Endotracheal Tube Holder and Bite Guard Research: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Endotracheal Tube Holder and Bite Guard Research (NCT02347488), a na phase 4 study. The primary outcome is Change in ETT Position.

2. Clinical Question

3. Trial Design

NCT02347488 is a completed phase 4 study sponsored by the University of California, Los Angeles. The registry record gives a start date of 2015-02 and a primary completion date of 2015-08. It records enrollment of 30. These registry entries describe the study, but enrollment should not be treated as the number with usable data for every outcome: outcome-specific analysis counts are not reported in the registry record.

The design is listed as single group, with allocation recorded as not applicable and masking recorded as none. The intervention description specifies a sequence: endotracheal tubes were secured with tape before surgery; following a traction test and measurement of displacement, tubes were secured with the combined Haider holder and bite guard. This sequence permits a within-participant comparison in principle, but the registry record does not report the statistical method used to analyze measurements from the two securing methods. Nor does it describe a separate concurrent control group.

The primary outcome concerns displacement under axial strain while participants are supine. The described force increased over approximately 5 seconds toward a target of 15 N, unless the principal investigator decided to stop the test to avoid possible tracheal extubation. The primary endpoint timeframe is 5 minutes after intubation, with the record noting that intubation occurs near the beginning of anesthesia.

Secondary outcomes listed in the record concern irritation or minor injury to facial and oral structures thought likely attributable to the device, clinically significant movement, and potentially high extubation risk. The registry record does not report results for these outcomes. It also does not describe eligibility criteria, participant flow, protocol deviations, or the number of participants with complete measurements.

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 Change in ETT Position, measured over 5 minutes after intubation (which occurs at the beginning of the anesthesia about 2-5 minutes after the patient goes to sleep)..

The primary endpoint, change in endotracheal tube position, measures how far the tube moves when an axial pulling force is applied. The unit is centimeters, and the registry identifies the summary measure as a mean with standard deviation. The test is intended to reproduce a pulling force on the tube while the participant is supine. Force was increased over approximately 5 seconds toward 15 N, or stopped earlier if the principal investigator considered that necessary to prevent possible tracheal extubation. The stated timeframe is 5 minutes after intubation.

Displacement is relevant to the mechanical question being tested: whether a securing method resists movement under the specified test conditions. A continuous measurement can describe both the average movement and the variation among observed measurements. However, an average alone does not show the range of individual results or whether any movement reached a clinically important threshold. The registry record does not define a clinically important difference for this endpoint or report the observed means, standard deviations, participant-level values, or an estimated comparison.

The endpoint is a test measurement, not a direct report of routine clinical outcomes. The record does not establish how the measured displacement relates to subsequent extubation, injury, or other patient outcomes. Those distinctions matter when interpreting the purpose and scope of the result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record identifies the primary measure as continuous, reports it as a mean with standard deviation, and describes one analysis. These labels do not identify the statistical test or model used. The analysis method, the handling of repeated measurements, and any adjustment for participant characteristics are not reported in the registry record. The actual primary outcome summary is also not reported, so no trial-specific estimate or uncertainty measure can be interpreted.

What does a mean describe?

In general, a mean describes the central value of a set of measurements. For this endpoint, it would describe average tube-position change under a tested securing method. A mean can be useful for comparing average displacement, but it does not show how spread out measurements were or whether the average represents every participant’s experience. The registry identifies standard deviation as the measure of dispersion. In general, standard deviation describes variability among observations around the mean; it is not the same as the uncertainty in the estimated mean.

In general, a confidence interval expresses uncertainty around an estimate under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, while neither width nor location alone establishes clinical importance. The registry record does not report a confidence interval or any other uncertainty interval for the primary endpoint. It also does not give a threshold for interpreting a clinically meaningful difference in centimeters.

How does the sequence affect comparison?

The study description places tape first and the combined device second. When each participant contributes measurements under both conditions, a paired analysis can focus on the within-participant difference. In general, this approach uses the fact that measurements from the same person are related; it can reduce the influence of stable differences between people. It requires the analysis to preserve the pairing. Whether the trial used a paired method, and how it handled incomplete pairs, are not reported in the registry record.

The order is not randomized in the description. In general, a fixed order means that the method being tested second may also be associated with changes over time, repeated testing, or other order effects. A paired analysis does not by itself separate those effects from the method difference. The record does not report a design feature or analysis intended to address order effects.

What does the force procedure contribute?

The protocol description says that axial force rose over approximately 5 seconds until reaching 15 N or until the principal investigator decided to abort the test to prevent possible tracheal extubation. This defines the intended mechanical challenge, but the registry record does not state the number of tests that reached the target or the distribution of forces at which testing ended. In general, unequal exposure to a test condition can complicate comparison, particularly if early stopping differs between methods. The record does not report whether force or stopping was incorporated into the statistical analysis.

For continuous measurements, analysis choices may depend on the distribution of values, the relationship between paired observations, and the presence of unusual observations. In general, a model should match the design and the question being estimated. The statistical plan, distributional checks, treatment of outliers, and any sensitivity analyses are not reported in the registry record. There is no basis in the record to state that a particular method was used or that its assumptions were checked.

What can planning calculations tell readers?

In general, sample-size calculations use assumptions about the effect to detect, variability, significance level, allocation, and analysis method. The registry’s planning description specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect set as a stated fraction of the observed effect. That planning description is not evidence that the trial used a two-arm randomized design: the registry instead lists a single-group model and allocation as not applicable. Planning illustrations are not observed power and do not establish the precision of the actual trial result. The registry record does not report a trial-specific sample-size justification or the statistical plan that governed the completed study.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Adhesive Tape", "Haider ETT Tube Holder")
n   <- c(30, 30)
m   <- c(3.4, 0.3)
sp  <- c(1.8, 0.6)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Adhesive Tape  30  3.400  1.800  2.728  4.072
CARM  Haider ETT Tube Holder  30  0.300  0.600  0.076  0.524

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and one analysis. The primary outcome is change in endotracheal tube position; the secondary outcomes concern irritation or minor injury, clinically significant movement, and potentially high extubation risk. The record does not report how the analysis count relates to the listed outcomes, whether all outcomes were analyzed, or which results were designated confirmatory.

When a study examines multiple outcomes or multiple comparisons, the chance of obtaining at least one apparently notable result can increase. In general, a prespecified multiplicity strategy can help control that risk, while a clearly identified exploratory analysis can help readers calibrate interpretation. The registry record does not report a multiplicity adjustment, an outcome hierarchy, or a distinction between confirmatory and exploratory analyses. It is therefore not possible to determine how the number of outcomes was handled statistically.

Missing-data methods are not reported in the registry record. It does not state how incomplete traction tests, early-aborted tests, missing paired measurements, or unavailable secondary outcome assessments were handled. Nor does it report outcome-specific analysis populations, participant flow, exclusions from analysis, or an intention-to-treat or per-protocol definition. The recorded enrollment of 30 does not establish how many participants contributed to each endpoint.

The registry record also does not describe an estimand, meaning the exact treatment effect the analysis was intended to estimate and how events such as early test termination or missing measurements were treated. These omissions limit assessment of bias and reproducibility. They do not prove that the study lacked such methods; they mean that the methods are not reported in the registry record.

12. 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.

Most frequent non-serious adverse event terms

For the recorded group, the registry lists 30 participants at risk for serious adverse events and 0 participants affected. It lists 30 at risk for other adverse events and 2 affected. These counts are reported for the group titled “Tape, Followed by ETT Holder and Bite Guard.” The record lists no serious adverse-event terms. The deaths field is not populated with a value, so deaths are not reported in the registry record.

The other-event count should not be interpreted as a count specifically of irritation or minor injury: the registry lists that topic as a secondary outcome, but does not report its result or identify the two other events by term. The record also does not provide event severity details beyond the serious-versus-other categories, timing, relatedness assessments, or participant-level information. The counts describe the registry’s adverse-event entries; they do not establish the absence of unrecorded events or resolve the missing outcome reporting.

Because the study is single group and tests tape before the device, these adverse-event counts are not a randomized safety comparison between separate groups. They should be read as counts recorded for the stated sequence, not as an estimate of a relative risk or a causal difference between methods.

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

The record documents a planned evaluation of a combined endotracheal tube holder and bite guard using a traction test. It specifies the primary measurement, the test position, the target force, and the sequence in which tape and the device were used. It also records enrollment of 30 and lists secondary outcomes and adverse-event counts. These details help define what the study set out to assess.

The registry record does not report the primary displacement results. Without the means, standard deviations, or an estimate comparing the securing methods, it is not possible to say whether the observed measurements favored one method, how large any difference was, or how uncertain that estimate would be. The registry record also does not provide results for the listed secondary outcomes, so the primary endpoint cannot be supplemented with a reported account of clinically significant movement, device-attributed irritation or injury, or potentially high extubation risk.

The design does not provide a randomized parallel-group comparison. Tape was tested first and the combined device afterward. Any interpretation of a measured difference would need to consider that fixed order and whether analysis preserved the relationship between measurements from the same participant. The registry record does not report the statistical approach or how incomplete tests were handled.

The endpoint is a mechanical measurement under the described test conditions. It is not, by itself, evidence about routine clinical outcomes, and the registry record does not report a link between measured displacement and later patient outcomes. The reported adverse-event counts are also limited: they do not identify the other events, and the deaths value is not reported. Overall, the record describes the question and procedure but does not contain enough outcome information to judge the comparative result or its precision.

14. Why This Trial Matters Statistically

This study illustrates the difference between a clearly described measurement procedure and a reported statistical result. The registry specifies an axial traction test, a target force of 15 N, a stopping discretion intended to prevent possible tracheal extubation, and change in tube position as the primary endpoint. Those details make the intended mechanical question understandable. Without the endpoint values and analysis, however, readers cannot assess the observed size or precision of a comparison.

Its single-group, fixed-sequence design also makes the statistical structure important. Measurements made under two methods in the same participant are related, so an analysis that accounts for pairing may be appropriate in general. But the second method is always tested after tape in the registry description. The distinction between within-participant comparison and randomized group comparison matters: pairing can address stable participant-level variation, but does not by itself remove order effects or changes in testing conditions.

The record further shows why safety counts need context. It reports zero participants affected by serious adverse events and two affected by other adverse events among the recorded group, but it does not identify the other events or report the result for the named irritation-or-injury outcome. A count without event descriptions or a comparator cannot answer every safety question.

For clinical researchers and biostatisticians, the central lesson is that endpoint definitions, design, analysis, missingness, and reporting jointly determine what can be learned. Here the registry record documents the procedure and selected counts, but leaves the primary comparative estimate and key analysis details unreported. That boundary should guide interpretation rather than assumptions about what the unreported results might have shown.

15. 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 for interpretation is that the registry record does not report the primary outcome values or an estimated comparison. It gives no standard deviations, confidence intervals, or p-values for change in endotracheal tube position. The listed secondary outcomes also have no reported results. Consequently, readers cannot evaluate the magnitude, precision, or statistical evidence for any endpoint difference.

The design is single group, with tape followed by the combined device and no masking. This fixed sequence does not offer the protection against time or order effects that random assignment could provide. A within-participant comparison may account for stable differences between participants if analyzed appropriately, but the statistical method is not reported. The record also does not report whether test conditions, applied force, or stopping decisions were comparable across the two measurements.

The procedure allowed the investigator to abort increasing force if needed to prevent possible tracheal extubation. The registry record does not state how frequently tests stopped early or how such tests were treated analytically. It does not report missing-data handling, the number contributing to each analysis, participant flow, protocol deviations, or the definition of the analysis population. The enrollment entry alone cannot resolve those questions.

Finally, the registry does not report a clinically important threshold for tube displacement or explain how the mechanical endpoint relates to patient outcomes. The adverse-event entries do not identify the two other events, and deaths are not reported. These limitations are specific to the reported design and available registry entries; unreported information should not be treated as evidence that an analysis or procedure was absent.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Endotracheal Tube Holder and Bite Guard Research — NCT02347488.
• Registry record last updated 2017-04-17; status last verified 2017-03.
• Results first posted 2017-01-04.
• 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.

19. Record Summary

NCT02347488 is a completed phase 4, single-group study sponsored by the University of California, Los Angeles. The registry records enrollment of 30, a start date of 2015-02, and primary completion in 2015-08. Masking is listed as none, and allocation is not applicable.

The study tested a combined Haider endotracheal tube holder and bite guard after securing the tube with tape and performing a traction test. The primary endpoint was change in tube position, measured in centimeters, under axial strain. The record lists four outcome measures and one analysis.

Primary and secondary outcome results, the statistical analysis method, missing-data handling, and analysis populations are not reported in the registry record. For the recorded group, serious adverse events affected 0 of 30 at risk, and other adverse events affected 2 of 30 at risk. The other events are not identified in the record.