Score for Neonatal Acute Physiology: A Physiologic Severity Index for Neonatal Intensive Care

TLDR

Variation in birth‑weight‑adjusted mortality across NICUs likely reflects differences in illness severity. The authors aimed to develop an illness‑severity index to enable outcome comparisons across NICUs. They created and prospectively validated the Score for Neonatal Acute Physiology (SNAP) on 1,643 admissions in three units, scoring the worst derangement in each organ system during the first 24 h. SNAP was minimally correlated with birth weight yet strongly predicted mortality, distinguishing risk groups with 2–20‑fold differences and correlating with nursing workload, therapeutic intensity, physician risk estimates, and length of stay, making it a valuable NICU research tool.

Abstract

The substantial variation in birth weight-adjusted mortality among neonatal intensive care units (NICUs) may reflect differences in population illness severity. Development of an illness severity measure is essential for comparisons of outcomes. The Score for Neonatal Acute Physiology (SNAP) was developed and validated prospectively on 1643 admissions (114 deaths) in three NICUs. SNAP scores the worst physiologic derangements in each organ system in the first 24 hours. SNAP showed little correlation with birth weight and was highly predictive of neonatal mortality even within narrow birth weight strata. It was capable of separating patients into groups with 2 to 20 times higher mortality risk. It also correlated highly with other indicators of severity including nursing workload (r = .59), therapeutic intensity (r = .78), physician estimates of mortality risk (r = .65), and length of stay (R2 = .59). SNAP is an important new tool for NICU research.