Is MMODS better than SOFA?

MMODS is a simple modification of the Multiple Organ Dysfunction Score (MODS). MMODS is calculated by summing up MODS with the Organ Support Score (OSS). OSS is a dichotomous score of one or none, given to each organ support the patient received, namely: ventilation, inotropes and renal replacement therapy (CVVH). The maximum score a patient could receive was 3. The above modification was made as MODS variables do not account for the above therapeutic interventions, but can be affected by them. This could result in an apparent false improvement in the organ dysfunction parameters, which can affect quantification of organ dysfunction and thus fail to describe organ dysfunction precisely.

Objective

To compare the sensitivity of MMODS with Sequential Organ Failure Assessment (SOFA).

Design

A prospective trial in a tertiary referral multidisciplinary intensive care setting.

Patients and methods

All critically ill patients admitted to the ICU were studied. All necessary data to calculate daily MMODS and SOFA were collected and entered into a dedicated database. ICU outcomes of all patients were also recorded. The sensitivity of both MMODS and SOFA were compared and the statistical significance established using appropriate statistical tests.

Results

Ninety-two patients were studied with a male to female ratio of 2:1 and a mean length of stay of 8.72 ± 8.0 days. The mean age was 47.62 ± 22.1. The mean MMODS for all patients was 6.41 ± 3.74 and the mean SOFA was 6.66 ± 3.72. The mean MMODS for survivors was 5.23 ± 2.70 and that of nonsurvivors was 9.02 ± 4.34 (P ≤ 0.00). The mean SOFA for survivors was 5.61 ± 2.86 and that for nonsurvivors was 8.97 ± 4.32 (P ≤ 0.00). The contribution to ICU outcome (alive/dead) by both SOFA and MMODS was evaluated by determining their coefficients in a logistic regression model as shown in Table 1.

Table 1

The performance of the logistic model was determined by the area under the Receiver Operating Characteristic (ROC) curve. MMODS demonstrated a significant effect on the ICU outcome with an area under the ROC curve of 0.766 in comparison with that of SOFA (0.726) (P ≤ 0.002).

Conclusion

The sensitivity of MMODS was significantly better than SOFA. Increased sensitivity can augment the efficacy of a scoring system and thus the evaluation of novel ICU therapies. Further addition of the simple dichotomous OSS did not compromise the simplicity of the original MODS.