The Adverse Outcome Index: Putting Quality Into an Outcome Measure

The Adverse Outcome Index, originally designed to provide an objective inventory of adverse outcomes, is often promoted as a tool for assessing the quality of inpatient obstetric care. Although the Adverse Outcome Index is well described, and its outcomes are easy to collect, it has notable drawbacks such as "paradoxical measures" (eg, blood transfusions are counted as adverse measures even when they are used appropriately) and the dominance of certain measures within the Adverse Outcome Index that can drive scores (eg, neonatal intensive care unit admissions). In this article, we argue that in addition to the limitations noted, the Adverse Outcome Index, although providing a reasonable measure of inpatient obstetric acuity, fails to be a reliable measure of quality. This is particularly important because many organizations are seeking quality measures and the Adverse Outcome Index may become a candidate tool. We believe that introducing an adjudication process to the Adverse Outcome Index would greatly enhance its role as a quality indicator. Until newly proposed quality measures are perfected and adopted, a quality-adjusted Adverse Outcome Index will allow this widely used measure to provide a more reliable determination of those adverse events potentially amenable to performance improvement.