The CRIB (clinical risk index for babies) score was developed as a tool for assessing initial neonatal mortality risk. It is based on birthweight (BW), gestational age (GA), maximum and minimum fraction of inspired oxygen and maximum base excess during the first 12 h, and presence of congenital malformations. It has been shown to be a better predictor of mortality than BW. We evaluated whether CRIB was a predictor of morbidity as manifested in respiratory distress syndrome (RDS), chronic lung disease or death at 28 days(CLD28), chronic lung disease or death at 36 weeks post-menstrual age (CLD36), and mortality. We further evaluated whether it was a significant predictor above and beyond GA or BW using data from a randomized, placebo-controlled, blinded clinical trial of thyrotropin-releasing hormone (TRH) to prevent lung disease in the preterm infant. Women in labor before 30 weeks gestation at 13 North American centers were enrolled between October 1992 and December 1996. There were no differences between the treatment groups in sex, race, GA, BW, RDS, CLD28, CLD36, death or CRIB score. CRIB scores at the time of birth were available for 524 (78%) infants with BW <1500 grams at 12 of the 13 centers. Sex and race were not predictive for any outcome. Multiple births were predictive only of mortality. BW, GA, and CRIB were all predictive in single variable logistic models, for all 4 outcomes, all with p <.001. RDS and CLD28 were both best predicted jointly in a logistic model by GA (p<.0001) and CRIB (p<.0001). Mortality was best predicted jointly by GA(p=.013) and CRIB (p<.001). CLD36 was best predicted jointly by BW(p<.001) and CRIB (p<.001). CRIB improved the prediction above and beyond GA or BW in all 4 outcome variables (p<.001). The areas under the receiver operating characteristics curves (ROC) ranged from 79% to 82% for the 4 outcomes. We conclude that in a multi-center prospective well-controlled study, the CRIB score improved the predictive ability for chronic lung disease or mortality above and beyond GA or BW.
