Capsule Endoscopy for Post-Ablation Esophageal Lesion Assessment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Capsule Endoscopy for Post-Ablation Esophageal Lesion Assessment (NCT00990782), a na na study. The primary outcome is Number of Participants With Esophageal Lesions Identified Using Capsule Endoscopy.

2. Clinical Question

Statistically, the central question is descriptive: how many participants were recorded as having a capsule-identified esophageal lesion within the stated timeframe? The registered outcome is a count of participants, rather than a continuous measurement or a time-to-event endpoint. The record also names a secondary outcome concerning participants with capsule-identified injury who report symptoms after RFA. Its result is not reported in the registry record.

The question is limited by the single-group design. There is no registered like-for-like control group for estimating a contrast. The study can be described in terms of capsule findings in its enrolled group, but the registry information does not support attributing differences in findings to a comparative intervention or estimating performance relative to another test. The actual primary endpoint result and its analysis are not reported in the registry record.

3. Trial Design

The registry describes the CEPELA I Trial, “Capsule Endoscopy for Post-Ablation Esophageal Lesion Assessment,” as a completed, single-group study sponsored by The Cleveland Clinic. Enrollment is recorded as 93. The listed intervention is the PillCam ESO Capsule Endoscope, classified as a diagnostic test. The arm description states that all patients received capsule endoscopy before and after the RFA procedure.

The record lists allocation as not applicable and masking as none. It does not describe random assignment, blinding, or a control arm. As a result, the design is not a randomized comparison, and the groups should not be treated as comparable intervention and control groups. There is only one recorded arm, named PillCam ESO Capsule Endoscope.

The study summary gives the rationale as assessing the condition of the esophagus around the RFA procedure, because the injury rate had not been established. The primary outcome is the number of participants with esophageal lesions identified using capsule endoscopy, with a 14-day timeframe. A secondary outcome concerns capsule-identified injury accompanied by reported symptoms after RFA. The registry lists two outcome measures in total, but the actual results for these outcomes are not reported in the registry record.

The recorded start is 2009-09, and primary completion is 2010-06. The status is completed. The phase is listed as NA. Further design details—including eligibility criteria, site procedures, the exact timing of each assessment, and how observations were handled—are not reported in the registry record. The registry also does not report a protocol-level sample-size justification or a detailed statistical analysis plan.

These design features determine what can be interpreted. A single-group diagnostic assessment can describe recorded findings, but it does not provide a randomized estimate of a treatment contrast. The absence of masking is part of the registered design information; the record does not explain whether or how that feature affected assessment or reporting.

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

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 Esophageal Lesions Identified Using Capsule Endoscopy, measured over 14 days.

The primary endpoint is the number of participants with esophageal lesions identified using capsule endoscopy. Its unit is participants, and the registry gives a timeframe of 14 days. This is a binary participant-level outcome summarized as a count: a participant either contributes to the count as having a lesion identified or does not. The registry does not provide the operational definition of a lesion, the criteria for a positive capsule finding, or further details about how the outcome was adjudicated.

This type of endpoint is used to describe how often a finding is observed in the study group. In general, a participant count can be informative when the research question concerns the presence of a defined finding, rather than its size or severity. For interpretation, the count is ordinarily considered alongside the number of participants assessed and, when available, an uncertainty interval. The registry record does not report the primary count, the number assessed for this endpoint, or an uncertainty interval, so those features cannot be evaluated.

The study summary frames the assessment around the condition of the esophagus before and after RFA. However, the primary outcome entry does not specify whether the reported lesion count is a new finding, a finding at a particular assessment, or a change between assessments. That endpoint detail is not reported in the registry record. The registry also does not provide a result for the secondary outcome concerning symptoms among participants with capsule-identified injury.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry characterizes the primary outcome as a count of participants with an event. This makes the endpoint a binary participant-level measure summarized by a count. The relevant statistical description would ordinarily include the number meeting the lesion definition and the number assessed, with an uncertainty measure if one was calculated. The registry record does not report those primary outcome results or an analysis.

What does a participant count represent?

In general, a participant count records how many people satisfy a specified outcome definition. It is not the same as counting every lesion, every capsule image, or every examination unless the outcome definition explicitly says so. Here, the registered outcome is participants with lesions identified using capsule endoscopy. The detailed lesion definition, rules for multiple findings, and handling of repeat assessments are not reported in the registry record.

A count is most interpretable when its denominator is clear. The number assessed indicates the group in which the finding could have been detected; the count alone cannot describe its frequency. The registry records enrollment of 93 and gives safety denominators of 88, but does not state the denominator for the primary endpoint. These figures should not be substituted for one another. The record does not explain why the safety denominator differs from enrollment.

What would uncertainty add?

In general, an uncertainty interval communicates how much statistical uncertainty remains around an estimate. A narrow interval indicates greater precision under the chosen model, while a wide interval indicates less precision. An interval does not correct for biases in measurement, selection, or study design. No estimate or interval for the primary endpoint is reported in the registry record, so no statement about its precision is supported.

For binary outcomes, analysts may use methods based on a binomial model or another approach appropriate to the design and assumptions. The choice depends on matters such as the sampling process, repeated measurements, and the exact target of inference. The registry does not identify a method for the primary endpoint. It would therefore be inappropriate to assign a particular model or method to this study.

Why does the design matter?

The recorded design is single-group, with allocation listed as not applicable and masking listed as none. In general, a single-group study can describe observations in that group. It cannot, without a suitable comparator and assumptions, estimate a contrast between alternative interventions. The stated before-and-after capsule assessments do not by themselves establish that the primary outcome was analyzed as a paired change. The analysis details and endpoint timing needed to make that determination are not reported in the registry record.

Masking can matter in general when outcome classification involves judgment, because knowledge of study timing or participant status may influence assessment. Whether capsule lesion assessment involved subjective judgment, and what safeguards were used, are not reported in the registry record. No claim about the direction or extent of any such influence can be made from the recorded design alone.

How should the planning assumptions be read?

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. These assumptions are for a planning illustration, not evidence about the trial’s original design. The record describes this study as single-group, so the illustration’s equal-allocation, two-arm premise does not describe the registered trial design.

In general, a planning calculation estimates the sample size needed to detect an assumed effect under specified assumptions. Its result depends on those assumptions and should not be treated as an observed finding or as the probability that the completed study detected an effect. Such planning numbers are not observed power. The registry does not report the trial’s own sample-size justification, and no numerical planning results are included in the registry record for interpretation.

The record gives no statistical analysis plan, named test, model, confidence-interval method, handling of repeated assessments, or adjustment strategy. It also lists zero analyses. That registry entry indicates that no analyses are listed there; it does not establish whether analyses were performed elsewhere. Without a reported primary estimate and its method, statistical significance and precision cannot be evaluated.

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("PillCam ESO Capsule Endoscope")
n      <- c(88)
events <- c(15)
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  PillCam ESO Capsule Endoscope  88  15  17.0  9.9  26.6  10.6  26.2  10.6  26.3

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary count of participants with capsule-identified esophageal lesions and a secondary outcome concerning participants with capsule-identified injury who report symptoms after RFA. The secondary outcome’s result is not reported in the registry record. No analysis details are recorded for either outcome.

Multiplicity concerns arise in general when several outcomes or hypotheses are assessed, because repeated testing can increase the chance of a nominally notable result. The registry does not report whether any multiplicity procedure was planned or used, or how the primary and secondary outcomes were prioritized in analysis beyond their labels. No adjustment method should be assumed.

Missing-data handling is also not reported in the registry record. The record does not describe missing endpoint observations, exclusions, the number assessed for the primary outcome, or any imputation or sensitivity analysis. Enrollment is listed as 93, while safety entries show 88 at risk; the reason for this difference is not reported. It cannot be determined from these entries whether the difference reflects missing data, eligibility, follow-up, or another reason.

The analysis population is not reported in the registry record. There is no stated intention-to-treat, per-protocol, or other population definition. The registry lists zero analyses, but that does not prove that no analyses occurred; it means the record does not list analyses to interpret. Without analysis-population definitions, endpoint denominators, and missing-data methods, the completeness and reproducibility of an outcome analysis cannot be judged.

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 1% reporting threshold.

Most frequent non-serious adverse event terms

The registry safety entries list 88 participants at risk for serious adverse events and 0 affected, 88 at risk for other adverse events and 30 affected, and 0 deaths. The figures belong to the single PillCam ESO Capsule Endoscope group. The record does not provide further event descriptions for the serious category, and no serious terms are listed.

These are descriptive safety counts. They should not be read as a comparison with another group, because the registry records no comparator arm. They also do not provide a causal estimate of the capsule endoscope’s safety. The registry does not explain the safety observation period, event definitions, collection procedures, or why the at-risk count is 88 when enrollment is 93. Those details are not reported in the registry record.

The 30 figure is recorded under other adverse events; the registry does not provide further detail in the entry about the event types or severity. The zero counts mean no events were recorded in those specific fields for the stated at-risk group, not that every possible event was ruled out. Safety findings should be interpreted within the scope of the recorded categories and denominators, and not as a complete account of all possible harms.

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

The registry record establishes that CEPELA I was designed as a single-group assessment of esophageal findings using capsule endoscopy before and after RFA. It identifies the primary outcome as the number of participants with esophageal lesions identified using capsule endoscopy and gives a 14-day timeframe. It also records a secondary question about symptoms among participants with capsule-identified injury.

What the record does not establish is the observed primary outcome count. The primary result, its endpoint-specific denominator, and any uncertainty interval are not reported in the registry record. The secondary outcome result and its analysis are also not reported. Consequently, the posted information cannot quantify how often lesions were identified or how precisely that frequency was estimated.

In general, a descriptive count from one group can characterize observations in that group when the outcome definition and denominator are clear. It does not, by itself, show that one procedure caused an outcome, establish how results compare with another diagnostic method, or estimate what would have happened in a control group. Those distinctions are especially important because no comparator is recorded.

The safety entries provide limited descriptive information: zero serious adverse events and zero deaths are recorded, along with 30 under other adverse events, among 88 at risk in each safety field. Those figures do not fill the gap in the primary efficacy or diagnostic outcome reporting, and they are not a randomized safety comparison. The registry does not explain the difference between the enrollment entry and safety denominators.

Overall, the registry supports a description of the study question, single-group design, and selected safety counts. It does not support a conclusion about the frequency of capsule-identified lesions from the primary endpoint result, comparative diagnostic performance, or a causal effect. The absence of a reported result is a limitation of the registry record, not evidence that the outcome did or did not occur.

14. Why This Trial Matters Statistically

This trial is statistically notable because its question is framed around identifying esophageal lesions with a diagnostic test, while its registered design is a single-group assessment around an RFA procedure. That combination makes clear why the estimand—the quantity the analysis aims to describe or compare—needs to be distinguished from a treatment effect. The registered primary endpoint is a participant count, not a comparative effect.

For a count to answer a frequency question, the outcome definition and denominator need to be interpretable. The registry identifies the endpoint and its 14-day timeframe but does not report the observed count or the number assessed for that endpoint. As a result, neither the frequency nor its precision can be reviewed from the registry entry. The difference between enrollment of 93 and safety denominators of 88 further illustrates why denominators should be reported separately for each outcome, with reasons for any differences explained.

The record also demonstrates the distinction between study design and planning assumptions. The sample-size assumptions describe an illustration based on an observed effect, with equal allocation between two arms, whereas the registered design is single-group. In general, planning assumptions are not results and should not be mistaken for the design actually used or for observed power. The registry does not report the trial’s own sample-size justification.

Finally, the record names both a primary outcome and a secondary outcome but does not list analyses or results for them. Without outcome estimates, methods, and analysis populations, readers cannot assess multiplicity handling, missingness, or statistical precision. These are important reporting features in a diagnostic assessment because they determine what the observed counts can support. The trial’s registered question is clear; the statistical outcome record is not complete enough to answer it.

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.

A central limitation for interpretation is that the registry record does not report the primary endpoint result. The number of participants with capsule-identified lesions, the number assessed for that endpoint, and any uncertainty measure are absent. The secondary outcome result is also not reported. Thus, the study’s registered clinical question cannot be answered from the outcome data recorded in the registry.

The single-group design has no registered comparator and is not a randomized comparison. It can describe observations in the study group, but it does not establish a comparative diagnostic effect. The registry describes capsule assessments before and after RFA, but does not specify how findings across assessments were combined for the primary endpoint or whether the primary analysis concerned a new lesion, a particular assessment, or change over time.

Further limitations arise from missing design and analysis detail. Eligibility criteria, participant characteristics, lesion definition, assessment procedures, analysis population, missing-data handling, and statistical methods are not reported in the registry record. The record lists enrollment of 93 and safety denominators of 88, without explaining the difference. It also does not describe the safety observation period or the details of other adverse events.

The registry lists zero analyses and does not report the trial’s own sample-size justification. Neither entry establishes what may have been done outside the registry record, but both leave the posted statistical documentation limited. These gaps prevent evaluation of analysis reproducibility and the precision of the primary estimate.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Capsule Endoscopy for Post-Ablation Esophageal Lesion Assessment — NCT00990782.
• Registry record last updated 2017-07-02; status last verified 2017-05.
• Results first posted 2017-07-02.
• 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

The CEPELA I Trial is recorded as a completed, single-group study sponsored by The Cleveland Clinic, with enrollment of 93 and a registered start of 2009-09. Primary completion is recorded as 2010-06. The intervention was the PillCam ESO Capsule Endoscope, with capsule endoscopy described before and after RFA.

The primary outcome was the number of participants with esophageal lesions identified using capsule endoscopy, with a 14-day timeframe. A secondary outcome concerned symptoms after RFA among participants with capsule-identified injury. The registry record does not report results for either outcome or the analysis methods.

The safety entries record 0 serious adverse events, 30 under other adverse events, and 0 deaths, with 88 at risk in each category. The record does not explain the difference between the enrollment figure and safety denominators. Overall, the registry documents the study question and selected design and safety information, but not the primary outcome result needed to assess the lesion count or its precision.