CRIB, CRIB-II, birth weight or gestational age to assess mortality risk in very low birth weight infants?

Aim: The mortality risk of very low birth weight (VLBW) (<1500 g) infants has been estimated by the Clinical Risk Index for Babies (CRIB). Superior discriminatory power has been claimed for the revised CRIB-II score based on birth weight, gestational age, sex, temperature and base excess (BE) at admission. This analysis compared the power of CRIB, CRIB-II, birth weight and gestational age to predict death prior to discharge.

Methods: Of 1485 consecutive VLBW infants admitted between January 1, 1991 and December 31, 2006, who survived for >or=12 h, CRIB and CRIB-II calculations were possible in 1358 infants (92%). Predictive power of variables was assessed by comparing areas under receiver operator characteristics curves (AUC).

Results: CRIB (AUC [95% confidence intervals] 0.82 [0.78-0.86]) performed significantly better than birth weight (0.74 [0.69-0.79]) or gestational age (0.71 [0.66-0.76]), while CRIB-II (0.69 [0.64-0.74]) was rather inferior to CRIB and did not differ significantly from birth weight or gestational age. No substantial changes were seen when substituting worst BE during the first 12 h of life for BE at admission when calculating CRIB-II.

Conclusions: CRIB-II does not result in improved estimation of mortality risk in VLBW infants as compared to CRIB, birth weight or gestational age.