This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Rapid MRI for Acute Pediatric Head Trauma (NCT03291964), a registered phase not stated study. The primary outcome is Sensitivity: Percentage of MRIs Correctly Identifying Clinically Important Intracranial Injury (True Positives).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03291964 |
| Phase | Phase not stated |
| Condition | Head Trauma, Image, Body |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 76 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Oregon Health and Science University |
| Results posted | Yes |
2. Clinical Question
The registry describes a study of Rapid Brain MRI for acute pediatric head trauma. Its clinical question concerns whether the MRI identifies clinically important intracranial injury, using a sensitivity endpoint. The registry defines a true positive as an injury meeting clinical criteria for clinically important traumatic brain injury that is also found on imaging. The endpoint is framed within 6 hours from the initial head CT.
Population
Children and adolescents with acute head trauma are the population described in the study summary. The registry record does not report further eligibility details, such as age limits, injury severity criteria, or exclusions.
Intervention
The listed diagnostic test is Rapid Brain MRI. The summary describes rapid MRI as an imaging test that does not use radiation and states that the study evaluates it for acute pediatric head trauma.
Comparator
The record does not identify a randomized comparator or state an allocation method. The primary endpoint refers to an initial head CT as a timing reference, but the registry record does not provide enough information to characterize a like-for-like control comparison.
Primary question
Among the MRIs assessed, what percentage correctly identifies clinically important intracranial injury under the registry definition? The registry record names this sensitivity outcome but does not report its numerical result or the underlying counts.
This is a diagnostic-performance question, not a question about whether assignment to MRI changes health outcomes. The record also lists time from order to obtaining MRI and need for anxiolysis medication for imaging as secondary outcomes. It does not report numerical results for those outcomes.
3. Trial Design
The record identifies the study as Rapid MRI for Acute Pediatric Head Trauma, with the official title QuickBrain MRI for Acute Pediatric Head Trauma. Oregon Health and Science University is listed as the sponsor. The study is marked completed, with enrollment of 76. The listed intervention is Rapid Brain MRI, classified as a diagnostic test.
The registry record does not state an allocation method. It is not described as a randomized comparison, and the record cautions that any arms are not a like-for-like control comparison. No comparator arm details or arm-level outcome results are reported. Therefore, the record does not establish a randomized treatment contrast, and the study should not be interpreted as if it tested an intervention against a controlled alternative.
The primary outcome is sensitivity for identifying clinically important intracranial injury, assessed within 6 hours from the initial head CT. The stated definition counts an MRI as a true positive when the clinical criteria for clinically important traumatic brain injury are met and imaging finds the injury. The secondary outcomes concern time from order to obtaining MRI and the need for benzodiazepines for imaging-related anxiolysis.
The record lists 3 outcome measures and 0 analysis records. It does not report the protocol-level details needed to reconstruct how participants entered the study, how imaging assessments were organized, or how the outcome data were analyzed. In particular, eligibility criteria, recruitment procedures, blinding, the number of sites, and the planned analysis are not reported in the registry record. These absences limit what can be concluded about implementation and risk of bias from the registry alone.
The stated dates are a study start of 2017-09-03 and primary completion of 2019-08-01. Those dates and the completed status describe the registry timeline; they do not supply missing outcome estimates or establish that every planned analysis was reported.
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
| Stage | Quick Brain |
|---|---|
| STARTED | 73 |
| COMPLETED | 73 |
| NOT COMPLETED | 0 |
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.
Population: children being evaluated in the ED for head trauma.
| Characteristic | Unit | Quick Brain |
|---|---|---|
| Participants analysed | 73 | |
| Age, Categorical: <=18 years | Participants | 73 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 4.0 (1 to 10) |
| Sex: Female, Male: Female | Participants | 38 |
| Sex: Female, Male: Male | Participants | 35 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 73 |
| Region of Enrollment: United States | participants | 73 |
6. Primary Endpoint
The registry lists the primary outcome as Sensitivity: Percentage of MRIs Correctly Identifying Clinically Important Intracranial Injury (True Positives), measured over within 6 hours from the initial head CT.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of MRIs correctly identifying |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is sensitivity: the percentage of MRIs correctly identifying clinically important intracranial injury. Under the registry definition, a true positive requires both clinical criteria for clinically important traumatic brain injury and imaging that finds the injury. Sensitivity is calculated using true positives relative to true positives plus false negatives. The timeframe is within 6 hours from the initial head CT.
In general, sensitivity describes how often a test identifies the condition among cases defined as having that condition. It is useful when the concern is whether cases might be missed. The measure does not, by itself, describe how often a positive test is correct among all positive tests; that is a different diagnostic quantity. Nor does sensitivity alone describe image quality, time burden, patient experience, or whether use of a test changes clinical outcomes.
The registry record does not report the number of true positives, false negatives, the total evaluated for sensitivity, or a numerical sensitivity estimate. It also does not report a confidence interval. Without those quantities, the precision of the endpoint estimate cannot be assessed from the registry record. The endpoint definition identifies what the investigators intended to measure, but it is not itself a result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive point is that the registry names a diagnostic-performance endpoint but does not report its numerical result. The record therefore does not establish a sensitivity estimate for Rapid Brain MRI in this study. No true-positive or false-negative counts are reported, and no confidence interval or other uncertainty estimate is reported. There is consequently no basis in the registry record for describing the measured sensitivity as high, low, precise, or imprecise.
The endpoint definition is clinically specific in that a true positive depends on meeting clinical criteria for clinically important traumatic brain injury and having the injury identified on imaging. However, the registry does not report further details about how the clinical criteria were applied, who judged them, or how disagreements were handled. The record also does not provide enough information to determine whether all participants received assessments in a way that permits an unbiased sensitivity estimate.
The study summary gives a rationale for examining rapid MRI: it describes CT as the current standard of care for imaging when acute head injury is a concern and notes concern about radiation exposure. That rationale explains the topic of the study, but it does not substitute for outcome data. The registry does not report a comparative estimate showing how MRI performance relates to CT, nor does it report a randomized comparison of imaging strategies. The initial head CT appears in the endpoint timeframe, but its mention alone does not define all aspects of the reference standard or study design.
The record lists time from order to obtaining MRI and need for anxiolysis medication as secondary outcomes. No numerical results for either are reported. Those outcomes could address operational timing and the use of medication for imaging, but their presence in the registry does not show what occurred in participants.
Safety information lists 73 participants at risk in the Quick Brain group, with 0 serious adverse events, 0 other adverse events, and 0 deaths. These figures are a description of events recorded in that group, not proof that the test has no risks. The record does not explain why the safety population differs from enrollment of 76, or provide details on duration or completeness of safety follow-up. Thus, the safety counts should be read as bounded registry reporting rather than as a comprehensive estimate of risk.
Overall, the record supports describing the study question, endpoint definition, enrollment, listed outcomes, and reported safety counts. It does not support a quantitative conclusion about diagnostic accuracy, comparative performance, or the practical consequences of using MRI. The completed status does not resolve the absence of numerical primary and secondary outcome results.
9. Statistical Methods Explained
The registry record identifies sensitivity as the primary endpoint and describes how it is defined, but it does not report an analysis plan or numerical endpoint result. The methods discussion below explains the statistical ideas relevant to interpreting such an endpoint in general; it does not assert that the study used methods that are not documented in the registry.
What sensitivity measures
In general, sensitivity is the proportion of cases meeting a defined condition that a test correctly identifies. Here, the registry's definition of a true positive requires clinical criteria for clinically important traumatic brain injury as well as imaging that finds the injury. False negatives are part of the denominator but are not described numerically in the record. Sensitivity is therefore a conditional measure: it concerns detection among cases classified as having the target condition, rather than the overall chance that any scan is correct.
Diagnostic measures depend on how the target condition is defined and established. If the criteria used to classify injury are applied differently across participants, or if the assessment of imaging is influenced by knowledge of other findings, the resulting estimate may be affected. In general, independent and consistently applied assessment helps clarify what a diagnostic estimate represents. The registry record does not report assessor roles, blinding, adjudication procedures, or the detailed application of clinical criteria, so these features cannot be evaluated from the registry entry.
Why uncertainty matters
In general, a point estimate describes the observed result in the evaluated sample, while a confidence interval describes a range of values reasonably compatible with the data under the method used. The interval's width communicates precision: narrower intervals indicate less sampling uncertainty under the model, while wider intervals indicate more. A point estimate without its denominator and uncertainty interval can be difficult to interpret, especially when the number of cases meeting the target condition is unknown. The registry reports neither a sensitivity estimate nor a confidence interval, so neither the estimated performance nor its precision can be assessed.
In general, statistical uncertainty is not the only source of uncertainty. Selection of participants, outcome classification, missing assessments, and differences in how tests are performed can all affect how applicable an estimate is. A confidence interval does not correct for those design or measurement issues. The registry record does not provide enough details to assess these aspects of this study.
Diagnostic accuracy is not a treatment effect
In general, a diagnostic-performance study asks how a test classifies a condition according to a stated definition. A randomized treatment comparison instead asks whether assignment to one strategy rather than another changes outcomes. These are distinct questions. The record lists Rapid Brain MRI as a diagnostic test and does not describe a randomized comparison. It therefore should not be read as a randomized estimate of the effect of an imaging strategy on health outcomes. The description of an initial head CT in the endpoint timeframe does not, on its own, establish a fully specified comparator design.
Sensitivity also does not give the probability that a positive result represents a true case. That probability depends on the frequency of the target condition in the assessed population as well as test performance, and it is a separate quantity. The registry record does not provide the information needed to calculate or interpret such a quantity. No calculations should be inferred from the endpoint title alone.
Planning illustrations and observed results
The registry's planning assumptions describe an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated illustration treats the effect to detect as a fraction of the observed effect. It specifies that time-to-event calculations would express a total number of events, while other calculations would express participants per arm. These assumptions describe a planning framework; they are not evidence about the study's actual design or observed power.
The registry record does not report the numerical observed effect needed to understand such an illustration, and it does not report the resulting planning sample sizes. Any sample-size values associated with that framework are planning illustrations, not observed participant outcomes and not observed power. In general, observed power is not a substitute for reporting an effect estimate with its uncertainty. A planning calculation cannot fill in a missing endpoint result.
More generally, sample-size planning depends on an assumed effect, variability or event rate, significance level, desired power, allocation, and analysis model. These choices should be specified before interpreting a planning result. The registry does not report the study's own sample-size justification, so the illustration should not be treated as the protocol rationale. This distinction matters especially because the record does not describe a randomized, like-for-like two-arm comparison.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 3 outcome measures and 0 analysis records. The primary outcome is sensitivity for clinically important intracranial injury. The listed secondary outcomes are time from order to obtaining MRI and need for benzodiazepines for imaging-related anxiolysis. The registry record does not report numerical results for these outcomes, nor does it describe how multiple outcomes were handled in statistical testing.
In general, multiplicity arises when investigators assess several outcomes, subgroups, time points, or statistical comparisons. If each is tested separately, the chance of at least one apparently unusual finding can increase. A prespecified hierarchy, adjustment method, or emphasis on estimation rather than isolated significance tests can help readers understand the analysis. The registry record does not report whether any such approach was planned or used. It also does not report p-values or confidence intervals for the listed outcomes.
Missing-data methods are not reported in the registry record. The record does not state whether all enrolled participants contributed data to every outcome, how unavailable imaging or incomplete assessments were handled, or whether any imputation was used. Enrollment is 76, while the safety group lists 73 at risk; the reason for that difference is not reported in the registry record. It should not be labeled as loss to follow-up or attributed to any particular exclusion without further information.
The analysis populations are likewise not described. The record does not state which participants were included in the primary sensitivity calculation, how participants without an evaluable scan were treated, or whether any per-protocol or other analysis set was defined. These omissions matter because diagnostic estimates can depend on which participants have both the relevant condition assessment and an interpretable test. The record's completed status and its listed endpoint definitions do not resolve these questions.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Quick Brain | 0 | 73 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Quick Brain | 0 of 73 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Quick Brain | 0 of 73 |
The registry safety entry lists the Quick Brain group with 73 participants at risk. It reports 0 serious adverse events, 0 other adverse events, and 0 deaths. No serious adverse event terms are listed. These figures describe events recorded for the listed safety group; they do not establish that no event could occur or that safety was completely assessed.
In general, an event count should be interpreted alongside the number of participants assessed, the period and completeness of follow-up, and the rules used to collect and classify events. The registry record does not report those details. It also does not explain why the safety denominator is 73 when enrollment is 76. The difference should not be interpreted as a particular form of missingness or exclusion without documentation.
Zero recorded events can be compatible with uncertainty about the underlying event rate, especially when the assessed group and follow-up are limited or incompletely described. The registry record does not provide a comparative safety estimate or detail about event surveillance. The counts therefore support only a narrow statement: no serious adverse events, other adverse events, or deaths are reported for the listed group in this entry. They should not be generalized beyond that record.
12. What the Result Does, and Does Not, Mean
The registry record documents a completed study of Rapid Brain MRI for acute pediatric head trauma, with enrollment of 76 and a primary endpoint intended to measure sensitivity for clinically important intracranial injury. It also names outcomes for MRI timing and anxiolysis medication. These details establish the study's subject and stated measurement goals.
What the record does not provide is the numerical sensitivity result, the true-positive and false-negative counts, or an interval expressing uncertainty. It also does not report numerical results for the secondary outcomes. As a result, the record cannot establish how often MRI identified injury in the assessed participants, how precise any estimate was, how quickly MRI was obtained, or how often medication was needed.
The registry's background summary explains the motivation for evaluating MRI, including radiation concerns associated with CT. A rationale for conducting a study is not evidence of a measured benefit or comparative performance. The record does not describe a randomized comparison, and the allocation method is not stated. It therefore does not provide a basis for causal claims about choosing one imaging strategy rather than another.
The safety entry reports 0 serious adverse events, 0 other adverse events, and 0 deaths among 73 participants at risk in the listed group. This is a report of recorded counts, not proof of an absence of risk. Follow-up and safety ascertainment details are not reported in the registry record.
In general, diagnostic evidence is most informative when the target condition, test interpretation, participant flow, and uncertainty around estimates are clear. Here, the registry defines the intended sensitivity calculation but leaves its result and important analysis details unreported. The completed status indicates the registry's study status, not completeness of public numerical outcome reporting. The appropriate interpretation is therefore descriptive and limited: the research question and endpoint are documented, but the central performance estimate is not reported in the registry record.
13. Why This Trial Matters Statistically
This study matters statistically because diagnostic performance depends on both a clearly defined target condition and a clearly reported denominator. The registry specifies that a true positive requires clinical criteria for clinically important traumatic brain injury and an imaging finding. That definition makes clear that sensitivity is not simply a count of positive MRI findings; it depends on how cases and missed cases are classified.
For readers assessing diagnostic evidence, the missing counts and estimate are consequential. Without true positives, false negatives, and an uncertainty interval, it is not possible to judge the observed sensitivity or its precision. A study can have a relevant question and a defined endpoint while still leaving the reader unable to assess the central result from the registry record.
The entry also illustrates why diagnostic performance should be separated from comparative effectiveness. A test's ability to identify a defined condition is not, by itself, evidence that a strategy using that test improves outcomes or is superior to another strategy. The record does not describe a randomized comparison, and its stated endpoint is diagnostic sensitivity rather than a patient outcome.
Finally, transparency about study flow, analysis populations, missing data, and safety follow-up helps readers understand what the reported figures cover. Those details are not reported in the registry record. Their absence does not show that the study lacked such procedures, but it prevents assessment of them from this record. The statistical importance of the entry lies in the contrast between a stated, clinically relevant measurement goal and the lack of a reported numerical outcome needed to evaluate it.
14. 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 principal limitation of interpretation is that the registry record does not report the numerical primary endpoint or its underlying counts. No confidence interval is reported, so the precision of the intended sensitivity estimate cannot be evaluated. Numerical results for the listed secondary outcomes are also not reported.
The record does not state the allocation method and does not describe a randomized comparison. It cautions that the arms are not a like-for-like control comparison. This limits comparative interpretation and precludes treating the record as a randomized estimate of one imaging strategy versus another. The initial head CT is mentioned in the primary endpoint timeframe, but the registry does not provide enough detail to characterize the full diagnostic reference process.
Eligibility criteria, participant flow, assessor blinding, imaging interpretation procedures, handling of disagreements, missing-data methods, and analysis populations are not reported in the registry record. These omissions make it difficult to assess selection, measurement, and analysis issues that could affect diagnostic estimates. The reason that enrollment is 76 while 73 are listed as at risk for safety is also not reported.
The record lists 3 outcome measures and 0 analysis records, but does not describe multiplicity handling or provide a statistical analysis plan. Its sample-size assumptions are planning illustrations, not the study's reported design justification or evidence of observed power. Safety counts are limited to the listed group and are not accompanied by detailed follow-up or ascertainment information.
These are limitations of what can be established from the registry record. They should not be taken to prove that unreported methods were not used or that unreported outcomes were not collected. They do mean that the registry entry alone does not support a quantitative conclusion about diagnostic performance, comparative effects, or complete safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Rapid MRI for Acute Pediatric Head Trauma — NCT03291964.
- Registry record last updated 2023-01-26; status last verified 2022-04.
- Results first posted 2023-01-26.
- 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.
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18. Record Summary
The registry record concerns Rapid MRI for Acute Pediatric Head Trauma, with the official title QuickBrain MRI for Acute Pediatric Head Trauma. Oregon Health and Science University is listed as sponsor. The study is marked completed, with enrollment of 76 and dates of 2017-09-03 for study start and 2019-08-01 for primary completion.
Rapid Brain MRI is the listed diagnostic test. The primary outcome is sensitivity for identifying clinically important intracranial injury within 6 hours from the initial head CT. Secondary outcomes concern time from order to obtaining MRI and need for benzodiazepines for imaging-related anxiolysis. The record lists 3 outcome measures and 0 analysis records.
The numerical primary and secondary outcome results are not reported in the registry record. Safety reporting lists 73 participants at risk in the Quick Brain group, with 0 serious adverse events, 0 other adverse events, and 0 deaths. Allocation details, the analysis plan, missing-data handling, and the reason for the difference between enrollment and the safety denominator are not reported in the registry record.