Organ dysfunction as an outcome measure in clinical trials.

Serious infection is responsible for both morbidity and mortality. The morbidity of life-threatening infection is reflected in the development of the multiple organ dysfunction syndrome (MODS), so the availability of reliable and valid tools to quantify MODS is an important prerequisite for the evaluation of treatment of patients with infection. In general terms, outcome measures in clinical trials are used to answer one of two questions--does the intervention work (is a biological effect evident?) and does the intervention help? (is there evidence of clinical benefit?) The requirements for measures differ. Measures of biological effect should be sensitive, continuous variables, while those of clinical benefit should be robust and unequivocally relevant. We describe a model, based on our previously published MOD score (a measure of biological effect) that permits evaluation of both biological effect and clinical benefit, using readily available and commonly measured variables. Such a measure is potentially useful in evaluating the effects of new treatments, and in understanding the interactions of the biological process of MODS and its familiar clinical signs.