COMMENTARY p

odds of developing an outcome (death) among groups (gender, age group, and so on) with respect to their * Correspondence: donald.w.marion.ctr@mail.mil hypothermia versus normothermia treatment and six pro-spective cohort studies that provided ICP data before and during hypothermia treatment found that therapeutic mod-erate hypothermia was surpassed only by hypertonic saline, lumbar cerebrospinal fluid drainage, and decompressive craniectomy in the level of ICP reduction [2]. There are several mechanisms through which cooling may reduce a separate analysis of data from studies with a low risk of bias. Both the cumulative and ‘low risk of bias ’ data sets showed significant positive effects of hypothermia. The authors used relative risk (RR) as their measure of the analysis. Outcome events (death and poor outcomes such as long-term disability) in the TBI population are not rare events and, under such a scenario, RR tends to be biased and odds ratios are preferred by some. How-ever, since the authors are not actually comparing thetrials have, and a recent meta-analysis by Crossley and colleagues now finds that the cumulative findings of those single-center trials dilute the multi-center trial results and show an overall reduction in mortality and poor outcomes associated with cooling. The need for consistent support of key physiologic parameters during cooling is emphasized by this finding