Improved SNAPPE-II and CRIB II scores over a 15-year period.

Objective: During the last decades mortality and morbidity of preterm infants have declined in the Western world. We hypothesized that the decrease in mortality in preterm infants was associated with a decrease in illness severity scores (SNAPPE-II and CRIB II scores).

Study Design: Subjects were inborn infants born between January 1997 and December 1999 (period 1) and between January 2006 and December 2011 (period 2) with a gestational age of 26+0 through 28+6 weeks and without congenital malformations (n=394). SNAPPE-II, CRIB II scores, mortality, severe morbidity and survival without morbidity were recorded. Outcomes between the two periods were analyzed using multivariable analysis.

Results: SNAPPE-II, but not CRIB II, scores were significantly lower for all GAs in period 2 compared with period 1. The risk of mortality for identical SNAPPE-II scores and CRIB II scores did not differ between the two periods. The risk of morbidity for identical SNAPPE-II scores and CRIB II scores was significantly lower in period 2 versus period 1. Hence, the chance of survival without morbidity for identical SNAPPE-II scores and CRIB II scores increased significantly in period 2 versus period 1.

Conclusions: SNAPPE-II, but not CRIB II, scores decreased over 15 years. The risk of mortality for identical SNAPPE-II and CRIB II scores did not change, but the risk of morbidity decreased and the chance of survival without morbidity increased for identical SNAPPE-II and CRIB II scores. These findings suggest substantial improvements in both obstetrical and neonatal care.