Measuring Illness Severity in Newborn Intensive Care

Abstract

Measurement of illness severity has found increasing use in adult and pediatric intensive care research over the past decade. The development of illness severity indices for neonatal intensive care has lagged because birth weight has served as an excellent proxy for illness severity. However, a number of recent studies have shown marked variation in survival and morbidity among neonatal intensive care units (NICUs) despite birth weight adjustment, making clear the need for neonatal illness severity scoring. We discuss advantages and disadvantages of the 4 types of scoring systems used in adult intensive care—diagnosis, risk-factor, therapeutic, and physiological—and review their applications in adult and pediatric ICU research. Criteria for score design, as well as standards for validation and performance, are enumerated. The 30 neonatal scores fall in 5 major categories: obstetric risk, general use pediatric scores, predictors of developmental outcome, bronchopulmonary dysplasia risk, and acute mortality risk. Few have been adequately validated on large, concurrent independent samples. The most promising scores are those that measure acute physiological derangement on admission. Potential applications for these new illness severity scores are discussed.