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 Evaluation to Confirm Safety and Efficacy of Sinuplasty in the Paranasal Sinuses (CLEAR) (NCT00231062), a non-randomized phase 3 study. The primary outcome is Number of Sinuses With Patency of Sinus Ostium After Sinuplasty.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00231062 |
| Phase | Phase 3 |
| Condition | Chronic Sinusitis |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 115 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Integra LifeSciences Corporation |
| Results posted | Yes |
2. Clinical Question
Population
The evaluation concerned people with chronic sinusitis. The registry records an enrollment of 115 and describes the study as a multi-center, prospective post-market evaluation. The primary endpoint population was defined as the per-protocol sinuses of subjects who were not lost to follow-up at 24 weeks; the record does not give the number of sinuses or subjects included in that endpoint population.
Intervention
The intervention was sinuplasty, listed as a device intervention. The adverse-event grouping is titled Balloon Dilation of Sinus Ostia. The registry does not provide further details about how the procedure was performed, which sinuses were treated, or whether treatment varied among participants.
Comparator
There was no separate comparator group in the registry design. Allocation is listed as non-randomized and the model as single-group. Consequently, this record does not offer a concurrent control comparison for interpreting outcomes.
Primary question
The primary endpoint asks how many sinuses had a patent sinus ostium after sinuplasty at 24 weeks. Patency was assessed by nasal endoscopic examination, with the investigator making a clinical judgment about whether it had been achieved. The registry does not report the observed count or an analysis of that endpoint.
In practical statistical terms, this is a question about a post-procedure count of sinuses judged patent, not a randomized estimate of the difference between treatments. The record also lists relief of sinus symptoms as a secondary outcome, but gives no results for it. It therefore describes the outcome being assessed and the study population, while leaving the size and precision of the observed clinical findings unavailable in the registry record.
3. Trial Design
CLEAR is listed as a Phase 3, completed, single-group study with non-randomized allocation and no masking. Its brief summary describes a multi-center, prospective post-market evaluation of sinuplasty in the paranasal sinuses. Enrollment is recorded as 115. The study start is listed as 2005-04 and primary completion as 2006-06. Integra LifeSciences Corporation is identified as the sponsor.
Because the study had a single group, there is no separate treatment arm against which to compare the endpoint. Non-randomized allocation is not a substitute for random assignment: in this design, the registry does not establish a contemporaneous control group or a like-for-like comparison. The lack of masking also means that treatment and outcome assessment were not described as blinded. For the primary outcome, the investigator made a clinical judgment from nasal endoscopic examination, so the recorded classification depended on that assessment.
The primary outcome is a count of sinuses judged to have a patent ostium at 24 weeks. Its stated population is per protocol and includes all sinuses of subjects not lost to follow-up at that time. The record does not report how many sinuses contributed, how many subjects were assessed, or how many were unavailable for follow-up. Those omissions prevent reconstruction of the endpoint denominator from the enrollment figure alone.
The record lists three outcome measures and identifies relief of sinus symptoms as a secondary outcome. It does not report the details of the other outcome measures or any analysis results. The status is completed, but completion status does not supply an estimate of the primary outcome or establish how it was analyzed. The statistical plan, including any prespecified models or decision rules, is not reported in the registry record.
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
| Stage | Balloon Dilation of Sinus Ostia |
|---|---|
| STARTED | 115 |
| COMPLETED | 109 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | Balloon Dilation of Sinus Ostia |
|---|---|
| Physician Decision | 6 |
Analysis population for the primary outcome, as defined in the registry: Analysis per Protocol; based on all sinuses of subjects not lost to follow-up at 24 weeks
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 | Balloon Dilation of Sinus Ostia |
|---|---|---|
| Participants analysed | 115 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 102 |
| Age, Categorical: >=65 years | Participants | 13 |
| Age, Continuous | years | 47.8 (SD 12.59) |
| Sex: Female, Male: Female | Participants | 74 |
| Sex: Female, Male: Male | Participants | 41 |
| Region of Enrollment: United States | participants | 115 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Sinuses With Patency of Sinus Ostium After Sinuplasty, measured over 24 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Sinuses |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of sinuses with patency of the sinus ostium after sinuplasty, assessed at 24 weeks. The ostium is the opening of a sinus; the registry defines patency through nasal endoscopic examination and an investigator’s clinical judgment about whether patency has been achieved. The measurement unit is sinuses, rather than participants.
This outcome is used to describe whether the treated sinus opening is judged to be open at the specified follow-up. In general, an anatomical assessment can provide information about the condition of the treated structure. It is distinct from a patient-reported symptom outcome: a finding about ostium patency does not by itself establish the degree of symptom relief. The registry separately lists relief of sinus symptoms as a secondary outcome, but does not report its result.
The specified analysis population is per protocol and includes all sinuses of subjects not lost to follow-up at 24 weeks. The record does not report the observed number of patent sinuses, the denominator assessed, or a measure of uncertainty. The endpoint’s definition is available, but its numerical outcome and precision are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes the question and measurement procedure, but it does not provide an observed primary-endpoint result. There is no reported count of sinuses judged patent, no endpoint denominator, and no confidence interval or other uncertainty estimate. Accordingly, the posted record cannot establish the frequency of patency among the sinuses assessed or how precisely that frequency was estimated.
The study is single-group and non-randomized. Its endpoint can therefore describe findings after sinuplasty within the assessed group, but this record cannot support a randomized treatment contrast. Without a concurrent comparator, changes attributable to treatment cannot be separated from other explanations using this design alone. The record also does not state a baseline patency result against which the 24-week endpoint could be compared.
The primary assessment was an investigator’s judgment based on nasal endoscopy. That makes the definition clinically assessed rather than a count generated by a stated automated rule. The record does not report assessment blinding, assessor agreement, or criteria beyond the judgment of whether patency was achieved. These details would be relevant for understanding how consistently the endpoint might be classified, but are not reported in the registry record.
Enrollment is listed as 115, while the primary endpoint applies to sinuses from subjects not lost to follow-up. Enrollment is not the endpoint denominator: the unit is sinuses, and the specified per-protocol population excludes subjects lost to follow-up at 24 weeks. The record gives neither the number of eligible sinuses nor the number retained for endpoint assessment. It is therefore not possible to infer completion or missingness from the enrollment figure.
The record lists three outcome measures, but only the primary endpoint and one secondary outcome are described in the registry entries. It lists zero analyses. This means the registry record does not supply statistical analysis results; it does not establish that no analyses were performed outside the record. No conclusion about the magnitude, uncertainty, or statistical significance of the primary finding can be drawn from the endpoint definition alone. The same applies to symptom relief, for which no outcome result is reported.
9. Statistical Methods Explained
The registry identifies the primary outcome as a count: the number of sinuses judged to have a patent ostium at 24 weeks. A count outcome records how many units meet a condition, rather than measuring a continuous quantity such as a laboratory value. Here, the unit is the sinus and the condition is endoscopically assessed patency. The record gives no observed count, denominator, dispersion measure, or analysis output, so no numerical estimate or precision can be described.
What does a count outcome represent?
A count is interpreted in relation to the number of units that could have met the outcome definition. For this endpoint, the denominator would need to reflect the sinuses assessed in the defined per-protocol population. The registry says that population includes all sinuses of subjects not lost to follow-up at 24 weeks, but does not report the resulting number of sinuses. Enrollment alone cannot provide that denominator because the measured units are sinuses and the endpoint population is defined by follow-up status.
In general, count data may vary more than a simple probability model expects. Over-dispersion is the term for this extra variation relative to a model’s assumptions. When it is present, a model that assumes less variation can produce uncertainty estimates that are too narrow. This is a general statistical consideration, not a finding about CLEAR: the record does not provide the outcome data or a fitted model from which to assess over-dispersion.
Why does the unit of analysis matter?
The endpoint counts sinuses belonging to subjects. When a study records multiple units from the same person, those units may be related rather than statistically independent. In general, treating related observations as independent can understate uncertainty, because the amount of information is less than it would be if every observation were unrelated. Analysis may need to account for clustering by subject. The registry does not report the number of sinuses per subject or whether any analysis accounted for within-subject dependence, so it is not possible to determine how this issue was handled.
The per-protocol definition also matters. It specifies the population for the primary endpoint as sinuses from subjects not lost to follow-up at 24 weeks. This is a restricted analysis population, rather than an outcome reported for everyone enrolled regardless of follow-up. In general, excluding unavailable follow-up can affect interpretation if the included and excluded subjects differ in ways related to the endpoint. The record does not give loss-to-follow-up counts or reasons, so the extent and potential effect of missing follow-up cannot be assessed.
What can uncertainty measures tell the reader?
In general, a confidence interval expresses a range of estimates compatible with the data and a stated statistical procedure. Its width reflects precision: a wider interval indicates greater uncertainty about the estimate. A point estimate alone would not show that uncertainty, and a count without its denominator is particularly difficult to interpret as a rate. For CLEAR, neither a numerical primary estimate nor an interval is reported in the registry record, so precision cannot be evaluated.
A p-value, when reported, describes how compatible data are with a specified statistical null model under its assumptions; it is not the probability that a treatment works or that a result is true. The registry lists zero analyses and provides no p-value or stated inferential model for the primary endpoint. There is therefore no basis in this record for discussing statistical significance. General explanations of p-values do not replace the missing outcome analysis.
How should the planning calculations be understood?
The registry’s planning assumptions describe an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The target effect is described as a stated fraction of the observed effect. These are planning assumptions, not results from this single-group trial. The record does not include the effect value, the fractions, or the resulting sample-size figures in the registry record for this analysis.
Such calculations are generally used to illustrate the number of participants per arm for a chosen power under specified assumptions. They are not observed power and should not be read as a retrospective measure of whether the completed study was adequately powered. In addition, an equal-allocation, two-arm planning framework does not match the recorded single-group design. The trial’s own sample-size justification is not reported in the registry record. No sample-size illustration can fill in the missing endpoint result or establish a treatment comparison.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, names the primary endpoint, and identifies relief of sinus symptoms as a secondary outcome. It does not describe the remaining outcome measure in the registry record, nor does it report outcome results. The relationship between the outcomes, any hierarchy for interpreting them, or any adjustment for multiple testing is not reported in the registry record.
Multiplicity arises when several outcomes or comparisons are tested: the more opportunities there are to identify a nominally notable finding, the greater the chance of at least one misleading result under a set of null hypotheses. Statistical plans can address this through prespecified priorities or adjusted procedures. This is a general concern, not evidence that the CLEAR analysis used or needed a particular adjustment. The registry does not provide an analysis plan or tests with which to assess multiplicity.
The primary population is stated as per protocol and includes sinuses of subjects not lost to follow-up at 24 weeks. The record does not give the number of subjects or sinuses missing, reasons for missing follow-up, or any method for handling missing outcomes. It also does not state whether another analysis population was used. The stated population therefore defines who was intended to contribute to the endpoint, but does not show how complete follow-up was or how missingness was treated.
These gaps limit interpretation of both the primary and secondary outcomes. The registry reports zero analyses, which means no analysis results are listed in the record. It does not establish that analyses were not conducted elsewhere.
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 |
|---|---|---|---|
| Balloon Dilation of Sinus Ostia | 0 | 109 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Balloon Dilation of Sinus Ostia | 9 of 109 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Balloon Dilation of Sinus Ostia |
|---|---|---|
| bacterial sinusitis | General disorders | 9 of 109 |
For the adverse-event grouping titled Balloon Dilation of Sinus Ostia, the registry records 109 at risk for serious adverse events and 0 affected. For other adverse events, it records 109 at risk and 9 affected. These are the counts in the registry categories; the record does not provide further detail about the events represented by the other-adverse-event count.
The serious-event terms list is empty. Deaths are not reported in the registry record: the death entry is not a reported count, and it should not be interpreted as evidence that no deaths occurred. The at-risk figures are safety denominators and should not be substituted for the primary endpoint population, whose unit and follow-up definition differ.
These safety figures are descriptive registry entries. They do not by themselves establish a comparative safety profile, because the study has a single group and no control arm. The record does not give event timing, severity detail beyond the serious/other categorization, or additional context needed to compare risks. No percentages or comparative estimates are reported.
12. What the Result Does, and Does Not, Mean
The registry record establishes that CLEAR was a prospective, multi-center post-market evaluation of sinuplasty for chronic sinusitis, with a single-group, non-randomized design. It defines a primary endpoint based on investigator-assessed sinus ostium patency at 24 weeks. It also records adverse-event counts and identifies relief of sinus symptoms as a secondary outcome. These are descriptions of study design and planned measurement, not a complete presentation of clinical findings.
The primary endpoint result is not reported in the registry record. Without the number of patent sinuses and the number assessed, readers cannot determine the observed proportion or count in context. Without an uncertainty estimate, they cannot assess the precision of an endpoint estimate. The enrollment figure does not resolve these gaps because the endpoint counts sinuses in a per-protocol population of subjects not lost to follow-up.
The single-group design also does not provide a randomized comparison with an alternative or control. Any observed post-procedure outcome, if reported elsewhere, would need to be interpreted in light of that design and the lack of a concurrent comparator. The record does not state a baseline outcome or provide an analysis that estimates change attributable to the intervention.
The safety entries report 0 affected in the serious-event category and 9 affected in the other-adverse-event category, each with 109 at risk. Those categories are descriptive, not comparative. Deaths are not reported in the registry record, and no serious-event terms are listed. The safety figures cannot answer questions about comparative risks or the nature and timing of events beyond what the record states.
Accordingly, the available information supports a description of the study’s question, structure, endpoint definition, and listed adverse-event counts. It does not establish the size or precision of the primary outcome, statistical significance, a treatment effect relative to a control, or a definitive safety comparison.
13. Why This Trial Matters Statistically
This study illustrates why an endpoint’s definition and its result must be distinguished. CLEAR specifies a clinically assessed endpoint: the number of sinuses with a patent ostium at 24 weeks. But without the observed count and the number of sinuses assessed, the endpoint cannot be interpreted quantitatively. A clearly named outcome is not itself evidence about its magnitude or precision.
The unit of measurement also matters. The primary outcome counts sinuses, while enrollment counts participants. The endpoint population is further restricted to sinuses of subjects not lost to follow-up and is described as per protocol. These distinctions mean that the enrollment figure cannot stand in for the endpoint denominator. They also raise a general analysis issue: observations from multiple sinuses in the same person may be related, and uncertainty estimates should reflect such clustering when appropriate. The registry does not report how this was handled.
Finally, the design shapes the claims the data could support. A single-group, non-randomized evaluation can describe outcomes in its assessed group, but it does not create a randomized comparison. Registry entries about completed status and safety counts do not replace the missing endpoint analysis or supply a comparator. CLEAR therefore provides a useful example of how design, outcome definition, analysis population, and reporting completeness jointly govern what statistical conclusions are available.
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 limitation for statistical interpretation is that the registry record does not report the primary endpoint result. It also omits the number of sinuses assessed and the number of subjects contributing to that assessment. Since the endpoint unit is sinuses and the population is per protocol, the enrollment count cannot be used as its denominator.
The primary outcome relies on an investigator’s clinical judgment from nasal endoscopy. The registry does not describe more detailed criteria for classifying patency, assessor agreement, or blinded assessment. The study is listed as having no masking, and the record does not report any approach to reduce or evaluate potential assessment variability.
The single-group, non-randomized design provides no concurrent control group for a like-for-like comparison. The registry also does not report a baseline endpoint measure or a statistical analysis that would address change over time. The study’s own statistical plan and sample-size justification are not reported in the registry record.
Follow-up and analysis details are incomplete. The primary population excludes subjects lost to follow-up at 24 weeks, but the record does not give the number lost, reasons for missingness, or methods for handling missing outcomes. It lists three outcome measures but provides limited detail about them and no analysis results. The possibility of related sinus observations within subjects is also relevant to count-data analysis, but the record does not say whether clustering was addressed.
These limitations concern what can be learned from the registry record; they do not establish that the study lacked additional procedures or analyses outside it.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Clinical Evaluation to Confirm Safety and Efficacy of Sinuplasty in the Paranasal Sinuses (CLEAR) — NCT00231062.
- Registry record last updated 2024-08-06; status last verified 2024-07.
- Results first posted 2011-07-08.
- 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
CLEAR is a completed, Phase 3, multi-center, prospective post-market evaluation of sinuplasty for chronic sinusitis. The registry lists enrollment of 115, a single-group model, non-randomized allocation, and no masking. The study start is 2005-04 and primary completion is 2006-06.
The primary outcome is the number of sinuses with a patent ostium at 24 weeks, determined by nasal endoscopic examination and investigator judgment. Its stated population is per protocol and includes sinuses of subjects not lost to follow-up. Relief of sinus symptoms is listed as a secondary outcome. The registry lists three outcome measures and zero analyses.
The primary outcome result, its denominator, uncertainty estimates, and the statistical analysis plan are not reported in the registry record. Safety entries list 0 affected for serious adverse events and 9 affected for other adverse events, with 109 at risk in each category.