Evaluation of the Impact of a Forward Viewing Scope at Time of ERCP: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of the Impact of a Forward Viewing Scope at Time of ERCP (NCT05627882), a registered phase not stated study. The primary outcome is Number of Participants With Clinically Significant Endoscopic Findings.

2. Clinical Question

3. Trial Design

The record describes a prospective, tandem-designed study at Brigham and Women's Hospital. Its brief summary says consecutive adult patients undergoing ERCP for traditional reasons undergo back-to-back tandem EGD and ERCP examinations. First, an attending gastroenterologist performs EGD. A second attending gastroenterologist, described as blinded, then performs ERCP immediately after the index EGD. Each endoscopist records clinically significant findings independently of the other provider's procedural findings.

The posted intervention is a forward viewing endoscope, while the recorded Standard ERCP arm is described as using a standard side viewing scope. The record also states that allocation was not stated and identifies the arms as not a like-for-like control comparison. These descriptions do not fully specify how participants or procedures map to the listed intervention and arm. The exact allocation process, any pairing structure used in analysis, and the handling of the tandem observations are not reported in the registry record.

The registry lists enrollment of 163 and status COMPLETED. The recorded study start is 2022-10-14, and primary completion is 2024-05-01. These dates and status describe the registry record, not the availability of outcome results. The study's brief summary notes that some institutions already routinely perform EGD with every ERCP; it does not report how common that practice is or how it affected enrollment or conduct.

The record lists two outcome measures: the primary measure of clinically significant endoscopic findings and a secondary measure of non-clinically significant endoscopic findings. It does not provide outcome counts or analysis results for either measure. Statistical analysis details, including how within-participant or within-procedure dependence was handled, 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: Patients with differences found on Forward Viewing Scope

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 Clinically Significant Endoscopic Findings, measured over Intra-procedural, up to 2 hours post-procedure.

The primary endpoint is the number of participants with clinically significant endoscopic findings. The registry defines these as findings that alter medical or procedural management. Examples in the endpoint description include erosive disease, Barrett's esophagus, peptic ulcer, gastrointestinal malignancy, and other findings. The brief summary also gives examples such as esophageal varices, hemorrhage, and a mass.

This endpoint focuses on whether an examination identifies a finding with potential to change management, rather than simply counting every visible abnormality. That distinction is the stated reason for separating clinically significant findings from the secondary outcome of non-clinically significant findings. The endpoint is recorded as a participant count, and its timeframe is intra-procedural, up to 2 hours post-procedure.

The registry identifies the endpoint population as patients with differences found on the Forward Viewing Scope. It does not report the count of participants meeting the endpoint, the denominator actually analyzed, or a comparative estimate between scope types. The endpoint is therefore defined, but its observed value and precision cannot be assessed from the posted record. The phrase “number of participants” indicates a count outcome; it does not by itself establish whether the intended comparison was a difference in proportions, a paired comparison, or another analysis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a count of participants meeting a binary definition: a participant either has a clinically significant finding as defined by the study or does not. This is a general description of the outcome type, not a report of an analysis performed in this trial. A count alone is not enough to compare groups unless the relevant denominators and comparison structure are also clear. The registry reports enrollment of 163, but the analyzed endpoint denominator and the number of participants meeting the endpoint are not reported in the registry record.

What does a binary endpoint describe?

In general, a binary endpoint records whether an event or condition is present. Analysts may describe it with a count and a proportion, then estimate a contrast between study groups or procedures. The appropriate contrast depends on the design. For separate, independent groups, an analysis may compare proportions. When each participant contributes observations under more than one examination or procedure, an analysis may need to account for that pairing. Pairing can change both the estimate and its uncertainty because two observations from the same participant are not necessarily independent.

The brief summary describes a tandem sequence, with one endoscopist performing EGD and a second endoscopist performing ERCP, and says findings are recorded independently. However, the record does not specify the statistical unit for comparison, whether the same participants contribute to both scope assessments, or how such dependence was handled. The listed intervention and arm descriptions do not resolve those details. The analysis method is not reported in the registry record, so a particular test or model should not be attributed to the study.

Why do denominators matter?

A participant count is interpretable only alongside the population at risk of being counted. The primary endpoint population is described as patients with differences found on the Forward Viewing Scope, but the number of participants in that population is not reported. The overall enrollment of 163 does not establish that every enrolled participant was evaluable for the primary endpoint. The record does not report exclusions, missing endpoint observations, or the number analyzed. Without those details, an endpoint frequency cannot be reconstructed or checked.

How should uncertainty be read?

General statistical explanation: an estimate describes the observed data, while a confidence interval communicates uncertainty around that estimate under a specified method and assumptions. A narrow interval usually indicates greater precision than a wide interval, but the interval does not resolve bias from an unsuitable comparison or incomplete data. The registry record does not report a primary effect estimate, confidence interval, or p-value. It therefore provides no basis for judging statistical precision or evidence against a null hypothesis.

The record lists no analysis entries. This means that an analysis method and inferential results are not reported in the registry record; it does not establish what analyses may have been conducted outside the posted record. There is no stated adjustment strategy, model specification, or approach to repeated or paired observations.

What do the planning assumptions mean?

The registry record describes a planning illustration 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 planning assumptions, not evidence that the trial used those assumptions to choose its enrollment. The record does not report a protocol sample-size justification or the numerical planning results in the registry record for this analysis.

In general, a sample-size illustration asks how many participants per arm would be needed under stated assumptions to target a chosen power for a specified effect. Such a calculation is not “observed power,” and it does not show that an observed result is reliable. When an effect estimate comes from the same study, planning based on that estimate can be particularly dependent on the estimate's uncertainty. The record's general note that time-to-event displays use total events under a Schoenfeld approach does not apply to this binary participant-count endpoint as described. No time-to-event outcome is identified among the two recorded outcomes.

Over-dispersion is a general issue when variability in count data exceeds what a model assumes. It is not automatically relevant to every endpoint called a count. Here the primary endpoint is described as participants with an event, a binary outcome at participant level, rather than a repeated event count per participant. The registry does not report a model or diagnostic assessment, so it is not possible to say whether over-dispersion was assessed or relevant in the study's analysis.

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("Standard ERCP")
n      <- c(69)
events <- c(37)
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  Standard ERCP  69  37  53.6  41.2  65.7  42.0  64.9  41.9  64.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: clinically significant endoscopic findings as the primary outcome and non-clinically significant endoscopic findings as a secondary outcome. It does not report a multiplicity strategy, such as whether formal hypothesis tests were planned for both outcomes or whether any adjustment was intended. The statistical analysis plan is not reported in the registry record, so the consequences of testing multiple outcomes cannot be assessed from this record.

General statistical explanation: when several hypotheses are tested, the chance of at least one false-positive finding can increase if each test is interpreted independently at the same threshold. A prespecified hierarchy, adjustment method, or emphasis on estimation rather than multiple significance tests can help frame interpretation. None of these approaches should be attributed to this study without a report.

Missing-data handling is also not reported. The registry does not state whether endpoint observations were missing, how missing observations would be treated, or whether any sensitivity analyses were planned. Enrollment of 163 does not establish the number included in the primary endpoint analysis. The population description for the primary outcome refers to patients with differences found on the Forward Viewing Scope, but the size of this endpoint population is not reported.

The registry record does not define analysis populations, such as whether all enrolled participants or only participants with evaluable procedures were intended for analysis. It also does not report exclusions, protocol deviations, or the handling of participants with incomplete tandem examinations. These omissions limit assessment of the endpoint denominator and potential selection effects. They do not demonstrate that missing data occurred; the presence and handling of missing data are not reported in the registry record.

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 5% reporting threshold.

For the Standard ERCP group, the record reports 163 at risk for serious adverse events and 0 affected; it reports 163 at risk for other adverse events and 0 affected. Deaths are reported as 0. These figures are descriptive entries for the recorded group and should not be interpreted as a complete assessment of safety across every procedure or scope comparison in the study.

The record does not define the observation period for these adverse-event figures in the registry record, nor does it describe how events were collected or adjudicated. It lists no serious adverse-event terms. Zero reported events in a registry entry does not establish that an event is impossible, and it does not quantify the uncertainty around the underlying event frequency. The record also does not provide a comparative safety analysis between forward-viewing and side-viewing scopes.

Accordingly, the figures should be read narrowly as the posted counts for the Standard ERCP group. The record does not provide enough detail to infer whether adverse events were systematically sought in the same way across the tandem procedures or whether the figures cover all enrolled participants. No conclusion about relative safety should be drawn from these entries alone.

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

The registry record establishes that a completed study was intended to examine clinically significant endoscopic findings in a tandem EGD and ERCP setting. It defines clinical significance by whether a finding alters medical or procedural management and identifies the number of participants with such findings as the primary endpoint. It also identifies non-clinically significant findings as a secondary outcome.

What the record does not establish is the observed primary endpoint result. It does not report how many participants had clinically significant findings, the relevant analyzed denominator, or an estimate comparing the scope approaches. There is no reported confidence interval or p-value. Therefore, the registry entry cannot establish the size or precision of any observed difference, or whether any result supports a particular interpretation.

The record also does not establish a randomized comparison. It explicitly says allocation was not stated and warns that the arms are not a like-for-like control comparison. The brief describes back-to-back examinations by different attending gastroenterologists, with the second provider blinded, but does not report how the tandem observations were analyzed. This leaves important design and analysis details unresolved.

General statistical interpretation: a study's result depends not only on the observed counts but also on how participants entered each comparison, the endpoint definition, missing observations, and the method used to quantify uncertainty. A clear endpoint definition is useful, but it cannot replace outcome data or analysis details.

The study's status is COMPLETED and enrollment is 163. Those details describe study conduct as registered; they do not reveal the endpoint outcome. The safety figures are limited to the recorded Standard ERCP group, where zero affected participants are listed for serious and other adverse events and deaths are listed as zero. They do not constitute a comparative safety result. The defensible interpretation is therefore that the registry record describes a clinical question and design, while the posted result information is insufficient to answer that question statistically.

14. Why This Trial Matters Statistically

This study raises a practical measurement question: whether different endoscope viewing orientations identify clinically significant findings in patients undergoing ERCP. The registry focuses on findings that alter management rather than treating all visible findings as equivalent. That endpoint distinction matters statistically because the event definition determines what is counted and what the resulting estimate would mean.

The tandem description also highlights the importance of design-aware analysis. When observations arise in sequence within a clinical encounter, analysts need to know whether comparisons are paired, independent, or structured in another way. The record describes independent documentation by two endoscopists but does not provide the analysis details needed to determine how the observations were compared. This is a useful reminder that procedural descriptions alone do not specify the statistical model.

Another important issue is whether the intended arms are comparable. The record itself notes that allocation was not stated and that the arms are not a like-for-like control comparison. Such a warning should temper any attempt to interpret a simple between-arm contrast as a causal effect. The registry does not report an adjusted analysis or other method that would address potential differences between comparison groups.

Finally, a completed status and a defined endpoint do not make a result interpretable when outcome counts and uncertainty are absent. The registry entry identifies the question, but it does not provide the primary result needed to judge its magnitude or precision. This case illustrates why statistical interpretation requires transparent reporting of outcome counts, denominators, analysis populations, methods, and uncertainty—not just a study objective and enrollment figure.

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 limitations are specific to the information in this registry record. First, the primary endpoint count, analyzed denominator, effect estimate, confidence interval, and p-value are not reported. This prevents assessment of the outcome's frequency, comparative magnitude, and precision.

Second, the study description and comparison fields are not fully aligned. The brief describes tandem EGD and ERCP examinations, while the listed intervention is a forward viewing endoscope and the recorded Standard ERCP arm uses a side viewing scope. The record says allocation was not stated and that the arms are not a like-for-like control comparison. It does not fully explain how the intervention and arm descriptions correspond to the tandem procedures.

Third, the analysis plan is not reported. The registry does not specify how paired or repeated observations were handled, what statistical method was used, or how any potential differences between groups were addressed. It also does not report missing-data handling, analysis populations, exclusions, or whether all enrolled participants completed evaluable procedures.

The endpoint population is described as patients with differences found on the Forward Viewing Scope, but the number in that population is not reported. The secondary outcome is named, but its results and fuller operational definition are not reported in the registry record. Multiplicity handling is also not reported.

Finally, the adverse-event entries are limited to the Standard ERCP group, with no description in the registry entries of collection methods or observation period. These limitations concern what can be interpreted from the record; they do not establish that the underlying study lacked procedures or analyses that are not reported.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of the Impact of a Forward Viewing Scope at Time of ERCP — NCT05627882.
• Registry record last updated 2026-03-02; status last verified 2026-02.
• Results first posted 2026-03-02.
• 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

NCT05627882 is a completed prospective, tandem-designed study sponsored by Brigham and Women's Hospital. Enrollment is 163. The registered question concerns clinically significant endoscopic findings in the setting of forward-viewing and side- or oblique-viewing scopes during ERCP-related procedures.

The primary outcome is the number of participants with clinically significant findings that alter medical or procedural management, with an intra-procedural timeframe up to 2 hours post-procedure. A secondary outcome concerns non-clinically significant findings. The registry describes a sequence of EGD followed by ERCP, but says allocation was not stated and warns that the recorded arms are not a like-for-like control comparison.

Primary and secondary outcome results, statistical analyses, analysis populations, and missing-data methods are not reported in the registry record. For the Standard ERCP group, serious adverse events and other adverse events are each reported as 0 affected among 163 at risk; deaths are reported as 0. These entries do not provide a comparative safety analysis.