Modified system outcome score and outcome index—Method of monitoring patient care in a special care area

Abstract

A scoring system intended both to assess mortality risk and permit surveillance, evaluation, and comparison of medical care was developed in our surgical ICU. Five simple clinical indices of organ system failure were selected and weighted according to their statistically validated relationship to mortality, resulting in a daily System Outcome Score (SOS). Cluster analysis was used to divide the creation data set of 2,777 patients into suitable groupings of scores to predict mortality; the clustering was confirmed for reproducibility with a validation set of an additional 2,860 patients. Based on this validation of the scoring system, two computer-controlled patient care surveillance techniques were developed. The first involved the definition of three unfavorable SOS patterns evolving during the course of a patient's admission. Detection of one or more of these patterns, described by the acronym SDL, permits review of the care administered to the specific patient generating the pattern. A global assessment of care is achieved with the Outcome Index (OI), which relates overall mortality risk in the ICU to the actual mortality rate over a given time period. Effectiveness of care can then be compared between different time periods within the one unit or between different units with similar patient mix. The overall system offers the potential for a surveillance-based quality assurance system with widespread applicability.