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 OCT Pilot in Esophagus (NCT03434834), a na na study. The primary outcome is Percentage of Imaged Sites Correctly Categorized as Squamous Mucosa.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03434834 |
| Phase | NA |
| Condition | Barrett Esophagus |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 53 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Duke University |
| Results posted | Yes |
2. Clinical Question
Population
Participants who completed the study were the population specified for the primary outcome. The study concerned Barrett Esophagus and assessed imaged esophageal sites. The registry record lists an enrollment of 53, but does not state how many participants completed the study.
Intervention
The intervention was optical coherence tomography of the esophagus using a device. The pilot sought to assess whether the device could obtain high-quality images with adequate tissue contact and whether those images could distinguish squamous from Barrett’s Esophagus epithelium.
Comparator
This was a single-group study, not a randomized comparison. Endoscopy was the reference for determining whether imaged sites were squamous mucosa in the primary outcome; it was not a separate treatment arm. The registry record does not report a concurrent control group.
Primary question
At baseline, what percentage of imaged sites were correctly categorized by OCT as squamous mucosa when compared with endoscopy? This is a site-level classification question. It asks how often the OCT classification agreed with the specified reference for this category; it is not a comparison of clinical outcomes between treatments.
The pilot’s broader stated aims included assessing image acquisition as well as tissue categorization. These are distinct tasks: obtaining an image of adequate quality is a prerequisite for interpreting it, while classification concerns what the image indicates about the tissue. The listed primary outcome addresses categorization of squamous mucosa. The registry record does not give a numerical estimate for that outcome, so the degree of agreement cannot be assessed from the reported information.
3. Trial Design
The registry record describes a completed pilot study of an optical coherence tomography device in the esophagus. It lists Duke University as sponsor, an enrollment of 53, and the condition Barrett Esophagus. The recorded study dates are 2018-09-25 for start and 2020-02-25 for primary completion. The phase is listed as NA.
The design is single-group, with allocation listed as NA and masking listed as NONE. The intervention is optical coherence tomography of the esophagus. There is no randomized treatment contrast, and the registry record does not describe a parallel control arm. Endoscopy appears as the reference used for the primary site-classification outcome, not as a separately assigned intervention.
The pilot’s stated purpose was to test whether adequate tissue contact could be achieved to acquire high-quality images and whether those images could distinguish squamous from Barrett’s Esophagus epithelium. The listed primary outcome is the percentage of imaged sites correctly categorized as squamous mucosa compared with endoscopy, at baseline. A secondary outcome concerns the percentage of imaged sites with adequate tissue contact for a high-quality image.
The primary outcome population is participants who completed the study. The registry record does not report the number who completed it, the number of sites assessed, or details of how sites were selected or measured. It lists 3 outcome measures and 0 analyses. The record does not report a sample-size justification, a protocol-level analysis plan, or a reason for the enrollment target.
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 | OCT of Esophagus |
|---|---|
| STARTED | 53 |
| COMPLETED | 37 |
| NOT COMPLETED | 16 |
Reasons for not completing this period:
| Reason | OCT of Esophagus |
|---|---|
| unable to swallow OCT probe | 16 |
Analysis population for the primary outcome, as defined in the registry: Participants who completed the study.
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 | OCT of Esophagus |
|---|---|---|
| Participants analysed | 53 | |
| Age, Continuous | years | 66.3 (SD 11.9) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 48 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 53 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 53 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 53 |
| Stage of Barrett's Esophagus: non-dysplastic Barrett's Esophagus | Participants | 8 |
| Stage of Barrett's Esophagus: Barrett's Esophagus with low grade dysplasia | Participants | 24 |
| Stage of Barrett's Esophagus: Barrett's Esophagus with high grade dysplasia | Participants | 21 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Imaged Sites Correctly Categorized as Squamous Mucosa, measured over at baseline.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of imaged sites |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percentage of imaged sites correctly categorized by OCT as squamous mucosa when compared with endoscopy. It is specified at baseline, and the stated population is participants who completed the study. The unit is imaged sites, so the outcome concerns classification at the site level rather than a clinical outcome measured across participants.
For this type of measure, the reference assessment gives the basis for judging whether the device’s category assignment is correct. The endpoint therefore describes agreement for the named tissue category against endoscopy. It does not, by itself, describe classification of every tissue type, performance in every clinical setting, or effects on decisions or patient outcomes.
General statistical context: a percentage can be informative as a summary of classification, but its interpretation depends on the number and selection of sites, how image quality and unclassifiable images are handled, and whether observations from multiple sites in one participant are treated as related. The registry record does not report these details or the numerical primary result. As a result, the observed level of correct categorization and the precision of any estimate are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a practical, device-focused pilot question: whether the OCT system can acquire high-quality images with adequate tissue contact and whether the images can be used to categorize imaged tissue. The primary endpoint narrows the classification question to the percentage of sites identified as squamous mucosa when compared with endoscopy. The stated secondary outcome addresses adequate contact for image acquisition. Together, these measures concern image collection and a specified form of tissue categorization.
The record does not report the numerical value of the primary endpoint, its denominator, a confidence interval, or a test result. It therefore does not support a quantitative statement about how often sites were correctly categorized or how precisely that percentage was estimated. The record also lists no analyses. The outcome definition alone is not evidence of the device’s observed classification performance.
The study has one group rather than a randomized treatment comparison. Accordingly, the primary question is not whether OCT performs better than an assigned alternative or changes an outcome relative to a control arm. Endoscopy is the stated reference for the primary classification, but the record does not describe details of reference assessment, whether assessors were blinded, or the rules used to resolve disagreement.
General statistical context: a point estimate describes the observed result in the analyzed sample, while a confidence interval describes uncertainty around an estimate under the analysis assumptions. Neither can be interpreted without the result and relevant denominator. If multiple sites are measured for one participant, those observations may be correlated rather than independent; accounting for that structure can affect uncertainty. The registry record does not report the number of sites per participant or how such clustering was handled.
The registry enrollment is 53, but that figure is not itself the primary endpoint denominator. The primary population is participants who completed the study, and the number of completers is not reported in the registry record. Nor is the count of imaged sites reported. Thus, enrollment should not be substituted for the number of participants analyzed or the number of sites contributing to the outcome.
The record lists 3 outcome measures and 0 analyses. Without reported results or an analysis description, it is not possible to assess estimates across outcomes, compare alternative analytic choices, or determine whether the registered outcome definitions were followed as planned. The appropriate reading is limited to the design and intended measurement described in the registry record, not a conclusion about observed device performance.
9. Statistical Methods Explained
There is no statistical analysis reported in the registry record. The primary outcome is a percentage, but a percentage alone does not show its numerator, denominator, uncertainty, or the method used to account for the study design. The record gives the outcome definition and population but not the numerical estimate or a confidence interval. No hypothesis test, model, or analysis specification is reported.
General: a percentage for a classification endpoint usually relates the number of units meeting the stated criterion to the number of units assessed. Here, the stated unit is imaged sites, and the criterion is correct categorization as squamous mucosa compared with endoscopy. The registry record does not state the number of sites evaluated or give counts of correct and incorrect classifications. Those quantities should not be inferred from the enrollment figure.
General: precision is commonly conveyed with a confidence interval. Its width depends on the amount of information and on the assumptions used to calculate it. For a site-level outcome, the number of participants and the number of sites can both matter. If several sites come from one participant, the results from those sites may be more alike than results from unrelated participants. An analysis that treats related observations as independent can misstate uncertainty; methods that account for clustering may be appropriate depending on the actual data and design. The registry record does not report site counts, within-participant structure, or any method for handling it.
General: an imaging study may also need to define what happens when an image cannot be interpreted, when tissue contact is inadequate, or when OCT and the reference assessment disagree. These decisions can change which observations contribute to a classification estimate. The study’s stated aims include adequate tissue contact and high-quality image acquisition, and a secondary outcome addresses contact. However, the registry record does not describe missing or uninterpretable images, exclusions, adjudication procedures, or how such cases entered the primary endpoint.
The primary outcome is specified for participants who completed the study. The registry record does not define completion, report how many participants completed, or explain whether all enrolled participants contributed to the primary outcome. It also does not describe an intention-to-measure approach, a per-protocol population, or another analysis population beyond the stated completed-study population. These omissions prevent assessment of attrition and the relationship between enrollment and analysis.
There is no reported randomized comparison, so methods for estimating a between-arm treatment effect are not described. The reference role of endoscopy should be kept distinct from a control arm: the endpoint compares device categorization with a reference, rather than comparing assigned treatments. The record does not report whether the OCT reader or the endoscopy assessor was masked to the other assessment, or whether the interpretations were made independently.
The registry’s planning description characterizes sample-size calculations as illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are described as planning assumptions, not as the design of this single-group pilot or as observed power. The registry record does not report the study’s own sample-size justification, and it does not give values for an observed effect or the resulting planning estimates in the registry record for this analysis. A planning illustration cannot establish the precision achieved in the completed study.
General: a significance level is a rule used in a specified hypothesis-testing procedure; it is not a measure of effect size or certainty. A normal approximation is a computational approach whose suitability depends on the data and analysis. Equal allocation between two arms is an assumption for a hypothetical two-group planning exercise and does not describe the single-group study recorded. Since no analysis is reported, these assumptions do not supply a result for the primary endpoint.
Over-dispersion is general statistical terminology for variation greater than a particular model assumes. When present, a model that fails to allow for it can understate uncertainty. The registry record does not report a count model, dispersion estimate, or any evidence that over-dispersion was assessed; this concept should not be taken to imply that such a model was used for this endpoint.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 3 outcome measures and 0 analyses. It names a primary outcome and a secondary outcome concerning adequate tissue contact, but the third outcome measure is not identified in the registry record for this analysis. No results or statistical analysis are reported. The record does not describe a multiplicity strategy, such as an order for interpreting multiple outcomes or an adjustment for multiple testing. This means the role of any statistical tests across outcomes is not reported in the registry record; it does not establish that a particular adjustment was or was not used outside the record.
The primary population is participants who completed the study, but the number of completers is not given. The enrollment of 53 should not be treated as the analyzed population size. The record does not explain withdrawals, exclusions, incomplete examinations, or whether every enrolled participant had an evaluable image. It also does not describe how missing site classifications or inadequate-quality images were handled.
General: missingness matters because the observations that can be analyzed may differ from those that cannot be evaluated. For an imaging endpoint, the handling of a failed acquisition or an indeterminate classification can affect the meaning of the reported percentage. A complete analysis description would distinguish attempted sites from evaluable sites and explain how each category contributes to the outcome. Those details are not reported in the registry record.
The record also does not define a separate safety analysis population or explain whether adverse-event follow-up covered all enrolled participants for the same period. No particular missing-data method, sensitivity analysis, or analysis-population rule is reported. These gaps limit assessment of how representative any analysis might be, especially because no numerical endpoint results are listed.
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 |
|---|---|---|---|
| OCT of Esophagus | 0 | 53 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| OCT of Esophagus | 0 of 53 |
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 |
|---|---|
| OCT of Esophagus | 8 of 53 |
Most frequent non-serious adverse event terms
| Event term | Organ system | OCT of Esophagus |
|---|---|---|
| sore throat | Surgical and medical procedures | 4 of 53 |
| bloating | Surgical and medical procedures | 1 of 53 |
| nausea / vomiting | Surgical and medical procedures | 1 of 53 |
| epigastric pain | Surgical and medical procedures | 1 of 53 |
| esophageal pain | Surgical and medical procedures | 1 of 53 |
The registry record lists 53 participants at risk for serious adverse events and 0 participants affected. It lists 53 participants at risk for other adverse events and 8 affected. Deaths are listed as 0. These are the reported counts; no percentages are calculated.
The serious-event count should be read separately from the count for other adverse events. The record does not provide serious-event terms, and no top serious-event terms are listed. It also does not give the specific terms included among the other adverse events, their timing, severity, duration, or relationship to the device. The counts alone therefore do not describe the nature or clinical significance of those events.
General: an adverse-event count is a safety summary for the population and observation period used in the record. Interpretation depends on how events were defined, collected, and attributed, and on whether follow-up was complete. The registry record does not report those details or a separate safety analysis population. The listed counts should not be treated as a comparison with another group, since this was a single-group study and no control arm is reported.
12. What the Result Does, and Does Not, Mean
The registry record describes a pilot intended to examine image acquisition and tissue categorization using optical coherence tomography in the esophagus. Its primary outcome asks what percentage of imaged sites were correctly categorized as squamous mucosa compared with endoscopy. The stated secondary outcome concerns adequate tissue contact for obtaining a high-quality image. These descriptions establish what the study set out to measure, not what it found.
The numerical result for the primary endpoint is not reported in the registry record. Neither a denominator nor a confidence interval is listed, and the record reports 0 analyses. Consequently, the available information does not establish the observed frequency of correct categorization or the precision of an estimate. It also does not establish how often adequate contact was achieved.
The study was single-group, with no randomized control comparison. Endoscopy served as the reference for the primary classification, rather than as a separately assigned treatment. The record therefore does not provide evidence from a randomized contrast between OCT and another intervention, and the endpoint is not a measure of a treatment effect.
General: a pilot study can be useful for examining whether a measurement process is workable and for informing later study questions. Its interpretation still depends on the actual observations, the number of evaluable participants and sites, and the methods used to address repeated observations and missing images. Those results and methods are not reported in the registry record.
The record lists an enrollment of 53, but it does not state how many participants completed the study or how many imaged sites were included. The enrollment count therefore cannot stand in for the primary outcome denominator. The safety counts are separately reported and should be interpreted only as the recorded counts for the listed groups, without assuming a comparator or additional details about event types.
13. Why This Trial Matters Statistically
This study raises statistical questions that are particularly relevant to diagnostic and imaging pilots. Its primary outcome is defined at the imaged-site level, while the stated analysis population is participants who completed the study. Connecting site-level measurements to participant-level enrollment requires clear reporting of the number of sites and how sites are distributed across participants. The registry record does not report those quantities.
Image acquisition and image interpretation are also different measurement stages. Adequate tissue contact and high-quality image acquisition can determine whether a site is assessable at all; classification concerns the interpretation of an acquired image. Reporting each stage distinctly helps readers understand whether an apparent classification result reflects performance among all attempted sites or only among evaluable images. The record identifies both aims but does not report their results or how unevaluable images were handled.
Use of endoscopy as the reference makes the comparison within each site meaningful as a classification question, but the record does not explain assessor masking, independent readings, or disagreement resolution. These design details can affect the interpretation of agreement. They are not reported in the registry record and should not be assumed.
The single-group structure also matters. It limits the question to the device assessment described in the record; there is no randomized treatment contrast. The planning assumptions described for a two-arm sample-size illustration should therefore be distinguished from the actual pilot design. The registry record provides neither a sample-size justification for the pilot nor results that allow readers to evaluate the precision of its primary measure.
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 registry record provides the study purpose and outcome definitions but no numerical result for the primary endpoint. It does not give a numerator, a site-level denominator, or an interval estimate. The number of participants who completed the study is also not reported, although the primary outcome population is defined as completers. This makes it impossible to connect the enrollment count to the analyzed outcome population.
The number of imaged sites and the number of sites contributed by each participant are not reported. Without this information, the scale of the site-level evidence and any within-participant dependence cannot be assessed. The record also does not explain how inadequate contact, low-quality images, indeterminate interpretations, or disagreements between OCT and endoscopy were handled.
The registry record does not describe whether assessors were masked, how endoscopy classifications were assigned, or whether discordant readings were adjudicated. It does not report a statistical analysis, confidence intervals, or methods for handling repeated sites. It lists 3 outcome measures and 0 analyses, and the third measure is not specified in the registry record for this analysis.
The single-group design has no randomized control arm, so it cannot supply a randomized between-group comparison. The registry record does not report a protocol-level sample-size justification or explain whether the enrollment target was based on precision, feasibility, or another consideration. The planning assumptions mentioned in the record are illustrative rather than a description of the pilot’s actual allocation or a report of observed power.
For safety, the record gives counts but not event terms, event timing, follow-up details, or attribution. These omissions restrict interpretation of the safety summary as well as the primary measurement results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: OCT Pilot in Esophagus — NCT03434834.
- Registry record last updated 2021-04-06; status last verified 2021-03.
- Results first posted 2021-04-06.
- 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 describes a completed, single-group pilot study of optical coherence tomography of the esophagus, sponsored by Duke University. It lists Barrett Esophagus as the condition, enrollment of 53, and study dates from 2018-09-25 to 2020-02-25. The primary outcome is the percentage of imaged sites correctly categorized as squamous mucosa compared with endoscopy at baseline, among participants who completed the study.
The stated aims include adequate tissue contact for high-quality image acquisition and classification of squamous or Barrett’s Esophagus epithelium. The record lists 3 outcome measures and 0 analyses. The numerical primary outcome, the number of completers, and the number of imaged sites are not reported in the registry record. Safety counts list 0 serious adverse events among 53 at risk, 8 other adverse events among 53 at risk, and 0 deaths.