Serial evaluation of SOFA score in a Brazilian teaching hospital

Objective

To evaluate the application of the Sequential Organ Failure Assessment (SOFA) in describing the severity of organ dysfunctions and the associated mortality rates in critically ill patients of a teaching hospital.

Methods

A prospective longitudinal study was performed at University Hospital – Londrina State University between January 2004 and December 2005. For static evaluation, we considered the daily SOFA, SOFA Max and Mean SOFA. To analyze dynamic changes in the SOFA scores, we stratified the patients into three groups: low (0 to 5), medium (6 to 9) and high (>10) SOFA upon ICU admission. The three groups of patients were evaluated after 48 hours in the ICU to detect whether the SOFA scores decreased, increased or were unchanged. The discriminative power of SOFA was evaluated using ROC curves.

Results

We analyzed 1,164 adult patients with a mean age of 56.7 ± 19.1 years, and a hospital mortality rate of 47.9%. The Mean SOFA for all of the patients was 6.38 upon admission and was statistically higher in nonsurvivors (P χ²_trend = 272.08, P < 0.001, increase rate = 0.13). The SOFA score on the third day in the ICU had the highest area under the curve for hospital mortality (AUC = 0.817 ± 0.0133, 95% CI = 0.792 to 0.840). Organ failure occurred in 699 patients. Respiratory failure was most frequent, but cardiovascular failure had the highest associated risk of death (RR = 4.10, 95% CI = 3.12 to 5.38, P < 0.001).

Conclusion

Applying SOFA to critically ill patients admitted to the adult ICU effectively described the severity of organ dysfunctions, and higher SOFA scores had a positive association with mortality.