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 Post Market Evaluation of Aer-O-Scope Visualization (NCT02926209), a randomized na study. The primary outcome is Adenoma Miss Rates.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02926209 |
| Phase | NA |
| Condition | Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 104 |
| Arms in the primary outcome | 2 |
| Lead sponsor | GI View Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
People undergoing the study’s tandem colonoscopy procedures. More detailed eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
Colonoscopy using the Aer-O-Scope Colonoscope System as the first procedure for participants assigned to the Aer-O-Scope First sequence.
Comparator
Colonoscopy using a conventional colonoscope as the first procedure for participants assigned to the Conventional Colonoscope First sequence. Each participant was scheduled to undergo both procedures.
Primary question
How many adenomas detected on the second-pass colonoscopy had been missed during the first-pass colonoscopy, according to the device used first?
The registry describes a prospective, multicenter, multinational comparative investigation. Its central comparison concerns the order of the two colonoscopy procedures: Aer-O-Scope followed by conventional colonoscopy, or conventional colonoscopy followed by Aer-O-Scope. The first procedure was randomized. The same investigator was to perform both procedures for each participant.
In this tandem design, a lesion detected on the second pass and not marked during the first pass was treated as having been missed initially. The registry says adenoma status was based on histopathology. It records three lesions missed by Aer-O-Scope and detected during the subsequent conventional colonoscopy; two were not removed and one was not retrieved. It also notes missing data for two lesions by conventional colonoscopy.
The registry’s outcome label refers to adenoma miss rates, while the posted arm results are counts of missed adenomas. The record does not state a rate denominator or provide an inferential comparison. The population details needed to judge how broadly these findings apply are not reported in the registry record.
3. Trial Design
This was a randomized, non-blinded, parallel-assignment investigation with a tandem procedure for each participant. The registry describes the study as prospective, multicenter, and multinational. Participants were assigned to one of two sequences: Aer-O-Scope first and conventional colonoscopy second, or conventional colonoscopy first and Aer-O-Scope second. The first procedure was randomized, and each participant served as their own control in the tandem assessment. The same investigator was to perform both procedures for a participant.
The registry lists enrollment as 104. For the primary endpoint, the arm entries list 41 participants in the Aer-O-Scope First group and 37 in the Conventional Colonoscope First group. The relationship between the enrollment figure and the endpoint arm counts, including any participant flow or exclusions, is not reported in the registry record. The trial phase is listed as not applicable.
The primary completion date was 2017-11-08, and the study start date was 2017-02-21. The registry status is terminated. A reason for termination and a separate overall completion date are not reported in the registry record.
The second-pass examination was used to identify lesions that had not been found on the first pass. The registry says pathologies found were to be removed or tattooed, with unmarked lesions found on the second pass counted as missed on the first pass. Tattooed lesions that could be removed endoscopically could be addressed in an additional colonoscopy. The record gives a specific example of a large polyp that could not be removed for any reason with Aer-O-Scope but could be removed with conventional colonoscopy. The number of participants who underwent additional procedures 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.
Study Cohort
| Stage | Aer-O-Scope First | Conventional Colonoscope First |
|---|---|---|
| STARTED | 42 | 37 |
| COMPLETED | 41 | 37 |
| NOT COMPLETED | 1 | 0 |
Reasons for not completing this period:
| Reason | Aer-O-Scope First | Conventional Colonoscope First |
|---|---|---|
| Poor Bowel Preparation | 1 | 0 |
Training Cohort - First Patients
| Stage | Aer-O-Scope First | Conventional Colonoscope First |
|---|---|---|
| STARTED | 20 | 0 |
| COMPLETED | 20 | 0 |
| NOT COMPLETED | 0 | 0 |
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.
Population: These patients were part of the physician training cohort. The first 10 subjects for each physician constitute this cohort
| Characteristic | Unit | Training Cohort |
|---|---|---|
| Participants analysed | 98 | |
| Age, Customized: Overall Total Subjects | years | 55.41 (SD 5.84) |
| Age, Customized: Study Cohort | years | 55.33 (SD 5.99) |
| Sex: Female, Male: Female | Participants | 40 |
| Sex: Female, Male: Male | Participants | 58 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: Israel | Participants | 98 |
6. Primary Endpoint
The registry lists the primary outcome as Adenoma Miss Rates, measured over Through study completion, an average of one year.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | missed adenomas |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled Adenoma Miss Rates and is described as the number of adenomas missed during the first-pass colonoscopy, identified by the second-pass examination. Adenoma status was based on histopathology. Under the registry’s definition, an unmarked lesion detected on the second pass represented a lesion missed on the first pass. This approach uses the subsequent examination to identify lesions not detected initially, rather than relying only on a retrospective report of the first examination.
The registry describes three lesions missed by Aer-O-Scope and detected by the subsequent conventional colonoscopy. It notes that two of these polyps were not removed and one was not retrieved. The primary outcome arm entries list 3 missed adenomas for Aer-O-Scope First and 2 for Conventional Colonoscope First. The record also says data were missing for two lesions by conventional colonoscopy.
Although the endpoint title uses the term “rates,” the posted primary values are counts. A rate requires a denominator, such as the number of adenomas assessed or the number of participants under a specified definition. Such a denominator is not reported in the registry record. The counts therefore describe the recorded number of misses but do not, on their own, quantify the proportion of lesions missed. The record does not post an uncertainty interval or an inferential comparison for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome values are 3 missed adenomas in the Aer-O-Scope First group and 2 in the Conventional Colonoscope First group. These are counts, not estimates of a miss rate with a stated denominator. The arm entries also list 41 and 37 participants, respectively, but participant counts alone do not establish how many lesions were examined or how the lesion-level outcome should be converted into a rate. No new rate or contrast can be inferred from the posted counts without additional information.
The registry separately describes three lesions missed by Aer-O-Scope and found at the subsequent conventional colonoscopy. It states that two were not removed and one was not retrieved, and that data were missing for two lesions by conventional colonoscopy. These details matter because the outcome depends on detecting and characterizing lesions across consecutive procedures. The record does not explain how the missing lesion data affected the reported arm values or whether any adjustment was made.
No analysis results are posted in the registry record. There are no reported confidence intervals, p-values, adjusted estimates, or formal comparison of the two sequences. The recorded counts should therefore be read descriptively. They do not establish the size or precision of a difference between devices, and the counts do not show whether any observed contrast could be explained by chance.
The design has a within-participant feature: each participant was intended to undergo both procedures, with the first procedure randomized. That makes the sequence important. A comparison based only on the arm-level counts may not capture the paired information from each participant, including which lesions were detected by which procedure. The registry record does not report participant-level paired results or the statistical method used to account for the tandem design.
In general, a confidence interval expresses the range of effect estimates compatible with the data under a specified statistical model. Its absence means the precision of the posted contrast cannot be assessed from the registry results. In general, a p-value addresses compatibility with a null model, not the clinical importance or reliability of a result. Neither type of inferential statistic is reported for this primary outcome. The available record supports a description of reported counts and missingness, not a conclusion about comparative performance.
The study is listed as terminated, and the reason is not reported in the registry record. Termination status does not by itself explain the outcome pattern or establish why the study stopped. With no posted analysis results, details of the endpoint denominator, or explanation of the missing data, interpretation should remain limited to the observed counts and the registry’s stated data limitations.
9. Statistical Methods Explained
The registry identifies the allocation as randomized and the masking as none. Randomization applied to which procedure came first: Aer-O-Scope or conventional colonoscopy. In general, random assignment helps prevent the planned order from being chosen according to participant characteristics or investigator preference. It does not ensure that the groups will be identical in every respect, particularly when the number of participants with endpoint data is limited. The record does not describe the randomization sequence-generation or concealment procedures.
How the tandem comparison works
Each participant was intended to receive both colonoscopy procedures, making the participant their own control in the registry’s description. The first examination identifies lesions initially; the second can reveal lesions that were missed. Under the stated endpoint definition, lesions found on the second pass and not marked on the first pass count as first-pass misses. This method uses the second examination as a reference for finding lesions missed on the first.
In general, a paired analysis compares outcomes within the same participant, whereas an unpaired analysis compares separate groups as if their outcomes came from unrelated participants. Pairing can account for participant-level characteristics shared across procedures, but it requires analysis methods that preserve the within-participant relationship. The registry does not report whether the primary analysis used paired data, how lesion-level observations were linked to participants, or how it handled the randomized order in the analysis.
Counts, rates, and denominators
The primary outcome is named Adenoma Miss Rates, but the posted arm entries are counts of missed adenomas. A count reports how many events were recorded. A rate or proportion also requires a clearly defined denominator. For example, a lesion-based proportion would need the number of eligible adenomas examined, while a participant-based measure would need a defined participant-level outcome. These measures answer different questions. The denominator and the precise calculation of a miss rate are not reported in the registry record, so the posted counts should not be interpreted as rates.
In general, counts can be analyzed using models designed for event data. Such models need to reflect how observations are grouped and how much variation there is between participants. Over-dispersion means the observed variation in counts exceeds what a simple model assumes; if present and ignored, uncertainty estimates may be too small. This is a general statistical consideration for count outcomes, not a reported feature of this trial. The registry does not identify a count model or report a dispersion estimate.
Uncertainty and comparative testing
In general, an estimate describes the observed result, while a confidence interval communicates its statistical precision under a model. A hypothesis test can assess whether data are compatible with a specified null hypothesis, but it does not establish that a result is important or rule out bias. The registry posts no confidence intervals, p-values, or formal comparative estimate for the primary endpoint. It also lists no analyses in the analysis record. The posted results therefore do not allow a reader to assess statistical uncertainty or to reproduce a comparative test.
The arm entries give the participant counts and missed-adenoma counts, but not the number of lesions assessed in each arm. Lesions are also observed within participants, so treating every lesion as independent could fail to account for clustering. In general, analysis of lesion outcomes can require methods that account for both participant-level grouping and the paired sequence. The registry does not report whether clustering, pairing, or multiple lesions within a participant were addressed.
Planning assumptions
The registry’s planning illustration is described as using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It is based on the observed effect, with the effect to detect expressed as a stated fraction of that observed effect. Such calculations are planning illustrations, not evidence about the study’s actual probability of detecting an effect. They do not represent observed power. The record does not report the trial’s own sample-size justification or say that these illustration assumptions were used to design the trial. For outcomes other than time-to-event measures, the illustration is expressed as participants per arm; time-to-event illustrations use total events.
In general, planning calculations depend on the effect chosen for detection, the variability or event frequency assumed, the test specification, and the intended allocation. If the observed effect is used as a planning reference, that does not establish that the effect is stable or clinically meaningful. The registry does not report the protocol’s planning assumptions, a target effect, or a formal sample-size rationale. The enrollment value and endpoint arm counts describe record entries, not a justification for the design.
Multiplicity and missing observations
The registry lists polyp miss rates and advanced adenoma miss rates as secondary outcomes in addition to the primary adenoma outcome. When several outcomes are tested, the chance of at least one apparently positive finding can increase if each is tested separately. In general, prespecified methods such as hierarchical testing or adjustment can address multiplicity, but the choice depends on the study plan. The registry does not report a multiplicity strategy or secondary-outcome analysis results.
Missing data can affect both the estimate and its precision. Here, the record specifically notes missing data for two lesions by conventional colonoscopy. It does not report why those data were missing, how missing observations were handled, or whether the analysis used an imputation or sensitivity analysis. The analysis population definitions, participant flow, and analysis exclusions are also not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two secondary outcomes: polyp miss rates for each study arm and advanced adenoma miss rates for each study arm. The primary endpoint is adenoma miss rates. The record does not report whether the primary and secondary outcomes were tested as a family, whether any hierarchy was prespecified, or whether an adjustment for multiple testing was used. No secondary-outcome analysis results are posted.
In general, when several outcomes are examined, interpreting each result as if it were the only test can overstate the strength of evidence. A multiplicity plan can define which outcome is primary, how secondary outcomes will be interpreted, and whether statistical thresholds are adjusted. That is a general explanation; the registry record does not identify such a plan for this investigation.
For the primary endpoint, the registry states that data were missing for two lesions by conventional colonoscopy. It does not report the reason for missingness, whether those lesions were included in the arm count, or how missing data were handled. It also does not describe imputation, sensitivity analyses, or rules for excluding participants or lesions.
The registry lists enrollment as 104, while primary endpoint arm entries list 41 participants in Aer-O-Scope First and 37 in Conventional Colonoscope First. The relationship between these figures is not explained. A participant flow account, definitions of the analysis populations, and the number of participants with complete endpoint data are not reported in the registry record. The results do not identify whether all randomized participants were analyzed in their assigned sequence.
These gaps limit assessment of potential bias and precision. Missing lesion information may affect the observed count, while absent analysis-population details make it difficult to establish which participants and lesions contributed to the endpoint. The record does not provide enough information to determine the direction or size of any such effect.
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 |
|---|---|---|---|
| Training Cohort | 0 | 20 | 0.0% |
| Aer-O-Scope First | 0 | 40 | 0.0% |
| Conventional Colonoscope First | 0 | 38 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Training Cohort | 0 of 20 |
| Aer-O-Scope First | 0 of 40 |
| Conventional Colonoscope First | 0 of 38 |
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 |
|---|---|
| Training Cohort | 0 of 20 |
| Aer-O-Scope First | 0 of 40 |
| Conventional Colonoscope First | 0 of 38 |
The registry reports safety information for three groups: Training Cohort, Aer-O-Scope First, and Conventional Colonoscope First. The numbers at risk for serious adverse events are 20, 40, and 38, respectively. Serious adverse events are recorded as 0 in each group. The numbers at risk for other adverse events are also 20, 40, and 38, with 0 other adverse events recorded in each group. Deaths are recorded as 0 for all three groups.
These entries describe what the registry reports for the listed groups and safety categories. They do not show that no event could occur, nor do they establish that the procedures have no risks. A zero count is an observed count within the recorded group and follow-up, not proof of zero underlying risk. The record does not provide event definitions, detailed follow-up by participant, or an explanation of the Training Cohort’s relation to the randomized sequences.
The top serious adverse event terms list is empty. The registry’s safety counts should be read separately from the adenoma miss outcome: they address recorded adverse events and deaths, not comparative lesion detection. The record does not provide a statistical comparison of safety outcomes between groups.
12. What the Result Does, and Does Not, Mean
The registry record describes a randomized comparison of procedure order in a tandem colonoscopy investigation. Its primary endpoint uses lesions detected on the second pass to identify adenomas missed on the first pass. The posted values are 3 missed adenomas for Aer-O-Scope First and 2 for Conventional Colonoscope First, with participant counts of 41 and 37, respectively. The record also reports three Aer-O-Scope misses detected by subsequent conventional colonoscopy and notes missing data for two lesions by conventional colonoscopy.
These results do not establish a comparative miss rate. The values are counts, and the denominator needed to interpret them as rates is not reported. Nor does the registry post a comparative estimate, uncertainty interval, or test result. The counts alone cannot establish the magnitude or precision of a difference, or whether the recorded contrast is compatible with chance variation.
The tandem design gives each participant both procedures, but order is randomized and the second examination follows the first. Interpretation therefore depends on how lesions and participants were analyzed, including how the pairing and order were represented. Those analytical details are not reported in the registry record. The available information cannot show whether any analysis accounted for within-participant dependence or missing lesion data.
The safety entries report zero serious adverse events, zero other adverse events, and zero deaths in each listed group. These are registry counts, not evidence that risk is absent. The record does not report the reason the trial was terminated, and termination status alone does not explain the endpoint findings.
Overall, the posted information supports a narrow descriptive reading of the recorded lesion counts and safety entries. It does not support a claim that one procedure detects more adenomas, that the procedures are equivalent, or that either procedure is safer. Participant eligibility details, endpoint denominators, missing-data methods, and inferential analyses are not reported in the registry record.
13. Why This Trial Matters Statistically
This investigation raises a useful statistical question about how to compare detection procedures when each participant undergoes both. A tandem design can make within-participant comparison possible because outcomes from the two procedures arise in the same person. At the same time, the randomized order and the sequence of examinations are central to interpreting the comparison. The analysis needs to preserve those relationships rather than treating all observations as unrelated.
The endpoint also illustrates the difference between a count and a rate. The registry calls the endpoint Adenoma Miss Rates but posts counts of missed adenomas. Counts are informative descriptions, but their meaning depends on the number of lesions that could have been detected and the unit of analysis. Without a stated denominator, readers cannot translate the posted counts into a miss proportion or judge how the counts relate to the number of participants.
Missing lesion data make this issue more consequential. The registry notes missing data for two lesions by conventional colonoscopy, but does not report how the missing observations were handled. In a paired design, incomplete information can affect both which participants contribute to a comparison and how much precision is available. Transparent accounting of participants, lesions, and missingness is important for understanding the evidence.
Finally, the record distinguishes descriptive endpoint values from inferential results: no analysis results are posted. This is a reminder that observed counts alone do not provide a measure of statistical uncertainty. The study’s randomized order and tandem structure are important design features, but meaningful interpretation also requires a clear denominator, a stated analysis method, and reporting of uncertainty.
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 primary limitation in the posted endpoint information is that the outcome is titled as a rate but reported as counts. The number of eligible adenomas or other denominator used to define a miss rate is not reported in the registry record. The arm entries provide participant counts, but those do not substitute for a lesion denominator when the endpoint concerns missed adenomas.
The registry reports missing data for two lesions by conventional colonoscopy without explaining the reason, the handling method, or the impact on the arm results. It also does not report participant flow or explain the relationship between enrollment of 104 and the primary endpoint arm entries of 41 and 37 participants. This makes it difficult to determine which participants and lesions contributed to the reported values.
The design’s within-participant feature creates an analysis consideration: the same participant underwent both procedures, and the order was randomized. The registry does not report whether the analysis accounted for pairing, sequence, or multiple lesions within participants. No confidence intervals, p-values, or other comparative analysis results are posted, and no statistical analysis plan is reported.
The study is listed as terminated, but the reason is not reported. The record does not provide detailed eligibility criteria or participant characteristics, limiting assessment of which populations the findings may represent. Although the registry describes a prospective, multicenter, multinational study, the number and characteristics of sites are not reported. The report also notes that some polyps were not removed or retrieved, but does not explain how this affected ascertainment beyond the stated missing lesion data.
These are limitations of the information reported in the registry record. They do not establish that a particular analysis was incorrect or that the missing information would change the results; the effect of these gaps cannot be determined from the posted record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Post Market Evaluation of Aer-O-Scope Visualization — NCT02926209.
- Registry record last updated 2019-07-16; status last verified 2019-06.
- Results first posted 2019-07-16.
- 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
The registry record identifies NCT02926209 as Post Market Evaluation of Aer-O-Scope Visualization, sponsored by GI View Ltd. It describes a prospective, multicenter, multinational, non-blinded randomized investigation using tandem colonoscopies. Participants were assigned to receive Aer-O-Scope or conventional colonoscopy first, with the other procedure following.
The primary endpoint is adenoma misses identified through the second-pass examination. The arm entries report 3 missed adenomas among 41 participants in Aer-O-Scope First and 2 among 37 participants in Conventional Colonoscope First. The registry notes missing data for two lesions by conventional colonoscopy. Polyp miss rates and advanced adenoma miss rates are listed as secondary outcomes, but analysis results are not posted.
Enrollment is listed as 104. The study started on 2017-02-21, had a primary completion date of 2017-11-08, and is listed as terminated. The reason for termination is not reported in the registry record. Safety entries report no serious adverse events, other adverse events, or deaths in the listed groups.