Robotic Bronchoscopy for Peripheral Pulmonary Lesions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Robotic Bronchoscopy for Peripheral Pulmonary Lesions (NCT03727425), a na na study. The primary outcome is Number of Participants With Device or Procedure Related Adverse Events.

2. Clinical Question

The study's stated purpose was to evaluate the feasibility of robotic navigation of peripheral airways in human subjects for biopsying peripheral lung lesions. The primary outcome focuses on participants with device- or procedure-related adverse events, rather than diagnostic performance or a comparison with another procedure. The registry also names diagnostic yield, lesion localization, procedure time, and complications unrelated to the device among secondary outcomes.

Because this is a single-group pilot and feasibility study, its clinical question is descriptive. It asks what was observed among participants who underwent the procedure; it does not ask whether robotic bronchoscopy performs better than another approach. The primary outcome description identifies a procedure-based population of 54 patients, while the adverse-event record gives a group at-risk count of 55. The record does not explain that difference. The primary outcome count itself is not reported in the registry record, so its result cannot be assessed from the listed information.

3. Trial Design

The registry identifies this as a completed, multicenter pilot and feasibility study of robotic bronchoscopy for peripheral pulmonary lesions. Its model is single group, with allocation recorded as NA and masking recorded as NONE. Enrollment is 55. The study start date is 2018-11-01, and primary completion is recorded as 2019-09-12. The sponsor is Auris Health, Inc.

The intervention is robotic-assisted bronchoscopy, described as using the Monarch platform. The study summary says the purpose was to evaluate the feasibility of robotic navigation of peripheral airways for biopsying peripheral lung lesions. No separate control intervention or comparison group is described. Accordingly, outcomes should be read as observations within the treated group, not as contrasts between treatments.

The primary outcome is the number of participants with device- or procedure-related adverse events in the 24-84 hours post-procedure timeframe. The registry's outcome description identifies 54 patients who underwent the procedure as the primary-outcome population. Separately, the adverse-event record lists 55 at risk for the robotic-assisted bronchoscopy group. The registry does not explain how those populations relate.

Secondary outcomes named in the record include incidence of complications unrelated to the device, time to R-EBUS confirmation for lesion localization, total procedure time, and diagnostic yield. The record lists six outcome measures, but does not provide a statistical analysis for the primary outcome; it lists zero analyses. Allocation, masking, and the single-group structure mean that the record does not support a randomized or blinded comparison. Further protocol details, including any planned sample-size justification or interim analyses, 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

Analysis population for the primary outcome, as defined in the registry: 54 patients underwent the robotic bronchoscopy procedure

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 Number of Participants With Device or Procedure Related Adverse Events, measured over 24-84 hours post-procedure.

The primary endpoint counts participants with device- or procedure-related adverse events during the 24-84 hours post-procedure timeframe. Its unit is participants, and the registry describes it as a count of patients with such events among patients who underwent robotic bronchoscopy. This is a participant-level outcome: it is intended to count people with an event, rather than the total number of event episodes.

For a feasibility study of a procedure, monitoring device- or procedure-related adverse events can help characterize the experience of performing that procedure. As a general statistical point, a binary endpoint such as whether a participant experienced an event can be summarized as a count and a proportion, with uncertainty depending in part on the number of participants observed. That does not by itself establish how frequently an event would occur in other settings or populations.

The registry identifies 54 patients as having undergone the procedure for the primary-outcome description, but does not report the number of those patients who experienced the specified events. It therefore does not provide a primary endpoint estimate or an interval describing its precision. The separate adverse-event figures cannot be assumed to be the primary endpoint result: the record does not state that the adverse-event categories and timeframe are identical to the primary endpoint definition, and it lists 55 at risk in the safety group. The relation between those figures and the primary outcome population is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary endpoint as a count of participants with an event. This is a binary outcome at the participant level: each participant is classified according to whether the specified event occurred during the defined observation period. A count can be paired with a denominator to form a proportion, which is commonly used to describe the observed frequency in a group. The registry supplies the endpoint unit, event definition, timeframe, and the number of patients described as having undergone the procedure, but not the primary event count. No primary proportion can therefore be recovered from the record without inventing information.

In general, uncertainty around a binary-outcome estimate reflects both the observed frequency and the amount of information in the data. Confidence intervals are one way to express that uncertainty. Their interpretation is tied to the estimator and method used, so reporting the interval and its method helps readers assess precision. The registry record does not report a confidence interval, a standard error, or the method used to estimate uncertainty for the primary endpoint. General statistical explanations cannot fill in those missing trial results.

The design is single group, not a randomized comparison. In a comparative trial, an analysis may estimate a difference between groups and quantify uncertainty around that contrast. Here, no control group is described, so there is no between-group treatment effect to estimate from the registry entry. A within-group event count is a descriptive result, not evidence of a causal difference. Even if a group estimate were reported, the design would not answer what would have happened to those same participants under a different procedure.

The record lists the planning assumptions used for sample-size illustrations: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects defined as stated fractions of the observed effect. Those are planning illustrations computed from an observed effect, not the study's own design. The trial itself is recorded as single group, and the primary outcome result is absent, so the illustrations should not be interpreted as observed power or as a sample-size justification for this study. Sample-size planning asks what information a future design might need under stated assumptions; it does not establish that a completed study had adequate precision.

In general, the normal approximation is a simplifying method for estimating uncertainty or planning sample sizes. Its appropriateness depends on the setting and the amount and pattern of information. For binary data with limited observations or uncommon events, approximations may not describe uncertainty well; exact or other methods may be considered. This is general statistical context, not a claim about which method was used for this trial. The registry does not report an outcome analysis method, so the approach actually used cannot be identified.

Over-dispersion is a general concern when observed variation exceeds what a chosen model assumes. It is often discussed for count outcomes when observations are more variable than a basic model allows. The primary endpoint is a count of participants with an event, which is distinct from a count of repeated event episodes. The record does not describe a model, repeated-event analysis, or any adjustment for over-dispersion. There is therefore no basis for attributing a particular modeling choice or concern to the trial. A suitable analysis would depend on the precise endpoint and data structure, neither of which is fully documented in the posted outcome results.

The study is described as multicenter, but the registry information does not state how many centers contributed data or whether the analysis accounted for center-level variation. In general, participants treated at the same center may share features that make their outcomes more alike than outcomes from participants at other centers. If a study's analysis needs to account for that structure, it should report its method. No such method is listed, and no inference about center effects is warranted.

The outcome list includes measures with different forms, such as event counts, time measures, and diagnostic yield. Different outcome types may call for different estimators and uncertainty measures. A statistical analysis plan would clarify which methods were assigned to which endpoints, how missing values were handled, and how multiple outcomes were interpreted. Those details are not reported in the registry record. The record lists zero analyses, so no endpoint-specific statistical procedure can be described as having been reported.

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("Robotic Assisted Bronchoscopy")
n      <- c(54)
events <- c(2)
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  Robotic Assisted Bronchoscopy  54  2  3.7  0.5  12.7  1.0  12.5  1.1  12.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and names secondary outcomes covering complications unrelated to the device, time to R-EBUS confirmation, total procedure time, and diagnostic yield. It does not report a multiplicity adjustment or describe a hierarchy for interpreting the outcomes. In general, when several outcomes are examined, the chance of a positive finding by chance can increase if each is tested separately. Methods such as prespecifying a primary outcome or adjusting inference can address particular multiplicity concerns, but the record does not say whether any such plan was used. The listed zero analyses also means no multiplicity-adjusted result is reported.

Missing-data methods are not reported in the registry record. The primary outcome description refers to 54 patients who underwent the procedure, while the adverse-event listing gives 55 at risk. The record does not explain whether these counts reflect different analysis populations, missing endpoint data, or another reason. They should not be reconciled by assumption. No information is given on withdrawals, exclusions, incomplete observations, imputation, or sensitivity analyses.

The registry does not define an intention-to-treat population or another analysis population for the primary outcome. It does identify the 54 patients who underwent the procedure in the endpoint description, but does not state whether that population was used in an analysis or how participants without an observed endpoint were handled. The 55 at-risk figure belongs to the separate adverse-event entry. Without a documented relationship among these counts, analysis populations and denominators remain uncertain. This limits reproducibility and makes it difficult to judge whether the posted safety counts and the primary endpoint would describe the same participants.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: pneumothorax (3.6%).

The registry's adverse-event entry for robotic-assisted bronchoscopy lists 55 participants at risk, with 2 participants affected by serious adverse events. It records 0 affected by other adverse events and 0 deaths. These are group-level counts in the adverse-event record; they are not the reported primary endpoint result, which is not given. The registry also lists pneumothorax among the top serious terms at 3.6%. The denominator and counting basis for that percentage are not specified in the record.

Serious adverse events and other adverse events are separate categories in the entry. The counts do not indicate how events were judged to be related to the device or procedure, beyond the registry's category labels, and the entry does not provide event-level detail. The primary endpoint has its own description and timeframe, while the adverse-event entry does not establish that its categories correspond exactly to that endpoint. The primary endpoint population is described as 54 patients, whereas the safety entry lists 55 at risk; the reason is not reported in the registry record.

These observations describe the listed group only. Without a comparator, an analysis of uncertainty, and clarification of the event definitions and populations, the counts cannot establish a comparative safety difference or characterize risk in other settings.

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

The study record gives useful context about what was evaluated: a robotic-assisted bronchoscopy procedure using the Monarch platform, in a multicenter pilot and feasibility study with a single group. It identifies a primary outcome focused on participants with device- or procedure-related adverse events and specifies the post-procedure timeframe. The record also lists adverse-event counts and names secondary outcomes.

Those details do not amount to a reported primary result. The number of participants meeting the primary endpoint is absent, as are an estimate of its frequency and an interval expressing uncertainty. The safety counts are not a substitute, because the registry does not establish that they use the same event definition, timeframe, or population as the primary outcome. The record's 54-patient primary-outcome population and 55-person safety at-risk count are not reconciled.

The single-group structure also limits what can be concluded. The data do not compare robotic bronchoscopy with another procedure, and no causal contrast is reported. A descriptive count, even when available, would speak to the recorded experience in the study group rather than establish a comparative effect. The record does not report diagnostic-yield results or results for the other secondary outcomes, so those outcomes cannot support conclusions from this entry.

In general, a pilot and feasibility study can describe whether a procedure was undertaken and characterize outcomes for further study. Its value for statistical interpretation depends on transparent outcome definitions, denominators, missing-data handling, and estimates of uncertainty. The registry does not report many of those analysis details. Thus the posted information documents the study's intent, design, and selected safety counts, but does not establish the primary endpoint estimate, its precision, or how the procedure compares with alternatives. No treatment recommendation follows from these registry data.

14. Why This Trial Matters Statistically

This record illustrates why a trial's design and its outcome reporting must be read together. A single-group feasibility study can describe a procedure and record adverse events, but it does not create the concurrent comparison needed to estimate a difference between treatment approaches. The registry makes that design feature explicit through its single-group model and lack of a comparator.

The primary endpoint is defined as a participant count within a stated post-procedure timeframe, and its population is described. Yet the result is not reported. Without the event count, readers cannot estimate the endpoint's observed frequency from the registry entry, and without an uncertainty measure they cannot assess its precision. This is a practical example of the difference between a well-specified outcome and a reported outcome analysis: defining what should be measured does not communicate what was observed.

The separate safety figures also show the importance of clear denominators and endpoint alignment. The adverse-event group has 55 at risk, while the primary outcome description refers to 54 patients who underwent the procedure. Both entries may be meaningful in their own context, but the record does not explain their relationship. Statistical interpretation depends on knowing which participants and events contributed to each result.

Finally, the record includes planning assumptions for illustrative sample-size calculations, while the actual study is single group and its primary result is not listed. Keeping planning illustrations separate from trial results prevents them from being mistaken for observed evidence or a justification of the completed design. Clear reporting of analyses, populations, and uncertainty would make the findings more assessable.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpretation is that the registry does not report the primary endpoint result. The endpoint definition, timeframe, and primary-outcome population are identified, but the count of participants with device- or procedure-related adverse events is absent. No estimate of precision or statistical test is listed. The registry lists zero analyses, so there is no reported analysis to evaluate.

The record's safety information is limited to group counts and a listed serious-event term. It does not supply event-level descriptions, a definition clarifying how events were classified, or the denominator and counting basis for the 3.6% listed for pneumothorax. The safety entry reports 55 at risk, while the primary endpoint description refers to 54 patients who underwent the procedure; the record does not explain the difference. This leaves uncertainty about population alignment.

The single-group design has no comparator, and the record gives no comparative estimate. It therefore cannot answer a comparative question using the reported design. Although the study is described as multicenter, details about center contributions or any handling of center-level variation are not reported. Missing-data procedures, analysis-population definitions, multiplicity handling, and interim analyses are also not reported in the registry record.

The registry names secondary outcomes, but their results are not included in the information recorded for this analysis. The planning assumptions describe illustrations rather than the trial's own design, and the record does not provide a sample-size justification. Taken together, these limits mean the entry describes the study and some safety counts, but does not permit a full assessment of its primary outcome, precision, or secondary findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Robotic Bronchoscopy for Peripheral Pulmonary Lesions — NCT03727425.
• Registry record last updated 2020-12-14; status last verified 2020-10.
• Results first posted 2020-12-14.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record identifies NCT03727425 as a completed, multicenter pilot and feasibility study of robotic bronchoscopy for peripheral pulmonary lesions. It records enrollment of 55, a single-group design, and robotic-assisted bronchoscopy using the Monarch platform. The stated purpose was to evaluate robotic navigation of peripheral airways for biopsy of peripheral lung lesions.

The primary outcome is the number of participants with device- or procedure-related adverse events during the 24-84 hours post-procedure timeframe. Its population description refers to 54 patients who underwent the procedure, but the primary event count is not reported in the registry record. The adverse-event entry lists 2 participants with serious events among 55 at risk, 0 with other events, 0 deaths, and pneumothorax at 3.6% among the top serious terms.

The record names secondary outcomes but lists zero analyses. It does not report a comparator, primary outcome estimate, confidence interval, or detailed analysis and missing-data methods. The safety counts should therefore be read descriptively and separately from the unreported primary endpoint result.