Evaluating illness severity for very low birth weight infants: CRIB or CRIB-II?

Background. Estimating the risk of in-hospital mortality provides essential information in the neonatal intensive care unit (NICU). The clinical risk index for babies (CRIB) is a widely used, risk-adjustment instrument to determine illness severity in infants of gestational age ⩽ 31 wks, or birth weight ⩽ 1,500 g, recently updated and simplified into a five-items scoring system (CRIB-II). Aim. The accuracy values of CRIB and CRIB-II scores in predicting in-hospital mortality were compared in a tertiary level, minimal intubation policy NICU setting. Methods. A total of 147 very low birth weight (VLBW) infants were examined. Both CRIB and CRIB-II scores were calculated for each newborn, and death before hospital discharge was selected as the outcome measure. Comparisons were performed by receiver-operating characteristic (ROC) curve analysis, and the area under the curve (AUC) was used as a measure of predictor accuracy. Results. Mean AUCs for CRIB, CRIB-II, gestational age and birth weight in identifying neonatal mortality in VLBW infants ranged from 0.924 (CRIB) to 0.869 (gestational age). No significant differences were found for the AUCs of CRIB versus CRIB-II, CRIB versus gestational age, CRIB versus birth weight, CRIB-II versus gestational age, or CRIB-II versus birth weight. Conclusions. Our findings show that; 1) CRIB and CRIB-II show similar accuracy values in predicting in-hospital neonatal mortality in VLBW infants; and 2) neither score offers an advantage in predicting mortality, as compared to gestational age or birth weight, thus suggesting that treatment modalities may modify predictive accuracy.