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 Diagnosis and Monitoring of Eosinophilic Esophagitis Using the Cytosponge (NCT02114606), a na na study. The primary outcome is Percent Agreement Between Cytosponge and Endoscopic Biopsy Results.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02114606 |
| Phase | NA |
| Condition | Eosinophilic Esophagitis, EoE |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 86 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of North Carolina, Chapel Hill |
| Results posted | Yes |
2. Clinical Question
Population
Patients diagnosed with eosinophilic esophagitis (EoE) were eligible for the study. The record describes samples being collected in patients who had been diagnosed according to recent guidelines. It reports 86 enrolled participants; the outcome description separately states that 105 procedures were performed on 80 participants, with paired Cytosponge and endoscopy-with-biopsy results available for comparison from 101 procedures.
Intervention
The study assessed the Cytosponge cell collection device. Samples were obtained before participants’ routine endoscopy with biopsy. The registry describes the device as a way to collect esophageal tissue using a non-endoscopic procedure. Its clinical performance and acceptability were study questions, not established findings in the record.
Comparator
Cytosponge findings were compared with upper endoscopy and biopsy. The registry identifies endoscopy with biopsy as the gold standard for diagnosis and monitoring of EoE. This is a within-participant diagnostic comparison, not a randomized comparison between separate treatment groups.
Primary question
How often did Cytosponge results agree with endoscopic biopsy results, including how well the device identified active and inactive EoE? Active EoE was defined as >=15 eos/HPF. The primary outcome was intended to assess overall agreement, sensitivity, and specificity. Those outcome values are not reported in the registry record.
3. Trial Design
This was a prospective cohort study with a single group, as described in the registry record. The record lists no randomized allocation and no masking. Participants diagnosed with EoE underwent Cytosponge sampling before their routine endoscopy with biopsy, allowing results from the two methods to be compared. The endoscopic biopsy was the reference method for the diagnostic comparison; it was not a parallel control group.
The intervention was the Cytosponge cell collection device. The primary outcome concerned agreement between Cytosponge and endoscopic biopsy results, with sensitivity and specificity defined around active versus inactive EoE. Additional outcomes concerned overall agreement measured by kappa and acceptability measured by a visual analog scale and the Impact of Events Scale. The record lists five outcome measures, but it does not report their numerical results.
The enrollment field reports 86 participants. Separately, the primary outcome description reports 105 procedures performed on 80 participants, of which 101 had results from both procedures available for comparison. The record does not explain the relationship between the enrollment figure and the participant count in the outcome description, nor does it explain why some procedures did not yield paired results. Repeated procedures were within the stated outcome timeframe of study enrollment and the initial procedure, with additional procedures possible up to 1 year after enrollment.
The record gives a study start of 2015-07 and a primary completion of 2016-06, and lists the status as terminated. It does not report a reason for termination. The study is not described as a comparison of treatment effects, and no conclusions about treatment efficacy follow from this design. Its central statistical purpose was to evaluate concordance and diagnostic classification by comparing two assessment methods.
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 | EoE Patients |
|---|---|
| STARTED | 86 |
| COMPLETED | 80 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | EoE Patients |
|---|---|
| Unable to swallow Cytosponge | 6 |
Analysis population for the primary outcome, as defined in the registry: Of the 105 procedures performed on 80 participants, 101 yielded results from both Cytosponge and endoscopy with biopsy for comparison.
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: Baseline characteristics unavailable for the 6 participants who were unable to swallow the Cytosponge.
| Characteristic | Unit | EoE Patients |
|---|---|---|
| Participants analysed | 80 | |
| Age, Continuous | years | 42 (18 to 69) |
| Sex: Female, Male: Female | Participants | 27 |
| Sex: Female, Male: Male | Participants | 53 |
| 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 | 80 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 80 |
6. Primary Endpoint
The registry lists the primary outcome as Percent Agreement Between Cytosponge and Endoscopic Biopsy Results, measured over At study enrollment and initial procedure and each additional procedure, up to 1 year after enrollment.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percent |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percent agreement between Cytosponge and endoscopic biopsy results. The registry further describes sensitivity as the percentage of Cytosponge positive results among results indicating active EoE by biopsy, and specificity as the percentage of Cytosponge negative results among results indicating inactive EoE by biopsy. Active EoE is defined as >=15 eos/HPF.
These measures address different aspects of classification. Sensitivity describes whether the device identifies cases classified as active by the reference method; specificity describes whether it identifies cases classified as inactive by that method. Overall agreement captures the proportion of procedures for which the methods give consistent results. Agreement alone can be difficult to interpret when one result category is much more common than another, so the record also lists kappa as a secondary measure. In general, kappa assesses agreement while accounting for agreement expected by chance under its assumptions.
These measures are used because the study asks whether a less-invasive sampling method produces findings that align with endoscopic biopsy. They do not establish that the two methods are interchangeable in every setting, and their interpretation depends on the reference classification and the participants and procedures evaluated. The registry record does not report the observed endpoint values, uncertainty intervals, or the distribution of biopsy-positive and biopsy-negative results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a diagnostic agreement study, but it does not report the primary outcome results. It gives no numerical estimate for overall agreement, sensitivity, or specificity, and no confidence interval or other measure of uncertainty for those outcomes. Therefore, the record does not allow a reader to judge the observed level or precision of agreement between Cytosponge and endoscopic biopsy.
The outcome description does provide information about the analysis base: it reports 105 procedures performed on 80 participants and paired results from both methods for 101 procedures. These figures describe procedures and availability of paired results; they are not estimates of diagnostic performance. A paired comparison requires results from both methods for the same procedure. The registry does not say how the procedures without paired results were handled, or whether the reported figures refer to every planned outcome analysis.
The record defines active EoE as >=15 eos/HPF and specifies how positive and negative results enter the sensitivity and specificity calculations. This makes the intended classification rule clear, but does not reveal how many procedures fell into each biopsy category or how often Cytosponge results matched them. Without those outcome data, claims about diagnostic accuracy, the direction of disagreement, or the reliability of estimates would be unsupported.
The secondary outcomes also require restraint. Kappa was listed for overall agreement, while acceptability was to be measured using a visual analog scale and the Impact of Events Scale. No results for these measures are reported in the registry record. The planned assessment of acceptability should not be treated as evidence that participants found the device acceptable.
The record lists the study as terminated but does not state why. That status alone does not establish whether termination was related to safety, recruitment, feasibility, data quality, or another cause. Nor does it indicate whether all intended analyses were completed. The registry record does not report a statistical analysis plan, prespecified hypotheses beyond the outcome descriptions, or an explanation of the relationship between 86 enrolled participants and the 80 participants in the outcome description.
Overall, the record establishes the study question, the comparison method, the diagnostic threshold, and some information about the procedures with paired results. It does not establish the study’s numerical findings. Readers should distinguish these design and denominator details from the missing performance estimates, which are necessary to evaluate the strength and precision of the diagnostic comparison.
9. Statistical Methods Explained
The study compares two methods applied around the same clinical procedure: Cytosponge sampling and endoscopy with biopsy. In general, this paired design focuses on whether both methods classify the same procedure similarly. It is different from comparing outcomes between separate randomized groups. The registry identifies endoscopy with biopsy as the gold standard for diagnosis and monitoring of EoE, so the diagnostic measures are defined relative to that reference.
What does agreement measure?
Overall agreement is the percentage of Cytosponge procedures with results consistent with biopsy results. It summarizes matches across the result categories, but does not show whether a mismatch is a false positive or a false negative relative to the biopsy reference. The pattern of disagreements matters: a method might agree well overall while performing differently for positive and negative biopsy classifications. For that reason, the registry also defines sensitivity and specificity.
How are sensitivity and specificity interpreted?
In general, sensitivity is the proportion of reference-positive observations classified as positive by the test under evaluation. Specificity is the proportion of reference-negative observations classified as negative. The registry applies these concepts to active and inactive EoE, respectively, and defines active disease as >=15 eos/HPF. These quantities depend on the reference classification and on having paired results. They do not by themselves describe how often a positive or negative Cytosponge result is correct in a particular clinical population; that question also depends on how common the reference-positive category is in that population.
Because the registry record does not report the primary estimates or the counts in the relevant result categories, the observed sensitivity and specificity cannot be reconstructed from the record. The figures for procedures and paired results do not supply the missing classification counts.
Why include kappa?
The listed secondary outcome includes overall agreement measured by kappa. In general, kappa compares observed agreement with agreement that would be expected from the marginal distributions of the classifications under the measure’s assumptions. It can add context when agreement might be high partly because one category is common. Kappa is not identical to sensitivity, specificity, or raw percent agreement, and it can be influenced by how often each category occurs. The registry record does not report a kappa estimate or the result distribution needed to interpret it.
What do the acceptability measures address?
The listed acceptability outcomes use a visual analog scale and the Impact of Events Scale. These address participant-reported experience rather than diagnostic classification. In general, a scale score needs its scoring direction and interpretation to be clear, and its result is most informative alongside information about who completed it and whether responses were missing. The registry record names the measures but does not provide their results, scoring details, or completion information.
How should repeated procedures be considered?
The outcome timeframe includes enrollment and the initial procedure, with additional procedures possible up to 1 year after enrollment. The record reports procedures as well as participants, which indicates that observations may include repeated procedures for some participants. In general, repeated observations from the same participant may be statistically related; treating them as independent can make uncertainty estimates too small. Appropriate methods may account for clustering or repeated measurements, but the registry record does not report whether or how such dependence was handled.
The record states that 105 procedures were performed on 80 participants and that 101 procedures had paired results. It does not give the number of repeated procedures per participant, explain the procedures without paired results, or state the analysis population for each measure. These omissions limit assessment of the denominators and of how representative the paired comparisons may be.
What does uncertainty add?
In general, a confidence interval describes the range of estimates compatible with the data and the method used, under its assumptions. A narrow interval indicates greater precision than a wide interval, but does not by itself establish that a method is clinically suitable. For diagnostic agreement, intervals around sensitivity, specificity, agreement, or kappa help distinguish a stable estimate from one that is imprecise. No such intervals are reported in the registry record.
General statistical methods also need to account for the source of the reference result, the classification threshold, incomplete paired observations, and possible clustering from repeat procedures. The record supplies the threshold and some procedure counts, but it does not report the statistical analysis plan, uncertainty calculations, handling of missing paired results, or methods for repeated observations. Consequently, readers can understand the intended measures but cannot verify how their uncertainty was estimated or whether all analysis assumptions were addressed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and several secondary outcomes: overall agreement measured by kappa, and acceptability assessed with a visual analog scale and the Impact of Events Scale. It also describes sensitivity and specificity as primary outcome variables. When several outcomes are examined, the chance of at least one apparently notable result can increase if each is tested separately. General approaches to this issue include prioritizing a prespecified primary outcome, adjusting for multiple comparisons, or treating secondary findings as exploratory. The registry record does not report a multiplicity strategy, a hierarchy of tests, or how the several primary outcome components were handled.
The record does not report an analysis plan, detailed analysis populations, or procedures for handling missing data. It reports 105 procedures on 80 participants and paired Cytosponge and biopsy results for 101 procedures. It does not explain why paired results were unavailable for other procedures, whether missingness differed by result or participant characteristics, or whether all outcome measures used the same analysis set. Without those details, the potential effect of missing paired observations cannot be assessed.
Repeated procedures may also create dependence among observations from the same participant. In general, statistical analyses should account for that structure when estimating uncertainty. The registry gives no account of how repeated procedures were treated. The relationship between the 86 enrolled participants and the 80 participants named in the outcome description is also not explained in the registry record. These are reporting gaps; they do not establish that a particular analysis was or was not conducted.
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 |
|---|---|---|---|
| EoE Patients | 0 | 86 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| EoE Patients | 0 of 86 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| EoE Patients | 0 of 86 |
The registry lists one group, EoE Patients, and reports zero serious adverse events among 86 participants at risk. It also reports zero other adverse events among 86 participants at risk, and zero deaths. No serious adverse event terms are listed.
These figures describe the adverse-event entries in the registry record. They do not provide detail about how events were defined, how they were collected, the length of safety follow-up, or whether every participant completed follow-up. The record does not report those details. The listed zeros therefore should not be read as proof that no event of any kind occurred; they indicate that no events were recorded in the stated serious and other categories in this entry.
The study was a single-group cohort, so the safety figures do not provide a randomized comparison with another procedure or control group. They also do not quantify the risk of rare events precisely. The record’s terminated status is not explained, and it should not be interpreted as evidence of a safety-related termination. No reason for termination is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The study asks whether Cytosponge results align with endoscopic biopsy results in patients diagnosed with EoE, and whether the device is acceptable to participants. The registry specifies a diagnostic threshold of >=15 eos/HPF for active EoE, identifies biopsy as the reference, and describes the intended measures of agreement, sensitivity, and specificity. It also reports the number of procedures and paired comparisons described for the primary outcome.
What the record does not provide is the numerical result of the primary comparison. No agreement, sensitivity, or specificity estimates are reported, and no precision estimates are given. The secondary kappa and acceptability results are also absent. As a result, the record cannot show how often the methods agreed, what kind of disagreement occurred, or how precisely any performance measure was estimated.
Even if performance estimates were available, diagnostic agreement would not by itself establish that one method can replace another in every setting. Interpretation would depend on the study population, result distributions, missing paired observations, and the way repeated procedures were analyzed. The record does not provide enough information to evaluate those issues fully. It also does not report a reason for the terminated status, so that status cannot be used to infer the study’s results or the reason the study ended.
The record therefore supports a description of the question and intended comparison, not a conclusion about clinical performance. It does not establish that Cytosponge is accurate, inaccurate, safe, unsafe, acceptable, or unacceptable. Those judgments require outcome results and methodological details that are not reported in the registry record.
13. Why This Trial Matters Statistically
Statistically, this study is notable for asking a paired diagnostic question rather than a treatment-effect question. Cytosponge results were intended to be compared with endoscopic biopsy results from participants, with biopsy serving as the reference method. That design makes agreement and classification performance central, while making clear that a comparison between randomized treatment arms is not the relevant framework.
The outcome definitions distinguish overall agreement from sensitivity and specificity. This distinction matters because a single agreement percentage can conceal whether mismatches occur among active or inactive EoE classifications. The record’s threshold of >=15 eos/HPF also makes the classification rule explicit. At the same time, the absence of numerical results prevents assessment of whether the intended diagnostic measures were high, low, or precise.
The record also draws attention to the difference between participant counts and procedure counts. It describes repeated procedures as possible up to 1 year after enrollment and reports paired results at the procedure level. In general, repeated measurements from a participant may be correlated, so analytic choices about dependence can affect uncertainty. The registry record does not describe those choices.
Finally, the record names acceptability outcomes alongside diagnostic outcomes. These are distinct questions: a measure of diagnostic agreement does not answer how participants experienced the procedure, and an acceptability score does not establish diagnostic performance. Because neither set of results is reported, the record is most useful for understanding the planned questions and the limits of what can be concluded from the available registry information.
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 most important limitation of the registry record for interpretation is that it does not report numerical results for the primary or secondary outcomes. Without estimates for overall agreement, sensitivity, specificity, kappa, or acceptability, the study’s findings cannot be evaluated from this record. No confidence intervals or other uncertainty measures are reported.
The outcome description reports 105 procedures on 80 participants, with paired results from both methods for 101 procedures, while the enrollment field reports 86 participants. The registry does not explain the difference between these participant figures, the procedures without paired results, or which analysis populations were used for each outcome. These gaps make it difficult to assess the denominators and the possible impact of unavailable comparisons.
The record allows additional procedures up to 1 year after enrollment but does not report how repeat observations were distributed across participants or how statistical analyses accounted for their possible correlation. It also does not provide details on missing-data handling, outcome scoring, the statistical analysis plan, or multiplicity. The listed secondary measures may involve distinct scales, but scoring and interpretation details are not reported.
The record lists the study as terminated without giving a reason. It does not report whether termination affected enrollment, follow-up, outcome collection, or analysis. These limitations concern what can be established from the registry record; they should not be taken as evidence that a particular problem occurred during the study.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Diagnosis and Monitoring of Eosinophilic Esophagitis Using the Cytosponge — NCT02114606.
- Registry record last updated 2021-02-17; status last verified 2020-11.
- Results first posted 2021-02-17.
- 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
NCT02114606 is a single-group prospective cohort study of the Cytosponge cell collection device in patients diagnosed with EoE. Cytosponge samples were collected before routine endoscopy with biopsy, which the registry identifies as the reference method. The primary outcome concerns percent agreement, sensitivity, and specificity, using >=15 eos/HPF to define active EoE.
The record reports 86 enrolled participants and separately describes 105 procedures on 80 participants, with paired results for 101 procedures. It lists kappa and two acceptability measures as secondary outcomes. Numerical outcome results are not reported in the registry record. The study status is terminated, with no reason given.