Effect of Mentoring on Endotracheal Tube Exchange Using a New Device: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Mentoring on Endotracheal Tube Exchange Using a New Device (NCT02763189), a randomized na study. The primary outcome is Apnea Time.

2. Clinical Question

The trial asks about performance during a specific tube-exchange procedure using a new device, and about whether the preparation approach is associated with the time without ventilation during that exchange. The registry describes the study as a pilot. Its summary says investigators expected the mentored group to change the tube faster and wanted to estimate how much faster before proceeding to a larger study. That expectation is a stated prediction, not a result.

The primary outcome is a measure of elapsed time, rather than a direct measure of overall procedural quality or patient outcome. A shorter apnea time would represent a shorter recorded interval between the specified ventilator disconnection and reconnection events. The registry also lists Performance Score as a secondary outcome, but a secondary outcome result is not reported in the registry record.

The posted group summaries are descriptive. The registry record reports no analysis comparing the groups, so it does not establish whether the observed summaries reflect a reproducible difference or what uncertainty surrounds a group contrast. The clinical question is therefore identifiable, but the posted results do not answer it with an inferential estimate.

3. Trial Design

The registry describes a randomized, parallel-group study with no masking. It lists two study approaches: self-study of the learning materials, and study followed by expert mentoring. The study summary says participants would perform the procedure for the first time after their assigned preparation. The registry does not report details of the randomization process, how assignment was concealed, or whether outcome assessment was masked.

Enrollment is reported as 8. The posted primary outcome summaries list 4 participants in the Control group and 4 in the Mentored group. The record gives the study start as 2016-06 and primary completion as 2017-01. Its status is TERMINATED. The reason for termination is not reported in the registry record, so the status alone does not explain why the study ended or whether it ended as planned.

The study is classified as phase NA and its condition is Effects of Training. The sponsor is Wake Forest University Health Sciences. These registry classifications describe the record but do not add information about the way the study was conducted or analyzed.

The design is suited to an initial comparison of two preparation approaches in a small pilot, but the record does not report a statistical analysis plan or a completed between-group analysis. It also does not report planned recruitment targets, a sample-size justification, or whether the enrollment reflects the original plan. Without those details, the reported enrollment cannot be interpreted as evidence that the study had a particular level of statistical precision or was designed to detect a specified effect.

Randomization can support a causal comparison when allocation and conduct are implemented appropriately, but the registry record does not describe those implementation details. The absence of masking is explicitly recorded; whether that could have affected performance or measurement in this study is not assessed by the posted results. The record does not report an analysis of protocol adherence or deviations.

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

Reasons for not completing this period:

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 Apnea Time, measured over immediately after the procedure.

The primary endpoint is Apnea Time, measured in seconds immediately after the procedure. It is defined as the time from disconnection of the ventilator from the original endotracheal tube to connection of the ventilator to the new endotracheal tube. Thus, the endpoint captures the interval without ventilation during the specified tube exchange, rather than the total procedure duration.

This type of elapsed-time measure can describe how long a defined procedural step takes. In general, a shorter recorded interval means less time between the two specified events; it does not by itself describe every aspect of technique, safety, or procedural success. The registry does not report additional endpoint definitions such as a threshold for an acceptable time, a rule for handling unusual measurements, or details on who recorded the times.

The endpoint is reported as a mean with a full range for each group. The Control mean is 146 seconds, with a range from 129 to 164 seconds. The Mentored mean is 111 seconds, with a range from 111 to 111 seconds. No standard deviation, confidence interval, or inferential comparison is reported in the registry record. The endpoint definition gives the time anchors, but the record does not state whether timing was independently verified or whether any measurements were missing or excluded.

Performance Score is listed as a secondary outcome, but its results are not reported in the registry record. The primary endpoint therefore provides the only posted outcome values described in this analysis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized, parallel, and unmasked. In general, random allocation is intended to make the comparison between groups less dependent on investigators choosing which participants receive each approach. A parallel design assigns participants to one approach or the other rather than having the same participant receive both approaches. The registry record does not describe the random sequence, allocation concealment, implementation of assignments, or masking of the people recording apnea time.

What do the reported means describe?

A mean is a summary of the observed measurements in a group. Here, the registry reports a mean apnea time of 146 seconds for Control and 111 seconds for Mentored. These numbers describe the posted group summaries; they are not an estimate with a stated measure of uncertainty. The record does not give a standard deviation or standard error, and it does not report a confidence interval for either mean or for a between-group contrast.

A confidence interval is a general statistical method for expressing uncertainty around an estimate under a specified model and sampling process. It is not simply a range of observed values. The full range reported for each group describes the lowest and highest values in the posted observations, whereas a confidence interval would address uncertainty in an estimated quantity. No confidence interval is reported in the registry record.

What does the full range show?

The registry reports a full range of 129 to 164 seconds for Control and 111 to 111 seconds for Mentored. A range records the endpoints of the observed values, but leaves out how values between those endpoints are distributed. It is sensitive to the extreme observations and does not provide a stand-alone measure of precision. The Mentored range has the same lower and upper endpoint; that feature describes the posted range, not the expected variability in a broader population.

For small groups, estimates of spread and uncertainty can be unstable. This is a general statistical concern: a limited set of observations may not represent the range of performance that would occur in other settings. The record does not provide individual measurements, so additional distributional summaries cannot be evaluated from the posted results.

Why is there no inferential comparison?

The record reports zero analyses and does not post a test, estimated group contrast, confidence interval, or p-value for the primary outcome. A statistical test would address a defined comparison under specified assumptions; a p-value would summarize how compatible the data are with a null model under those assumptions. Neither can be reconstructed from the registry summaries alone in a way that would replace the investigators' analysis. The registry record does not report a statistical analysis plan, so the intended test, model, covariate adjustment, and handling of assumptions are unknown.

Some statistical methods assume that measurements have a particular distribution or that their variability is adequately represented by a chosen model. In general, over-dispersion means the observed variability is greater than a model expects; ignoring it can make uncertainty appear too small. No model or dispersion assessment is reported for this trial, and the posted summaries are insufficient to assess such assumptions.

How should planning illustrations be understood?

The planning illustration uses the observed effect as its starting point, assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It considers detecting a stated fraction of the observed effect. These are planning assumptions, not outcomes from the trial, and any sample-size values are illustrations rather than observed power. The registry does not report its own sample-size justification or indicate that these illustration assumptions were the trial's original design assumptions.

In general, a sample-size calculation asks how many participants would be needed under specified assumptions to target a level of power for a defined effect. It does not show the probability that the observed study result is true, and it is not a substitute for a confidence interval or a reported analysis. Because the record does not include a completed statistical comparison, the posted planning framework should not be treated as evidence that a group effect was demonstrated.

What can be inferred from randomization?

Randomization describes assignment, not the statistical analysis itself. It does not automatically resolve concerns about missing outcome data, protocol deviations, measurement, or the size and precision of an estimate. The record does not report how these issues were handled, nor does it describe an intention-to-treat or per-protocol analysis population. Those omissions limit assessment of how the design translated into the posted summaries.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists Apnea Time as the primary outcome and Performance Score as a secondary outcome. It reports two outcome measures and one posted secondary outcome, but no secondary result is given in the registry record. No analysis is posted for the primary outcome either. The record does not describe a hierarchy of tests, an adjustment for multiple comparisons, or a plan for interpreting several outcomes together.

Multiplicity is a general concern when several outcomes or statistical tests are considered: the chance of a seemingly notable result can increase as more comparisons are examined. Whether that issue applied in this study, and how it would have been addressed, cannot be determined because the statistical plan and outcome analyses are not reported. The number of outcomes listed does not by itself reveal how many were tested or whether any results were selectively reported.

Missing-data handling is not reported in the registry record. The posted primary summaries list 4 participants in each group, but the record does not state whether all assigned participants had an evaluable primary outcome, whether any measurements were excluded, or how missing values would have been handled. It also does not report reasons for missingness or protocol deviations. Therefore, the posted group summaries cannot be assumed to represent a particular prespecified analysis population.

The registry does not identify an intention-to-treat, per-protocol, or other analysis population. It also does not explain whether participants were analyzed according to randomized assignment or according to the preparation they received. These details matter for interpreting a randomized comparison, but they are not reported in the registry record. No further conclusion about multiplicity, missing data, or analysis populations is supported by the posted information.

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 registry reports zero serious adverse events among 4 participants at risk in the Control group and zero among 4 participants at risk in the Mentored group. It also reports zero other adverse events among 4 participants at risk in each group. These are the posted event counts; they do not establish that the approaches are free of risk.

Event counts in a small pilot can provide only limited information about uncommon harms. In general, observing no events does not rule out the possibility of events in a larger group or with different conditions. The registry record does not report a safety analysis, confidence intervals for event rates, or details about the adverse-event collection period and definitions beyond the distinction between serious and other events.

Deaths are not reported in the registry record. No serious adverse event terms are listed. These entries should be read as registry reporting, not as evidence that all possible safety outcomes were assessed or that no events occurred outside the reported categories. The record does not give a reason for its TERMINATED status, so that status cannot be interpreted as a safety finding.

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

The posted results show descriptive apnea-time summaries following tube exchange with a novel device after two different preparation approaches. The Control mean is 146 seconds, with a full range of 129 to 164 seconds. The Mentored mean is 111 seconds, with a full range of 111 to 111 seconds. The summaries give readers the observed group-level values recorded in the registry.

The results do not establish the size or precision of a between-group effect. The record includes no statistical comparison, confidence interval, or p-value. It therefore does not show whether the displayed difference in means is distinguishable from chance variation under a specified statistical model. The registry summary says the investigators predicted faster tube exchange with expert mentoring, but a prediction is not confirmation of that prediction.

The study addresses apnea time, a narrowly defined interval from ventilator disconnection from the original tube to connection to the new tube. The result does not, by itself, establish a difference in overall procedural performance, successful completion, other safety outcomes, or patient outcomes. Performance Score is listed as a secondary outcome, but results are not reported in the registry record.

The pilot designation and the limited enrollment mean the findings should be treated as preliminary descriptions rather than a definitive estimate that can be generalized broadly. The record does not provide a sample-size justification, a statistical plan, or details of the reasons for termination. It also does not report the analysis population, missing-data handling, or whether protocol deviations occurred.

Accordingly, the posted data are useful for understanding what outcome was measured and what group summaries were recorded. They do not support a claim that mentoring does or does not change apnea time, nor do they establish safety or effectiveness. Further interpretation would require an analysis and methodological details that are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically notable as a pilot that compares two preparation approaches for a specific procedural task using a novel device. Its central outcome, apnea time, is defined around two observable events: ventilator disconnection from the original endotracheal tube and reconnection to the new tube. A precise outcome definition is important because the meaning of a time measure depends on where timing starts and stops.

The registry records a randomized parallel design, which makes the intended comparison clear, but it does not post an inferential analysis. This distinction is important for statistical reading: group summaries can describe what was observed, while a comparative estimate and its uncertainty are needed to assess how precisely the groups differ. The means and ranges are informative descriptively but cannot stand in for that missing inferential result.

The record also illustrates why pilot findings should be interpreted cautiously. A pilot may help motivate further study, but small-group summaries can be imprecise and may not reliably describe performance in a broader population. The registry summary explicitly frames the study as a preliminary effort to estimate how much faster the mentored group might be before a larger study. The posted data do not establish that such a difference exists.

Finally, this record highlights the value of reporting methods alongside results. A statistical analysis plan, analysis populations, missing-data handling, and outcome results would help readers assess how the randomized design was used and what conclusions are warranted. In their absence, the most defensible statistical account is limited to the recorded group summaries and the important uncertainties left unresolved.

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 registry record does not report a statistical comparison for the primary outcome, despite providing group means and ranges. Without an estimated contrast and its uncertainty, the precision of the between-group comparison cannot be assessed. The record also does not report the planned statistical method or whether any adjustment was intended.

Enrollment is reported as 8, and each posted group summary lists 4 participants. This small pilot dataset limits the information available about variability and the extent to which the summaries might apply beyond the observations recorded. No individual-level measurements are reported, which prevents independent examination of the distribution or unusual observations.

The trial is marked TERMINATED, but the reason is not reported in the registry record. The record does not state whether termination was related to recruitment, feasibility, safety, or another issue. It also does not describe protocol deviations, timing procedures, assessor training, or whether apnea time was measured with a standardized or independently checked process.

The record lists Performance Score as a secondary outcome but does not report its result. It does not report missing-data handling, analysis populations, or a multiplicity strategy. Masking is listed as none, while further details about who knew assignments and who assessed the endpoint are not reported. These gaps make it difficult to assess possible measurement or analysis biases.

Finally, the record does not give a sample-size justification or its own statistical plan. The planning illustration assumptions do not establish the original design rationale or observed power. These limitations do not invalidate the descriptive values, but they restrict the strength and scope of conclusions that can be drawn from them.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effect of Mentoring on Endotracheal Tube Exchange Using a New Device — NCT02763189.
• Registry record last updated 2022-03-11; status last verified 2018-08.
• Results first posted 2017-03-29.
• 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

NCT02763189 is a randomized, unmasked, parallel pilot comparing self-study with study followed by expert mentoring before endotracheal tube exchange using a novel device. Enrollment is reported as 8, with 4 participants listed in each group. The record gives a start of 2016-06, primary completion of 2017-01, and status TERMINATED.

The primary outcome is apnea time in seconds immediately after the procedure. The registry reports a mean of 146 seconds and a full range of 129 to 164 seconds for Control, and a mean of 111 seconds and a full range of 111 to 111 seconds for Mentored. No statistical analysis is posted. Performance Score is listed as a secondary outcome, with no result reported in the registry record. The reason for termination, analysis plan, missing-data handling, and analysis populations are not reported.