Accuracy of Sequential Organ Failure Assessment (SOFA) scoring in clinical practice

Abstract

Background: The Sequential Organ Failure Assessment (SOFA) score is used to quantify the severity of illness daily during intensive care. Our aim was to evaluate how accurately SOFA is recorded in clinical practice, and whether this can be improved by a refresher course in scoring rules.

Methods: The scores recorded by physicians in a university hospital intensive care unit (ICU) were compared with the gold standard determined by two expert assessors. Data concerning all consecutive patients during two 6-week-long observation periods (baseline and after the refresher course) were compared.

Results: SOFA was accurate on 75/158 (48%) patient days at baseline. The cardiovascular, coagulation, liver, and renal component scores showed excellent accuracy (>or=82%, weighted kappa >or=0.92), while the neurological score showed only moderate (70%, weighted kappa 0.51) and the respiration score showed good accuracy (75%, weighted kappa 0.79). After the refresher course, the number of >or=2 point errors decreased (P<0.01). Sedation precluded neurological evaluation on 135/311 (43%) days. The accuracy of the assumed neurological scores was lower than those based on timely data: 89/135 (66%, weighted kappa 0.55) vs. 125/176 (71%, weighted kappa 0.81) (P<0.01).

Conclusion: Only half of the SOFA scores were accurate. In most cases, they were accurate enough to allow the recognition of organ failure and detection of change. The component scores showed good to excellent accuracy, except the neurological score. After the refresher course, the results improved slightly. The moderate accuracy of the neurological score was not amended. A simpler neurological classification tool than the Glasgow Coma Scale is needed in the ICU.