T raumaTic brain injury (TBI) is a common cause of death and disability worldwide. 17 Despite some claims to the contrary, no clear decrease in severe TBI-related mortality or improvement in overall outcome has been observed over the past 2 decades. 24 Recently, many studies have shown that the presence and frequency of high intracranial pressure (ICP) are predictive of the outcome of severe TBI. 18,23 Thus, ICP monitoring has been widely used in the management of severe TBI. Indeed, the Brain Trauma Foundation (BTF) guideabbreviatioNs BTF = Brain Trauma Foundation; GCS = Glasgow Coma Scale; ICP = intracranial pressure; ICU = intensive care unit; MD = mean difference; STROBE = Strengthening the Reporting of Observational Studies in Epidemiology; TBI = traumatic brain injury. submitted January 9, 2014. accepted October 22, 2014. iNclude wheN citiNg Published online December 5, 2014; DOI: 10.3171/2014.10.JNS1460. disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. This work was supported by the National Natural Science Foundation of China (NSFC Grants 30371454, 81271375, and 81171133), the Science and Technology Commission of Shanghai Municipality Project (10JC1402300), and Shanghai Nature Science Foundation (08411952000). * Drs. Qiang Yuan, Xing Wu, and Yirui Sun contributed equally to this work. obJect Some studies have demonstrated that intracranial pressure (ICP) monitoring reduces the mortality of traumatic brain injury (TBI). But other studies have shown that ICP monitoring is associated with increased mortality. Thus, the authors performed a meta-analysis of studies comparing ICP monitoring with no ICP monitoring in patients who have suffered a TBI to determine if differences exist between these strategies with respect to mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. methods The authors systematically searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (Central) from their inception to October 2013 for relevant studies. Randomized clinical trials and prospective cohort, retrospective observational cohort, and case-control studies that compared ICP monitoring with no ICP monitoring for the treatment of TBI were included in the analysis. Studies included had to report at least one point of mortality in an ICP monitoring group and a no-ICP monitoring group. Data were extracted for study characteristics, patient demographics, baseline characteristics, treatment details, and study outcomes. results A total of 14 studies including 24,792 patients were analyzed. The meta-analysis provides no evidence that ICP monitoring decreased the risk of death (pooled OR 0.93 [95% CI 0.77-1.11], p = 0.40). However, 7 of the studies including 12,944 patients were published after 2012 (January 2012 to October 2013), and they revealed that ICP monitoring was significantly associated with a greater decrease in mortality than no ICP monitoring (pooled OR 0.56 [95% CI 0.41-0.78...