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.