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 Ultrathin Bronchoscope and Radial Endobronchial Ultrasound (R-EBUS) With Fluoroscopy Versus Standard Fiberoptic Bronchoscopy (FB) (P00029233 ) (NCT02146131), a randomized na study. The primary outcome is Diagnostic Yield of Procedures; Number of Positive Diagnosis of Pulmonary Lesions.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02146131 |
| Phase | NA |
| Condition | Pulmonary Lesions, Pulmonary Nodules, Pulmonary Mass |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 339 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medical University of South Carolina |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with pulmonary lesions, including pulmonary nodules and masses. The primary-outcome description specifies lung lesions 2-5 cm. Further eligibility details and participant characteristics are not reported in the registry record.
Intervention
The intervention is bronchoscopy using an ultrathin bronchoscope with radial endobronchial ultrasound (R-EBUS) and fluoroscopy. The outcome description includes procedures with or without a Guidesheath. The arm description indicates an attempt to locate the lesion with mechanical R-EBUS, but the registry record does not give a complete procedural description.
Comparator
The comparator is standard fiberoptic bronchoscopy (FB) with fluoroscopy, using a standard adult bronchoscope. The record describes the two approaches as methods for obtaining lung tissue samples.
Primary question
The clinical question is whether the diagnostic yield, expressed as the number of positive diagnoses of pulmonary lesions, differs between the two bronchoscopy approaches. The record identifies this outcome but does not report the primary-outcome results or a between-group estimate.
In general, a randomized comparison is intended to assess outcomes between groups assigned to different procedures. Random assignment can help balance prognostic factors across groups on average, although the registry record does not describe the randomization procedure or report baseline characteristics with which to assess balance. The study is described as multicenter, prospective, randomized, and parallel, with no masking. The record lists an enrollment of 339, but does not give the number included in the primary-outcome analysis or explain how the enrollment relates to the adverse-event groups.
The stated diagnostic-yield description is limited to lesions 2-5 cm. Other boundaries of the population, such as detailed inclusion and exclusion criteria, are not reported in the registry record. The record also does not state the expected direction or size of a difference. The study’s stated purpose is to compare the yield of the two methods and assess whether R-EBUS provides better results than standard bronchoscopy; that purpose is not itself evidence of an observed difference.
3. Trial Design
This is a multicenter, prospective, randomized, parallel-group trial with no masking. The registry lists an enrollment of 339 and marks the study as completed. The sponsor is the Medical University of South Carolina. The listed start is 2014-07, and the primary completion date is 2017-07-14. The phase is listed as NA.
Participants were assigned to one of two procedure groups: standard FB with fluoroscopy, or R-EBUS with an ultrathin bronchoscope. Both approaches use fluoroscopy, according to the study description. The standard-FB arm description refers to moderate or deep sedation, a standard adult bronchoscope, topical anesthesia, and fluoroscopic localization. The ultrathin-bronchoscope description refers to moderate or deep sedation, an ultrathin bronchoscope, topical anesthesia, and an attempt to locate the lesion with mechanical R-EBUS. The registry descriptions are incomplete, so further procedural details are not reported in the registry record.
In general, a parallel design assigns participants to a group and compares outcomes between groups; it does not imply that each participant receives both procedures. Randomization describes how assignment is intended to occur, but the registry does not give the sequence-generation method, allocation concealment procedures, or group sizes at randomization. No masking is listed. The record does not explain whether outcome assessors, pathologists, or other personnel were masked.
The primary outcome is described as the number of positive diagnoses of pulmonary lesions, with a timeframe stated as from randomization until first documented progression or death from any cause, whichever came first, assessed up to 12 months. The outcome description also characterizes diagnostic yield for lung lesions 2-5 cm. The registry record does not clarify how that stated timeframe was used to determine a positive diagnosis or how a diagnostic-yield event was operationalized. It lists one outcome measure, but does not report an analyzable primary-outcome comparison. Details on recruitment, participant flow, protocol deviations, and the analysis population are 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 | Standard FB With Fluoroscopy | R-EBUS With Ultrathin Bronchoscope |
|---|---|---|
| STARTED | 170 | 169 |
| COMPLETED | 109 | 113 |
| NOT COMPLETED | 61 | 56 |
Reasons for not completing this period:
| Reason | Standard FB With Fluoroscopy | R-EBUS With Ultrathin Bronchoscope |
|---|---|---|
| Physician Decision | 61 | 56 |
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 | Standard FB With Fluoroscopy | R-EBUS With Ultrathin Bronchoscope | Total |
|---|---|---|---|---|
| Participants analysed | 109 | 113 | 222 | |
| Age, Continuous | years | 67.6 (SD 11.2) | 70.1 (SD 9.9) | 68.9 (SD 10.6) |
| Sex: Female, Male: Female | Participants | 56 | 51 | 107 |
| Sex: Female, Male: Male | Participants | 53 | 62 | 115 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): Asian | Participants | 1 | 2 | 3 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 29 | 26 | 55 |
| Race (NIH/OMB): White | Participants | 76 | 85 | 161 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 2 | 0 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Diagnostic Yield of Procedures; Number of Positive Diagnosis of Pulmonary Lesions, measured over From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 12 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is titled “Diagnostic Yield of Procedures; Number of Positive Diagnosis of Pulmonary Lesions.” It is expressed as a number of participants and described as comparing diagnostic yield for standard FB with fluoroscopy against bronchoscopy using an ultrathin bronchoscope with R-EBUS, with or without Guidesheath, for lung lesions 2-5 cm.
In general, diagnostic yield describes how often a procedure produces a diagnosis under a defined outcome rule. For a comparison between procedures, the rule must specify what counts as a positive diagnosis, how uncertain or non-diagnostic samples are classified, and how the result is attributed to the procedure. These details matter because changing the classification rule can change the event count. The registry record does not describe the positive-diagnosis criteria or give the number of positive diagnoses in either group.
The listed timeframe runs from randomization until first documented progression or death from any cause, whichever came first, assessed up to 12 months. The record does not explain how progression or death relates to the diagnostic-yield outcome, or whether these events determine censoring, outcome status, or follow-up duration for this measure. The primary endpoint therefore identifies the intended subject of comparison, but its operational definition and observed group results are not reported in the registry record. Without those results, the size and precision of any difference in diagnostic yield cannot be described.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a randomized comparison of two bronchoscopy approaches and names diagnostic yield as the primary outcome. However, it does not report positive-diagnosis counts by group, a treatment-effect estimate, a confidence interval, or a p-value. It lists zero analyses. The record also flags that the primary outcome has several categories or time points and was not reduced to one comparison. As a result, no single primary-outcome result can be interpreted from the registry information.
This absence is important for statistical interpretation. A study question can be stated without a result being available. The trial purpose says the procedures were compared to assess whether R-EBUS provides better results, but that wording does not establish that one procedure had greater yield. No claim about the direction, size, or statistical significance of a difference is supported by the posted registry results.
In general, an effect estimate describes the observed contrast between groups, while a confidence interval describes the range of values compatible with the data and the stated analysis assumptions. A p-value, when reported, assesses compatibility with a specified null hypothesis under the statistical model; it does not measure the probability that a treatment is effective. None of these quantities is reported for the primary endpoint in the registry record. Thus, neither the magnitude of an observed contrast nor its precision can be assessed from this record.
The enrollment is 339, while adverse-event groups list 109 participants at risk in the standard-FB group and 113 in the R-EBUS group. Those adverse-event denominators should not be treated as primary-outcome denominators: the registry does not say that they represent the outcome-analysis populations, and the primary endpoint counts are not reported. The reason the denominators differ from the enrollment is also not reported in the registry record.
The registry lists no masking and gives limited information about outcome assessment. In general, an outcome requiring judgment can be affected by knowledge of group assignment, depending on how the outcome is defined and assessed. The record does not explain the diagnostic adjudication process, so the potential role of assessor knowledge cannot be evaluated. Likewise, without participant flow, missing-data information, or analysis-population definitions, it is not possible to determine how completeness of follow-up or exclusions might affect the primary comparison.
The adverse-event figures describe recorded counts, not the diagnostic-yield result. They show no serious adverse events among the participants listed at risk in either group, and they list other adverse events in both groups. The registry does not provide definitions, follow-up details, or a statistical comparison for these figures. They should not be used to infer the relative safety of the procedures beyond the limited counts reported.
Overall, the registry supports a description of the trial design, intended endpoint, and listed adverse-event counts. It does not support a conclusion about the primary endpoint’s comparative result, statistical significance, or precision. The registry record also does not report whether additional analyses were conducted elsewhere.
9. Statistical Methods Explained
The trial is described as randomized, parallel, prospective, and unmasked. Those labels summarize broad design features, but do not provide the full statistical analysis plan. The registry record does not report the randomization method, allocation concealment, planned model, covariate adjustments, hypothesis-testing procedure, confidence-interval method, or handling of missing outcomes. No specific method should be attributed to the trial without those details.
What does randomization contribute?
In general, randomization assigns participants to groups using a chance-based process. Its purpose is to reduce systematic differences between groups at assignment, including differences in measured and unmeasured characteristics. Randomization does not guarantee that every characteristic will be balanced in a particular trial, especially when groups are limited in size. Assessing the realized groups requires information such as baseline characteristics and participant flow, which are not reported in the registry record. The record states that allocation was randomized, but does not describe how the sequence was generated or concealed before assignment.
What does a binary outcome require?
The registry classifies the outcome as binary and describes it as participants with an event, in this context a positive diagnosis. In general, a binary endpoint requires an explicit rule that classifies each participant as having or not having the event. The event definition, assessment process, and treatment of indeterminate results are important because they determine which observations count in each category. The registry record does not specify these rules or report the positive-diagnosis counts. It also identifies several categories or time points rather than one reduced comparison, so the intended primary comparison cannot be reconstructed from the registry entry.
For a binary outcome, investigators may report group-specific event counts and denominators, then estimate a contrast such as a difference or ratio between groups. The appropriate estimand and analysis depend on the question and the design. No such effect estimate or model is reported in the registry record, and no new estimate can be recovered from the adverse-event counts because those are different outcomes.
How should uncertainty be understood?
In general, a confidence interval expresses uncertainty around an estimated quantity under a specified method and assumptions. A narrower interval indicates greater precision for that estimate; a wider interval indicates less precision. An interval’s interpretation depends on the estimand, data, and method used. Since the primary-outcome estimate and interval are not reported, the precision of the diagnostic-yield comparison cannot be evaluated.
A p-value is a measure calculated under a statistical model and a null hypothesis. It is not an effect size, a measure of clinical importance, or the probability that the null hypothesis is true. Its interpretation also depends on which comparisons were planned and how multiplicity was handled. The registry record lists no analyses and supplies no primary-outcome p-value, so no significance assessment is available.
Why do missing-data and analysis-population rules matter?
In general, missing outcome data can affect estimates when the availability of outcome information is related to group assignment or participant characteristics. Analysis populations can also differ: some analyses may follow randomized assignment, while others may be restricted according to treatment received or outcome availability. These choices affect what question an estimate answers. The registry record does not report missing-data counts, reasons for missingness, participant disposition, or the analysis population used for the primary endpoint.
The adverse-event groups list participants at risk, but those figures do not establish the primary-outcome analysis denominators. The registry gives 109 at risk for standard FB with fluoroscopy and 113 at risk for R-EBUS with an ultrathin bronchoscope in the adverse-event data. It does not explain how these groups relate to the enrollment of 339 or whether their denominators apply to other outcomes. No inference about exclusions or missing primary outcomes follows from these counts.
What do the planning assumptions mean?
The registry’s sample-size assumptions describe planning illustrations computed from the observed effect, not the trial’s own design. They specify a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. The assumptions say that time-to-event illustrations give total events using Schoenfeld, while other illustrations give participants per arm. These are planning conventions, not observed trial outcomes and not observed power. The registry record does not report the trial’s own sample-size justification or the numerical planning illustrations in the information available for this account. The primary-outcome effect itself is also not reported, so the planning assumptions cannot establish the trial’s achieved precision.
In general, sample-size planning depends on assumptions about the outcome frequency or effect, variability, allocation, significance level, and desired power. An illustration based on an observed effect is conditional on that effect and does not show what power the completed trial had. A completed trial’s interpretation should instead focus on its estimated effect and uncertainty, neither of which is reported for the primary endpoint in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record flags that the primary outcome has several categories or time points and was not reduced to one comparison. It does not report which comparison was designated as primary for analysis, how categories or time points were handled, or whether any multiplicity procedure was planned. It lists no analyses and provides no primary-outcome test results. Therefore, the risk of inflated false-positive findings from examining multiple comparisons cannot be assessed from this record.
In general, multiplicity arises when several hypotheses, outcomes, time points, or subgroups are examined. If many tests are interpreted without accounting for the number of opportunities to find a result, the chance of at least one apparently unusual result can increase. Methods for handling multiplicity depend on the analysis plan and the inferential goal. No particular correction or testing hierarchy is reported in the registry record.
The record does not report missing primary-outcome data, reasons for missingness, or how such data were handled. It also does not identify the primary analysis population or state whether participants were analyzed according to randomized assignment. These omissions prevent assessment of whether the reported enrollment corresponds to the group included in an outcome analysis, and whether any exclusions or incomplete follow-up could affect the estimate. The adverse-event at-risk counts are not identified as primary-outcome denominators. Any assumptions about missingness or analysis populations would therefore be speculative.
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 |
|---|---|---|---|
| Standard FB With Fluoroscopy | 0 | 109 | 0.0% |
| R-EBUS With Ultrathin Bronchoscope | 0 | 113 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard FB With Fluoroscopy | 0 of 109 |
| R-EBUS With Ultrathin Bronchoscope | 0 of 113 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Standard FB With Fluoroscopy | 6 of 109 |
| R-EBUS With Ultrathin Bronchoscope | 5 of 113 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Standard FB With Fluoroscopy | R-EBUS With Ultrathin Bronchoscope |
|---|---|---|---|
| Adverse Event | Respiratory, thoracic and mediastinal disorders | 6 of 109 | 5 of 113 |
The adverse-event record lists serious adverse events in 0 of 109 participants at risk in the Standard FB With Fluoroscopy group and 0 of 113 participants at risk in the R-EBUS With Ultrathin Bronchoscope group. It lists other adverse events in 6 of 109 participants at risk in the standard-FB group and 5 of 113 participants at risk in the R-EBUS group. Deaths are listed as 0 in each group.
These are recorded counts, not a statistical comparison. The registry record does not give definitions for “serious” or “other” adverse events, describe how events were collected, specify the relevant safety follow-up period, or report whether events were considered related to a procedure. It also does not provide confidence intervals or a test comparing groups. The at-risk denominators are reported for the adverse-event data only; the registry does not establish that they are the denominators for the primary endpoint.
In general, zero recorded events in a group does not establish that the underlying risk is zero. Interpretation depends on the amount and duration of observation, event definitions, and completeness of reporting. The limited counts in the registry record do not by themselves establish a comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The registry record describes a completed randomized trial intended to compare diagnostic yield for standard fiberoptic bronchoscopy with fluoroscopy and an ultrathin bronchoscope with R-EBUS and fluoroscopy. Its primary outcome is identified as the number of positive diagnoses of pulmonary lesions, with a description focused on lesions 2-5 cm. The record also gives limited adverse-event counts.
What the record does not provide is the central evidence needed to interpret the primary comparison: positive-diagnosis counts by group, an effect estimate, a confidence interval, or a p-value. It also does not give the primary analysis population, missing-outcome information, or a detailed definition of a positive diagnosis. The stated study purpose cannot substitute for those results. It indicates what the trial sought to compare, not what the comparison found.
In general, a difference in event counts or an estimated contrast should be interpreted alongside its uncertainty and the outcome definition. A result can be imprecise even when the observed groups appear different, and an estimate can be precise without establishing that a difference is important for a clinical decision. The registry record supplies no primary-outcome estimate with which to make either assessment. No claim about benefit, lack of benefit, or equivalence between procedures is supported by the posted results.
The adverse-event data show the recorded counts within the reported at-risk groups. They do not provide a full safety analysis, and they should not be used as evidence about diagnostic yield. Likewise, the enrollment figure does not reveal how many participants contributed outcome data or why the adverse-event denominators differ from enrollment.
Accordingly, the most defensible reading is descriptive: the registry documents the design, intervention groups, endpoint description, and a small set of safety counts, while the comparative primary-outcome result is not reported in the registry record. Any further conclusion would require outcome results and analysis details not available in this record.
13. Why This Trial Matters Statistically
This trial poses a clear statistical comparison: two randomized procedure groups, a parallel design, and a named diagnostic-yield outcome. That structure makes the distinction between a research question and an analysis result especially important. The record states what the study set out to compare, but does not report the primary-outcome counts or an estimate of the difference. Without those, the comparison cannot be quantified or assessed for precision.
There is also an important issue of endpoint definition. The registry describes positive diagnoses and specifies lesions 2-5 cm, while its timeframe refers to progression or death up to 12 months. It also flags several categories or time points and does not reduce them to one comparison. These details leave unresolved how the outcome was operationalized and which contrast was intended to answer the primary question. A statistical analysis is interpretable only when the event definition and comparison are clear.
The trial record also illustrates why study design labels alone do not complete an evaluation. Randomization is reported, but details of the sequence, concealment, outcome assessment, analysis population, and missing data are not. In general, these features help readers assess whether the observed groups remain comparable and how robust an estimate might be. Their absence from the registry entry limits that assessment.
Finally, sample-size planning illustrations are distinct from evidence about the completed comparison. The registry describes assumptions for illustrations based on an observed effect, but these do not replace an outcome estimate or show observed power. The central statistical value of a completed randomized trial comes from its estimated effect and uncertainty, interpreted under a transparent outcome definition and analysis plan. Those primary results are not reported in the registry record.
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 most consequential limitation of the registry record is that it does not report the primary-outcome results, despite identifying diagnostic yield as the primary outcome. Positive-diagnosis counts, group denominators for that outcome, a comparative estimate, confidence interval, and p-value are not reported. The registry lists zero analyses and notes that the primary outcome has several categories or time points without a single comparison. The magnitude and precision of the intended comparison therefore cannot be assessed.
The endpoint description leaves questions about operational definition. It names positive diagnoses and lung lesions 2-5 cm, and gives a timeframe extending from randomization to progression or death, assessed up to 12 months. The relationship between that timeframe and diagnostic yield is not explained. Criteria for positive, negative, or indeterminate findings are not reported in the registry record.
Information about participant flow is also limited. The record gives an enrollment of 339, while the safety groups list 109 and 113 participants at risk. It does not explain the relationship between these figures, identify primary-outcome denominators, or report exclusions and missing data. The analysis population is not reported.
The registry lists no masking, but does not say whether diagnostic assessment was blinded or describe adjudication. It does not provide the randomization method, allocation concealment, detailed eligibility criteria, or a complete account of the procedures. The record also does not report a statistical analysis plan, multiplicity handling, or the trial’s sample-size justification. These are limitations of what can be assessed from the registry record; they do not establish that such procedures or analyses were absent from the conduct of the trial.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Ultrathin Bronchoscope and Radial Endobronchial Ultrasound (R-EBUS) With Fluoroscopy Versus Standard Fiberoptic Bronchoscopy (FB) (P00029233 ) — NCT02146131.
- Registry record last updated 2018-09-25; status last verified 2018-08.
- Results first posted 2018-09-25.
- 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
NCT02146131 is a completed, multicenter, prospective, randomized, parallel-group trial with no masking. It compares standard fiberoptic bronchoscopy with fluoroscopy against R-EBUS using an ultrathin bronchoscope, for pulmonary lesions. The listed enrollment is 339; the sponsor is the Medical University of South Carolina. The start is listed as 2014-07, and primary completion is listed as 2017-07-14.
The primary outcome is diagnostic yield, described as the number of positive diagnoses of pulmonary lesions, with the outcome description focused on lesions 2-5 cm. The primary-outcome comparison and analysis are not reported in the registry record. The adverse-event record lists no serious adverse events or deaths in either group, and lists other adverse events in both groups. Safety definitions, follow-up details, and comparative analyses are not reported.