Background The aim of this study was to determine if the National Institute of Child Health and Human Development (NICHD) calculator, designed to predict mortality or neurosensory disability in infants 22–25 weeks’ gestation, was valid for contemporary Australian infants.

Method Outcome data at 2 years of age for 114 infants who were liveborn in Victoria, Australia, in 2005, between 22 and 25 completed weeks’ gestation, weighing 401–1000 g at birth, and free of lethal anomalies, were entered into the NICHD online calculator. Predicted outcomes were then compared with the actual outcomes.

Results Of the 114 infants, 99 (87%) were inborn and 15 (13%) were outborn. The overall prediction of death for inborn infants was 47.1% compared with the actual death rate to 2 years of age of 49.5%. The area under the curve (AUC) was 0.803 (95% CI 0.718 to 0.888; p<0.001) for mortality, comparable with the AUC for the NICHD study (AUC: 0.753; 95% CI 0.737 to 0.769; p<0.001). The accuracy for predicting death was not as precise for outborn infants (AUC: 0.643; 95% CI 0.337 to 0.949; p=0.36). The calculator overestimated the combined outcome of death or survival with major disability at 72.0%, compared with an actual rate of 60.5%.

Conclusions The NICHD outcome estimator was helpful in predicting mortality for inborn infants, 22–25 weeks’ gestation, but was less precise for outborn infants. It overestimated the combined outcome of death or major disability in infants born in Victoria, Australia, in 2005.