Background: Most maternal deaths result from severe maternal morbidity (SMM with subsequent organ/system dysfunction and organ failure. The objective was to assess the performance of Sequential Organ Failure Assessment (SOFA) score in cases of SMM admitted to the high dependency obstetric unit.Methods: Organ/system dysfunction and failure were assessed according to the maximum score for the six components (respiratory, neurological, renal, hepatic, cardiovascular and coagulation system). The total maximum SOFA score was estimated using the worst result each component on a single day. The distribution of SOFA scores was assessed for normality by using the Shapiro Wilk Test, [p=003]. The mean maximum SOFA scores for each organ/system were computed according to according to outcome (survival or death), using the Mann-Whitney test. The sensitivity, specificity, and the area under the curve (AUC) for each organ/system were evaluated. A Receiver Operator Characteristic (ROC) curve was fitted using maximum likelihood estimates for the total maximum SOFA score, in order to assess the sensitivity, specificity and discriminatory abilities of the maximum SOFA scores.
Results:Of the 425 patients with SMM, 345 (81.2%, 95%CI 71.8-82.4) survived while 80 (18.8%, 95% CI: 12.9, 22.6) did not survive. All the non-survivors and 64 (18.5%) of the survivors presented with multiple organ/system dysfunction. Nonsurvivors were more likely to present with more severe and with multiple organ/ system dysfunction. The maximum total SOFA score had good discrimination in the respiratory, cardiovascular and neurological systems, but poor discrimination in the renal, hepatic and coagulatory systems. The total maximum SOFA score displayed an area under the curve (AUC) of 0.83 (95% CI: 0.56, 1.00), with a cutoff value of at least 8.0 sensitivity of 86.7%, and specificity of 90.0%.
Conclusion:The total maximum SOFA score showed good predictive and discriminative abilities for maternal mortality in women with severe maternal morbidity.