the type of hospital in which the delivery was carried out. Data. The Medical Birth Registry of Norway provided detailed medical information for all births in Norway. Study design. Hospitals were classified into two groups: local hospitals/maternity clinics versus central/regional hospitals. Outcomes were neonatal and infant mortality. The data were analyzed using propensity score weighting to make adjustments for differences in case mix between the two groups of hospitals. This analysis was supplemented with analyses of 13 local hospitals that were closed. Using a difference-in-difference approach, the effects that these closures had on neonatal and infant mortality were estimated. Principal finding. Neonatal and infant mortality were not affected by the type of hospital where the delivery took place. Conclusion. A regionalized maternity service does not lead to increased neonatal and infant mortality. This is mainly because high risk deliveries were identified well in advance of the birth, and referred to a larger hospital with sufficient perinatal resources to deal with these deliveries