SOFA is superior to MOD score for the determination of non-neurologic organ dysfunction in patients with severe traumatic brain injury: a cohort study

OBJECTIVE To compare the discriminative ability of the SOFA and MOD scoring systems with respect to hospital mortality and unfavorable neurologic outcome in patients with severe traumatic brain injury admitted to intensive care. METHODS We performed a prospective cohort study at Foothills Medical Centre, the sole adult tertiary care trauma center servicing southern Alberta (population approximately 1.3 million) All patients >or=16 years of age and older with severe traumatic brain injury (sTBI) and intensive care unit length of stay > 48 hours between May 1, 2000 and April 31, 2003 were included. Non-neurologic organ dysfunction was measured by the SOFA and MODS scoring systems. Comparison of the SOFA and MOD score determination of organ dysfunction for each non-neurological organ system was examined by calculating the proportion of patients with SOFA and MOD component score defined organ failure. Consistent with previous literature, organ system failure was defined as a component score >or=3. RESULTS The odds of death and unfavorable neurologic outcome in patients with SOFA defined cardiovascular failure were 14.7 times (95% CI: 5.9-36.3) and 7.6 times (95% CI 3.5-16.3) respectively, that of those without cardiovascular failure. The development of SOFA defined cardiovascular failure was a reasonable discriminator of hospital mortality and unfavorable neurologic outcome (AuROC=0.75 and 0.73, respectively). The odds of death and unfavorable neurologic outcome in patients with MOD defined cardiovascular failure were 2.6 times (95% CI: 1.24-5.26) and 4.1 times (95% CI 1.3-12.4) respectively, that of those without cardiovascular failure. The development of MOD defined cardiovascular failure was a poor discriminator of hospital mortality and unfavorable neurologic outcome (AuROC=0.57 and 0.59 respectively). Both SOFA and MOD defined respiratory failure were not statistically associated with hospital mortality. CONCLUSIONS In patients with brain injury, the SOFA scoring system has superior discriminative ability and stronger association with outcome compared to the MOD scoring system with respect to hospital mortality and unfavorable neurologic outcome.