CRIB II score versus gestational age and birth weight in preterm infant mortality prediction: who will win the bet?

Introduction. In neonatology, various illness severity scores have been developed to predict mortality and morbidity risk in neonates. The aim of our study was to validate the ability of the ‘Clinical Risk Index for Babies’ (CRIB) II score to predict mortality in neonates born before 32 weeks’ gestation in a level 3 neonatal intensive care unit (NICU), setting.

Materials and Methods. Prospective birth cohort study including all live-born neonates of 32 weeks’ gestation or less. . CRIB II score was calculated and the predicted mortality was compared with the observed mortality. Discrimination (the ability of the score to correctly predict survival or death) was assessed by calculating the receiver operating characteristic curve (ROC curve) and its associated area under the curve (AUC).

Results. The ROC curve analysis in our study showed that the AUC was 0.9008 suggesting that mortality prediction was 90% accurate for all infants. Sensitivity and specificity were 77% and 88% respectively. In our study population, the CRIB II score appears to be more accurate than gestational age and birth weight in predicting mortality.

Conclusions. The CRIB II scoring system is a useful tool for predicting mortality and morbidity in NICUs, and also a useful tool for evaluating the variations in mortality and other outcomes seen between different NICUs.

CRIB, CRIB II, mortality, neonates, outcome, prematurity, scoring system

1. Dorling JS, Field DJ, Manktelow B. Neonatal disease severity scoring systems. Arch Dis Child Fetal Neonatal Ed 2005; 90:F11-F16.

2. Signorini DF, Weir NU. Any variability in outcome comparisons adjusted for case mix must be accounted for. BMJ 1999;318(7176):128.

3. The International Neonatal Network. The CRIB (clinical risk index for babies) score: a tool for assessing initial neonatal risk and comparing performance of neonatal intensive care units. Lancet 1993;342:193-8.

4. Mohkam M, Afjeii A, Payandeh P, Zadkarami M, Kazemian M, Fakhraii H, et al. A comparison of CRIB, CRIB II, SNAP, SNAPII and SNAP-PE scores for prediction of mortality in critically ill neonates. MJIRI

2011;24(4):193-9.

5. Parry G, Tucker J, Tarnow-Mordi W. CRIB II: an update of the clinical risk index for babies score. Lancet 2003;361:1789-91.

6. Rastogi PK, Sreenivas V, Kumar N. Validation of CRIB II for prediction of mortality in premature babies. Indian Pediatrics 2010;47:145-7.

7. Hanley JA, Mcneil BJ. The meaning and the use of the area under a receiver operating characteristic (ROC) curve. Radiology 1982;143:29-36.

8. Fleisher BE, Murthy L, Lee S, Constantinou JC, Benitz WE, Stevenson DK. Neonatal severity of illness scoring systems: a comparison. Clin Pediatr 1997;36:223-7.

9. Van Erkel AR, Pattynama PMT. Receiver Operating Characteristic (ROC) analysis: basic principles and applications in radiology. Eur J Radiol 1998;27:88-94.

10. Bührer C, Metze B, Obladen M. CRIB, CRIB-II, birth weight or gestational age to assess mortality risk in very low birth weight infants?Acta Paediatr 2008; 97(7):899-903.

11. De Felice C, Del Vecchio A, Latini G. Evaluating illness severity for very low birth weight infants: CRIB or CRIB-II? J Matern Fetal Neonatal Med 2005;17(4):257-60.

12. Gooden M, Younger N, Trotman H. What is the Best Predictor of Mortality in a Very Low Birth Weight Infant Population with a High Mortality Rate in a Medical Setting with Limited Resources? Am J Perinatol 2014;31(6):441-6.

13. Greenwood S1, Abdel-Latif ME, Bajuk B, Lui K; NSW and ACT Neonatal Intensive Care Units Audit Group. Can the early condition at admission of a high-risk infant aid in the prediction of mortality and poor neurodevelopmental outcome? A population study in Australia. J Paediatr Child Health 2012;48(7):588-95.

14. 14. Miletin J, Pichova K, Doyle S, Dempsey EM. Serum cortisol values, superior vena cava flow and illness severity scores in very low birth weight infants. J Perinatol 2010;30(8):522-6.

15. Zhang Y, Chan GS, Tracy MB, Lee QY, Hinder M, Savkin AV, et al. Spectral analysis of systemic and cerebral cardiovascular variabilities in preterm infants: relationship with clinical risk index for babies (CRIB). Physiol Meas 2011;32(12):1913-28.

16. Manktelow BN, Draper ES, Field D. Predicting neonatal mortality among very preterm infants: a comparison of three versions of the CRIB score. Arch Dis Child Fetal Neonatal E 2010; 95(1):F9-F13.