Transforming Research and Clinical Knowledge in TBI Pilot: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transforming Research and Clinical Knowledge in TBI Pilot (NCT01565551), a registered phase not stated study. The primary outcome is Glasgow Outcome Scale Extended (GOSE).

2. Clinical Question

The question is therefore descriptive and infrastructure-oriented: can common data elements and related research practices be tested and refined across traumatic brain injury settings, with clinical outcomes including GOSE captured as part of the resulting data resources? The record describes a prospective, multicenter observational study and names three acute Level I Trauma Centers and one rehabilitation center. It does not report a randomized intervention, an assigned control condition, or a prespecified between-cohort causal contrast. Differences between people studied at acute sites and those studied at a rehabilitation center cannot automatically be interpreted as effects of a treatment or care setting. The groups differ by presentation context, and the registry does not report an adjustment strategy for such differences.

3. Trial Design

This is a completed observational study sponsored by the University of California, San Francisco. The registry record gives a start date of 2010-04 and a primary completion date of 2012-08. Its recorded enrollment is 650. The study’s stated global aim is to test and refine Common Data Elements, neuroimaging standards, and practices for genetics and proteomics in traumatic brain injury studies. It also describes expanding repositories covering demographics, neuroimaging, plasma biomarkers, genetics, and multivariate outcomes.

The study is described as prospective and multicenter. Its early-presenting cohort includes people studied after acute presentation within 24 hours of traumatic brain injury at San Francisco General Hospital, the University of Pittsburgh Medical Center, or University Medical Center Brackenridge. Its late-presenting cohort includes people studied after presentation to Mount Sinai Rehabilitation Center. These descriptions define the settings and presentation categories; they do not establish that the cohorts are comparable on clinical characteristics.

The listed intervention is “N/A (Observational Study).” Random allocation is not stated, and the registry record explicitly characterizes the arms as not being a like-for-like control comparison. The design should therefore not be read as a randomized trial of an assigned treatment. The record does not report a detailed analysis plan, eligibility criteria, recruitment flow, follow-up completion, or how differences between centers were addressed. Those details are not reported in the registry record.

The registry lists one outcome measure and zero analyses. The primary outcome is GOSE at 6 Months Post-Injury, summarized in the outcome definition by a median and inter-quartile range. A numerical result for that endpoint is not reported in the registry record. Completion status indicates the study is marked completed in the registry; it does not, on its own, establish that outcome findings or all planned analyses were posted.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Glasgow Outcome Scale Extended (GOSE), measured over 6 Months Post-Injury.

The primary endpoint is the Glasgow Outcome Scale Extended (GOSE) at 6 Months Post-Injury. The registry describes GOSE as an overall measure of disability based on cognition, independence, employability, and social or community participation, assessed through a structured interview. It places people in one of eight outcome categories: Dead (1), Vegetative State (2), Lower Severe Disability (3), Upper Severe Disability (4), Lower Moderate Disability (5), Upper Moderate Disability (6), Lower Good Recovery (7), and Upper Good Recovery (8). The definition groups scores 7-8 as Good Recovery, 5-6 as Moderate Disability, and 3-4 as Severe Disability.

GOSE is used in traumatic brain injury research because it represents several aspects of functioning rather than a single symptom or test result. Its ordered categories distinguish levels of outcome, while retaining a compact scale suitable for describing a cohort. The registry specifies the median and inter-quartile range as the endpoint summary. In general, the median identifies the central position of ordered observations, and the inter-quartile range describes the spread of the middle portion of those observations. These summaries can be useful for an ordinal outcome whose values represent ordered categories rather than equal-interval measurements.

The record does not state a numerical GOSE result, an analysis population, or how the outcome was handled for people without a recorded interview. Thus, the endpoint definition explains what was intended to be assessed, but does not establish the observed distribution of outcomes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the project as a prospective observational study, rather than a randomized comparison of assigned treatments. This distinction governs what statistical conclusions can be drawn. In a randomized study, allocation is intended to make comparison groups similar on average at the start of follow-up. In an observational study, group membership follows the circumstances described in the record—in this case, acute presentation at trauma centers or presentation at a rehabilitation center. General statistical principle: observed differences between such groups can be associated with their differing characteristics and settings, and should not automatically be attributed to a causal effect.

What does the GOSE summary describe?

The endpoint definition calls for the median and inter-quartile range. In general, the median is a measure of the middle of an ordered set of observations. The inter-quartile range describes the central spread of the observations, rather than the full range or the uncertainty in the estimate. These statistics answer different questions: one describes location, while the other describes dispersion. Neither is reported numerically for this study in the registry record.

GOSE consists of ordered categories, from Dead (1) through Upper Good Recovery (8), with the intermediate states defined in the endpoint description. Ordered categories have a meaningful ranking, but the scale does not by itself establish that the gap between each pair of adjacent scores is identical. General statistical principle: a median can retain the ordering of such categories without assuming equal distances between them. The registry’s choice of median and inter-quartile range is consistent with describing an ordered outcome, but the record does not include observed values with which to inspect the distribution.

What would an uncertainty interval mean?

General statistical principle: a confidence interval expresses the uncertainty around an estimate under a specified statistical model and sampling process. Its interpretation depends on the estimate, the data, and the method used to calculate it. A narrow interval generally indicates greater precision under those assumptions; a wide interval indicates less precision. No confidence interval or method for calculating one is reported in the registry record, so no precision claim about GOSE can be made from the posted information.

A p-value, if reported, would address how compatible the data are with a specified null model, under the assumptions of the analysis. It would not establish clinical importance, prove that groups are equivalent, or resolve confounding in an observational comparison. The registry lists zero analyses and does not report a p-value or a hypothesis test. The direction and magnitude of any cohort contrast are also not reported.

How should the planning assumptions be read?

The record describes sample-size illustrations based on a fraction of an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that illustrations for non-time-to-event outcomes refer to participants per arm, while time-to-event illustrations use the total number of events. These are planning assumptions, not a description of the study’s actual allocation or a documented sample-size justification. No numerical illustration results are reported in the registry record.

Such illustrations are not observed power. General statistical principle: observed power, when calculated from an observed effect and its uncertainty, does not provide an independent substitute for an effect estimate and confidence interval. Planning calculations instead describe sample sizes associated with selected assumptions about an effect and analysis. Because the registry does not report a numerical GOSE effect estimate or the study’s own design justification, the illustrations should not be interpreted as evidence that the study had a particular ability to detect a clinical difference.

Why can over-dispersion matter?

General statistical principle: over-dispersion occurs when outcome variability is greater than a model assumes. If a model understates variability, its standard errors may be too small and its confidence intervals may be too narrow, leading to overly optimistic assessments of precision. The appropriate model depends on the outcome and design. The registry record does not report a model for GOSE, an over-dispersion assessment, or any model diagnostics. This concept is relevant as a general modeling consideration, not as a reported feature of this study.

What analysis details are absent?

The registry record lists zero analyses and does not report the statistical test or model, covariate adjustment, handling of clustering by center, or sensitivity analyses. The prospective multicenter setting makes those details potentially important for interpreting an eventual comparison, but their absence does not establish which methods were or were not used outside the registry. The appropriate conclusion is limited to the record: the endpoint and summary measure are specified, while the analysis methods and numerical results are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, with GOSE at 6 Months Post-Injury designated as primary, and zero analyses. It does not report a statistical testing plan, a hierarchy of outcomes, or a procedure for controlling multiplicity. A multiplicity plan addresses the increased chance of false-positive findings when multiple outcomes, time points, subgroups, or contrasts are tested. General statistical principle: the need for such control depends on the questions and analyses actually planned; the registry does not provide enough detail to determine whether additional tests were planned outside the record.

Missing-data handling is not reported in the registry record. The endpoint description refers to assessment through a structured interview, but does not state how unavailable interviews, incomplete responses, or other missing outcome values were treated. The record also does not report the number of people with an observed GOSE result or the proportion with follow-up information. Without these details, readers cannot evaluate whether the posted outcome summaries, if available elsewhere, reflect all enrolled participants or a subset.

The analysis population is likewise not reported in the registry record. There is no description of inclusion rules for an endpoint analysis, exclusions after enrollment, or whether all people with available outcome data would be included. The record’s zero analysis count means no analysis population can be reconstructed from the posted registry information.

These omissions are especially relevant in an observational study with cohorts defined by different presentation settings. General statistical principle: if outcome availability or cohort membership is associated with participants’ characteristics, an analysis limited to observed outcomes may not describe the full enrolled group. The registry record does not report whether this issue was assessed or how it might have been addressed. No assumption about missingness or multiplicity procedures should be inferred from the endpoint definition alone.

11. What the Result Does, and Does Not, Mean

The record establishes that the study was designed as a prospective, multicenter observational project focused on traumatic brain injury research infrastructure, with GOSE at 6 Months Post-Injury as its primary outcome. It identifies the two presentation cohorts, the outcome’s category structure, and the intended median and inter-quartile range summary. It also records enrollment of 650 and marks the study COMPLETED.

Those details do not establish a clinical treatment effect. No treatment was assigned, allocation is not stated, and the cohorts are not described as a like-for-like control comparison. The registry lists zero analyses and does not report numerical GOSE findings or an inferential comparison. Therefore, neither a benefit nor a lack of benefit can be concluded from the registry record. The absence of a posted result is not evidence that the cohorts had identical outcomes, and it is not evidence that an effect was present.

The GOSE definition identifies the domains and ordered categories intended for assessment, but it does not reveal how participants were distributed across those categories. Without a reported median and inter-quartile range, readers cannot judge the observed outcome level or its variability. Without an estimate and uncertainty interval, readers cannot assess the precision of a cohort estimate or contrast.

The record’s broader aims concern common data elements, neuroimaging standards, genetics and proteomics practices, and research repositories. The stated aims are important context for understanding why the study was conducted, but the registry information does not report whether those standards were validated or how the repositories performed. Completion status alone is not a statistical evaluation of those aims.

General statistical principle: observational results can describe patterns and support research infrastructure, but causal interpretation requires design and analysis details that address differences between groups. The record does not report such an adjustment strategy. Accordingly, the defensible interpretation is limited: this was a completed observational study with a defined clinical endpoint, while its numerical outcome findings and analyses are not reported in the registry record.

12. Why This Trial Matters Statistically

This study is statistically notable for combining a clinical outcome with an infrastructure objective. Its stated purpose is to test and refine common data elements, neuroimaging standards, and research practices for genetics and proteomics in traumatic brain injury studies. A multicenter prospective design can support the collection of harmonized information across different clinical settings. The registry also describes repositories spanning demographics, imaging, plasma biomarkers, genetics, and multivariate outcomes.

Such work matters because analysis depends on how data are defined and collected. General statistical principle: common definitions can make information more consistently interpretable across sites, while inconsistent measurement can complicate comparisons and synthesis. Prospective collection can also make the intended variables and follow-up context clearer than relying only on retrospective records. These are general reasons why data standards and infrastructure are important; the registry record does not report measured validation results for this project.

The study’s clinical endpoint also illustrates a measurement choice: GOSE captures ordered categories of disability and recovery across several functional domains. Describing its median and inter-quartile range is a way to summarize an ordinal outcome without requiring a numerical treatment contrast. However, the record does not post the outcome values or analyses, so the clinical findings cannot be assessed from the registry information.

Finally, the two cohorts arise from different presentation settings rather than randomized assignment. That design can be useful for studying real-world populations and research workflows, but it places limits on causal interpretation. The record’s explicit distinction between acute and rehabilitation settings is therefore central to reading any comparison cautiously. The statistical contribution that can be established from the registry is primarily the study’s design and measurement framework, not a reported effect on GOSE.

13. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation of the registry record is the absence of numerical primary-outcome results. Although GOSE at 6 Months Post-Injury is defined and a median with inter-quartile range is specified, neither summary is reported. The record lists zero analyses, so it does not give a statistical comparison, confidence interval, p-value, or model result.

The study is observational, and the early-presenting acute-site cohort and late-presenting rehabilitation-center cohort represent different presentation contexts. The record does not describe random allocation or a like-for-like control group. It also does not report whether analyses adjusted for participant characteristics, center, or other potential differences between cohorts. These design features limit the causal conclusions that could be drawn from a cohort contrast, even if numerical results were available.

Important information about the analyzed population and outcome completeness is not reported in the registry record. The record does not specify how many participants had a GOSE assessment, how missing assessments were handled, or what rules defined inclusion in an analysis. It also does not provide the detailed statistical methods, multiplicity strategy, or sensitivity analyses.

The broader project aims include testing and refining data standards and expanding research repositories, but validation findings and repository performance are not reported in the registry record. Adverse-event entries include zeros for the listed counts and null entries for deaths, without an explanation of the entries; they cannot be interpreted as a detailed safety result. These limitations concern what can be learned from the registry record and do not establish what analyses or findings may exist elsewhere.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Transforming Research and Clinical Knowledge in TBI Pilot — NCT01565551.
• Registry record last updated 2014-02-17; status last verified 2014-01.
• Results first posted 2014-02-17.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

17. Record Summary

NCT01565551, titled “Transforming Research and Clinical Knowledge in TBI Pilot,” is marked COMPLETED and lists the University of California, San Francisco as sponsor. The registry record gives a start date of 2010-04, a primary completion date of 2012-08, and enrollment of 650. It describes a prospective, multicenter observational study with an early-presenting acute-site cohort and a late-presenting rehabilitation-center cohort.

The project aims to test and refine common data elements, neuroimaging standards, and practices for genetics and proteomics in traumatic brain injury research, while expanding research repositories. The primary outcome is GOSE at 6 Months Post-Injury, summarized by median and inter-quartile range. The registry lists one outcome measure and zero analyses. Numerical GOSE results, analysis methods, missing-data procedures, and a detailed analysis population are not reported in the registry record.