Re-orientation of clinical research in traumatic brain injury: report of an international workshop on comparative effectiveness research

Validation of the revised injury severity classification score in patients with moderate-to-severe traumatic brain injury

INTRODUCTION

By analysing risk-adjusted mortality ratios, weaknesses in the process of care might be identified. Traumatic brain injury (TBI) is the main cause of death in trauma, and thus it is crucial that trauma prediction models are valid for TBI patients. Accordingly, we assessed the validity of the RISC score in TBI patients by internal and external validation analyses.

METHODS

Patients with moderate-to-severe TBI admitted to the TraumaRegister DGU® (TR-DGU) and the trauma registry of Helsinki University Hospital (TR-THEL) in 2006-2011 were included in this retrospective open cohort study. Definition of moderate-to-severe TBI was head abbreviated injury scale of 3 or higher. Subgroup analysis for patients with isolated and polytrauma TBI was performed. The performance of the RISC score was evaluated by assessing its discrimination (area under the curve, AUC) and calibration (Hosmer-Lemeshow [H-L] test).

RESULTS

Among the 9106 and 809 patients with moderate-to-severe TBI admitted to TR-DGU and TR-THEL, unadjusted mortality was 26% and 23%, respectively. Internal and external validation of the RISC score showed good discrimination (TR-DGU AUC 0.89, 95% confidence interval [CI] 0.88-0.90 and TR-THEL AUC 0.84, 95% CI 0.81-0.87), but poor calibration (p<0.001) in patients with moderate-to-severe TBI. Subgroup analysis found the discrimination only to be modest in isolated TBI (AUC 0.76) and calibration to be particularly poor in polytrauma TBI (TR-DGU H-L=4356, p<0.001; TR-THEL H-L 112, p<0.001).

CONCLUSION

The RISC score was found to be of limited predictive value in patients with moderate-to-severe TBI. A new general trauma scoring system that includes TBI specific prognostic factors is warranted.

Special considerations in infants and children

Head injury in children is one of the most common causes of death and disability in the US and, increasingly, worldwide. This chapter reviews the causes, patterns, pathophysiology, and treatment of head injury in children across the age spectrum, and compares pediatric head injury to that in adults. Classification of head injury in children can be organized according to severity, pathoanatomic type, or mechanism. Response to injury and repair mechanisms appear to vary at different ages, and these may influence optimal treatment; however, much work is still needed before investigation leads to clearly effective clinical interventions. This is true both for the more severe injuries as well as those at the milder end of the injury spectrum, the latter of which have received increasing attention. In this chapter, neuroassessment tools for each age, newer imaging modalities including magnetic resonance imaging (MRI), and specific pediatric management issues, including intracranial pressure (ICP) monitoring and seizure prophylaxis, are reviewed. Finally, specific head injury patterns and functional outcomes relevant to pediatric patients are discussed. While head injury is common, the number of head-injured children is significantly smaller than the corresponding adult head-injured population. When divided further by specific ages, injury types, and other sources of heterogeneity, properly powered clinical research is likely to require large data sets that will allow for stratification across variables, including age. While much has been learned in the past several decades, further study will be required to determine the best management practices for optimizing recovery in individual pediatric patients. This approach is likely to depend on collaborative international head injury databases that will allow researchers to better understand the nuanced evolution of different types of head injury in patients at each age, and the pathophysiologic, treatment-related, and genetic factors that influence recovery.

Ethical and regulatory considerations in the design of traumatic brain injury clinical studies

Research is essential for improving outcomes after traumatic brain injury (TBI). However, the ubiquity, variability, and nature of TBI create many ethical issues and accompanying regulations for research. To capture the complexity and importance of designing and conducting TBI research within the framework of key ethical principles, a few highly relevant topics are highlighted. The selected topics are: (1) research conducted in emergency settings; (2) maintaining equipoise in TBI clinical trials; (3) TBI research on vulnerable populations; and (4) ethical considerations for sharing data. The topics aim to demonstrate the dynamic and multifaceted challenges of TBI research, and also to stress the value of addressing these challenges with the key ethical principles of respect, beneficence, and justice. Much has been accomplished to ensure that TBI research meets the highest ethical standards and has fair and enforceable regulations, but important challenges remain and continued efforts are needed by all members of the TBI research community.

Intracranial pressure after the BEST TRIP trial: a call for more monitoring

PURPOSE OF REVIEW

Increased intracranial pressure (ICP) is associated with worse outcome after traumatic brain injury (TBI), but whether its management improves the outcome is unclear. In this review, we will examine the implications of the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure (BEST TRIP) trial, evidence for an influence of ICP care on outcome, and a need for greater understanding of the pathophysiology than just ICP through multimodal monitoring (MMM) to enhance the outcome.

RECENT FINDINGS

The primary impact of the BEST TRIP trial, a randomized clinical trial that examined two TBI management strategies, one that used an ICP monitor, is in research and should not alter clinical practice. Analyses of large databases suggest TBI care based on the Brain Trauma Foundation guidelines and management of intracranial hypertension can improve patient outcome. However, accumulating evidence demonstrates there are several mechanisms of secondary brain injury (SBI), for example, microvascular dysfunction or alterations in glucose utilization that cannot be detected using an ICP monitor. In these patients, growing clinical evidence suggests that MMM can help manage SBI and improve TBI outcome.

SUMMARY

ICP-based monitoring and treatment alone may not be enough to enhance TBI outcome, but ICP and cerebral perfusion pressure therapy remain important in TBI care. Although high-quality evidence for MMM is limited, it should be more widely adapted to better understand the complex pathophysiology after TBI, better target care, and identify new therapeutic opportunities.

Top-cited articles in traumatic brain injury

A review of the top-cited articles in a scientific discipline can identify areas of research that are well established and those in need of further development, and may, as a result, inform and direct future research efforts. Our objective was to identify and characterize the top-cited articles in traumatic brain injury (TBI). We used publically available software to identify the 50 TBI articles with the most lifetime citations, and the 50 TBI articles with the highest annual citation rates. A total of 73 articles were included in this review, with 27 of the 50 papers with the highest annual citation rates common to the cohort of 50 articles with the most lifetime citations. All papers were categorized by their primary topic or focus, namely: predictor of outcome, pathology/natural history, treatment, guidelines and consensus statements, epidemiology, assessment measures, or experimental model of TBI. The mean year of publication of the articles with the most lifetime citations and highest annual citation rates was 1990 ± 14.9 years and 2003 ± 6.7 years, respectively. The 50 articles with the most lifetime citations typically studied predictors of outcome (34.0%, 17/50) and were specific to severe TBI (38.0%, 19/50). In contrast, the most common subject of papers with the highest annual citation rates was treatment of brain injury (22.0%, 11/50), and these papers most frequently investigated mild TBI (36.0%, 18/50). These findings suggest an intensified focus on mild TBI, which is perhaps a response to the dedicated attention these injuries are currently receiving in the context of sports and war, and because of their increasing incidence in developing nations. Our findings also indicate increased focus on treatment of TBI, possibly due to the limited efficacy of current interventions for brain injury. This review provides a cross-sectional summary of some of the most influential articles in TBI, and a bibliometric examination of the current status of TBI research.

Predicting outcome after traumatic brain injury: development of prognostic scores based on the IMPACT and the APACHE II

Prediction models are important tools for heterogeneity adjustment in clinical trials and for the evaluation of quality of delivered care to patients with traumatic brain injury (TBI). We sought to improve the predictive performance of the IMPACT (International Mission for Prognosis and Analysis of Clinical Trials) prognostic model by combining it with the APACHE II (Acute Physiology and Chronic Health Evaluation II) for 6-month outcome prediction in patients with TBI treated in the intensive care unit. A total of 890 patients with TBI admitted to a large urban level 1 trauma center in 2009-2012 comprised the study population. The IMPACT and the APACHE II scores were combined using binary logistic regression. A randomized, split-sample technique with secondary bootstrapping was used for model development and internal validation. Model performance was assessed by discrimination (by area under the curve [AUC]), calibration, precision, and net reclassification improvement (NRI). Overall 6-month mortality was 22% and unfavorable neurological outcome 47%. The predictive power of the new combined IMPACT-APACHE II models was significantly superior, compared to the original IMPACT models (AUC, 0.81-0.82 vs. 0.84-0.85; p<0.05) for 6-month mortality prediction, but not for unfavorable outcome prediction (AUC, 0.81-0.82 vs. 0.83; p>0.05). However, NRI showed a significant improvement in risk stratification of patients with unfavorable outcome by the IMPACT-APACHE II models, compared to the original models (NRI, 5.4-23.2%; p<0.05). Internal validation using split-sample and resample bootstrap techniques yielded equivalent results, indicating low grade of overestimation. Our findings show that by combining the APACHE II with the IMPACT, improved 6-month outcome predictive performance is achieved. This may be applicable for heterogeneity adjustment in forthcoming TBI studies.

Minimizing errors in acute traumatic spinal cord injury trials by acknowledging the heterogeneity of spinal cord anatomy and injury severity: an observational Canadian cohort analysis

Clinical trials of therapies for acute traumatic spinal cord injury (tSCI) have failed to convincingly demonstrate efficacy in improving neurologic function. Failing to acknowledge the heterogeneity of these injuries and under-appreciating the impact of the most important baseline prognostic variables likely contributes to this translational failure. Our hypothesis was that neurological level and severity of initial injury (measured by the American Spinal Injury Association Impairment Scale [AIS]) act jointly and are the major determinants of motor recovery. Our objective was to quantify the influence of these variables when considered together on early motor score recovery following acute tSCI. Eight hundred thirty-six participants from the Rick Hansen Spinal Cord Injury Registry were analyzed for motor score improvement from baseline to follow-up. In AIS A, B, and C patients, cervical and thoracic injuries displayed significantly different motor score recovery. AIS A patients with thoracic (T2-T10) and thoracolumbar (T11-L2) injuries had significantly different motor improvement. High (C1-C4) and low (C5-T1) cervical injuries demonstrated differences in upper extremity motor recovery in AIS B, C, and D. A hypothetical clinical trial example demonstrated the benefits of stratifying on neurological level and severity of injury. Clinically meaningful motor score recovery is predictably related to the neurological level of injury and the severity of the baseline neurological impairment. Stratifying clinical trial cohorts using a joint distribution of these two variables will enhance a study's chance of identifying a true treatment effect and minimize the risk of misattributed treatment effects. Clinical studies should stratify participants based on these factors and record the number of participants and their mean baseline motor scores for each category of this joint distribution as part of the reporting of participant characteristics. Improved clinical trial design is a high priority as new therapies and interventions for tSCI emerge.

An optimal frequency range for assessing the pressure reactivity index in patients with traumatic brain injury

The objective of this study was to identify the optimal frequency range for computing the pressure reactivity index (PRx). PRx is a clinical method for assessing cerebral pressure autoregulation based on the correlation of spontaneous variations of arterial blood pressure (ABP) and intracranial pressure (ICP). Our hypothesis was that optimizing the methodology for computing PRx in this way could produce a more stable, reliable and clinically useful index of autoregulation status. The patients studied were a series of 131 traumatic brain injury patients. Pressure reactivity indices were computed in various frequency bands during the first 4 days following injury using bandpass filtering of the input ABP and ICP signals. Patient outcome was assessed using the extended Glasgow Outcome Scale (GOSe). The optimization criterion was the strength of the correlation with GOSe of the mean index value over the first 4 days following injury. Stability of the indices was measured as the mean absolute deviation of the minute by minute index value from 30-min moving averages. The optimal index frequency range for prediction of outcome was identified as 0.018-0.067 Hz (oscillations with periods from 55 to 15 s). The index based on this frequency range correlated with GOSe with ρ=-0.46 compared to -0.41 for standard PRx, and reduced the 30-min variation by 23%.

Surgical management of traumatic brain injury: a comparative-effectiveness study of 2 centers

Object

Mass lesions from traumatic brain injury (TBI) often require surgical evacuation as a life-saving measure and to improve outcomes, but optimal timing and surgical technique, including decompressive craniectomy, have not been fully defined. The authors compared neurosurgical approaches in the treatment of TBI at 2 academic medical centers to document variations in real-world practice and evaluate the efficacies of different approaches on postsurgical course and long-term outcome.

Methods

Patients 18 years of age or older who required neurosurgical lesion evacuation or decompression for TBI were enrolled in the Co-Operative Studies on Brain Injury Depolarizations (COSBID) at King's College Hospital (KCH, n = 27) and Virginia Commonwealth University (VCU, n = 24) from July 2004 to March 2010. Subdural electrode strips were placed at the time of surgery for subsequent electrocorticographic monitoring of spreading depolarizations; injury characteristics, physiological monitoring data, and 6-month outcomes were collected prospectively. CT scans and medical records were reviewed retrospectively to determine lesion characteristics, surgical indications, and procedures performed.

Results

Patients enrolled at KCH were significantly older than those enrolled at VCU (48 vs 34 years, p < 0.01) and falls were more commonly the cause of TBI in the KCH group than in the VCU group. Otherwise, KCH and VCU patients had similar prognoses, lesion types (subdural hematomas: 30%–35%; parenchymal contusions: 48%–52%), signs of mass effect (midline shift ≥ 5 mm: 43%–52%), and preoperative intracranial pressure (ICP). At VCU, however, surgeries were performed earlier (median 0.51 vs 0.83 days posttrauma, p < 0.05), bone flaps were larger (mean 82 vs 53 cm2, p < 0.001), and craniectomies were more common (performed in 75% vs 44% of cases, p < 0.05). Postoperatively, maximum ICP values were lower at VCU (mean 22.5 vs 31.4 mm Hg, p < 0.01). Differences in incidence of spreading depolarizations (KCH: 63%, VCU: 42%, p = 0.13) and poor outcomes (KCH: 54%, VCU: 33%, p = 0.14) were not significant. In a subgroup analysis of only those patients who underwent early (< 24 hours) lesion evacuation (KCH: n = 14; VCU: n = 16), however, VCU patients fared significantly better. In the VCU patients, bone flaps were larger (mean 85 vs 48 cm2 at KCH, p < 0.001), spreading depolarizations were less common (31% vs 86% at KCH, p < 0.01), postoperative ICP values were lower (mean: 20.8 vs 30.2 mm Hg at KCH, p < 0.05), and good outcomes were more common (69% vs 29% at KCH, p < 0.05). Spreading depolarizations were the only significant predictor of outcome in multivariate analysis.

Conclusions

This comparative-effectiveness study provides evidence for major practice variation in surgical management of severe TBI. Although ages differed between the 2 cohorts, the results suggest that a more aggressive approach, including earlier surgery, larger craniotomy, and removal of bone flap, may reduce ICP, prevent cortical spreading depolarizations, and improve outcomes. In particular, patients requiring evacuation of subdural hematomas and contusions may benefit from decompressive craniectomy in conjunction with lesion evacuation, even when elevated ICP is not a factor in the decision to perform surgery.

Cross-sectional analysis of data from the U.S. clinical trials database reveals poor translational clinical trial effort for traumatic brain injury, compared with stroke

Traumatic brain injury (TBI) is an important public health problem, comparable to stroke in incidence and prevalence. Few interventions have proven efficacy in TBI, and clinical trials are, therefore, necessary to advance management in TBI. We describe the current clinical trial landscape in traumatic brain injury and compare it with the trial efforts for stroke. For this, we analysed all stroke and TBI studies registered on the US Clinical Trials (www.clinicaltrials.gov) database over a 10-year period (01/01/2000 to 01/31/2013). This methodology has been previously used to analyse clinical trial efforts in other specialties. We describe the research profile in each area: total number of studies, total number of participants and change in number of research studies over time. We also analysed key study characteristics, such as enrolment number and scope of recruitment. We found a mismatch between relative public health burden and relative research effort in each disease. Despite TBI having comparable prevalence and higher incidence than stroke, it has around one fifth of the number of clinical trials and participant recruitment. Both stroke and TBI have experienced an increase in the number of studies over the examined time period, but the rate of growth for TBI is one third that for stroke. Small-scale (<1000 participants per trial) and single centre studies form the majority of clinical trials in both stroke and TBI, with TBI having significantly fewer studies with international recruitment. We discuss the consequences of these findings and how the situation might be improved. A sustained research effort, entailing increased international collaboration and rethinking the methodology of running clinical trials, is required in order to improve outcomes after traumatic brain injury.

Existing data analysis in pediatric critical care research

Our objectives were to review and categorize the existing data sources that are important to pediatric critical care medicine (PCCM) investigators and the types of questions that have been or could be studied with each data source. We conducted a narrative review of the medical literature, categorized the data sources available to PCCM investigators, and created an online data source registry. We found that many data sources are available for research in PCCM. To date, PCCM investigators have most often relied on pediatric critical care registries and treatment- or disease-specific registries. The available data sources vary widely in the level of clinical detail and the types of questions they can reliably answer. Linkage of data sources can expand the types of questions that a data source can be used to study. Careful matching of the scientific question to the best available data source or linked data sources is necessary. In addition, rigorous application of the best available analysis techniques and reporting consistent with observational research standards will maximize the quality of research using existing data in PCCM.

Advancing care for traumatic brain injury: findings from the IMPACT studies and perspectives on future research

Research in traumatic brain injury (TBI) is challenging for several reasons; in particular, the heterogeneity between patients regarding causes, pathophysiology, treatment, and outcome. Advances in basic science have failed to translate into successful clinical treatments, and the evidence underpinning guideline recommendations is weak. Because clinical research has been hampered by non-standardised data collection, restricted multidisciplinary collaboration, and the lack of sensitivity of classification and efficacy analyses, multidisciplinary collaborations are now being fostered. Approaches to deal with heterogeneity have been developed by the IMPACT study group. These approaches can increase statistical power in clinical trials by up to 50% and are also relevant to other heterogeneous neurological diseases, such as stroke and subarachnoid haemorrhage. Rather than trying to limit heterogeneity, we might also be able to exploit it by analysing differences in treatment and outcome between countries and centres in comparative effectiveness research. This approach has great potential to advance care in patients with TBI.

A Drosophila model of closed head traumatic brain injury

Traumatic brain injury (TBI) is a substantial health issue worldwide, yet the mechanisms responsible for its complex spectrum of pathologies remains largely unknown. To investigate the mechanisms underlying TBI pathologies, we developed a model of TBI in Drosophila melanogaster. The model allows us to take advantage of the wealth of experimental tools available in flies. Closed head TBI was inflicted with a mechanical device that subjects flies to rapid acceleration and deceleration. Similar to humans with TBI, flies with TBI exhibited temporary incapacitation, ataxia, activation of the innate immune response, neurodegeneration, and death. Our data indicate that TBI results in death shortly after a primary injury only if the injury exceeds a certain threshold and that age and genetic background, but not sex, substantially affect this threshold. Furthermore, this threshold also appears to be dependent on the same cellular and molecular mechanisms that control normal longevity. This study demonstrates the potential of flies for providing key insights into human TBI that may ultimately provide unique opportunities for therapeutic intervention.

Metabolic crisis in severely head-injured patients: is ischemia just the tip of the iceberg?

Ischemia and metabolic crisis are frequent post-traumatic secondary brain insults that negatively influence outcome. Clinicians commonly mix up these two types of insults, mainly because high lactate/pyruvate ratio (LPR) is the common marker for both ischemia and metabolic crisis. However, LPR elevations during ischemia and metabolic crisis reflect two different energetic imbalances: ischemia (Type 1 LPR elevations with low oxygenation) is characterized by a drastic deprivation of energetic substrates, whereas metabolic crisis (Type 2 LPR elevations with normal or high oxygenation) is associated with profound mitochondrial dysfunction but normal supply of energetic substrates. The discrimination between ischemia and metabolic crisis is crucial because conventional recommendations against ischemia may be detrimental for patients with metabolic crisis. Multimodal monitoring, including microdialysis and brain tissue oxygen monitoring, allows such discrimination, but these techniques are not easily accessible to all head-injured patients. Thus, a new “gold standard” and adapted medical education are required to optimize the management of patients with metabolic crisis.

Study of therapeutic hypothermia (32 to 35°C) for intracranial pressure reduction after traumatic brain injury (the Eurotherm3235Trial): outcome of the pilot phase of the trial

Background

Clinical trials in traumatic brain injury (TBI) are challenging. Previous trials of complex interventions were conducted in high-income countries, reported long lead times for site setup and low screened-to-recruitment rates.

In this report we evaluate the internal pilot phase of an international, multicentre TBI trial of a complex intervention to assess: design and implementation of an online case report form; feasibility of recruitment (sites and patients); feasibility and effectiveness of delivery of the protocol.

Methods

All aspects of the pilot phase of the trial were conducted as for the main trial. The pilot phase had oversight by independent Steering and Data Monitoring committees.

Results

Forty sites across 12 countries gained ethical approval. Thirty seven of 40 sites were initiated for recruitment. Of these, 29 had screened patients and 21 randomized at least one patient. Lead times to ethics approval (6.8 weeks), hospital approval (18 weeks), interest to set up (61 weeks), set up to screening (11 weeks), and set up to randomization (31.6 weeks) are comparable with other international trials. Sixteen per cent of screened patients were eligible. We found 88% compliance rate with trial protocol.

Conclusion

The pilot data demonstrated good feasibility for this large international multicentre randomized controlled trial of hypothermia to control intracranial pressure. The sample size was reduced to 600 patients because of homogeneity of the patient group and we showed an optimized cooling intervention could be delivered.

Trial registration

Current Controlled Trials: ISRCTN34555414.

Toward an international initiative for traumatic brain injury research

The European Commission (EC) and the National Institutes of Health (NIH) jointly sponsored a workshop on October 18-20, 2011 in Brussels to discuss the feasibility and benefits of an international collaboration in the field of traumatic brain injury (TBI) research. The workshop brought together scientists, clinicians, patients, and industry representatives from around the globe as well as funding agencies from the EU, Spain, the United States, and Canada. Sessions tackled both the possible goals and governance of a future initiative and the scientific questions that would most benefit from an integrated international effort: how to optimize data collection and sharing; injury classification; outcome measures; clinical study design; and statistical analysis. There was a clear consensus that increased dialogue and coordination of research at an international level would be beneficial for advancing TBI research, treatment, and care. To this end, the EC, the NIH, and the Canadian Institutes of Health Research expressed interest in developing a framework for an international initiative for TBI Research (InTBIR). The workshop participants recommended that InTBIR initially focus on collecting, standardizing, and sharing clinical TBI data for comparative effectiveness research, which will ultimately result in better management and treatments for TBI.

Physiological monitoring of the severe traumatic brain injury patient in the intensive care unit

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Despite encouraging animal research, pharmacological agents and neuroprotectants have disappointed in the clinical environment. Current TBI management therefore is directed towards identification, prevention, and treatment of secondary cerebral insults that are known to exacerbate outcome after injury. This strategy is based on a variety of monitoring techniques that include the neurological examination, imaging, laboratory analysis, and physiological monitoring of the brain and other organ systems used to guide therapeutic interventions. Recent clinical series suggest that TBI management informed by multimodality monitoring is associated with improved patient outcome, in part because care is provided in a patient-specific manner. In this review we discuss physiological monitoring of the brain after TBI and the emerging field of neurocritical care bioinformatics.

Parenchymal brain oxygen monitoring in the neurocritical care unit

Patients admitted to the neurocritical care unit (NCCU) often have serious conditions that can be associated with high morbidity and mortality. Pharmacologic agents or neuroprotectants have disappointed in the clinical environment. Current NCCU management therefore is directed toward identification, prevention, and treatment of secondary cerebral insults that evolve over time and are known to aggravate outcome. This strategy is based on a variety of monitoring techniques including use of intraparenchymal monitors. This article reviews parenchymal brain oxygen monitors, including the available technologies, practical aspects of use, the physiologic rationale behind their use, and patient management based on brain oxygen.

Comparative effectiveness research in neurotrauma

Comparative effectiveness research (CER) is emerging as a commonly applied technique to determine the usefulness of medical interventions. Such research aims to compare various treatments for specific disease entities for overall effectiveness and potential for harm. According to the Centers for Disease Control, an estimated 1.7 million patients sustain a traumatic brain injury (TBI) annually in the US. In this review the authors examine the existence of CER reports in the area of neurotrauma to date and consider the context in which clinical research and evidence-based guidelines have and will continue to inform such analyses, with special attention to TBI.

Publication patterns of comparative effectiveness research in spine neurosurgery

OBJECT

The purpose of this study was to investigate publication patterns for comparative effectiveness research (CER) on spine neurosurgery.

METHODS

The authors searched the PubMed database for the period 1980-2012 using the key words "cost analysis," "utility analysis," "cost-utility," "outcomes research," "practical clinical research," "comparator trial," and "comparative effectiveness research," linked with "effectiveness" and "spine neurosurgery."

RESULTS

From 1980 through April 9, 2012, neurosurgery CER publications accounted for 1.38% of worldwide CER publications (8657 of 626,330 articles). Spine neurosurgery CER accounted for only 0.02%, with 132 articles. The journal with the greatest number of publications on spine neurosurgery CER was Spine, followed by the Journal of Neurosurgery: Spine. The average annual publication rate for spine neurosurgery CER during this period was 4 articles (132 articles in 33 years), with 68 (51.52%) of the 132 articles being published within the past 5 years and a rising trend beginning in 2008. The top 3 contributing countries were the US, Turkey, and Japan, with 68, 8, and 7 articles, respectively. Only 8 regular articles (6.06%) focused on cost analysis.

CONCLUSIONS

There is a paucity of publications using CER methodology in spine neurosurgery. Few articles address the issue of cost analysis. The promotion of continuing medical education in CER methodology is warranted. Further investigations to address cost analysis in comparative effectiveness studies of spine neurosurgery are crucial to expand the application of CER in public health.

Acute traumatic brain injury: is current management evidence based? An empirical analysis of systematic reviews

Traumatic brain injury (TBI) is a major health and socioeconomic problem worldwide with a high rate of death and long-term disability. Previous studies have summarized evidence from large-scale randomized trials, finding no intervention showing convincing efficacy for acute TBI management. The present empirical study set out to assess another crucial component of evidence base-systematic review, which contributes a lot to evidence-based health care, in terms of clinical issues, methodological aspects, and implication for practice and research. A total of 44 systematic reviews pertaining to therapeutic interventions for acute TBI were identified through electronic database searching, clinical guideline retrieval, and expert consultation, of which 21 were published in Cochrane Library and 23 in peer-reviewed journals. Their methodological quality was generally satisfactory, with the median Overview Quality Assessment Questionnaire score of 5.5 (interquartile range 2-7). Cochrane reviews are of better quality than regular journal reviews. Twenty-nine high-quality reviews provided no conclusive evidence for the investigated 22 interventions except for an adverse effect of corticosteroids. Less than one-third of the component trials were reported with adequate allocation concealment. Additionally other methodological flaws in design-for example, ignoring heterogeneity among the TBI population-also contributed to the failure of past clinical research. Based on the above findings, evidence from both systematic reviews and clinical trials does not fully support current management of acute TBI. Translating from laboratory success to clinical effect remains an unique challenge. Accordingly it may be the time to rethink the way in future practice and clinical research in TBI.

TBI surveillance using the common data elements for traumatic brain injury: a population study

BACKGROUND

To characterize the patterns of presentation of adults with head injury to the Emergency Department.

METHODS

This is a cohort study that sought to collect injury and outcome variables with the goal of characterizing the very early natural history of traumatic brain injury in adults. This IRB-approved project was conducted in collaboration with our Institution's Center for Translational Science Institute. Data were entered in REDCap, a secure database. Statistical analyses were performed using JMP 10.0 pro for Windows.

RESULTS

The cohort consisted of 2,394 adults, with 40% being women and 79% Caucasian. The most common mechanism was fall (47%) followed by motor vehicle collision (MVC) (36%). Patients sustaining an MVC were significantly younger than those whose head injury was secondary to a fall (P < 0.0001). Ninety-one percent had CT imaging; hemorrhage was significantly more likely with worse severity as measured by the Glasgow Coma Score (chi-square, P < 0.0001). Forty-four percent were admitted to the hospital, with half requiring ICU admission. In-hospital death was observed in 5.4%, while neurosurgical intervention was required in 8%. For all outcomes, worse TBI severity per GCS was significantly associated with worse outcomes (logistic regression, P < 0.0001, adjusted for age).

CONCLUSION

These cohort data highlight the burden of TBI in the Emergency Department and provide important demographic trends for further research.

Clinical review: neuromonitoring - an update

Critically ill patients are frequently at risk of neurological dysfunction as a result of primary neurological conditions or secondary insults. Determining which aspects of brain function are affected and how best to manage the neurological dysfunction can often be difficult and is complicated by the limited information that can be gained from clinical examination in such patients and the effects of therapies, notably sedation, on neurological function. Methods to measure and monitor brain function have evolved considerably in recent years and now play an important role in the evaluation and management of patients with brain injury. Importantly, no single technique is ideal for all patients and different variables will need to be monitored in different patients; in many patients, a combination of monitoring techniques will be needed. Although clinical studies support the physiologic feasibility and biologic plausibility of management based on information from various monitors, data supporting this concept from randomized trials are still required.

SAHIT Investigators--on the outcome of some subarachnoid hemorrhage clinical trials

Outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved over the last decades. Yet, case fatality remains nearly 40% and survivors often have permanent neurological, cognitive and/or behavioural sequelae. Other than nimodipine drug or clinical trials have not consistently improved outcome. We formed a collaboration of SAH investigators to create a resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase 3 trials in aneurysmal SAH. We identified investigators with data from randomized, clinical trials of patients with aneurysmal SAH or prospectively collected single- or multicentre databases of aneurysmal SAH patients. Data are being collected and proposals to use the data and to design future phase 3 clinical trials are being discussed. This paper reviews some issues discussed at the first meeting of the SAH international trialists (SAHIT) repository meeting. Investigators contributed or have agreed to contribute data from several phase 3 trials including the tirilazad trials, intraoperative hypothermia for aneurysmal SAH trial, nicardipine clinical trials, international subarachnoid aneurysm trial, intravenous magnesium sulphate for aneurysmal SAH, magnesium for aneurysmal SAH and from prospectively-collected data from four institutions. The number of patients should reach 15,000. Some industry investigators refused to provide data and others reported that their institutional research ethics boards would not permit even deidentified or anonymized data to be included. Others reported conflict of interest that prevented them from submitting data. The problems with merging data were related to lack of common definitions and coding of variables, differences in outcome scales used, and times of assessment. Some questions for investigation that arose are discussed. SAHIT demonstrates the possibility of SAH investigators to contribute data for collaborative research. The problems are similar to those already documented in other similar collaborative efforts such as in head injury research. We encourage clinical trial and registry investigators to contact us and participate in SAHIT. Key issues moving forward will be to use common definitions (common data elements), outcomes analysis, and to prioritize research questions, among others.

Subarachnoid Hemorrhage International Trialists data repository (SAHIT)

The outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved slowly over the past 25 years. This improvement may be due to early aneurysm repair by endovascular or open means, use of nimodipine, and better critical care management. Despite this improvement, mortality remains at about 40%, and many survivors have permanent neurologic, cognitive, and neuropsychologic deficits. Randomized clinical trials have tested pharmacologic therapies, but few have been successful. There are numerous explanations for the failure of these trials, including ineffective interventions, inadequate sample size, treatment side effects, and insensitive or inappropriate outcome measures. Outcome often is evaluated on a good-bad dichotomous scale that was developed for traumatic brain injury 40 years ago. To address these issues, we established the Subarachnoid Hemorrhage International Trialists (SAHIT) data repository. The primary aim of the SAHIT data repository is to provide a unique resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase III trials in aneurysmal SAH. With this aim in mind, we convened a multinational investigator meeting to explore merging individual patient data from multiple clinical trials and observational databases of patients with SAH and to create an agreement under which such a group of investigators could submit data and collaborate. We welcome collaboration with other investigators.

Early management of severe traumatic brain injury

Severe traumatic brain injury remains a major health-care problem worldwide. Although major progress has been made in understanding of the pathophysiology of this injury, this has not yet led to substantial improvements in outcome. In this report, we address present knowledge and its limitations, research innovations, and clinical implications. Improved outcomes for patients with severe traumatic brain injury could result from progress in pharmacological and other treatments, neural repair and regeneration, optimisation of surgical indications and techniques, and combination and individually targeted treatments. Expanded classification of traumatic brain injury and innovations in research design will underpin these advances. We are optimistic that further gains in outcome for patients with severe traumatic brain injury will be achieved in the next decade.

Comparative effectiveness in neurosurgery: what it means, how it is measured, and why it matters

Comparative effectiveness research has recently been the subject of intense discussion. With congressional support, there has been increasing funding and publication of studies using comparative effectiveness and related methodology. The neurosurgical field has been relatively slow to accept and embrace this approach. The author outlines the procedures and rationale of comparative effectiveness, illustrates how it applies to neurosurgical topics, and explains its importance.

New considerations in the design of clinical trials for traumatic brain injury

Randomized controlled trials in traumatic brain injury (TBI) pose several complicated methodological challenges related to the heterogeneity of the population. Several strategies have been proposed to deal with these challenges. Recommendations presented by the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) study group include the use of relatively broad enrollment criteria combined with covariate adjustment for strong predictors of outcome in the analysis phase, rather than the use of strict enrollment criteria. Furthermore, an ordinal rather than a dichotomized analysis of the Glasgow Outcome Scale - the outcome measure in most TBI trials - will increase the statistical power significantly. This review discusses the issue of heterogeneity in TBI trials and summarizes the value of different innovative methods for the design and statistical analysis of randomized controlled trials in TBI. Future directions highlight the opportunities offered by alternative strategies, such as comparative effectiveness research, to investigate the clinical benefits of established and novel therapies in TBI.