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 Clinical Study of the Tympanostomy Tube Delivery System (NCT00939796), a na na study. The primary outcome is Device Success.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00939796 |
| Phase | NA |
| Condition | Otitis Media With Effusion |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 16 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Integra LifeSciences Corporation |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients indicated for tympanostomy tube placement for chronic otitis media with effusion or recurrent acute otitis media. The listed condition is otitis media with effusion. The primary endpoint description refers to test-cohort subjects, but the number in that cohort and how it relates to the enrolled group are not reported in the registry record.
Intervention
The intervention was the Acclarent Tympanostomy Tube Delivery System (TTDS), a device used for tympanostomy tube placement. The study objective was to evaluate safety and performance of the system.
Comparator
There was no randomized comparator group: the study is recorded as single-group, with allocation listed as NA. Cross-over to manual myringotomy and tube placement is named as a secondary outcome, but it is not a parallel control arm.
Primary question
At the procedure visit, how many attempted TTDS devices achieved successful tube deployment in each indicated ear? The endpoint is described as applying to all TTDS devices attempted and to test-cohort subjects only, not lead-in subjects. The result itself is not reported in the registry record.
This is a device-performance question within an investigational study, not a randomized estimate of comparative treatment effect. With no like-for-like control group, the design cannot directly establish how device performance compares with another placement approach. The named cross-over outcome may describe use of manual placement after an attempted device procedure, but its result and definition are not reported in the registry record. The clinical question therefore needs to be read narrowly: the stated primary measure concerns successful deployment with the TTDS in the defined test cohort, while the registry record does not report the number of successful deployments or a statistical estimate of performance.
3. Trial Design
The study, titled “Clinical Study of the Tympanostomy Tube Delivery System,” evaluated the Acclarent Tympanostomy Tube Delivery System for tympanostomy tube placement. Its official title identifies the study as inVENT and describes patients requiring tube insertion for otitis media. The registry lists otitis media with effusion as the condition. The brief summary states that the intended population included patients indicated for treatment of chronic otitis media with effusion or recurrent acute otitis media.
The study is recorded as single-group, with allocation listed as NA and masking as none. These features mean the registry does not describe a randomized allocation or a masked comparison. The intervention group is tympanostomy tube placement with the Acclarent delivery system. Enrollment is recorded as 16. The study started in 2009-03, had primary completion in 2009-06, and is marked completed. The phase is listed as NA.
The primary endpoint is device success at the procedure visit. Its description defines success as deployment of the tube in each indicated ear using the TTDS. It applies to all attempted TTDS devices and to test-cohort subjects only, not lead-in subjects. How subjects were assigned to lead-in or test cohorts, the size of either cohort, and the detailed analysis population are not reported in the registry record.
Two secondary outcomes are named: cross-over to manual myringotomy and tube placement, and tube retention. The registry lists three outcome measures, but results for these outcomes are not reported in the registry record. The sponsor is Integra LifeSciences Corporation. The record does not describe a concurrent control arm; the named cross-over outcome should not be interpreted as one.
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.
Before assignment: Investigators treated a minimum of 1 subject (or 2 ears) as lead-in procedures prior to enrolling test cohort. 3 lead-in subjects were enrolled and were required to meet the same eligibility criteria and protocol-required procedures as the test cohort. Lead-in efficacy data have been separately analyzed. 13 subjects enrolled in the test cohort.
Overall Study
| Stage | Tympanostomy Tube Delivery System (TTDS) |
|---|---|
| STARTED | 16 |
| COMPLETED | 16 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: All TTDS devices attempted
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.
| Characteristic | Unit | Tympanostomy Tube Delivery System (TTDS) |
|---|---|---|
| Participants analysed | 16 | |
| Age, Customized: <=5 years | participants | 14 |
| Age, Customized: >5 years | participants | 2 |
| Sex: Female, Male: Female | Participants | 9 |
| Sex: Female, Male: Male | Participants | 7 |
| Region of Enrollment: United States | participants | 16 |
6. Primary Endpoint
The registry lists the primary outcome as Device Success, measured over At procedure visit.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | devices |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is “Device Success,” measured as a number of devices at the procedure visit. Success is defined as successful deployment of the tube in each indicated ear using the TTDS. The population is all TTDS devices attempted, with the description specifying test-cohort subjects only and excluding lead-in subjects.
As a general statistical concept, a count endpoint can give a direct description of how many attempted devices meet a prespecified success definition. Its interpretation depends on a clear definition of the unit being counted and the population in which the count was assessed. Here, the stated unit is devices, and success concerns deployment in each indicated ear. The record does not explain whether any additional rules were used for attempts involving more than one indicated ear or for classifying an unsuccessful or incomplete deployment.
The registry identifies the endpoint and its assessment time, but does not report the observed success count, a denominator for the test cohort, or an uncertainty interval. It is therefore possible to explain what the measure was intended to capture, but not to quantify the observed device-success result or its precision from the registry record. The endpoint is a procedural performance measure; by itself, it does not establish comparative effectiveness or describe longer-term tube retention.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an investigational, single-group device study and specifies a primary measure of device success at the procedure visit. It does not report the observed value of that endpoint. Consequently, the record information available for this analysis does not establish how many attempted devices met the success definition, nor how precisely that result was estimated. No conclusion about the device’s performance can be drawn from an endpoint definition alone.
The primary measure is tied to tube deployment in each indicated ear using the TTDS. Its stated population is all attempted TTDS devices, but the description limits assessment to test-cohort subjects and excludes lead-in subjects. The number of attempts and the size of the test cohort are not reported in the registry record. Without those details and the observed count, the endpoint cannot be converted into a proportion or otherwise summarized as a success rate. No such calculation should be inferred from the enrollment figure, which describes study enrollment rather than the number of devices in the primary analysis.
The design also limits what can be learned about comparison with other approaches. The study is listed as single-group, allocation is NA, and masking is none. The registry does not describe a randomized control group. Cross-over to manual myringotomy and tube placement appears among the secondary outcomes, but its result is not reported in the registry record, and the outcome is not a parallel control arm. Any comparison with manual placement would require details about who crossed over, why, and how outcomes were analyzed; those details are not reported in the registry record.
The two other named outcomes are cross-over to manual placement and tube retention. Their definitions, assessment times, and observed results are not reported in the registry record. Thus the available information does not provide a reported result about subsequent tube retention or the frequency of cross-over. The record lists three outcome measures and no analysis records, so there is no reported statistical analysis to interpret for these measures.
The adverse-event figures describe the TTDS group: 16 were at risk for serious adverse events and 0 were recorded as affected; 16 were at risk for other adverse events and 2 were recorded as affected. These are descriptive counts, not evidence from a controlled comparison. The record does not report event terms for serious events, and deaths are not reported in the registry record. The available figures should not be stretched into claims about comparative safety, rare risks, or outcomes beyond the recorded categories.
Overall, the registry record provides a study framework, a procedural endpoint definition, and limited adverse-event counts, but not the primary outcome result or results for the named secondary outcomes. The distinction between an endpoint being specified and an endpoint result being reported is central to interpreting this study.
9. Statistical Methods Explained
The statistical methods that can be interpreted are limited by the information recorded for this study. The registry identifies a count-type primary outcome and a single-group design, but does not report an analysis plan, statistical test, estimate, confidence interval, or p-value. No analysis records are listed. Any explanation of statistical concepts beyond those details is general and does not describe a method confirmed for this study.
What does a device count represent?
As a general concept, a count records the number of units meeting a stated condition. For this endpoint, the condition is successful deployment of the tube in each indicated ear using the TTDS. The unit is devices, and the endpoint is assessed at the procedure visit. A count is interpretable only in relation to the full number of eligible attempts. The primary endpoint description says the population is all attempted TTDS devices, but the number of attempts and the observed success count are not reported in the registry record. Enrollment of 16 does not supply those missing quantities: the enrollment count is not itself a device-attempt denominator.
The endpoint also has a stated analysis-population qualification: test-cohort subjects only, not lead-in subjects. This distinction matters because including or excluding different participants can change the population to which a result applies. The criteria for those cohorts, their sizes, and how they relate to all enrolled participants are not reported in the registry record. Therefore, a reader cannot reconstruct the primary analysis population from the recorded enrollment figure.
Why would an uncertainty interval matter?
As a general explanation, a confidence interval expresses uncertainty around an estimated quantity under a specified statistical method and its assumptions. For a count or a proportion derived from a count, the interval helps distinguish the observed estimate from the range of values that may be compatible with the data. It does not guarantee that the true value lies within the interval, and it cannot correct for a poorly defined population or biased data collection. No confidence interval or underlying primary outcome count is reported in the registry record, so the precision of device success cannot be assessed in the registry record recorded for this study.
For a single-group device study, the primary endpoint can describe performance in the observed study population if the result and denominator are available. It cannot, without a suitable comparison, isolate how outcomes would differ under another procedure or device. This is a design issue rather than a calculation issue: statistical methods cannot create a randomized comparator that the study design does not include.
What can be said about the analysis plan?
The registry does not report a statistical analysis plan, the statistical test for the primary outcome, a method for handling missing data, or a strategy for analysis populations beyond the endpoint’s test-cohort wording. These details are not reported in the registry record. It would be inappropriate to assume a particular test, adjustment, interim analysis, or sample-size justification. The status of completed does not fill in those methodological details.
The record lists three outcome measures, including device success and the two named secondary outcomes. It lists no analysis records. This means the outcomes can be identified, but there is no registry-recorded analysis result available to assess for statistical uncertainty, significance, or consistency across endpoints. As a general matter, the numerical result, denominator, and analysis method are needed together to judge an outcome; an outcome title alone is not an estimate.
How should planning calculations be read?
The accompanying planning illustration is described as a calculation based on the observed effect, rather than the trial’s own design. Its stated assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. The record does not give the effect value or the fraction in the information available for this analysis. The illustration is therefore a hypothetical planning exercise, not a description of the single-group study’s actual enrollment plan or an observed trial result.
As a general concept, a sample-size calculation estimates how many participants a proposed study might need under specified assumptions. Such a calculation is sensitive to the assumed effect, variability, allocation, statistical method, and target power. It does not show that an existing study had a particular probability of finding a result after the fact. In particular, planning figures should not be read as observed power. Because this study is single-group while the described illustration assumes two arms with equal allocation, those planning assumptions do not describe the recorded study design.
The illustration distinguishes between participants per arm for non-time-to-event outcomes and total events for time-to-event outcomes using a Schoenfeld approach. The primary endpoint is a procedure-visit device count, not a time-to-event endpoint. The registry does not provide a study-specific sample-size rationale or explain how the planning illustration relates to the trial’s enrollment. Its assumptions should therefore remain separate from the interpretation of the recorded study.
Why can over-dispersion matter?
As a general concept, over-dispersion occurs when count variability is greater than a statistical model assumes. If it is ignored, uncertainty can be understated and intervals or tests may appear more precise than warranted. Whether over-dispersion is relevant depends on the data structure and chosen model. The registry record does not report a count model or enough outcome data to assess dispersion, so no claim about its presence or its handling can be made for this study.
10. Multiplicity, Missing Data and Analysis Populations
The record lists three outcome measures: device success as the primary outcome, and cross-over to manual myringotomy and tube placement and tube retention as secondary outcomes. It does not report results for these measures or an analysis strategy for handling multiple outcomes. The number of analysis records is 0. There is therefore no reported basis for determining whether statistical tests were conducted, whether any adjustment for multiple testing was planned, or how outcome-specific results should be prioritized beyond the primary and secondary labels.
As a general statistical concern, testing multiple outcomes can increase the chance that at least one result appears notable by chance if each is assessed separately. Methods for addressing this depend on the study’s objectives and prespecified analysis plan. No multiplicity method or statistical analysis plan is reported in the registry record; it would not be appropriate to assume one.
Information about missing outcome data, exclusions, and missing-data handling is not reported in the registry record. The primary endpoint description does specify test-cohort subjects and excludes lead-in subjects, but does not give cohort sizes or explain how incomplete attempts or unavailable outcome assessments were treated. The definition of the analysis population beyond that wording is not reported in the registry record.
These omissions matter because outcome counts are interpretable only when the population, denominator, and handling of unavailable observations are clear. They also limit assessment of whether the reported safety counts cover the same analysis population as the primary endpoint. The registry record does not provide enough information to make that comparison.
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 |
|---|---|---|---|
| Tympanostomy Tube Delivery System (TTDS) | 0 | 16 | 0.0% |
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 |
|---|---|
| Tympanostomy Tube Delivery System (TTDS) | 2 of 16 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Tympanostomy Tube Delivery System (TTDS) |
|---|---|---|
| tympanic membrane perforation | Ear and labyrinth disorders | 2 of 16 |
The registry lists adverse-event counts for the Tympanostomy Tube Delivery System group. For serious adverse events, 16 were at risk and 0 were recorded as affected. For other adverse events, 16 were at risk and 2 were recorded as affected. These are the reported counts; the registry record does not give event descriptions for the serious-event category or details about the two other adverse events.
These figures are descriptive. They do not compare the TTDS group with a control group, because the study is recorded as single-group and no randomized comparator is described. The counts also do not establish that an unrecorded event could not occur, or quantify risks beyond the recorded observations. The registry does not report follow-up details for these adverse-event figures in the information, so the duration and completeness of event ascertainment cannot be assessed.
Deaths are not reported in the registry record. That is different from a reported count of zero. The safety figures should therefore be read as limited recorded counts, not as a comprehensive or comparative assessment of safety.
12. What the Result Does, and Does Not, Mean
The study addresses whether the Acclarent Tympanostomy Tube Delivery System can successfully deploy a tympanostomy tube in each indicated ear, as defined by its procedure-visit endpoint. The registry record establishes that this was the stated primary performance question and identifies a test-cohort population for its assessment. It does not report the observed device-success count or denominator, so the outcome’s magnitude and precision cannot be described from the registry record.
The study’s single-group design can provide a description of outcomes among those assessed if the underlying counts and methods are available. It does not provide a randomized, like-for-like comparison with manual placement or another device. Cross-over to manual myringotomy and tube placement is listed as a secondary outcome, but no result is reported. The record also names tube retention as a secondary outcome without reporting its result.
The adverse-event information records 0 affected by serious adverse events among 16 at risk and 2 affected by other adverse events among 16 at risk. These counts do not establish comparative safety, and deaths are not reported in the registry record. No event descriptions are given for the serious category. The available information therefore supports only a narrow description of the recorded counts.
The record does not report an analysis plan, confidence intervals, p-values, missing-data methods, or results for any of the three listed outcome measures. It also does not report details needed to reconstruct the test cohort or assess the endpoint denominator. These gaps prevent a statistical judgment about how certain the primary result is, because that result itself is not reported.
Accordingly, the record documents the study purpose, design, endpoint definitions, and limited safety counts. It does not establish a numerical device-success result, a comparative effect, or a broader conclusion about outcomes beyond the recorded measures. Those distinctions are important: a specified endpoint describes what investigators intended to assess, while a reported result is needed to say what the study observed.
13. Why This Trial Matters Statistically
This study illustrates why a registry record should be read at two levels: what a study set out to measure, and what outcome data it reports. The record gives a clear procedural definition for device success and identifies the assessment time as the procedure visit. Yet the observed success count and its denominator are not reported. Without those quantities, the endpoint cannot be interpreted as a numerical performance estimate.
The single-group design is also statistically important. It can describe outcomes in the group assessed, but it does not offer a randomized comparison with another method. A secondary outcome involving cross-over to manual placement does not substitute for a concurrent control arm. The design therefore shapes the kinds of claims that could be supported even if outcome counts were available.
The endpoint population is qualified as test-cohort subjects only, not lead-in subjects. This makes clear population reporting especially important. The record does not provide the cohort sizes or describe how they were formed, so the enrolled population cannot simply be assumed to match the primary analysis population.
The safety counts demonstrate another interpretive principle: a small set of descriptive event counts is not equivalent to a comparative safety analysis. The record lists serious and other adverse events separately, but does not give event descriptions for serious events, and deaths are not reported. The counts should be kept within those limits.
Finally, the distinction between planning calculations and trial design matters. The accompanying planning illustration uses assumptions for a two-arm comparison, whereas the recorded study is single-group. Such calculations are hypothetical planning aids and do not describe the trial’s own design or constitute observed power. Reading these elements separately prevents planning assumptions from being mistaken for evidence about the completed study.
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 for interpretation is that the registry record does not report the primary device-success result. The endpoint definition is available, but the observed count and denominator are not. Without them, neither the magnitude nor the precision of the primary outcome can be assessed.
The study is recorded as single-group, with no randomized comparator described. This limits conclusions to the study’s own assessed group and prevents a direct randomized comparison with another placement approach. The secondary cross-over outcome does not, by itself, provide a control group, and its result is not reported in the registry record.
The primary endpoint description restricts assessment to test-cohort subjects and excludes lead-in subjects, but the cohort sizes, selection process, and relationship to enrollment are not reported. The record also does not report how incomplete attempts, missing measurements, or exclusions were handled. These gaps make the analysis population and denominator difficult to reconstruct.
The registry names tube retention and cross-over as secondary outcomes, but does not report their definitions in detail, assessment times, or results. It lists no analysis records and does not report a statistical analysis plan, inferential method, confidence interval, or p-value. This prevents review of the statistical uncertainty or any approach to multiple outcomes.
Safety information is limited to affected and at-risk counts for serious and other adverse events. Serious-event terms are not reported, and deaths are not reported in the registry record. The information available does not establish the duration or completeness of safety follow-up. Finally, the planning illustration is not described as the trial’s design, and its assumptions do not resolve the missing study-specific sample-size rationale.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Clinical Study of the Tympanostomy Tube Delivery System — NCT00939796.
- Registry record last updated 2024-08-06; status last verified 2024-07.
- Results first posted 2014-06-09.
- 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
NCT00939796 is a completed, single-group study of the Acclarent Tympanostomy Tube Delivery System for tympanostomy tube placement. Enrollment is 16; the study started in 2009-03 and reached primary completion in 2009-06. Allocation is listed as NA, masking as none, and phase as NA.
The primary outcome is device success at the procedure visit, defined as successful tube deployment in each indicated ear using the TTDS. It applies to all attempted devices and is described for test-cohort subjects only, not lead-in subjects. The observed primary result is not reported in the registry record. Cross-over to manual placement and tube retention are named as secondary outcomes, with no results reported.
The registry lists 0 affected by serious adverse events among 16 at risk and 2 affected by other adverse events among 16 at risk. Deaths are not reported in the registry record. No analysis records are listed.