Study of the ENTact Septal Staple System for Tissue Approximation During Septoplasty: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of the ENTact Septal Staple System for Tissue Approximation During Septoplasty (NCT00740480), a registered phase not stated study. The primary outcome is Coaptation (Tissue Approximation).

2. Clinical Question

In statistical terms, the central question is descriptive: among participants covered by the primary analysis, how many had complete tissue approximation at the specified follow-up? The outcome definition describes a binary status for each participant: complete approximation or not complete approximation. The registry record does not provide further criteria for classifying that status, nor does it report an estimate of the frequency of complete approximation.

Because the study is non-randomized and the arms are not described as a like-for-like control comparison, the record does not support treating an arm contrast as a randomized estimate of a treatment effect. The primary question should therefore be read as an assessment of the endpoint within the evaluation, rather than as a comparative efficacy question. The outcome result and its precision are not reported in the registry record.

3. Trial Design

The registry describes a prospective, non-randomized, limited-use evaluation of the ENTact Septal Staple System for tissue approximation during septoplasties. The study status is completed. The recorded start is 2008-04, and primary completion is recorded as 2009-02. Enrollment is 25. The sponsor is ENTrigue Surgical, Inc.

The arm description identifies a surgical group of adults ages 18-65 with clinically significant nasal septum deviation. The registry record does not state the allocation method. It also flags that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The available description does not establish the details of any comparison condition, or explain how participants were assigned among arms.

The stated purpose was to learn more about device performance and to collect information to support a premarket application. This purpose is consistent with an evaluation centered on recording outcomes after device use, but details of the protocol beyond the registry descriptions are not reported in the registry record. In particular, the record does not report the rationale for enrollment, the number of participants planned for each arm, or the operational procedures for device use and follow-up.

The primary endpoint is complete tissue approximation at one week after surgery, recorded as a number of participants in the ITT population. Tissue Reaction to Implant is listed as a secondary outcome. The registry lists two outcome measures, but does not give a result for the primary endpoint or a detailed result for the secondary outcome. No analysis records are listed. The meaning of the ITT label, the handling of participants without an observed endpoint, and any adjustment or subgroup procedures are not reported in the registry record.

Consequently, the design can be described from its prospective, non-randomized, limited-use label and its recorded population and endpoint, but not reconstructed in full. The registry record does not report a protocol-level account of the comparison, the statistical analysis plan, or procedures intended to control bias.

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:

Analysis population for the primary outcome, as defined in the registry: ITT

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 Coaptation (Tissue Approximation), measured over One week post surgery.

The primary endpoint is complete tissue approximation at one week after surgery. It is measured as a number of participants, and the record identifies the analysis population as ITT. The endpoint is binary at the participant level: each participant is classified according to whether complete tissue approximation was recorded at that follow-up. The exact assessment criteria and the method used to determine completeness are not reported in the registry record.

A participant count can communicate how many people met a prespecified clinical or procedural condition. To interpret that count as a rate, readers also need the relevant denominator and a clear account of who was assessed. The registry record does not report the endpoint count, denominator, or an estimate with an uncertainty interval. As a result, the magnitude and precision of the primary endpoint cannot be described from the registry information available for this analysis.

In general, a fixed follow-up time makes the endpoint easier to interpret than an outcome whose timing varies across participants, because the assessment refers to a defined point after surgery. That benefit depends on consistent assessment and complete follow-up. The record does not describe assessment consistency, missing endpoint handling, or whether all participants had an assessment at one week.

The endpoint is relevant to the stated device-performance purpose because it measures tissue approximation after use during septoplasty. However, the endpoint alone does not establish how the device compares with another approach, how durable approximation is beyond the specified follow-up, or how participants experienced the procedure. Those questions are not answered by the primary endpoint description.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the primary outcome as a participant count for complete tissue approximation at one week after surgery. The statistical ideas below are general explanations of how such an endpoint can be analyzed; they are not descriptions of analyses documented for this evaluation. No analysis records are listed, and the registry record does not report a statistical analysis plan.

What does a binary participant outcome represent?

For a binary outcome, each participant falls into one of two categories according to the endpoint definition. A count reports the number assigned to one category. A count by itself is difficult to interpret without knowing how many participants were eligible for assessment and how many had an observed outcome. A proportion uses the count together with that denominator, and an interval estimate can express the uncertainty associated with the estimated proportion. The registry record identifies the endpoint as a count but does not report the count, denominator, or interval estimate.

The classification also depends on a clear outcome definition. Here, the listed definition is complete tissue approximation at one week. The registry record does not describe thresholds, assessor procedures, or rules for ambiguous assessments. In general, consistent definitions and blinded or otherwise standardized assessment can reduce the risk that outcome classification varies according to expectations or study group. Whether such procedures were used is not reported in the registry record.

What would an uncertainty interval convey?

In general, a confidence interval describes a range of values compatible with the observed data under a specified statistical method and its assumptions. A narrow interval indicates greater statistical precision than a wide interval, although neither interval width nor statistical precision alone establishes clinical importance. For a binary endpoint, interval estimation depends on the event count and the number assessed, as well as the method selected. Since those values and the interval are not reported in the registry record, the precision of the primary endpoint cannot be assessed.

An interval is not a guarantee that the true value lies within its limits, and it does not account automatically for biases in design, measurement, or missing data. In this evaluation, non-randomized allocation and the stated lack of a like-for-like control comparison are important design considerations separate from sampling uncertainty. A narrow interval, if one were available, would not remove those limitations.

How does non-randomized allocation affect interpretation?

In general, random allocation can help balance participant characteristics across comparison groups, on average, and supports stronger causal interpretation when other design features are appropriate. Non-randomized groups may differ in ways related to both the intervention and outcome. Statistical adjustment can sometimes address measured differences, but it cannot necessarily remove bias from unmeasured factors or poor overlap between groups. The registry record does not report an adjustment plan, group characteristics, or sufficient comparison details to judge whether adjustment would be appropriate.

The record states that allocation is not stated and that the arms are not a like-for-like control comparison. Thus, a difference between arms, if available, would not automatically represent the effect of the staple system. The comparison condition and assignment process would need to be understood, along with potential confounding, before an arm contrast could be given a causal interpretation.

What is the role of planning calculations?

The record describes sample-size assumptions for a planning illustration based on the observed effect, not the trial's own design. The illustration assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers effects expressed as a stated fraction of the observed effect. For non-time-to-event outcomes, the planning results are framed as participants per arm. These are planning assumptions, not documented evidence that the evaluation was designed or conducted with those targets.

A sample-size calculation generally estimates how much information would be needed to detect a specified effect under stated assumptions. Its result depends on the expected effect, variability or event frequency, significance level, allocation, and chosen power. The observed effect and the calculated planning values are not reported in the registry record available for this analysis. The planning illustration therefore cannot be interpreted numerically. It is not observed power, and it cannot substitute for a confidence interval or for reporting the outcome data.

In general, an observed effect can be unstable in a small evaluation, and using it as the assumed effect for a planning illustration makes the resulting estimate dependent on that observed value. Illustrations using fractions of an observed effect can help show how planning needs change when the target effect differs from the observed one. They do not prove that any target is plausible, nor do they determine whether an existing result is clinically important.

Why are analysis details important?

For a binary endpoint, an analysis plan should make clear the population, event definition, denominator, handling of missing observations, and method for estimating the outcome and its uncertainty. If there are comparison groups, it should also specify whether the aim is descriptive or comparative and how any adjustment will be handled. The registry record supplies the ITT label for the primary endpoint but does not define it or report the remaining analysis details.

Multiplicity concerns arise when investigators examine several outcomes, time points, groups, or statistical tests. Considering more analyses can increase the chance of finding an apparently unusual result by chance if results are interpreted without accounting for that search. The record lists two outcome measures and identifies Tissue Reaction to Implant as secondary, but does not report a multiplicity strategy. With no analysis records listed, it is not possible to determine which tests, if any, were planned or how they were interpreted.

Finally, statistical methods cannot repair missing design information or replace reporting the endpoint data. Clear reporting of counts, denominators, uncertainty, assessment procedures, and analysis populations is needed to evaluate both the numerical result and the assumptions behind it. Those details are not reported in the registry record for the primary outcome.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Septal Stapler Group")
n      <- c(25)
events <- c(23)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Septal Stapler Group  25  23  92.0  74.0  99.0  75.0  97.8  74.9  97.6

11. Multiplicity, Missing Data and Analysis Populations

The primary endpoint specifies an ITT population, but the registry record does not define that population. It does not report how many enrolled participants were assessed at one week, how many had missing endpoint data, or how missing observations were handled. It also does not state whether participants were included in the analysis if they did not receive the intended procedure or lacked a follow-up assessment. Without these details, the meaning of the ITT result cannot be evaluated beyond the label in the endpoint description.

For a binary outcome, missing data can affect both the event count and the denominator. In general, an analysis that excludes participants without endpoint data may differ from one that uses an explicit imputation or sensitivity-analysis approach. These methods rely on assumptions about why data are missing and how missing outcomes relate to observed outcomes. The registry record does not report a missing-data method or sensitivity analyses, so no conclusion about the impact of missingness is possible.

The registry lists two outcome measures and identifies Tissue Reaction to Implant as a secondary outcome. A multiplicity plan, including whether outcomes or analyses were prioritized and whether any adjustment was intended, is not reported in the registry record. No analysis records are listed. The registry information therefore does not show whether multiple outcomes, time points, or comparisons were statistically tested, or how any such testing would have been interpreted.

The one-week timeframe is specified for the primary endpoint, but timing details beyond that are not available. The record does not report the handling of assessments outside the intended window or the rules for incomplete or uncertain assessments. These omissions matter because analysis populations and classification rules can change the interpretation of a participant count.

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

The registry record establishes that the evaluation was intended to assess the ENTact Septal Staple System and identifies complete tissue approximation one week after surgery as the primary endpoint. It also records enrollment of 25 and describes the study as prospective, non-randomized, and limited-use. These details describe the scope and structure of the evaluation; they do not state what the endpoint result was.

The record does not report the number of participants with complete approximation, the number assessed, or an estimate of uncertainty. It therefore cannot show how frequently the endpoint occurred or how precisely that frequency was estimated. A result cannot be described as statistically significant or not statistically significant from the registry entries available, because no corresponding test result is reported.

The study design also limits the meaning of possible comparisons. The registry says the arms are not a like-for-like control comparison and does not state the allocation method. Even if arm-specific results were available, those details would not by themselves establish that differences were caused by the device. A comparison can be influenced by how groups were formed, by differences in participants or procedures, and by how outcomes were assessed.

The endpoint addresses tissue approximation at the specified follow-up, not all aspects of the procedure or longer-term outcomes. The registry lists Tissue Reaction to Implant as a secondary outcome, but its result is not reported. The record does not establish durability beyond one week, comparative performance against a well-matched alternative, or other outcomes not specified in the registry information.

In general, a prospective evaluation can systematically collect information, but prospective data collection does not by itself eliminate bias or establish a comparative effect. The stated study purpose was to learn about device performance and collect information to support a premarket application. That purpose describes the reason for the study; it is not itself evidence about the primary endpoint. The registry record supports describing what the study set out to measure, but not a conclusion about the observed outcome or the device's comparative performance.

13. Why This Trial Matters Statistically

This evaluation illustrates why design labels and endpoint definitions are not enough to interpret clinical data. The registry identifies a prospective, non-randomized, limited-use evaluation and a specific binary endpoint at one week. Those details clarify what the investigators intended to assess, while the absence of a reported endpoint count and denominator prevents assessment of the observed frequency and its precision.

The distinction between a count and an interpretable estimate is central. A count requires a denominator and a defined analysis population to indicate how often an event occurred. The ITT label is useful information, but without a definition and participant accounting it cannot resolve who contributed to the analysis. Reporting these elements allows readers to understand whether the estimate represents the enrolled population, those assessed, or another group.

The record also highlights the importance of comparability in interpreting group results. It explicitly notes that the study was not randomized and that the arms are not a like-for-like control comparison. This is not a minor technical detail: group differences can complicate attribution of any observed outcome to the device. Statistical methods can describe data and quantify sampling uncertainty, but they cannot make an inherently non-comparable design equivalent to a randomized comparison.

Finally, the presence of planning assumptions does not tell readers whether a study was adequately planned or whether an observed finding is reliable. A planning illustration based on an observed effect answers a hypothetical design question under stated assumptions. It is not the same as a prespecified design justification, a reported analysis, or evidence of observed power. Keeping these concepts separate helps prevent sample-size calculations from being mistaken for findings.

For biostatisticians and clinical researchers, the key lesson is the need to connect the endpoint, population, missing-data approach, comparison structure, and analysis plan. In this record, important links among those elements are not reported, so interpretation must remain limited to the study's stated aims and design descriptors.

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 main trial-specific limitation in interpreting the registry information is that the primary endpoint result is not reported. The record does not give the number of participants with complete tissue approximation, the denominator, an estimate of uncertainty, or an inferential result. Enrollment of 25 does not supply those missing outcome details and should not be treated as the analyzed sample size.

The population description is limited to adults ages 18-65 with clinically significant nasal septum deviation. The registry identifies the endpoint population as ITT but does not define that term or reconcile it with enrollment and follow-up. It does not report participant flow, the number assessed at the one-week follow-up, or how incomplete assessments were handled. These gaps preclude assessment of attrition and missing-outcome risks.

The design is non-randomized, the allocation method is not stated, and the record says the arms are not a like-for-like control comparison. Specific details of the arms and any comparison condition are not reported in the registry record. Consequently, the information does not permit a robust assessment of group comparability or confounding. Any contrast should not be read as a randomized causal estimate.

Additional limitations concern outcome measurement and analysis. The registry gives the endpoint label and timing but not the criteria for complete tissue approximation or the assessment procedures. It lists Tissue Reaction to Implant as a secondary outcome but does not report its result or detailed measurement information. No analysis records are listed, and the statistical plan, multiplicity approach, and missing-data procedures are not reported in the registry record.

These limitations concern what can be learned from the registry information; they do not establish that unreported procedures were not performed. They do mean that readers cannot evaluate those procedures from the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of the ENTact Septal Staple System for Tissue Approximation During Septoplasty — NCT00740480.
• Registry record last updated 2009-08-25; status last verified 2009-08.
• Results first posted 2009-08-21.
• 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

The registry record describes a completed, prospective, non-randomized, limited-use evaluation of the ENTact Septal Staple System during septoplasty. The recorded enrollment is 25, with a study start of 2008-04 and primary completion of 2009-02. The described population is adults ages 18-65 with clinically significant nasal septum deviation.

The primary endpoint is the number of participants with complete tissue approximation one week after surgery in the ITT population. Tissue Reaction to Implant is listed as a secondary outcome. The record states that allocation is not stated and that the arms are not a like-for-like control comparison. No analysis records are listed.

The primary endpoint result, denominator, uncertainty estimate, analysis details, and missing-data procedures are not reported in the registry record. The study purpose was to learn about device performance and collect information to support a premarket application. The available record therefore supports a description of the study aims and design, but not a quantitative interpretation of its primary outcome.