| Abstrakt: |
Increased early neonatal mortality rates have been reported for infants born at night and a more marked effect of nighttime birth on early neonatal deaths from asphyxia in preterm infants. This study compared risk-adjusted early neonatal deaths (within 7 days of neonatal intensive-care unit NICU admission) in infants admitted during the daytime (8 am to 5 pm) and at night. The study group included 5192 infants born at 24–32 weeks gestation and admitted to 17 Canadian NICUs in a 22-month period, January 1996 to October 1997. Nighttime admission to the NICU accounted for 60 of infants. Birth weight, gestational age, and 5-minute APGAR scores were similar for the 2 birth cohorts, as were rates of antenatal steroid treatment, congenital anomalies, male gender, and small-for-gestational-age infants. Cesarean section was done more often for daytime births. These infants also had lower Score for Neonatal Acute Physiology, version II (SNAP-II) scores than did infants admitted at night. The crude early neonatal mortality rate for infants admitted to the NICU at night was significantly higher than that of infants admitted during the day (5.4 vs. 4.0). Rates for daytime infants were similar for weekdays and weekends. Both neonatologists and housestaff were less available at night, but there was no difference in nurse–patient ratios. Multivariate logistic regression analysis showed that a 5-minute APGAR score of 7 or less, being outborn, the presence of congenital anomalies, low gestational age, and a high SNAP-II score on admission all predicted early neonatal death to a significant degree. Additional predictors for inborn infants were nighttime admission to the NICU (odds ratio OR, 1.6) and the presence of an in-house neonatal fellow or attending neonatologist at night (OR, 0.6). The mortality risk was increased for late-night admission but not for infants admitted in the early evening. Risk-adjusted analysis showed that the added risk incurred by nighttime admission was equivalent to 29 excess deaths per 1000 infants. Nighttime admission of outborn infants was not a predictor of early neonatal death. This study confirms nighttime birth as a risk factor for death within a week of admission to the NICU. The in-house availability of experienced physicians at night substantially lowered the mortality risk. |
