Dear Editor,

Phillips et.al (1) demonstrated the Neonatal Illness Prognosis Indicator (NIPI) to be a good predictor of mortality in very low birth weight neonates. We carried out a study replicating the design of the original research to evaluate the use of this newly developed scoring system in a different setting.

The study was based in Glan Clwyd District General Hospital, Boddelwyddan, which has approximately 2500 deliveries a year and provides Level 3 neonatal intensive care. Retrospective data on highest blood lactate concentration, gestation and life threatening malformations was collated to create an NIPI score for neonates weighing <1501 grams born in the hospital between October 2008 and January 2011. The primary outcome of death before discharge and secondary outcome of adverse event (using the same criteria used in Phillips et.al's study) were used to assess the NIPI's predictive ability. Local ethical and research approval was granted for the study.

97 eligible babies were inborn during this time period of which 12 were excluded due to still being an inpatient at the time of the study or transfer out to other hospitals. This left 85 babies which were included in the study cohort. Predictive ability was determined from area under the receiver operator curve (AUC). AUC for death before discharge was 0.932 (95 % confidence interval of 0.873 - 0.991) showing similar excellent predictive value as the original validation cohort. AUC for adverse outcome was calculated at 0.743 (95% confidence interval of 0.629 - 0.856) and therefore did not show a clinically significant predictive ability.

This small study provides evidence that the NIPI score retains its predictive ability for mortality when used in a different setting to that which it was originally validated in. Larger studies in other varied settings would be encouraged in order to fully assess its potential clinical application.

1. Phillips, L. A., C. J. Dewhurst, Yoxall,C.W. The Prognostic Value of Initial Blood Lactate Concentration Measurements in Very Low Birthweight Infants and their use in Development of a new Disease Severity Scoring System. Archives of disease in childhood. Fetal and neonatal edition; 2011;96(4): F275-F280

Conflict of Interest:

None declared