Observer variation in the assessment of outcome in traumatic brain injury: experience from a multicenter, international randomized clinical trial

Cost-effectiveness of craniotomy versus decompressive craniectomy for UK patients with traumatic acute subdural haematoma

OBJECTIVE

To estimate the cost-effectiveness of craniotomy, compared with decompressive craniectomy (DC) in UK patients undergoing evacuation of acute subdural haematoma (ASDH).

DESIGN

Economic evaluation undertaken using health resource use and outcome data from the 12-month multicentre, pragmatic, parallel-group, randomised, Randomised Evaluation of Surgery with Craniectomy for Patients Undergoing Evacuation-ASDH trial.

SETTING

UK secondary care.

PARTICIPANTS

248 UK patients undergoing surgery for traumatic ASDH were randomised to craniotomy (N=126) or DC (N=122).

INTERVENTIONS

Surgical evacuation via craniotomy (bone flap replaced) or DC (bone flap left out with a view to replace later: cranioplasty surgery).

MAIN OUTCOME MEASURES

In the base-case analysis, costs were estimated from a National Health Service and Personal Social Services perspective. Outcomes were assessed via the quality-adjusted life-years (QALY) derived from the EuroQoL 5-Dimension 5-Level questionnaire (cost-utility analysis) and the Extended Glasgow Outcome Scale (GOSE) (cost-effectiveness analysis). Multiple imputation and regression analyses were conducted to estimate the mean incremental cost and effect of craniotomy compared with DC. The most cost-effective option was selected, irrespective of the level of statistical significance as is argued by economists.

RESULTS

In the cost-utility analysis, the mean incremental cost of craniotomy compared with DC was estimated to be -£5520 (95% CI -£18 060 to £7020) with a mean QALY gain of 0.093 (95% CI 0.029 to 0.156). In the cost-effectiveness analysis, the mean incremental cost was estimated to be -£4536 (95% CI -£17 374 to £8301) with an OR of 1.682 (95% CI 0.995 to 2.842) for a favourable outcome on the GOSE.

CONCLUSIONS

In a UK population with traumatic ASDH, craniotomy was estimated to be cost-effective compared with DC: craniotomy was estimated to have a lower mean cost, higher mean QALY gain and higher probability of a more favourable outcome on the GOSE (though not all estimated differences between the two approaches were statistically significant).

ETHICS

Ethical approval for the trial was obtained from the North West-Haydock Research Ethics Committee in the UK on 17 July 2014 (14/NW/1076).

TRIAL REGISTRATION NUMBER

ISRCTN87370545.

Validity of Glasgow outcome scale-extended (GOSE) mobile application for assessment of outcome in traumatic brain injury patients

PURPOSE

To develop the Glasgow Outcome Scale-Extended (GOSE) mobile application and examine the validity of the application against GOSE scoring based on traditional interview method.

METHODS

Concurrent validity was determined by comparing two independent raters' scoring for GOSE of 102 patients with traumatic brain injury, who had attended outpatient department of a tertiary neuro hospital. Agreement was assessed between the traditional interview-based pen and paper scoring and algorithm based mobile application scoring of GOSE.

RESULTS

Agreement was tested using Cohen's kappa, and the analysis revealed near perfect agreement between two raters (0.89) (p < 0.01).

CONCLUSION

The GOSE mobile application can measure GOSE Score similar to the traditional interview method. This application may help fasten the process of assessing outcome in TBI patients in clinical practice and in research.

PREdiction and Diagnosis using Imaging and Clinical biomarkers Trial in Traumatic Brain Injury (PREDICT-TBI) study protocol: an observational, prospective, multicentre cohort study for the prediction of outcome in moderate-to-severe TBI

INTRODUCTION

Traumatic brain injury (TBI) is a heterogeneous condition with a broad spectrum of injury severity, pathophysiological processes and variable outcomes. For moderate-to-severe TBI survivors, recovery is often protracted and outcomes can range from total dependence to full recovery. Despite advances in medical treatment options, prognosis remains largely unchanged. The objective of this study is to develop a machine learning predictive model for neurological outcomes at 6 months in patients with a moderate-to-severe TBI, incorporating longitudinal clinical, multimodal neuroimaging and blood biomarker predictor variables.

METHODS AND ANALYSIS

A prospective, observational, cohort study will enrol 300 patients with moderate-to-severe TBI from seven Australian hospitals over 3 years. Candidate predictors including demographic and general health variables, and longitudinal clinical, neuroimaging (CT and MRI), blood biomarker and patient-reported outcome measures will be collected at multiple time points within the acute phase of injury. The predictor variables will populate novel machine learning models to predict the Glasgow Outcome Scale Extended 6 months after injury. The study will also expand on current prognostic models by including novel blood biomarkers (circulating cell-free DNA), and the results of quantitative neuroimaging such as Quantitative Susceptibility Mapping and Dynamic Contrast Enhanced MRI as predictor variables.

ETHICS AND DISSEMINATION

Ethical approval has been obtained by the Royal Brisbane and Women's Hospital Human Research Ethics Committee, Queensland. Participants or their substitute decision-maker/s will receive oral and written information about the study before providing written informed consent. Study findings will be disseminated by peer-review publications and presented at national and international conferences and clinical networks.

TRIAL REGISTRATION NUMBER

ACTRN12620001360909.

Improving the Precision of the Glasgow Outcome Scale-Extended Using Item Response Theory: A TRACK-TBI Study

The Glasgow Outcome Scale-Extended (GOSE) is a functional outcome measure intended to place individuals with traumatic brain injury (TBI) into one of eight broad levels of injury-related disability. This simplicity is not always optimal, particularly when more granular assessment of individuals' injury recovery is desired. The GOSE, however, is customarily assessed using a multi-question interview that contains richer information than is reflected in the GOSE score. Using data from the multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study (N = 1544), we used item response theory (IRT) to evaluate whether rescoring the GOSE using IRT, which posits that a continuous latent variable (disability) underlies responses, can yield a more precise index of injury-related functional limitations. We fit IRT models to GOSE interview responses collected at three months post-injury. Each participant's level of functional limitation was estimated from the model (GOSE-IRT) and comparisons were made between IRT-based and standard (GOSE-Ordinal) scores. The IRT scoring resulted in 141 possible scores (vs. 7 GOSE-Ordinal scores in this sample of individuals with GOSE scores ranging between 2 and 8). Moreover, GOSE-IRT scores were significantly more strongly associated with measures of TBI-related symptoms, psychological symptoms, and quality of life. Our findings demonstrate that rescoring the GOSE interview using IRT yields more granular, meaningful measurement of injury-related functional limitations, while adding no additional respondent or examiner burden. This technique may have utility for many applications, such as clinical trials aiming to detect small treatment effects, and small-scale studies that need to maximize statistical efficiency.

Functional Status Examination Yields Higher Measurement Precision than the Glasgow Outcome Scale-Extended after Moderate-to-Severe Traumatic Brain Injury

A limited evidence base supports the Functional Status Examination (FSE) as superior to the more commonly used Glasgow Outcome Scale-Extended (GOSE) for precisely characterizing injury-related functional limitations. The aim of this study was to use modern psychometric tools to test the hypothesis that the FSE is more precise than the GOSE in characterizing individual differences in functional limitations after moderate-to-severe traumatic brain injury (TBI). Secondarily, we sought to confirm that the type of interviewee (patient, significant other) does not affect the test performance of the FSE. Using data from 357 individuals with TBI who participated in the Magnesium Sulfate clinical trial and had six-month outcome data, we performed item response theory (IRT) analyses comparing the FSE and GOSE at six months post-injury. Results showed that the FSE yielded higher measurement precision (IRT test information) than the GOSE across most of the disability severity spectrum. The GOSE yielded more information than the FSE at a very high level of disability, because of the GOSE's assignment of a unique score for individuals who are in a vegetative state. Finally, the FSE showed no evidence of differential item functioning by interviewee, indicating it is appropriate to interview either persons with TBI or significant others and combine data across respondents as is typically done. The findings support the FSE as a viable and oftentimes advantageous substitute for the GOSE in clinical trials and translational studies of TBI.

Questionnaires vs Interviews for the Assessment of Global Functional Outcomes After Traumatic Brain Injury

IMPORTANCE

An interview is considered the gold standard method of assessing global functional outcomes in clinical trials among patients with acute traumatic brain injury (TBI). However, several multicenter clinical trials have used questionnaires completed by a patient or caregiver to assess the primary end point.

OBJECTIVE

To examine agreement between interview and questionnaire formats for assessing TBI outcomes and to consider whether an interview has advantages.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from patients enrolled in the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) project from December 2014 to December 2017. Data were analyzed from December 2020 to April 2021. Included patients were aged 16 years or older with TBI and a clinical indication for computed tomography imaging. Outcome assessments were completed using both an interview and a questionnaire at follow-up 3 and 6 months after injury.

EXPOSURES

Traumatic brain injury of all severities.

MAIN OUTCOMES AND MEASURES

Ratings on the Glasgow Outcome Scale-Extended (GOSE) administered as a structured interview rated by an investigator and as a questionnaire completed by patients or caregivers and scored centrally were compared, and the strength of agreement was evaluated using weighted κ statistics. Secondary outcomes included comparison of different sections of the GOSE assessments and the association of GOSE ratings with baseline factors and patient-reported mental health, health-related quality of life, and TBI symptoms.

RESULTS

Among the 3691 eligible individuals in the CENTER-TBI study, both GOSE assessment formats (interview and questionnaire) were completed by 994 individuals (26.9%) at 3 months after TBI (654 [65.8%] male; median age, 53 years [IQR, 33-66 years]) and 628 (17.0%) at 6 months (409 [65.1%] male; median age, 51 years [IQR, 31-64 years]). Outcomes of the 2 assessment methods agreed well at both 3 months (weighted κ, 0.77; 95% CI, 0.73-0.80) and 6 months (weighted κ, 0.82; 95% CI, 0.78-0.86). Furthermore, item-level agreement between the 2 methods was good for sections regarding independence in everyday activities (κ, 0.70-0.79 across both time points) and moderate for sections regarding subjective aspects of functioning such as relationships and symptoms (κ, 0.41-0.51 across both time points). Compared with questionnaires, interviews recorded more problems with work (294 [30.5%] vs 233 [24.2%] at 3 months and 161 [26.8%] vs 136 [22.7%] at 6 months), fewer limitations in social and leisure activities (330 [33.8%] vs 431 [44.1%] at 3 months and 179 [29.7%] vs 219 [36.4%] at 6 months), and more symptoms (524 [53.6%] vs 324 [33.1%] at 3 months and 291 [48.4%] vs 179 [29.8%] at 6 months). Interviewers sometimes assigned an overall rating based on judgment rather than interview scoring rules, particularly for patients with potentially unfavorable TBI outcomes. However, for both formats, correlations with baseline factors (ρ, -0.13 to 0.42) and patient-reported outcomes (ρ, 0.29 to 0.65) were similar in strength.

CONCLUSIONS AND RELEVANCE

In this cohort study, GOSE ratings obtained by questionnaire and interview methods were in good agreement. The similarity of associations of the ratings obtained by both GOSE methods with baseline factors and other TBI outcome measures suggests that despite some apparent differences, the core information collected by both interviews and questionnaires was similar. The findings support the use of questionnaires in studies in which this form of contact may offer substantial practical advantages compared with interviews.

Do state supports for persons with brain injury affect outcomes in the 5 Years following acute rehabilitation?

While a substantial literature has examined the effects of individual and family-level factors on outcomes following traumatic brain injury (TBI), minimal attention has been directed to the potential influence of the larger environmental context on outcomes. The purpose of the current study was to investigate the effects of state-level resources and supports as an environmental factor influencing long-term outcomes from TBI using data from the TBI Model Systems. We examined the effects of U.S. state supports that specifically target people with TBI (federal funding for state brain injury programs, per capita revenue generated by brain injury trust funds, and expenditures for brain injury specific Medicaid waivers) and one measure of the relative quality of a state's Long-Term Services and Supports (LTSS) for all people with disabilities. The primary hypothesis was that community participation, global functioning, and life satisfaction will be higher on average among people with TBI living in states with more brain injury specific programs and resources and better LTSS. The results of multilevel and fixed-effects modeling indicated that state supports have a small but significant impact on participation and life satisfaction. The most consistent finding indicated that states with better LTSS had higher levels of community participation and life satisfaction on average for people with TBI over and above individual-level differences and fluctuations in these outcomes over time. There was some indication that more brain injury specific supports also result in better participation in the community. These findings deserve replication and extension to include other environmental factors, particularly community level characteristics, that might affect outcomes from TBI.

Added Value of a Blinded Outcome Adjudication Committee in an Open-Label Randomized Stroke Trial

Supplemental Digital Content is available in the text.

Blinded outcome assessment in trials with prospective randomized open blinded end point design is challenging. Unblinding can result in misclassified outcomes and biased treatment effect estimates. An outcome adjudication committee assures blinded outcome assessment, but the added value for trials with prospective randomized open blinded end point design and subjective outcomes is unknown. We aimed to assess the degree of misclassification of modified Rankin Scale (mRS) scores by a central assessor and its impact on treatment effect estimates in a stroke trial with prospective randomized open blinded end point design.

A Manual for the Glasgow Outcome Scale-Extended Interview

The Glasgow Outcome Scale-Extended (GOSE) has become one of the most widely used outcome instruments to assess global disability and recovery after traumatic brain injury. Achieving consistency in the application of the assessment remains a challenge, particularly in multi-center studies involving many assessors. We present a manual for the GOSE interview that is designed to support both single- and multi-center studies and promote inter-rater agreement. Many patients fall clearly into a particular category; however, patients may have outcomes that are on the borderline between adjacent categories, and cases can present other challenges for assessment. The Manual includes the general principles of assessment, advice on administering each section of the GOSE interview, and guidance on "borderline" and "difficult" cases. Finally, we discuss the properties of the GOSE, including strengths and limitations, and outline recommendations for assessor training, accreditation, and monitoring.

Central Curation of Glasgow Outcome Scale-Extended Data: Lessons Learned from TRACK-TBI

The Glasgow Outcome Scale (GOS) in its original or extended (GOSE) form is the most widely used assessment of global disability in traumatic brain injury (TBI) research. Several publications have reported concerns about assessor scoring inconsistencies, but without documentation of contributing factors. We reviewed 6801 GOSE assessments collected longitudinally, across 18 sites in the 5-year, observational Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. We recorded error rates (i.e., corrections to a section or an overall rating) based on site assessor documentation and categorized scoring issues, which then informed further training. In cohort 1 (n = 1261; February 2014 to May 2016), 24% of GOSEs had errors identified by central review. In cohort 2 (n = 1130; June 2016 to July 2018), acquired after curation of cohort 1 data, feedback, and further training of site assessors, the error rate was reduced to 10%. GOSE sections associated with the most frequent interpretation and scoring difficulties included whether current functioning represented a change from pre-injury (466 corrected ratings in cohort 1; 62 in cohort 2), defining dependency in the home and community (163 corrections in cohort 1; three in cohort 2) and return to work/school (72 corrections in cohort 1; 35 in cohort 2). These results highlight the importance of central review in improving consistency across sites and over time. Establishing clear scoring criteria, coupled with ongoing guidance and feedback to data collectors, is essential to avoid scoring errors and resultant misclassification, which carry potential to result in "failure" of clinical trials that rely on the GOSE as their primary outcome measure.

The effect of head cooling and remote ischemic conditioning on patients with traumatic brain injury

Cerebral impairment caused by an external force to the head is known as traumatic brain injury (TBI). The aim of this study was to determine the role of local hypothermia and remote ischemic conditioning (RIC) on oxidative stress, inflammatory response after TBI, and other involved variables. The present study is a clinical trial on 84 patients with TBI who were divided into 4 groups. The head cooling for 1.5 to 6 hr was performed in the first three days after TBI. RIC intervention was performed within the golden time after TBI in the form of four 5-min cycles with full cuff and 5 min of emptying of cuff. The group receiving the head cooling technique recovered better than the group receiving the RIC technique. Generally, combination of the two interventions of head cooling and RIC techniques is more effective on the improvement of clinical status of patients than each separate technique.

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The effect of the head cooling method in controlling secondary injury in patients with TBI.

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The effect of the RIC method in controlling secondary injury in patients with TBI.

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Comparison of two interventions of head cooling and RIC.

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Evaluation of clinical and paraclinical parameters.

The Association Between Brain Reserve, Cognitive Reserve, and Neuropsychological and Functional Outcomes in Males With Chronic Moderate-to-Severe Traumatic Brain Injury

Purpose Moderate-to-severe traumatic brain injury (TBI) leads to significant neural and cognitive impairment, affecting functional outcome. This study investigated the chronic effects of moderate-to-severe TBI on brain reserve (BR), cognitive reserve (CR), and neuropsychological and functional outcome. Method The group with TBI consisted of 41 male participants with a primary diagnosis of moderate-to-severe closed head injury (time since injury [TSI], M = 6.12 years, range: 1-23, SD = 5.99, Mdn = 4). TBI survivors were compared to 24 neurotypical male participants, matched on age and education. Magnetic resonance imaging T1 anatomical images were used to calculate gray and white matter and cerebrospinal fluid volume. BR was calculated using the ventricle-to-brain ratio. CR was assessed using two hold measures: the Peabody Picture Vocabulary Test and the Pseudowords task. Functional outcome was measured using the Glasgow Outcome Scale-Extended. Results Neuropsychological performance of TBI survivors was significantly lower than their neurotypical controls, as measured by theoretically driven composites of verbal and visual memory, executive functions, attention, and CR. They presented greater ventricle-to-brain ratio volume, compared to noninjured controls, with higher scores indicating lower BR levels. Both BR and TSI were significantly associated with CR. Also, a median-split analysis revealed a TSI effect on CR. Significant associations were evident between the Glasgow Outcome Scale-Extended and the BR and CR measures. Conclusions Lingering neuropsychological deficits in chronic TBI support the role of BR and CR in functional outcome. Furthermore, TSI interferes with CR supporting the notion that TBI sets off a chronic neurodegenerative and progressive course that interferes with semantic knowledge. Supplemental Material https://doi.org/10.23641/asha.14049923.

Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). It is usually treated with general maneuvers (normothermia, sedation, etc.) and a set of first-line therapeutic measures (moderate hypocapnia, mannitol, etc.). When these measures fail, second-line therapies are initiated, which include: barbiturates, hyperventilation, moderate hypothermia, or removal of a variable amount of skull bone (secondary decompressive craniectomy).

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcomes of patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH METHODS

The most recent search was run on 8 December 2019. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP) and ISI Web of Science (SCI-EXPANDED & CPCI-S). We also searched trials registries and contacted experts.

SELECTION CRITERIA

We included randomized studies assessing patients over the age of 12 months with severe TBI who either underwent DC to control ICP refractory to conventional medical treatments or received standard care.

DATA COLLECTION AND ANALYSIS

We selected potentially relevant studies from the search results, and obtained study reports. Two review authors independently extracted data from included studies and assessed risk of bias. We used a random-effects model for meta-analysis. We rated the quality of the evidence according to the GRADE approach.

MAIN RESULTS

We included three trials (590 participants). One single-site trial included 27 children; another multicenter trial (three countries) recruited 155 adults, the third trial was conducted in 24 countries, and recruited 408 adolescents and adults. Each study compared DC combined with standard care (this could include induced barbiturate coma or cooling of the brain, or both). All trials measured outcomes up to six months after injury; one also measured outcomes at 12 and 24 months (the latter data remain unpublished). All trials were at a high risk of bias for the criterion of performance bias, as neither participants nor personnel could be blinded to these interventions. The pediatric trial was at a high risk of selection bias and stopped early; another trial was at risk of bias because of atypical inclusion criteria and a change to the primary outcome after it had started. Mortality: pooled results for three studies provided moderate quality evidence that risk of death at six months was slightly reduced with DC (RR 0.66, 95% CI 0.43 to 1.01; 3 studies, 571 participants; I2 = 38%; moderate-quality evidence), and one study also showed a clear reduction in risk of death at 12 months (RR 0.59, 95% CI 0.45 to 0.76; 1 study, 373 participants; high-quality evidence). Neurological outcome: conscious of controversy around the traditional dichotomization of the Glasgow Outcome Scale (GOS) scale, we chose to present results in three ways, in order to contextualize factors relevant to clinical/patient decision-making. First, we present results of death in combination with vegetative status, versus other outcomes. Two studies reported results at six months for 544 participants. One employed a lower ICP threshold than the other studies, and showed an increase in the risk of death/vegetative state for the DC group. The other study used a more conventional ICP threshold, and results favoured the DC group (15.7% absolute risk reduction (ARR) (95% CI 6% to 25%). The number needed to treat for one beneficial outcome (NNTB) (i.e. to avoid death or vegetative status) was seven. The pooled result for DC compared with standard care showed no clear benefit for either group (RR 0.99, 95% CI 0.46 to 2.13; 2 studies, 544 participants; I2 = 86%; low-quality evidence). One study reported data for this outcome at 12 months, when the risk for death or vegetative state was clearly reduced by DC compared with medical treatment (RR 0.68, 95% CI 0.54 to 0.86; 1 study, 373 participants; high-quality evidence). Second, we assessed the risk of an 'unfavorable outcome' evaluated on a non-traditional dichotomized GOS-Extended scale (GOS-E), that is, grouping the category 'upper severe disability' into the 'good outcome' grouping. Data were available for two studies (n = 571). Pooling indicated little difference between DC and standard care regarding the risk of an unfavorable outcome at six months following injury (RR 1.06, 95% CI 0.69 to 1.63; 544 participants); heterogeneity was high, with an I2 value of 82%. One trial reported data at 12 months and indicated a clear benefit of DC (RR 0.81, 95% CI 0.69 to 0.95; 373 participants). Third, we assessed the risk of an 'unfavorable outcome' using the (traditional) dichotomized GOS/GOS-E cutoff into 'favorable' versus 'unfavorable' results. There was little difference between DC and standard care at six months (RR 1.00, 95% CI 0.71 to 1.40; 3 studies, 571 participants; low-quality evidence), and heterogeneity was high (I2 = 78%). At 12 months one trial suggested a similar finding (RR 0.95, 95% CI 0.83 to 1.09; 1 study, 373 participants; high-quality evidence). With regard to ICP reduction, pooled results for two studies provided moderate quality evidence that DC was superior to standard care for reducing ICP within 48 hours (MD -4.66 mmHg, 95% CI -6.86 to -2.45; 2 studies, 182 participants; I2 = 0%). Data from the third study were consistent with these, but could not be pooled. Data on adverse events are difficult to interpret, as mortality and complications are high, and it can be difficult to distinguish between treatment-related adverse events and the natural evolution of the condition. In general, there was low-quality evidence that surgical patients experienced a higher risk of adverse events.

AUTHORS' CONCLUSIONS

Decompressive craniectomy holds promise of reduced mortality, but the effects of long-term neurological outcome remain controversial, and involve an examination of the priorities of participants and their families. Future research should focus on identifying clinical and neuroimaging characteristics to identify those patients who would survive with an acceptable quality of life; the best timing for DC; the most appropriate surgical techniques; and whether some synergistic treatments used with DC might improve patient outcomes.

Functional Status Examination Yields Higher Measurement Precision of Functional Limitations after Traumatic Injury than the Glasgow Outcome Scale-Extended: A Preliminary Study

The Glasgow Outcome Scale-Extended (GOSE) is one of the most widely used measures of functional limitations after traumatic brain injury (TBI), and is the primary outcome measure used in clinical trials of acute TBI treatment. However, the GOSE appears insensitive to the full spectrum of TBI-related functional limitations, which may limit its potential to capture treatment effects or correlate with other variables that impact outcome. The Functional Status Examination (FSE) was designed to improve on the assessment of injury-related functional limitations using a standardized assessment and wider possible score range. The aim of this pilot study was to employ item response theory (IRT) to test the hypothesis that the FSE yields more precise estimation of functional outcome than the GOSE. Traumatically injured patients (n = 100, 77 TBI, 23 orthopedic injuries) were interviewed at 3 months post-injury using both the GOSE and FSE structured interviews. IRT was used to quantify and compare the tests' information functions, which reflect the degree to which each instrument precisely measures functional limitations across the severity spectrum. Findings were consistent with predictions: the FSE yielded stronger measurement of functional limitations (i.e., higher test information) across a wider range of severity than the GOSE, whether scoring the GOSE from all interview items or using the traditional GOSE overall score. Although the FSE appears to be a promising alternative measure to the GOSE, further research is needed to cross-validate these findings in a larger sample and understand how to best deploy it in clinical and translational research.

Diagnosing the GOSE: Structural and Psychometric Properties Using Item Response Theory, a TRACK-TBI Pilot Study

The Glasgow Outcome Scale-Extended (GOSE) was designed to assess global outcome after traumatic brain injury (TBI). Since its introduction, several empirically founded criticisms of the GOSE have been raised, including poor reliability; an insensitivity to small, but potentially meaningful, changes; a tendency to produce ceiling effects; inconsistent associations with neurocognitive, psychological, and quality-of-life measures; and an inability to assess the multi-dimensional nature of TBI outcome. The current project took a diagnostic approach to identifying the underlying causes of reported limitations by exploring the internal construct validity of the GOSE at 3 and 6 months post-injury using item response theory (IRT) techniques. Data were from the TRACK-TBI Pilot Study, a large (N = 586), prospective, multi-site project that included TBI cases of all injury severity levels. To assess the level of latent functional "impairment" captured by GOSE items independent of the assigned outcome category or GOSE total score, items were modified so that higher scores reflected greater impairment. Results showed that although the GOSE's items capture varying levels of impairment across a broad disability spectrum at 3 and 6 months, there was also evidence at each time point of item redundancy (multiple items capturing similar levels of impairment), item deficiency (lack of items capturing lower levels of impairment), and item inefficiency (items only capturing minimal impairment information). The findings illustrate the value of IRT to illuminate strengths and weaknesses of clinical outcome assessment measures and provide a framework for future measure refinement.

Functional Status Examination versus Glasgow Outcome Scale Extended as Outcome Measures in Traumatic Brain Injuries: How Do They Compare?

Outcome measures are essential components of natural history studies of recovery and treatment effects after traumatic brain injury (TBI). The Glasgow Outcome Scale (GOS) and its revised version, the Glasgow Outcome Scale Extended (GOSE), are well accepted and widely used for both observational and intervention studies, but there are concerns about their psychometric properties and aptness as outcome measures for TBI. The present study compares the Functional Status Examination (FSE) with the GOSE to assess outcome after TBI in a sample of 533 participants with TBI from the Magnesium Sulfate study and the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study by evaluating the sensitivity of each measure to severity of brain injury and recovery of function over time. The results indicate that both measures are strongly correlated with TBI severity. At three months, the correlation strengths between injury severity and each outcome measure do not differ (p = 0.88 for Glasgow Coma Scale [GCS], p = 0.13 for computed tomography [CT] abnormalities) but at six months, the FSE is more strongly related to TBI severity indices than is the GOSE (p = 0.045 for GCS, p = 0.014 for CT abnormalities). In addition, the FSE generally shows significantly more improvement over time than the GOSE (p < 0.001). Detailed, structured administration rules and a wider score range of the FSE likely yields more sensitive and precise assessment of functional level than the GOSE. The FSE may be a valuable alternative to the GOSE for assessing functional outcome after TBI.

Pre-Clinical Testing of Therapies for Traumatic Brain Injury

Despite the large number of promising neuroprotective agents identified in experimental traumatic brain injury (TBI) studies, none has yet shown meaningful improvements in long-term outcome in clinical trials. To develop recommendations and guidelines for pre-clinical testing of pharmacological or biological therapies for TBI, the Moody Project for Translational Traumatic Brain Injury Research hosted a symposium attended by investigators with extensive experience in pre-clinical TBI testing. The symposium participants discussed issues related to pre-clinical TBI testing including experimental models, therapy and outcome selection, study design, data analysis, and dissemination. Consensus recommendations included the creation of a manual of standard operating procedures with sufficiently detailed descriptions of modeling and outcome measurement procedures to permit replication. The importance of the selection of clinically relevant outcome variables, especially related to behavior testing, was noted. Considering the heterogeneous nature of human TBI, evidence of therapeutic efficacy in multiple, diverse (e.g., diffuse vs. focused) rodent models and a species with a gyrencephalic brain prior to clinical testing was encouraged. Basing drug doses, times, and routes of administration on pharmacokinetic and pharmacodynamic data in the test species was recommended. Symposium participants agreed that the publication of negative results would reduce costly and unnecessary duplication of unsuccessful experiments. Although some of the recommendations are more relevant to multi-center, multi-investigator collaborations, most are applicable to pre-clinical therapy testing in general. The goal of these consensus guidelines is to increase the likelihood that therapies that improve outcomes in pre-clinical studies will also improve outcomes in TBI patients.

Feasibility of telephone-administered interviews to evaluate long-term outcomes of trauma patients in urban Ethiopia

Background

Little is known about long-term functional outcomes of trauma patients in low-income and middle-income countries. In sub-Saharan Africa most studies of injury only collect data through emergency department disposition or hospital discharge, and methods of collecting long-term data are subject to significant bias. With the recent increase in access to mobile telephone technology, we hypothesized that structured, telephone-administered interviews now offer a feasible means to collect data about the long-term functional outcomes of trauma patients in urban Ethiopia.

Methods

We piloted a telephone-administered interview tool based on the Glasgow Outcome Scale-Extended. Using departmental logbooks, 400 consecutive patients presenting to two public referral hospitals were identified retrospectively. Demographics, injury data, and telephone numbers were collected from medical records. When a telephone number was available, patients or their surrogates were contacted and interviewed 6 months after their injuries.

Results

We were able to contact 47% of subjects or their surrogates, and 97% of those contacted were able and willing to complete an interview. At 6-month follow-up, 22% of subjects had significant persistent functional disability. Many injuries had an ongoing financial impact, with 17% of subjects losing or changing jobs, 18% earning less than they had before their injuries, and 16% requiring ongoing injury-related medical care. Lack of documented telephone numbers and difficulty contacting subjects at recorded telephone numbers were the major obstacles to data collection. Language barriers and respondents’ refusal to participate in the study were not significant limitations.

Discussion

In urban Ethiopia, many trauma patients have persistent disability 6 months after their injuries. Telephone-administered interviews offer a promising method of collecting data about the long-term trauma outcomes, including functional status and the financial impact of injury. These data are invaluable for capacity building, quality improvement efforts, and advocacy for injury prevention and trauma care.

Level of evidence

III, retrospective cohort study.

Patient-Reported Outcome Measures in Neurosurgery: A Review of the Current Literature

BACKGROUND

Patient-reported outcome measures (PROMs) play an important role in the evaluation of health outcomes, quality of life, and satisfaction, and have been successfully utilized in many areas of clinical medicine and surgical practice. The prevalence of PROMs in neurosurgery is not known.

OBJECTIVE

To review the PROMs that have been utilized in the published neurosurgery literature to date.

METHODS

Articles were searched in MEDLINE, EMBASE, HMIC Health Management Information Consortium, PsycARTICLES, and PsycINFO using search terms related to neurosurgery and PROMs, published from 1806 to August 2016. A total of 268 articles were identified that were stratified by the inclusion and exclusion criteria leading to a total of 137 articles. Twenty-six PROMs, involving both adult and pediatric populations, were identified.

RESULTS

A large number of generic and disease-specific PROMs are used in the neurosurgical literature. Generic PROMs are usually nonspecific measures of health status. Disease-specific PROMs may not address issues relevant to neurosurgical procedures. There are very few neurosurgery-specific PROMs that take into account the impact of a neurosurgical procedure on a specific condition.

CONCLUSION

PROMs that currently feature in the neurosurgical literature may not address the specific outcomes relevant to neurosurgical practice. There is an emergent need for generic and disease-specific PROMs to be validated in neurosurgical patients and neurosurgery-specific PROMs developed to address unmet needs of patients undergoing neurosurgical procedures.

Randomized Controlled Trials in Adult Traumatic Brain Injury: A Systematic Review on the Use and Reporting of Clinical Outcome Assessments

As part of efforts to improve study design, the use of outcome measures in randomized controlled trials (RCTs) in traumatic brain injury (TBI) is receiving increasing attention. This review aimed to assess how clinical outcome assessments (COAs) have been used and reported in RCTs in adult TBI. Systematic literature searches were conducted to identify medium to large (n ≥ 100) acute and post-acute TBI trials published since 2000. Data were extracted independently by two reviewers using a set of structured templates. Items from the Consolidated Standards of Reporting Trials (CONSORT) 2010 Statement and CONSORT patient-reported outcomes (PROs) extension were used to evaluate reporting quality of COAs. Glasgow Outcome Scale/Extended (GOS/GOSE) data were extracted using a checklist developed specifically for the review. A total of 126 separate COAs were identified in 58 studies. The findings demonstrate heterogeneity in the use of TBI outcomes, limiting comparisons and meta-analyses of RCT findings. The GOS/GOSE was included in 39 studies, but implemented in a variety of ways, which may not be equivalent. Multi-dimensional outcomes were used in 30 studies, and these were relatively more common in rehabilitation settings. The use of PROs was limited, especially in acute study settings. Quality of reporting was variable, and key information concerning COAs was often omitted, making it difficult to know how precisely outcomes were assessed. Consistency across studies would be increased and future meta-analyses facilitated by (a) using common data elements (CDEs) recommendations for TBI outcomes and (b) following CONSORT guidelines when publishing RCTs.

Moderate Traumatic Brain Injury: Clinical Characteristics and a Prognostic Model of 12-Month Outcome

BACKGROUND

Patients with moderate traumatic brain injury (TBI) often are studied together with patients with severe TBI, even though the expected outcome of the former is better. Therefore, we aimed to describe patient characteristics and 12-month outcomes, and to develop a prognostic model based on admission data, specifically for patients with moderate TBI.

METHODS

Patients with Glasgow Coma Scale scores of 9-13 and age ≥16 years were prospectively enrolled in 2 level I trauma centers in Europe. Glasgow Outcome Scale Extended (GOSE) score was assessed at 12 months. A prognostic model predicting moderate disability or worse (GOSE score ≤6), as opposed to a good recovery, was fitted by penalized regression. Model performance was evaluated by area under the curve of the receiver operating characteristics curves.

RESULTS

Of the 395 enrolled patients, 81% had intracranial lesions on head computed tomography, and 71% were admitted to an intensive care unit. At 12 months, 44% were moderately disabled or worse (GOSE score ≤6), whereas 8% were severely disabled and 6% died (GOSE score ≤4). Older age, lower Glasgow Coma Scale score, no day-of-injury alcohol intoxication, presence of a subdural hematoma, occurrence of hypoxia and/or hypotension, and preinjury disability were significant predictors of GOSE score ≤6 (area under the curve = 0.80).

CONCLUSIONS

Patients with moderate TBI exhibit characteristics of significant brain injury. Although few patients died or experienced severe disability, 44% did not experience good recovery, indicating that follow-up is needed. The model is a first step in development of prognostic models for moderate TBI that are valid across centers.

Functional Status Examination in Patients with Moderate-to-Severe Traumatic Brain Injuries

The assessment of functional status after traumatic brain injury (TBI) is important. The Glasgow Outcome Scale (GOS) and its revised version, the Glasgow Outcome Scale Extended (GOSE), have been used most frequently in TBI research, but there are concerns about the sensitivity of these measures. The current study evaluated the psychometric properties of the Functional Status Examination (FSE) using a sample of 448 moderately to severely injured subjects with TBI. It was shown that the FSE is significantly related to other measures of functional status including the GOSE, Short Form Health Survey, and European Quality of Life Checklist (p < 0.001), is sensitive to TBI severity (p < 0.001), and is responsive to recovery from 3 to 6 months post-injury (p < 0.001). In addition, there was a significant agreement (r = 0.817, p < 0.001) between the patient and significant other's assessment of functional status on the FSE at 6 months post-injury. The FSE may be a valuable measure of functional status after TBI given its strong psychometric properties, including validity, sensitivity to brain injury severity, and recovery over time.

Traumatic brain injury (TBI) outcomes in an LMIC tertiary care centre and performance of trauma scores

BACKGROUND

This study evaluates post-ICU outcomes of patients admitted with moderate and severe Traumatic Brain Injury (TBI) in a tertiary neurocritical care unit in an low middle income country and the performance of trauma scores: A Severity Characterization of Trauma, Trauma and Injury Severity Score, Injury Severity Score and Revised Trauma Score in this setting.

METHODS

Adult patients directly admitted to the neurosurgical intensive care units of the National Hospital of Sri Lanka between 21st July 2014 and 1st October 2014 with moderate or severe TBI were recruited. A telephone administered questionnaire based on the Glasgow Outcome Scale Extended (GOSE) was used to assess functional outcome of patients at 3 and 6 months after injury. The economic impact of the injury was assessed before injury, and at 3 and 6 months after injury.

RESULTS

One hundred and one patients were included in the study. Survival at ICU discharge, 3 and 6 months after injury was 68.3%, 49.5% and 45.5% respectively. Of the survivors at 3 months after injury, 43 (86%) were living at home. Only 19 (38%) patients had a good recovery (as defined by GOSE 7 and 8). Three months and six months after injury, respectively 25 (50%) and 14 (30.4%) patients had become "economically dependent". Selected trauma scores had poor discriminatory ability in predicting mortality.

CONCLUSIONS

This observational study of patients sustaining moderate or severe TBI in Sri Lanka (a LMIC) reveals only 46% of patients were alive at 6 months after ICU discharge and only 20% overall attained a good (GOSE 7 or 8) recovery. The social and economic consequences of TBI were long lasting in this setting. Injury Severity Score, Revised Trauma Score, A Severity Characterization of Trauma and Trauma and Injury Severity Score, all performed poorly in predicting mortality in this setting and illustrate the need for setting adapted tools.

A comparison of approaches for adjudicating outcomes in clinical trials

Background

Incorrect classification of outcomes in clinical trials can lead to biased estimates of treatment effect and reduced power. Ensuring appropriate adjudication methods to minimize outcome misclassification is therefore essential. While there are many reported adjudication approaches, there is little consensus over which approach is best.

Methods

Under the assumption of non-differential assessment (i.e. that misclassification rates are the same in each treatment arm, as would typically be the case when outcome assessors are blinded), we use simulation and theoretical results to address four different questions about outcome adjudication: (a) How many assessors should be used? (b) When is it better to use onsite or central assessment? (c) Should central assessors adjudicate all outcomes, or only suspected events? (d) Should central assessment with multiple assessors be done independently or through group consensus?

Results

No one adjudication approach performs optimally in all settings. The optimal approach depends on the misclassification rates of site and central assessors, and the correlation between assessors. We found: (a) there will generally be little incremental benefit to using more than three assessors and, for outcomes with very high correlation between assessors, using one assessor is sufficient; (b) when choosing between site and central assessors, the assessor with the smallest misclassification rate should be chosen; when these rates are unknown, a combination of one site assessor and two central assessors will provide good results across a range of scenarios; (c) having central assessors adjudicate only suspected events will typically increase bias, and should be avoided, unless the threshold for sending outcomes for central assessment is extremely low; (d) central assessors can adjudicate either independently or in a group, and the preferred option should be dictated by whichever is expected to have the lowest misclassification rate.

Conclusions

Outcome adjudication is of critical importance to ensure validity of trial results, although no one approach is optimal across all settings. Investigators should choose the best strategy based on the specific characteristics of their trial. Regardless of the adjudication strategy chosen, assessors should be qualified and receive appropriate training.

Validating Multidimensional Outcome Assessment Using the TBI Common Data Elements: An Analysis of the TRACK-TBI Pilot Sample

The Glasgow Outcome Scale-Extended (GOSE) is often the primary outcome measure in clinical trials for traumatic brain injury (TBI). Although the GOSE's capture of global function outcome has several strengths, concerns have been raised about its limited ability to identify mild disability and failure to capture the full scope of problems patients exhibit after TBI. This analysis examined the convergence of disability ratings across a multidimensional set of outcome domains in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot study. The study collected measures recommended by the TBI Common Data Elements (CDE) Workgroup. Patients presenting to 3 emergency departments with a TBI of any severity enrolled in TRACK-TBI prospectively after injury; outcome measures were collected at 3 and six months postinjury. Analyses examined frequency of impairment and overlap between impairment status across the CDE outcome domains of Global Level of Functioning (GOSE), Neuropsychological (cognitive) Impairment, Psychological Status, TBI Symptoms, and Quality of Life. GOSE score correlated in the expected direction with other outcomes (M Spearman's rho = .21 and .49 with neurocognitive and self-report outcomes, respectively). The subsample in the Upper Good Recovery (GOSE 8) category appeared quite healthy across most other outcomes, although 19.0% had impaired executive functioning (Trail Making Test Part B). A significant minority of participants in the Lower Good Recovery subgroup (GOSE 7) met criteria for impairment across numerous other outcome measures. The findings highlight the multidimensional nature of TBI recovery and the limitations of applying only a single outcome measure.

Traumatic Brain Injury in the Workplace

Objectives: Work-related traumatic brain injuries (TBIs) are not well documented in the literature. Published studies mostly rely on worker databases that fail to provide clinically relevant information. Our objective is to describe the characteristics of hospitalized patients and their work-related TBI. Methods: We used the Québec provincial trauma and TBI program databases to identify all patients with a diagnosis of work-related TBI admitted to the Montreal General Hospital, a level 1 trauma center, between 2000 and 2014. Data from their medical records were extracted using a predetermined information sheet. Simple descriptive statistics (means and percentages) were used to summarize the data. Results: A total of 285 cases were analyzed. Workplace TBI patients were middle-aged (mean, 43.62 years), overwhelmingly male (male:female 18:1), mostly healthy, and had completed a high school level education. Most workers were from the construction industry; falling was the most common mechanism of injury. The majority of patients (76.8%) presented with a mild TBI; only a minority (14%) required neurosurgery. The most common finding on computed tomography was skull fracture. The median length of hospitalization was 7 days, after which most patients were discharged directly home. A total of 8.1% died of their injuries. Conclusions: Our study found that most hospitalized victims of work-related TBI had mild injury; however, some required neurosurgical intervention and a non-negligible proportion died of their injury. Improving fall prevention, accurately document helmet use and increasing the safety practice in the construction industry may help decrease work-related TBI burden.

Past, Present, and Future of Traumatic Brain Injury Research

Traumatic brain injury (TBI) is the greatest cause of death and severe disability in young adults; its incidence is increasing in the elderly and in the developing world. Outcome from severe TBI has improved dramatically as a result of advancements in trauma systems and supportive critical care, however we remain without a therapeutic which acts directly to attenuate brain injury. Recognition of secondary injury and its molecular mediators has raised hopes for such targeted treatments. Unfortunately, over 30 late-phase clinical trials investigating promising agents have failed to translate a therapeutic for clinical use. Numerous explanations for this failure have been postulated and are reviewed here. With this historical context we review ongoing research and anticipated future trends which are armed with lessons from past trials, new scientific advances, as well as improved research infrastructure and funding. There is great hope that these new efforts will finally lead to an effective therapeutic for TBI as well as better clinical management strategies.

The Glasgow Outcome Scale - 40 years of application and refinement

The Glasgow Outcome Scale (GOS) was first published in 1975 by Bryan Jennett and Michael Bond. With over 4,000 citations to the original paper, it is the most highly cited outcome measure in studies of brain injury and the second most-cited paper in clinical neurosurgery. The original GOS and the subsequently developed extended GOS (GOSE) are recommended by several national bodies as the outcome measure for major trauma and for head injury. The enduring appeal of the GOS is linked to its simplicity, short administration time, reliability and validity, stability, flexibility of administration (face-to-face, over the telephone and by post), cost-free availability and ease of access. These benefits apply to other derivatives of the scale, including the Glasgow Outcome at Discharge Scale (GODS) and the GOS paediatric revision. The GOS was devised to provide an overview of outcome and to focus on social recovery. Since the initial development of the GOS, there has been an increasing focus on the multidimensional nature of outcome after head injury. This Review charts the development of the GOS, its refinement and usage over the past 40 years, and considers its current and future roles in developing an understanding of brain injury.

Chronic impact of traumatic brain injury on outcome and quality of life: a narrative review

Traditionally seen as a sudden, brutal event with short-term impairment, traumatic brain injury (TBI) may cause persistent, sometimes life-long, consequences. While mortality after TBI has been reduced, a high proportion of severe TBI survivors require prolonged rehabilitation and may suffer long-term physical, cognitive, and psychological disorders. Additionally, chronic consequences have been identified not only after severe TBI but also in a proportion of cases previously classified as moderate or mild. This burden affects the daily life of survivors and their families; it also has relevant social and economic costs.

Outcome evaluation is difficult for several reasons: co-existing extra-cranial injuries (spinal cord damage, for instance) may affect independence and quality of life outside the pure TBI effects; scales may not capture subtle, but important, changes; co-operation from patients may be impossible in the most severe cases. Several instruments have been developed for capturing specific aspects, from generic health status to specific cognitive functions. Even simple instruments, however, have demonstrated variable inter-rater agreement.

The possible links between structural traumatic brain damage and functional impairment have been explored both experimentally and in the clinical setting with advanced neuro-imaging techniques. We briefly report on some fundamental findings, which may also offer potential targets for future therapies.

Better understanding of damage mechanisms and new approaches to neuroprotection-restoration may offer better outcomes for the millions of survivors of TBI.

Assessing the Relationship between Neurocognitive Performance and Brain Volume in Chronic Moderate-Severe Traumatic Brain Injury

Objectives

Characterize the scale and pattern of long-term atrophy in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in chronic moderate–severe traumatic brain injury (TBI) and its relationship to neurocognitive outcomes.

Participants

The TBI group consisted of 17 males with primary diagnosis of moderate–severe closed head injury. Participants had not received any systematic, post-acute rehabilitation and were recruited on average 8.36 years post-injury. The control group consisted of 15 males matched on age and education.

Main measures

Neurocognitive battery included widely used tests of verbal memory, visual memory, executive functioning, and attention/organization. GM, WM, and CSF volumes were calculated from segmented T1-weighted anatomical MR images. Voxel-based morphometry was employed to identify brain regions with differences in GM and WM between TBI and control groups.

Results

Chronic TBI results in significant neurocognitive impairments, and significant loss of GM and WM volume, and significant increase in CSF volume. Brain atrophy is not widespread, but it is rather distributed in a fronto-thalamic network. The extent of volume loss is predictive of performance on the neurocognitive tests.

Conclusion

Significant brain atrophy and associated neurocognitive impairments during the chronic stages of TBI support the notion that TBI results in a chronic condition with lifelong implications.

Reliability and Validity of the Therapy Intensity Level Scale: Analysis of Clinimetric Properties of a Novel Approach to Assess Management of Intracranial Pressure in Traumatic Brain Injury

We aimed to assess the reliability and validity of the Therapy Intensity Level scale (TIL) for intracranial pressure (ICP) management. We reviewed the medical records of 31 patients with traumatic brain injury (TBI) in two European intensive care units (ICUs). The ICP TIL was derived over a 4-day period for 4-h (TIL4) and 24-h epochs (TIL24). TIL scores were compared with historical schemes for TIL measurement, with each other, and with clinical variables. TIL24 scores in ICU patients with TBI were compared with two control groups: patients with extracranial trauma necessitating intensive care (Trauma_ICU; n = 20) and patients with TBI not needing ICU care (TBI_WARD; n = 19), to further determine the discriminative validity of the TIL for ICP-related ICU interventions. Interrater and intraobserver agreement were excellent for TIL4 and TIL24 (Cohen κ: 0.98-0.99; intraclass correlation coefficient: 0.99-1; p < 0.0005). The mean + standard deviation (SD) TIL24 in the ICU TBI cohort was significantly higher than the Trauma_ICU patients and the TBI_WARD patients (8.2 ± 3.2 vs. 2.2 ± 0.9 and 0.1 ± 0.1, respectively; p < 0.005 for both comparisons). Correlations between the TIL scale scores and historical TIL scores, between TIL24 and the Glasgow Coma Scale, and between a range of TIL metrics and summary measures of ICP over the 4-day period, were all highly significant (p < 0.01). The results were consistent with the expected direction. A linear mixed effect analysis, accounting for within-subjects repeated measures, showed strong correlation between TIL4 and 4-h ICP (p < 0.0000005). The TIL scale is a reliable measurement instrument with a high degree of validity for assessing the therapeutic intensity level of ICP management in patients with TBI.

Inter-rater agreement on assessment of outcome within a trauma registry

INTRODUCTION

To better evaluate the degree of ongoing disability in trauma patients, it has been recommended that trauma registries introduce routine long-term outcome measurement. One of the measures recommended for use is the Extended Glasgow Outcome Scale (GOS-E). However, few registries have adopted this measure and further research is required to determine its reliability with trauma populations. This study aimed to evaluate the inter-rater agreement of GOS-E scoring between an expert rater and trauma registry follow-up staff with a sample of detailed trauma case scenarios.

METHODS

Sixteen trauma registry telephone interviewers participated in the study. They were provided with a written summary of 15 theoretical adult trauma cases covering a spectrum of disability and asked to rate each case using the structured GOS-E interview. Their ratings were compared with those of an expert rater in order to calculate the inter-rater agreement for each individual rater-expert rater pair. Agreement was reported as the percentage of agreement, the kappa statistic, and weighted kappa. A multi-rater kappa value was also calculated for agreement between the 16 raters.

RESULTS

Across the 15 cases, the percentage of agreement between individual raters and the expert ranged from 63% to 100%. Across the 16 raters, the percentage of agreement with the expert rater ranged from 73-100% (mean=90%). Kappa values ranged from 0.65 to 1.00 across raters (mean=0.86) and weighted kappa values ranged from 0.73 to 1.00 (mean=0.89) The multi-rater kappa value was 0.78 (95% CI: 0.66, 0.89).

CONCLUSIONS

Sixteen follow-up staff achieved 'substantial' to 'almost perfect' agreement with an expert rater using the GOS-E outcome measure to score 15 sample trauma cases. The results of this study lend support to the use of the GOS-E within trauma populations and highlight the importance of ongoing training where multiple raters are involved to ensure reliable outcome reporting. It is also recommended that the structured GOS-E interview guide be used to achieve better agreement between raters. Ensuring the reliability of trauma outcome scores will enable more accurate evaluation of patient outcomes, and ultimately, more targeted trauma care.

Architecture design of a generic centralized adjudication module integrated in a web-based clinical trial management system

BACKGROUND

Centralized outcome adjudication has been used widely in multicenter clinical trials in order to prevent potential biases and to reduce variations in important safety and efficacy outcome assessments. Adjudication procedures could vary significantly among different studies. In practice, the coordination of outcome adjudication procedures in many multicenter clinical trials remains as a manual process with low efficiency and high risk of delay. Motivated by the demands from two large clinical trial networks, a generic outcome adjudication module has been developed by the network's data management center within a homegrown clinical trial management system. In this article, the system design strategy and database structure are presented.

METHODS

A generic database model was created to transfer different adjudication procedures into a unified set of sequential adjudication steps. Each adjudication step was defined by one activate condition, one lock condition, one to five categorical data items to capture adjudication results, and one free text field for general comments. Based on this model, a generic outcome adjudication user interface and a generic data processing program were developed within a homegrown clinical trial management system to provide automated coordination of outcome adjudication.

RESULTS

By the end of 2014, this generic outcome adjudication module had been implemented in 10 multicenter trials. A total of 29 adjudication procedures were defined with the number of adjudication steps varying from 1 to 7. The implementation of a new adjudication procedure in this generic module took an experienced programmer 1 or 2 days. A total of 7336 outcome events had been adjudicated and 16,235 adjudication step activities had been recorded. In a multicenter trial, 1144 safety outcome event submissions went through a three-step adjudication procedure and reported a median of 3.95 days from safety event case report form submission to adjudication completion. In another trial, 277 clinical outcome events were adjudicated by a six-step procedure and took a median of 23.84 days from outcome event case report form submission to adjudication procedure completion.

CONCLUSION

A generic outcome adjudication module integrated in the clinical trial management system made the automated coordination of efficacy and safety outcome adjudication a reality.

Improving early clinical trial phase identification of promising therapeutics

This review addresses decision-making underlying the frequent failure to confirm early-phase positive trial results and how to prioritize which early agents to transition to late phase. While unexpected toxicity is sometimes responsible for late-phase failures, lack of efficacy is also frequently found. In stroke as in other conditions, early trials often demonstrate imbalances in factors influencing outcome. Other issues complicate early trial analysis, including unequally distributed noise inherent in outcome measures and variations in natural history among studies. We contend that statistical approaches to correct for imbalances and noise, while likely valid for homogeneous conditions, appear unable to accommodate disease complexity and have failed to correctly identify effective agents. While blinding and randomization are important to reduce selection bias, these methods appear insufficient to insure valid conclusions. We found potential sources of analytical errors in nearly 90% of a sample of early stroke trials. To address these issues, we recommend changes in early-phase analysis and reporting: (1) restrict use of statistical correction to studies where the underlying assumptions are validated, (2) select dichotomous over continuous outcomes for small samples, (3) consider pooled samples to model natural history to detect early therapeutic signals and increase the likelihood of replication in larger samples, (4) report subgroup baseline conditions, (5) consider post hoc methods to restrict analysis to subjects with an appropriate match, and (6) increase the strength of effect threshold given these cumulative sources of noise and potential errors. More attention to these issues should lead to better decision-making regarding selection of agents to proceed to pivotal trials.

Design of acute neuroprotection studies

Traumatic brain injury (TBI) is a substantial public health problem. The discovery of progressive, ongoing damage to the brain by means of complex molecular mechanisms which follow the initial injury has raised the possibility of targeted therapeutic intervention. Despite a substantial investment in trials testing dozens of therapeutics in humans, however, to date none has demonstrated robust efficacy. Deficiencies in the design of human clinical trials is likely to explain many translational failures, at least in part. Here we review secondary injury mediators and key trials which have targeted them. We provide a thorough discussion of putative reasons why trials thus far have failed and suggestions for the design of future clinical studies. Important insights from the IMPACT study are also presented in detail; in addition to providing critical insights for future trial design and analysis it suggests that reanalysis of completed studies may reveal inappropriately discarded treatments. Unfortunately limited resources are available for translational research and it is difficult to procure funds needed for well-resourced, large and definitive studies. History suggests, however, that investing in studies that are unlikely to provide a definitive answer only serves to increase required investment as they tend to mandate further study.

Effect of cocaine use on outcomes in traumatic brain injury

Context:

Animal and molecular studies have shown that cocaine exerts a neuroprotective effect against cerebral ischemia.

Aims:

To determine if the presence of cocaine metabolites on admission following traumatic brain injury (TBI) is associated with better outcomes.

Settings and Design:

Level-1 trauma center, retrospective cohort.

Materials and Methods:

After obtaining Institutional Review Board (IRB) approval, the trauma registry was searched from 2006 to 2009 for all patients aged 15-55 years with blunt head trauma and non-head AIS <3. Exclusion criteria were pre-existing brain pathology and death within 30 min of admission. The primary outcome was in-hospital mortality; secondary outcomes were hospital length of stay (LOS), and Glasgow Outcome Score (GOS).

Statistical Analysis:

Logistic regression was used to determine the independent effect of cocaine on mortality. Hospital LOS was compared with multiple linear regression.

Results:

A total of 741 patients met criteria and had drug screens. The screened versus unscreened groups were similar. Cocaine positive patients were predominantly African-American (46% vs. 21%, P < 0.0001), older (40 years vs. 30 years, P < 0.0001), and had ethanol present more often (50.7% vs. 37.8%, P = 0.01). There were no differences in mortality (cocaine-positive 1.4% vs. cocaine-negative 2.7%, P = 0.6) on both univariate and multivariate analysis.

Conclusions:

Positive cocaine screening was not associated with mortality in TBI. An effect may not have been detected because of the low mortality rate. LOS is affected by many factors unrelated to the injury and may not be a good surrogate for recovery. Similarly, GOS may be too coarse a measure to identify a benefit.

Quantification of errors in ordinal outcome scales using shannon entropy: effect on sample size calculations

Objective

Clinical trial outcomes often involve an ordinal scale of subjective functional assessments but the optimal way to quantify results is not clear. In stroke, the most commonly used scale, the modified Rankin Score (mRS), a range of scores (“Shift”) is proposed as superior to dichotomization because of greater information transfer. The influence of known uncertainties in mRS assessment has not been quantified. We hypothesized that errors caused by uncertainties could be quantified by applying information theory. Using Shannon’s model, we quantified errors of the “Shift” compared to dichotomized outcomes using published distributions of mRS uncertainties and applied this model to clinical trials.

Methods

We identified 35 randomized stroke trials that met inclusion criteria. Each trial’s mRS distribution was multiplied with the noise distribution from published mRS inter-rater variability to generate an error percentage for “shift” and dichotomized cut-points. For the SAINT I neuroprotectant trial, considered positive by “shift” mRS while the larger follow-up SAINT II trial was negative, we recalculated sample size required if classification uncertainty was taken into account.

Results

Considering the full mRS range, error rate was 26.1%±5.31 (Mean±SD). Error rates were lower for all dichotomizations tested using cut-points (e.g. mRS 1; 6.8%±2.89; overall p<0.001). Taking errors into account, SAINT I would have required 24% more subjects than were randomized.

Conclusion

We show when uncertainty in assessments is considered, the lowest error rates are with dichotomization. While using the full range of mRS is conceptually appealing, a gain of information is counter-balanced by a decrease in reliability. The resultant errors need to be considered since sample size may otherwise be underestimated. In principle, we have outlined an approach to error estimation for any condition in which there are uncertainties in outcome assessment. We provide the user with programs to calculate and incorporate errors into sample size estimation.

Is a high initial World Federation of Neurosurgery (WFNS) grade really associated with a poor clinical outcome in elderly patients with ruptured intracranial aneurysms treated with coiling?

BACKGROUND

Coiling of ruptured intracranial aneurysms in elderly patients remains debatable in terms of technical feasibility and clinical outcome.

AIMS

In this observational cohort study we aimed to assess the technical feasibility, complication profile and clinical outcomes of elderly patients with subarachnoid hemorrhage (SAH) treated with endovascular therapy.

METHODS

The study included 59 consecutive patients (47 women) aged ≥70 years (mean age 76 years, range 71-84) admitted to our institution with SAH from January 2002 to July 2011. The patients were treated for 66 aneurysms (regular coiling: n=62 (94%), balloon-assisted technique: n=2 (3%), stent and coil technique: n=2 (3%)). World Federation of Neurosurgery (WFNS) grade at admission was 1 in 13 patients, 2 in 23 patients, 3 in 8 patients, 4 in 11 patients and 5 in 4 patients. We analysed data by univariate and multivariate statistical analyses with an emphasis on the initial clinical situation, complications and clinical outcome.

RESULTS

The technical success rate was 98% with a procedure-related deficit rate of 10% and procedure-related death rate of 5%. The Glasgow Outcome Scale score at 6 months was 1 in 15 patients (25.4%), 2 in 8 patients (13.6%), 3 in 14 patients (23.7%), 4 in 11 patients (18.6%) and 5 in 11 patients (18.6%). Patients admitted with a high initial WFNS grade did not differ statistically in terms of clinical outcome. The final clinical outcome was not significantly correlated with age, initial Fisher score or procedure-related complications.

CONCLUSIONS

Endovascular treatment of elderly patients with ruptured cerebral aneurysms is feasible, safe and beneficial regardless of the presenting WFNS score.

Prediction of outcome after moderate and severe traumatic brain injury: external validation of the International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) and Corticoid Randomisation After Significant Head injury (CRASH) prognostic models

OBJECTIVE

The International Mission on Prognosis and Analysis of Clinical Trials and Corticoid Randomisation After Significant Head injury prognostic models predict outcome after traumatic brain injury but have not been compared in large datasets. The objective of this is study is to validate externally and compare the International Mission on Prognosis and Analysis of Clinical Trials and Corticoid Randomisation after Significant Head injury prognostic models for prediction of outcome after moderate or severe traumatic brain injury.

DESIGN

External validation study.

PATIENTS

We considered five new datasets with a total of 9,036 patients, comprising three randomized trials and two observational series, containing prospectively collected individual traumatic brain injury patient data.

MEASUREMENTS AND MAIN RESULTS

Outcomes were mortality and unfavorable outcome, based on the Glasgow Outcome Score at 6 months after injury. To assess performance, we studied the discrimination of the models (by area under the receiver operating characteristic curves), and calibration (by comparison of the mean observed to predicted outcomes and calibration slopes). The highest discrimination was found in the Trauma Audit and Research Network trauma registry (area under the receiver operating characteristic curves between 0.83 and 0.87), and the lowest discrimination in the Pharmos trial (area under the receiver operating characteristic curves between 0.65 and 0.71). Although differences in predictor effects between development and validation populations were found (calibration slopes varying between 0.58 and 1.53), the differences in discrimination were largely explained by differences in case mix in the validation studies. Calibration was good, the fraction of observed outcomes generally agreed well with the mean predicted outcome. No meaningful differences were noted in performance between the International Mission on Prognosis and Analysis of Clinical Trials and Corticoid Randomisation After Significant Head injury models. More complex models discriminated slightly better than simpler variants.

CONCLUSIONS

Since both the International Mission on Prognosis and Analysis of Clinical Trials and the Corticoid Randomisation After Significant Head injury prognostic models show good generalizability to more recent data, they are valid instruments to quantify prognosis in traumatic brain injury.

Neuroradiology back to the future: brain imaging

The beginning of neuroradiology can be traced to the early 1900s with the use of skull radiographs. Ventriculography and pneumoencephalography were introduced in 1918 and 1919, respectively, and carotid angiography, in 1927. Technical advances were made in these procedures during the next 40 years that lead to improved diagnosis of intracranial pathology. Yet, they remained invasive procedures that were often uncomfortable and associated with significant morbidity. The introduction of CT in 1971 revolutionized neuroradiology. Ventriculography and pneumoencephalography were rendered obsolete. The imaging revolution continued with the advent of MR imaging in the early 1980s. Noninvasive angiographic techniques have curtailed the use of conventional angiography, and physiologic imaging gives us a window into the function of the brain. In this historical review, we will trace the origin and evolution of the advances that have led to the quicker, less invasive diagnosis and resulted in more rapid therapy and improved outcomes.

Impact of GOS misclassification on ordinal outcome analysis of traumatic brain injury clinical trials

This study extends our previous investigation regarding the effect of nondifferential dichotomous Glasgow Outcome Scale (GOS) misclassification in traumatic brain injury (TBI) clinical trials to the effect of GOS misclassification on ordinal analysis in TBI clinical trials. The impact of GOS misclassification and ordinal outcome analysis was explored via probabilistic sensitivity analyses using TBI patient datasets from the IMPACT database (n = 9205). Three patterns of misclassification were explored given the pre-specified misclassification distributions. For the random pattern, we specified a trapezoidal distribution (minimum: 80%, mode: 85%, and 95%, maximum: 100%) for both sensitivity and specificity; for the upward pattern, the same trapezoidal distribution for sensitivity but with a perfect specificity; and for the downward pattern, the same trapezoidal distribution for specificity but with a perfect sensitivity. The conventional 95% confidence intervals and simulation intervals, which accounts for the misclassification and random errors together, were reported. The results showed that given the specified misclassification distributions, the misclassification with a random or upward pattern would have caused a slightly underestimated outcome in the observed data. However, the misclassification with a downward pattern would have resulted in an inflated estimation. Thus the sensitivity analysis suggests that the nondifferential misclassification can cause uncertainties on the primary outcome estimation in TBI trials. However, such an effect is likely to be small when ordinal analysis is applied, compared with the impact of dichotomous GOS misclassifications. The result underlines that the ordinal GOS analysis may gain from both statistical efficiency, as suggested by several recent studies, and a relatively smaller impact from misclassification as compared with conventional binary GOS analysis.

A method for reducing misclassification in the extended Glasgow Outcome Score

The eight-point extended Glasgow Outcome Scale (GOSE) is commonly used as the primary outcome measure in traumatic brain injury (TBI) clinical trials. The outcome is conventionally collected through a structured interview with the patient alone or together with a caretaker. Despite the fact that using the structured interview questionnaires helps reach agreement in GOSE assessment between raters, significant variation remains among different raters. We introduce an alternate GOSE rating system as an aid in determining GOSE scores, with the objective of reducing inter-rater variation in the primary outcome assessment in TBI trials. Forty-five trauma centers were randomly assigned to three groups to assess GOSE scores on sample cases, using the alternative GOSE rating system coupled with central quality control (Group 1), the alternative system alone (Group 2), or conventional structured interviews (Group 3). The inter-rater variation between an expert and untrained raters was assessed for each group and reported through raw agreement and with weighted kappa (kappa) statistics. Groups 2 and 3 without central review yielded inter-rater agreements of 83% (weighted kappa = 0.81; 95% CI 0.69, 0.92) and 83% (weighted kappa = 0.76, 95% CI 0.63, 0.89), respectively, in GOS scores. In GOSE, the groups had an agreement of 76% (weighted kappa = 0.79; 95% CI 0.69, 0.89), and 63% (weighted kappa = 0.70; 95% CI 0.60, 0.81), respectively. The group using the alternative rating system coupled with central monitoring yielded the highest inter-rater agreement among the three groups in rating GOS (97%; weighted kappa = 0.95; 95% CI 0.89, 1.00), and GOSE (97%; weighted kappa = 0.97; 95% CI 0.91, 1.00). The alternate system is an improved GOSE rating method that reduces inter-rater variations and provides for the first time, source documentation and structured narratives that allow a thorough central review of information. The data suggest that a collective effort can be made to minimize inter-rater variation.

IMPACT recommendations for improving the design and analysis of clinical trials in moderate to severe traumatic brain injury

Clinical trials in traumatic brain injury (TBI) pose complex methodological challenges, largely related to the heterogeneity of the population. The International Mission on Prognosis and Clinical Trial Design in TBI study group has explored approaches for dealing with this heterogeneity with the aim to optimize clinical trials in TBI. Extensive prognostic analyses and simulation studies were conducted on individual patient data from eight trials and three observational studies. Here, we integrate the results of these studies into the International Mission on Prognosis and Clinical Trial Design in TBI recommendations for design and analysis of trials in TBI: Details of the major baseline prognostic characteristics should be provided in every report on a TBI study; in trials they should be differentiated per treatment group. We also advocate the reporting of the baseline prognostic risk as determined by validated prognostic models. Inclusion criteria should be as broad as is compatible with the current understanding of the mechanisms of action of the intervention being evaluated. This will maximize recruitment rates and enhance the generalizability of the results. The statistical analysis should incorporate prespecified covariate adjustment to mitigate the effects of the heterogeneity. The statistical analysis should use an ordinal approach, based on either sliding dichotomy or proportional odds methodology. Broad inclusion criteria, prespecified covariate adjustment, and an ordinal analysis will promote an efficient trial, yielding gains in statistical efficiency of more than 40%. This corresponds to being able to detect a 7% treatment effect with the same number of patients needed to demonstrate a 10% difference with an unadjusted analysis based on the dichotomized Glasgow outcome scale.

New approaches to increase statistical power in TBI trials: insights from the IMPACT study

INTRODUCTION

None of the multi-centre phase III randomized controlled trials (RCTs) performed in TBI have convincingly demonstrated efficacy. Problems in clinical trial design and analysis may have contributed to these failures. Clinical trials in the TBI population pose several complicated methodological challenges, related especially to the heterogeneity of the population. In this paper we examine the issue of heterogeneity within the IMPACT (International Mission on Prognosis and Clinical Trial design in TBI) database and investigate the application of conventional and innovative methods for the statistical analysis of trials in TBI.

METHODS AND RESULTS

Simulation studies in the IMPACT database (N = 9205) showed substantial gains in efficiency with covariate adjustment. Adjusting for 7 important predictors yielded up to a 28% potential reduction in trial size. Ongoing analyses on the potential benefit of ordinal analysis, such as proportional odds and sliding dichotomy, gave promising results with even larger potential reductions in trial size.

CONCLUSION

The statistical power of RCTs in TBI can be considerably increased by applying covariate adjustment and by ordinal analysis methods of the GOS. These methods need to be considered for optimizing future TBI trials.

Effects of Glasgow Outcome Scale misclassification on traumatic brain injury clinical trials

The Glasgow Outcome Scale (GOS) is the primary endpoint for efficacy analysis of clinical trials in traumatic brain injury (TBI). Accurate and consistent assessment of outcome after TBI is essential to the evaluation of treatment results, particularly in the context of multicenter studies and trials. The inconsistent measurement or interobserver variation on GOS outcome, or for that matter, on any outcome scales, may adversely affect the sensitivity to detect treatment effects in clinical trial. The objective of this study is to examine effects of nondifferential misclassification of the widely used five-category GOS outcome scale and in particular to assess the impact of this misclassification on detecting a treatment effect and statistical power. We followed two approaches. First, outcome differences were analyzed before and after correction for misclassification using a dataset of 860 patients with severe brain injury randomly sampled from two TBI trials with known differences in outcome. Second, the effects of misclassification on outcome distribution and statistical power were analyzed in simulation studies on a hypothetical 800-patient dataset. Three potential patterns of nondifferential misclassification (random, upward and downward) on the dichotomous GOS outcome were analyzed, and the power of finding treatments differences was investigated in detail. All three patterns of misclassification reduce the power of detecting the true treatment effect and therefore lead to a reduced estimation of the true efficacy. The magnitude of such influence not only depends on the size of the misclassification, but also on the magnitude of the treatment effect. In conclusion, nondifferential misclassification directly reduces the power of finding the true treatment effect. An awareness of this procedural error and methods to reduce misclassification should be incorporated in TBI clinical trials.