Higher mortality rates among inborn infants admitted to neonatal intensive care units at night

To examine circadian variation in deaths among infants ≤32 weeks' gestation admitted to Canadian neonatal intensive care units (NICU). We examined all infants (n=5192) between 24 and 32 weeks' gestation with complete data, who were admitted to 17 tertiary Canadian Neonatal Network NICUs from January 1996 to October 1997. Multivariable logistic regression was used to compare risk-adjusted early neonatal mortality rates (death within 7 days of NICU admission) of infants admitted during daytime (8 am to 5 pm) with infants admitted at night. Sixty percent (n=3131) of infants were admitted to the NICU at night. Patient risk factors significantly (P