This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Clinical Utility of ERCP Guided Cholangiopancreatoscopy With the SpyGlass DS (NCT02524418), a na na study. The primary outcome is Number of Participants With Procedure Technical Success.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02524418 |
| Phase | NA |
| Condition | Biliary Tract Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 88 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Florida |
| Results posted | Yes |
2. Clinical Question
Population
The registry record concerns people with biliary tract disease undergoing ERCP-guided cholangiopancreatoscopy. The record lists enrollment of 88 and notes that five subjects had both cholangioscopy and pancreatoscopy, with those procedure results recorded and analyzed separately. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
The procedure was cholangiopancreatoscopy using the SpyGlass DS during standard-of-care ERCP. The study aimed to document clinical utility and technical aspects of cholangioscopy and/or pancreatoscopy in diagnosing and managing pancreatic-biliary disorders. The record describes collecting and analyzing clinical outcomes.
Comparator
The record describes a single-group study, with allocation listed as NA. It does not identify a separate control group or a randomized comparison. The results therefore concern the recorded experience with the procedure, rather than a like-for-like estimate against another treatment or device.
Primary question
The primary outcome asks how many participants had procedure technical success on Day 1. Success was to be assessed through the ability to reach the target site, obtain samples, and deliver therapeutic intervention. The registry record does not report the number meeting this endpoint or the criteria used to combine these technical elements into a success classification.
3. Trial Design
The registry record describes a prospective evaluation of ERCP-guided cholangiopancreatoscopy with the SpyGlass DS. The study status is completed, and enrollment is listed as 88. The study is classified as a single-group model; allocation is NA, and masking is listed as none. The intervention is a procedure: cholangiopancreatoscopy performed with the SpyGlass DS during standard-of-care ERCP.
The stated aims were to document clinical utility and technical aspects of ERCP with cholangioscopy and/or pancreatoscopy in diagnosing and managing pancreatic-biliary disorders. The primary outcome was procedure technical success on Day 1. Listed secondary outcomes include time to set up the system, total procedure time, time spent on diagnostic and therapeutic maneuvers, detection of ductal stones, strictures found during the procedure, Spybite sampling attempts, and successful stone removal.
The record notes that five subjects had both cholangioscopy and pancreatoscopy and that those procedure results were recorded and analyzed separately. This matters when interpreting the unit of analysis: the primary endpoint is described as a number of participants, while some secondary outcomes refer to procedures or examinations. The registry record does not report the detailed approach for handling multiple procedures from the same person.
The record does not identify a concurrent comparator, a randomized allocation process, or a masking procedure. This design can describe technical experience and recorded outcomes in the study group, but it cannot by itself establish a comparative effect against another device or approach. The study's detailed eligibility criteria, recruitment methods, and protocol-level analysis plan 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 | Cholangiopancreatoscopy |
|---|---|
| STARTED | 88 |
| COMPLETED | 75 |
| NOT COMPLETED | 13 |
Analysis population for the primary outcome, as defined in the registry: Five of the subjects had both Cholangioscopy and Pancreatoscopy. The results of these procedures were recorded and analyzed separately
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: 88 subjects signed consent but in 13 subjects a Spyglass examination was not done because of the lack of indication after performing standard cholangiography or pancreatography
| Characteristic | Unit | Cholangiopancreatoscopy |
|---|---|---|
| Participants analysed | 75 | |
| Age, Continuous | years | 66 (22 to 96) |
| Sex: Female, Male: Female | Participants | 38 |
| Sex: Female, Male: Male | Participants | 37 |
| Region of Enrollment: United States | participants | 75 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Procedure Technical Success, measured over Day 1.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with procedure technical success on Day 1. The registry description says that performance during endoscopy would be based on the ability to reach the target site, obtain samples, and deliver therapeutic intervention. It is therefore a technical, participant-level endpoint intended to capture whether key procedural tasks could be carried out.
Such an endpoint can be useful in an evaluation of a procedure because it focuses on execution rather than only on a later clinical outcome. In general, recording technical success can help characterize whether the intended site was reached and whether diagnostic or therapeutic tasks were possible. It does not, on its own, establish diagnostic accuracy, durable clinical benefit, or comparative advantage.
The registry record does not report the observed number of participants with technical success, the denominator used for the endpoint analysis, or a confidence interval. It also does not fully specify whether every listed technical element had to be achieved for a participant to count as successful, or how missing or incomplete components were classified. Consequently, the endpoint's definition can be described, but its observed frequency and precision cannot be interpreted from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The key interpretive point is that the registry record identifies a primary technical-success outcome but does not report its result. It gives the endpoint definition and timeframe, Day 1, but no observed count, denominator, effect estimate, or confidence interval for that endpoint. The clinical success rate and the precision with which it was estimated are therefore not reported in the registry record.
The study is described as prospective and single-group, with allocation listed as NA and masking as none. These features frame the scope of inference. A single-group evaluation can describe what was recorded during procedures in that study group. Without a concurrent comparator, it does not estimate a between-group difference or separate the procedure's contribution from other influences. The registry record does not report a randomized comparison.
The aims include both diagnostic and therapeutic aspects, and the secondary outcomes cover procedural timing, findings, sampling attempts, and stone removal. These outcomes address different questions. A measure of setup or procedure time concerns workflow; a finding such as a ductal stone or stricture concerns what was observed during the examination; and successful removal concerns a therapeutic task. None should be treated as interchangeable with the primary technical-success endpoint.
The note that five subjects had both cholangioscopy and pancreatoscopy is relevant because results were recorded and analyzed separately for those procedures. The registry record does not give the corresponding outcome counts or explain how dependence between multiple procedure observations was addressed. It also does not report the primary endpoint's analysis population or handling of missing observations.
For safety, the record lists adverse-event counts for the Cholangiopancreatoscopy group, including one participant affected by a serious event and three affected by other events among 75 at risk for each category. A periampullary perforation is listed among the serious terms at 1.3%. These are descriptive entries; the record does not provide enough detail to establish event attribution, comparative risk, or a complete safety profile.
Overall, the record supports a description of the study question, design, endpoint definition, and selected adverse-event entries. It does not provide the primary outcome result or the analysis details needed to quantify technical performance or its uncertainty. Interpretation should remain limited to what the registry record actually reports.
9. Statistical Methods Explained
What does a single-group design estimate?
General explanation: A single-group study records outcomes among people who receive or undergo the intervention under study. It can describe observed performance and provide information about feasibility, procedure characteristics, or event frequency in that study setting. Without a concurrent comparison group, it does not directly estimate how outcomes would differ under an alternative. Differences from other settings or approaches can reflect variations in participants, practice, outcome definitions, or follow-up as well as the intervention itself.
In this record, the model is single group, allocation is NA, and masking is none. The record describes ERCP performed with the SpyGlass DS and states that clinical outcomes would be collected and analyzed. It does not report a separate comparator or a randomized allocation process. Accordingly, the primary question is descriptive: how many participants were recorded as having technical success, according to the endpoint definition. The observed result itself is not reported in the registry record.
How should a binary endpoint be understood?
General explanation: A binary outcome classifies each analysis unit into one of two categories, such as meeting or not meeting a defined success criterion. The count alone is not enough to interpret an event frequency; the denominator and the rules for classifying participants are also important. An uncertainty interval can express the range of values compatible with the data under the chosen statistical model. Wider intervals generally indicate less precision, while narrower intervals indicate more precision. Neither an interval nor a point estimate establishes causation in a non-comparative study.
The primary outcome is described as a number of participants with procedure technical success. The recorded criteria refer to reaching the target site, obtaining samples, and delivering therapeutic intervention. However, the registry record does not report the success count, endpoint denominator, classification rule for incomplete technical components, or an uncertainty interval. Thus, no event frequency or precision estimate can be interpreted from the listed primary outcome description alone.
Why distinguish participants from procedures?
General explanation: Repeated observations from the same person may be related rather than statistically independent. If a person contributes more than one procedure or examination, treating each observation as unrelated can misrepresent the amount of information in the data. Analyses may need to define the unit of analysis clearly or account for within-person dependence. The appropriate approach depends on the outcome and study design.
The record says that five subjects had both cholangioscopy and pancreatoscopy and that results were recorded and analyzed separately. It does not report the exact analysis method for these observations or explain whether outcomes were summarized by participant, procedure, or examination for each secondary endpoint. That distinction is especially relevant to outcomes phrased as numbers of examinations, sampling attempts, or successful removals.
What does over-dispersion mean in general?
General explanation: Over-dispersion occurs when observed variability in count data is greater than a statistical model expects. It can arise when observations differ across people or settings, or when events cluster. If over-dispersion is ignored, standard errors may be too small and uncertainty may appear lower than it is. Whether this issue applies depends on the data and the model. The registry record does not report a model for count outcomes or information that would establish whether over-dispersion was assessed.
How do timing and procedural findings differ?
General explanation: Time outcomes describe duration and may require a summary that accounts for skewness or extreme values. Findings such as stones or strictures are event counts or classifications whose interpretation depends on the examination process and definitions. Sampling attempts and removal outcomes describe procedural actions or results. These outcome types have different statistical properties and should not automatically be interpreted with the same summary measure or model.
The listed secondary outcomes include setup time, total procedure time, minutes for diagnostic and therapeutic maneuvers, ductal stone detection, strictures found, Spybite sampling attempts, and stone removal. The registry record does not report their observed values, distributions, summary methods, or analysis models. Their names establish the intended areas of measurement, not the magnitude or precision of any result.
What can confidence intervals and p-values contribute?
General explanation: A confidence interval communicates uncertainty around an estimate under a statistical procedure and its assumptions. A p-value assesses how compatible data are with a specified null model; it is not the probability that the null hypothesis is true and does not measure clinical importance. For a single-group estimate, these measures do not create a comparator or remove design limitations. The registry record does not report a primary endpoint confidence interval or p-value, and it does not list any analyses.
The record does not report a detailed statistical analysis plan, model specifications, adjustment variables, or interim analyses. These details should not be inferred from the prospective design or from the outcome list. Statistical interpretation is therefore limited to the design and definitions recorded, plus general principles about how such outcomes are usually assessed.
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.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Cholangioscopy | 75 | 70 | 93.3% | 85.1% to 97.8% | 85.3% to 97.1% | 85.3% to 97.0% |
| Pancreatoscopy | 5 | 3 | 60.0% | 14.7% to 94.7% | 23.1% to 88.2% | 22.3% to 88.2% |
R code and output
arm <- c("Cholangioscopy", "Pancreatoscopy")
n <- c(75, 5)
events <- c(70, 3)
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 Cholangioscopy 75 70 93.3 85.1 97.8 85.3 97.1 85.3 97.0
ARM Pancreatoscopy 5 3 60.0 14.7 94.7 23.1 88.2 22.3 88.211. Multiplicity, Missing Data and Analysis Populations
The registry record lists one primary outcome and multiple secondary outcomes, including procedural times, diagnostic findings, sampling attempts, and stone removal. When a study examines several outcomes, the chance of at least one apparently unusual result can increase if each is tested separately without a prespecified strategy. General explanation: Multiplicity procedures can control that risk, or investigators can define a small set of priority outcomes and interpret other analyses as exploratory. The registry record does not report a multiplicity adjustment, a hierarchy among secondary outcomes, or a detailed statistical analysis plan.
The record lists 9 outcome measures and 0 analyses. This does not establish that no analyses were conducted; it means analysis results are not listed in the registry record. The primary endpoint count and its denominator are not reported, and the registry record does not describe how missing endpoint data were handled. It also does not report analysis-population definitions, exclusions, or whether all enrolled participants contributed to each outcome.
Missing data can affect an estimate when outcome availability is related to participants' characteristics or procedural experience. General explanation: A clear analysis should identify the relevant denominator, describe missingness, and explain the handling strategy. For procedural outcomes, the opportunity to observe an outcome may also depend on whether a procedure reached a particular stage. The record does not report whether such circumstances occurred or how they were classified.
The note that some subjects underwent both types of examination raises a separate unit-of-analysis question. The record says the results were recorded and analyzed separately, but does not explain the treatment of repeated observations in statistical analyses. These omissions limit assessment of multiplicity, missingness, and population definition; they do not establish that any particular bias occurred.
12. 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 |
|---|---|---|---|
| Cholangiopancreatoscopy | 1 | 75 | 1.3% |
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 |
|---|---|
| Cholangiopancreatoscopy | 3 of 75 |
Most frequent serious adverse event terms
| Event term | Organ system | Cholangiopancreatoscopy |
|---|---|---|
| periampullary perforation | Gastrointestinal disorders | 1 of 75 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cholangiopancreatoscopy |
|---|---|---|
| mild Post ERCP pancreatitis | Gastrointestinal disorders | 3 of 75 |
Serious events with the highest arm-level rate: periampullary perforation (1.3%).
The adverse-event entry for the Cholangiopancreatoscopy group lists 75 at risk for serious events and 1 affected. For other adverse events, it lists 75 at risk and 3 affected. The serious-event terms include periampullary perforation, listed at 1.3%. These are descriptive registry entries, not a comparative estimate against another procedure or group.
The record does not provide event-level narratives, timing, severity grading beyond the serious-event classification, or an attribution assessment. It also does not explain the relationship between the term-level percentage and the serious-event count. Deaths are not reported in the registry record; a blank or unavailable entry should not be read as evidence that no deaths occurred.
General explanation: Adverse-event counts describe events observed and recorded under the study's reporting definitions. They do not by themselves establish that the procedure caused an event, and they do not quantify comparative risk without an appropriate comparator and compatible follow-up. The entries should therefore be read as the safety information recorded for this group, with the reporting limitations kept in view.
13. What the Result Does, and Does Not, Mean
The study addresses whether ERCP-guided cholangiopancreatoscopy with the SpyGlass DS could be used to perform technical tasks and document diagnostic and therapeutic aspects of pancreatic-biliary procedures. Its primary endpoint focuses on technical success on Day 1, defined in relation to reaching the target site, obtaining samples, and delivering therapeutic intervention. The secondary outcome list indicates interest in procedure time, diagnostic findings, sampling, and stone removal.
The registry record does not report the observed primary endpoint result. It therefore does not establish how many participants met the technical-success endpoint, the frequency of success, or the precision of that estimate. The outcome definitions and design can be described, but they cannot substitute for the missing result. The record also does not report the observed values for the listed secondary outcomes.
Even if a technical-success result were available, technical completion would not by itself demonstrate diagnostic accuracy, sustained clinical benefit, or superiority to another approach. Those questions require outcome definitions and comparative evidence suited to each claim. This record describes a single-group evaluation and does not identify a concurrent control group.
The adverse-event entries provide limited descriptive information: one serious event and three other events are listed among 75 at risk in their respective categories, with periampullary perforation listed at 1.3%. The registry record does not provide enough context to establish causation, comparative safety, or the completeness of event reporting.
Thus, the defensible conclusion is about the scope of the evaluation and what the registry records: a prospective single-group procedural study, a defined technical endpoint, several secondary measures, and selected adverse-event figures. A conclusion about the observed technical performance or a comparison with alternatives is not reported in the registry record.
14. Why This Trial Matters Statistically
This trial is statistically relevant because procedural evaluations often combine outcomes that answer different questions. Technical success concerns whether specified tasks could be performed; timing describes workflow; diagnostic findings record what was observed; and therapeutic outcomes describe actions such as stone removal. Keeping those outcomes distinct prevents a process measure from being mistaken for evidence of diagnostic accuracy or clinical benefit.
The single-group design also illustrates an important boundary on inference. Such a study can describe outcomes in the group undergoing the procedure, but it cannot estimate a between-group effect without a comparator. This distinction remains important even when an evaluation is prospective and collects several types of outcome. More measurements do not create a controlled comparison.
The record's note that some subjects had both cholangioscopy and pancreatoscopy draws attention to the unit of analysis. Participant counts, procedure counts, and examination counts can represent different quantities. If observations from one person are related, statistical methods and denominators should reflect that structure. The registry record does not report enough analysis detail to determine how this issue was addressed.
Finally, the gap between an endpoint definition and an endpoint result matters. A clear definition identifies what investigators intended to measure; interpretation also requires the observed count, denominator, and an account of uncertainty. Those primary result details are not reported in the registry record. This makes the record useful for understanding the study's question and design, while limiting conclusions about measured performance.
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.
Several trial-specific limitations are apparent from the registry record. The primary endpoint is defined, but its observed count, denominator, and uncertainty interval are not reported. The criteria are described in terms of reaching the target site, obtaining samples, and delivering therapeutic intervention, while the record does not explain how those elements were combined into a participant-level success classification.
The study is single group, with allocation listed as NA and masking as none. The record does not identify a concurrent comparator, so it cannot support a direct comparison with another device or approach. It also does not report detailed participant eligibility criteria, baseline characteristics, or the analysis population.
The note about five subjects having both cholangioscopy and pancreatoscopy indicates that some people contributed results for both procedure types. Although the record says results were recorded and analyzed separately, the statistical handling of repeated observations is not reported. Outcome-specific denominators and missing-data handling are also not reported in the registry record.
The registry lists secondary outcome topics but does not report their observed values or analysis methods. It does not report a detailed statistical plan, multiplicity strategy, interim analyses, or sample-size justification. These omissions limit evaluation of precision and analytic choices; they do not establish that the study lacked procedures for addressing them.
Safety interpretation is also constrained. The record lists event counts and a serious-event term but does not provide event narratives, attribution, or enough context to assess completeness. The listed entries should not be treated as a comprehensive comparative safety assessment.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Clinical Utility of ERCP Guided Cholangiopancreatoscopy With the SpyGlass DS — NCT02524418.
- Registry record last updated 2017-03-30; status last verified 2017-02.
- Results first posted 2017-03-30.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
The registry record describes a completed prospective, single-group evaluation of ERCP-guided cholangiopancreatoscopy with the SpyGlass DS for pancreatic-biliary disorders. Enrollment is listed as 88. The primary outcome is the number of participants with procedure technical success on Day 1, based on reaching the target site, obtaining samples, and delivering therapeutic intervention. Its observed result is not reported in the registry record.
Listed secondary outcomes cover setup and procedure time, diagnostic and therapeutic maneuver duration, ductal stones, strictures, sampling attempts, and stone removal. The record notes that five subjects had both cholangioscopy and pancreatoscopy, with results recorded and analyzed separately. Adverse-event entries list one serious event and three other events among 75 at risk in each category; periampullary perforation is listed at 1.3%. The design and missing outcome details limit conclusions about comparative performance and precision.