Early Propranolol After Traumatic Brain Injury: Phase II: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Early Propranolol After Traumatic Brain Injury: Phase II (NCT01202110), a non-randomized phase 2 study. The primary outcome is Determine in Patients With Traumatic Brain Injury (TBI) the Safe Dosing of Early Propranolol..

2. Clinical Question

The listed condition is traumatic brain injury, and the official title specifies a single-center, dose-escalation Phase II study. The clinical question is therefore about safety measurement and dose selection, not a reported estimate of treatment benefit. A no-treatment arm was described in the study summary, but the registry classifications and the available outcome information do not establish a valid comparative analysis. The record gives no account of how dose escalation was to proceed, what dose levels were planned beyond the arm description, or how the safety observations would guide dose selection.

3. Trial Design

The registry identifies this as a Phase II study with non-randomized allocation, no masking, and a single-group model. The official title describes a single-center, dose-escalation study. The named intervention is propranolol, with an arm description of propranolol 1mg iv; the control arm is described as routine care. The study summary says that a no-treatment arm was intended to establish the frequency of specified events without propranolol.

These descriptions do not amount to a randomized comparison. The registry explicitly classifies the arms as not being a like-for-like control comparison. Differences between groups, if any were available, could reflect how people entered or were assigned to each arm as well as treatment. The record does not report an allocation procedure, masking procedure beyond none, or a plan to adjust for group differences. The single-group model classification also sits alongside descriptions of both propranolol and control arms; the record does not explain that classification.

The study status is terminated. Its listed start is 2010-06 and its primary completion is 2015-02. The record lists enrollment as 10, while the primary-outcome population is stated to be terminated prior to enrolling. It does not reconcile these entries. Thus, the listed enrollment should not be treated as confirmation that the primary outcome was collected in that population.

The study is described as Phase II, but the protocol, dose-escalation rules, sample-size justification, and statistical analysis plan are not reported in the registry record. Nor does the record say why the study was terminated. Without these details, the design can be described from its registry classifications and stated objectives, but its intended analytic procedures cannot be reconstructed.

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

Analysis population for the primary outcome, as defined in the registry: Terminated prior to enrolling

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 Determine in Patients With Traumatic Brain Injury (TBI) the Safe Dosing of Early Propranolol., measured over 24 months.

The primary endpoint is described as the number of episodes of bradycardia, hypotension, or decreased cerebral perfusion pressure refractory to treatment. The definitions are heart rate below 60 beats per minute, systolic blood pressure below 90, or cerebral perfusion pressure below 60mmHg. The study summary links refractory events to Brain Trauma Foundation guidelines for treatment. The registry labels the timeframe as 24 months.

Counting episodes is intended to capture clinically relevant safety events during early propranolol treatment, rather than relying only on a general impression of tolerability. The refractory-to-treatment qualification distinguishes the events of interest from episodes that respond to treatment under the stated guideline framework. In general, an episode count can describe how often a specified event occurs, but interpretation depends on consistent event definitions, observation periods, and reporting of the population at risk.

The registry record does not report the primary endpoint result, episode counts, or a population in which the endpoint was assessed. It also does not specify how repeated episodes in the same person would be handled in the analysis, how observation time would be accounted for, or how the three event types would be combined. Those details matter because a count may reflect both the number of people experiencing events and the frequency of events among those people. The record describes what was intended to be measured, but it does not provide the data needed to estimate the endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does an episode count capture?

The primary outcome is framed as a count of episodes, not simply as whether a person had any event. In general, counts retain information about repeated occurrences: a person with recurring episodes contributes differently from a person with a single episode. That distinction can be useful when the question concerns the burden of events over an observation period. It also means that the analysis should state whether it models the total number of episodes, the chance of any episode, or another summary.

The registry record specifies three event types and a refractory-to-treatment condition. For interpretation, each part of that definition needs to be applied consistently. The record does not report episode-level data, rules for resolving overlapping event types, or how repeated events would be recorded. It also does not explain how observation time would be incorporated, beyond listing a timeframe of 24 months. These omissions prevent reconstruction of the endpoint analysis.

Why might counts need a count-data model?

In general, count outcomes are non-negative and may be concentrated at zero, while some participants may experience repeated events. A simple model can be misleading if the variation in counts is greater than the model expects; this is called over-dispersion. Over-dispersion matters because a model that understates variability can make confidence intervals too narrow and statistical evidence appear more precise than it is. Depending on the data and design, analysts may consider count models that allow extra variation, or methods that account for recurring events and differing observation time.

These are general considerations, not a description of the analysis used in this study. The statistical plan and analysis method are not reported in the registry record. The posted results list no analyses, so there is no basis for attributing a particular model, adjustment, or uncertainty calculation to the investigators.

What does a confidence interval convey?

In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the method used. A narrow interval indicates greater precision than a wide interval, but neither width nor location alone establishes that a comparison is free from bias. In a non-randomized comparison, an interval can quantify sampling uncertainty while leaving confounding and selection differences unresolved. The registry record reports no primary-outcome estimate or confidence interval, so precision cannot be assessed for the safety endpoint.

For event counts, interpretation also depends on the scale of the estimate. An absolute count, a rate accounting for observation time, and a relative comparison answer different questions. The record does not identify which summary was planned. No new rate or comparative quantity can be derived from the registry entries because the primary episode data are absent.

What can planning calculations say?

The planning assumptions describe a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The target effect is framed as a stated fraction of the observed effect. These calculations are planning illustrations; they are not measurements of the study’s achieved ability to detect an effect. In particular, observed power is not a substitute for the estimated effect and its uncertainty.

Planning calculations depend on their assumptions. Equal allocation may not match a non-randomized study’s actual group composition, and a normal approximation may not capture the behavior of sparse or highly variable episode counts. More fundamentally, the registry record does not report the primary outcome estimate needed to understand the observed effect underlying such illustrations. Any displayed planning scenario should therefore be treated as hypothetical design information rather than as a result of the trial. It cannot establish that the study was adequately powered or that a treatment effect was present or absent.

Why does the design affect interpretation?

Random allocation is intended, in general, to balance measured and unmeasured characteristics across comparison groups on average. This study is classified as non-randomized, and the registry warns that the arms are not a like-for-like control comparison. Thus, even a future or unreported difference in event counts would not automatically isolate the effect of propranolol. A careful interpretation would need information about how participants entered each arm, baseline characteristics, exposure and follow-up, and any adjustment strategy. Those details are not reported in the registry record.

The single-group model designation further complicates the description because the record also names a control arm. The registry does not explain whether the control group was part of the same analytic design or how it was intended to be used. Without a reconciled design description and outcome analysis, statistical comparisons should not be inferred from the arm labels alone.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint combines three types of event: bradycardia, hypotension, and decreased cerebral perfusion pressure, each with a refractory-to-treatment qualification. The registry record does not say whether these were to be analyzed as a single composite outcome, as separate outcomes, or in both ways. It does not report a plan for handling multiple tests or controlling the chance of false-positive findings when several outcomes are examined. The number of outcome measures listed is 1, but this does not explain how the component events were to be reported or analyzed.

Missing-data procedures are not reported in the registry record. There is no description of how incomplete monitoring, missing measurements, early discontinuation, or absent outcome observations would be handled. The record also does not describe an analysis population, such as whether analyses would include all assigned participants or only those who received treatment. The primary-outcome population entry says terminated prior to enrolling, while enrollment is listed as 10; the record does not reconcile these statements.

The record lists no analyses. It does not report an interim-analysis plan, stopping boundaries, or a statistical analysis plan. Their absence from the registry record should not be interpreted as proof that no such procedures existed, but they cannot be assessed from the available information. Without stated multiplicity, missing-data, and population procedures, readers cannot determine how selective outcome reporting or incomplete observations might affect a primary-outcome estimate.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event record lists the Control group with 10 at risk and 0 affected for serious adverse events. It also lists 10 at risk and 0 affected for other adverse events. These are the figures recorded for that group; they are not results for the propranolol arm and do not provide a comparison of treatment safety. The serious adverse event terms are not listed.

The deaths field is not reported as a numeric result. It should not be read as a zero count. Similarly, the adverse-event entries do not substitute for the primary endpoint, which concerns treatment-refractory episodes of bradycardia, hypotension, or reduced cerebral perfusion pressure. The record does not provide those endpoint counts.

In general, adverse-event counts are interpreted in relation to the population at risk, the observation period, event definitions, and completeness of reporting. Here, the registry gives the control-group at-risk and affected entries, but the primary-outcome population is described as terminated prior to enrolling and the overall enrollment entry is 10. The record does not clarify how these entries relate. The serious adverse-event figures therefore describe only what is recorded for the control group, not the safety profile of early propranolol.

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

The registry record documents an intended investigation of early propranolol dosing after traumatic brain injury, with a safety endpoint based on treatment-refractory episodes of bradycardia, hypotension, or reduced cerebral perfusion pressure. It also records the study as terminated and lists no analyses. These registry entries describe the study’s question and status; they do not provide an answer to the primary question.

The record does not establish how many primary endpoint episodes occurred, whether the event types differed between groups, or how precisely any treatment comparison could be estimated. It therefore cannot support a conclusion that early propranolol is safe or unsafe, nor can it demonstrate a benefit or lack of benefit. No efficacy endpoint result is reported, and the study’s stated objective is safety-focused.

The control-group adverse-event entries are limited: the registry lists 10 at risk and 0 affected for serious adverse events, and 10 at risk and 0 affected for other adverse events. They do not describe the propranolol group, and deaths are not reported as a numeric result. These figures should not be generalized to the intervention or substituted for the primary endpoint.

The non-randomized design and registry warning about non-comparable arms also constrain any interpretation of a group contrast. Even if outcome figures were available, differences could not automatically be attributed to propranolol. The enrollment entry and primary-outcome population description are not reconciled, leaving uncertainty about what population contributed data.

Accordingly, the defensible reading is that the registry records a terminated study with an intended safety question but no reported primary-outcome analysis. The record cannot determine the frequency of the specified events under propranolol, provide a reliable treatment comparison, or explain why the study ended.

13. Why This Trial Matters Statistically

This study illustrates how a clearly stated clinical safety question can remain unanswered in the registry record when outcome data and analysis are absent. The planned endpoint is specific about event types and includes a refractory-to-treatment condition. Yet a definition alone is not a result: without reported episode counts and an analysis population, neither event frequency nor precision can be assessed.

It also highlights the importance of matching interpretation to design. A control arm described as routine care may sound like a direct comparator, but the registry classifies allocation as non-randomized and explicitly warns that the arms are not like-for-like. Statistical comparisons require more than arm labels; group formation and comparability shape what a contrast can mean.

The record’s enrollment entry and primary-outcome population description show why internal consistency matters. Enrollment is listed as 10, while the primary outcome is described as terminated prior to enrolling. Without clarification, readers cannot confidently connect the enrollment figure to primary-outcome measurement. Careful reporting should distinguish planned enrollment, actual enrollment, and the population included in each analysis.

Finally, planning calculations have a different role from trial results. Assumptions such as a two-sided significance level of 0.05, equal allocation, and a normal approximation can frame hypothetical design scenarios. They do not replace an observed effect estimate, uncertainty interval, or analysis of the collected endpoint. When an outcome analysis is absent, planning illustrations should not be interpreted as evidence about what the study found.

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 most important limitation for interpreting this trial is the absence of reported primary-outcome results. The registry describes the intended event-count endpoint but gives no episode counts, treatment comparison, estimate, confidence interval, or analysis. The reason for termination is not reported in the registry record, so the circumstances leading to the lack of an outcome analysis are unclear.

Population reporting is also unresolved. Enrollment is listed as 10, while the primary-outcome population is described as terminated prior to enrolling. The record does not explain whether the enrollment entry refers to another stage or population, or how it relates to the control-group adverse-event risk count. These details should not be inferred from the entries alone.

The intended comparison is limited by non-randomized allocation and the explicit registry warning that the arms are not like-for-like. The single-group model classification is not reconciled with the descriptions of propranolol and control arms. The registry does not report how participants were assigned, baseline comparability, treatment exposure, or adjustment methods.

Other important analytic details are absent: the statistical analysis plan, sample-size justification, handling of repeat episodes, missing-data procedures, analysis populations, and approach to multiple event types are not reported in the registry record. The adverse-event figures are recorded only for Control and cannot establish the intervention’s safety. Taken together, these limitations prevent estimation of the primary endpoint and restrict interpretation to the study’s stated aims and registry status.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Early Propranolol After Traumatic Brain Injury: Phase II — NCT01202110.
• Registry record last updated 2016-05-13; status last verified 2016-05.
• Results first posted 2016-05-13.
• 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.

18. Record Summary

NCT01202110 is a Phase II study titled Early Propranolol After Traumatic Brain Injury: Phase II. It is listed as non-randomized, unmasked, and single-group, while the study description also names propranolol and routine-care control arms. The official title describes a single-center dose-escalation study. The intervention arm description is propranolol 1mg iv.

The intended primary outcome was the number of treatment-refractory episodes of bradycardia, hypotension, or decreased cerebral perfusion pressure, with a listed timeframe of 24 months. The study status is terminated. The record lists enrollment as 10 but describes the primary-outcome population as terminated prior to enrolling, and does not reconcile those entries.

No primary-outcome analysis is listed. The control-group adverse-event entries report 0 affected for serious and other adverse events, with 10 at risk in each category. The registry record does not report a propranolol-arm safety result, a primary endpoint result, or the reason for termination.