Methods of mortality risk adjustment in the NICU: a 20-year review.

BACKGROUND AND OBJECTIVES Improving the quality of care delivered in NICUs relies on the ability to partition variation associated with patient characteristics from those attributed to processes of care delivery through risk adjustment. Multiple methods of mortality risk adjustment have been proposed for NICU populations. We review existing literature pertaining to mortality risk adjustment in the NICU. METHODS PubMed and Scopus were searched to identify unique methods of mortality risk adjustment in the NICU and their trends in citation since original publication. Additional online searches were performed to identify organizational and government agency means of mortality risk adjustment for patients in the NICU. RESULTS Among 10 unique neonatal mortality risk adjustment scores identified by this review, there are >3 dozen different measurement components. No score includes >28 components; no score contains <6. Scores differ substantively in their intended purposes, component parameters and intensity of data collection. The Clinical Risk Index for Babies (CRIB) has been referenced most frequently in other research articles (447 citations), while the National Institutes of Child Health and Human Development "calculator" has the greatest rate of citations per year since initial publication (37). The scores are notably inconsistent in their approaches to timing of data collection and inclusion of comorbidity indicators. CONCLUSIONS Rigorous means of risk adjustment in the NICU are essential to enhancing the quality of care delivered to neonates, by facilitating more meaningful comparisons in quality improvement. Building on the first 20 years of neonatal mortality risk adjustment will ultimately allow researchers and quality improvement teams to apply measures that facilitate cross-institutional comparisons thoroughly and fairly.