Correlation of a computerized SOFA score and derived measures with length of stay at an operative ICU

Objective: The purpose of this study was to assess whether or not the information on progression of illness and therapeutic interventions included in a computerized SOFA (Sequential Organ Failure Assessment) score and derived measures (maximum SOFA, total maximum SOFA and delta SOFA) influences the correlation with length of stay (LOS) at an operative intensive care unit (ICU). Methods: During a period of one year 524 patients aging over 18 years who stayed more than 24 hours at an operative ICU were included into this study. Based on SQL scripts (Structured Query Language), a computerized SOFA score and the derived measures "maximum-SOFA", "total-maximum-SOFA" and "delta-SOFA" of all patients were retrospectively calculated for each day at ICU using routine data recorded with the patient data management system ICUData (IMESO GmbH, Huttenberg, Germany). "Maximum-SOFA" and "total-maximum-SOFA" are measures for the severity of illness or cumulative organ dysfunction. "Delta-SOFA" measures the magnitude of organ dysfunction developing during ICU stay and is therefore potentially influenced by therapeutic measures. Analysis was based on exact LOS in hours. Results: Mean LOS of the whole collective was 5.2 +/- 6.8 days (median 2.8, range 1-51). Correlation of LOS depending on score results increased from "admission-SOFA" (r=0.280), to,"maximum-SOFA" (r=0.444), "total-maximum-SOFA" (r=0.503), and "delta-SOFA" (r=0.576). Conclusion: Therefore, the sum of information on progression of illness and therapeutic interventions included in derived measures improves the correlation with LOS at an ICU compared to the,"admission-SOFA".