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 Study of the Efficiency of Esophageal Dilation on Patient With Eosinophilic Esophagitis (NCT00880906), a randomized na study. The primary outcome is Percent Change From Baseline in Dysphagia Score in Patients With Eosinophilic Esophagitis (EE).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00880906 |
| Phase | NA |
| Condition | Suspected Eosinophilic Esophagitis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 50 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Vanderbilt University |
| Results posted | Yes |
2. Clinical Question
Population
Patients with suspected eosinophilic esophagitis and a history of food impaction and/or difficulty swallowing, scheduled for endoscopy and biopsy. The registry summary describes the clinical context, while the primary outcome population field is blank.
Intervention
Esophageal dilation during the first endoscopy, alongside steroid and proton pump inhibitor therapy described as routine care.
Comparator
Steroid and proton pump inhibitor therapy without esophageal dilation during endoscopy. The official title mentions a sham comparison, but the arm descriptions do not explain a sham procedure.
Primary question
At 60 days, what percent change from baseline in dysphagia score was recorded for patients assigned to dilation plus routine care compared with routine care alone? The registry does not report an estimable statistical comparison between the groups.
The clinical rationale in the registry is uncertainty about whether early dilation adds benefit to drug treatment for people experiencing food impaction or swallowing difficulty. The trial compares two care strategies around the first endoscopy: dilation is included in one strategy and omitted in the other. Both arm descriptions include steroids and proton pump inhibitor therapy.
The primary outcome concerns change in dysphagia score, not the prevention of food impaction itself. The registry summary says the investigators also intended to examine whether dilation helps prevent food impaction and improves swallowing, but the posted primary outcome is the percent change in dysphagia score at 60 days. A secondary outcome is an immunological assessment into the etiology of eosinophilic esophagitis. The record does not report an outcome result for food impaction prevention or provide further results for that secondary assessment.
3. Trial Design
The registry identifies this as a prospective, randomized, parallel-group trial with single masking. Its official title describes a randomized controlled trial with sham, comparing standard therapy with or without esophageal dilation. However, the arm descriptions specify dilation alongside routine care in Group A and routine care alone in Group B; they do not describe what a sham procedure involved. The record does not report who was masked or how masking was maintained.
The study concerns patients with suspected eosinophilic esophagitis who had food impaction and/or difficulty swallowing and were scheduled for endoscopy and biopsy. The summary describes drug therapy including steroids and drugs used to treat reflux disease. The intervention listing names steroid and proton pump inhibitor therapy, and the arm descriptions include those therapies in both groups.
Enrollment is recorded as 50. For the primary outcome, the posted arm counts are 17 for Group A and 14 for Group B. The registry does not explain the relationship between the enrollment figure and the counts attached to these outcome results, so they should not be treated as interchangeable measures of the population enrolled, randomized, or analyzed.
The study is marked completed. The recorded start is 2008-08 and primary completion is 2013-12. The registry lists phase as NA, which is not a phase designation. The record does not report the allocation procedure beyond randomized allocation, such as sequence generation or concealment details. It also does not describe adherence, treatment crossover, or the timing and conduct of follow-up beyond the 60-day primary outcome timeframe.
The study summary also describes taking and storing extra esophageal biopsies for future research. That purpose is separate from the posted primary dysphagia outcome. The record does not provide further methodological details about the collection or analysis of those samples.
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 | Group A Drug Therapy Plus Dilation | Group B Drug Therapy Only |
|---|---|---|
| STARTED | 29 | 21 |
| COMPLETED | 17 | 14 |
| NOT COMPLETED | 12 | 7 |
Reasons for not completing this period:
| Reason | Group A Drug Therapy Plus Dilation | Group B Drug Therapy Only |
|---|---|---|
| Lost to Follow-up | 0 | 1 |
| Did not meet criteria following patholog | 12 | 6 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Group A Receives Routine Care and Esophageal Dilatation | Group B Receives SOC Only | Total |
|---|---|---|---|---|
| Participants analysed | 29 | 21 | 50 | |
| Age, Continuous | Years | 35 (19 to 61) | 32 (20 to 69) | 33 (19 to 69) |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 29 | 20 | 49 |
| Age, Categorical: >=65 years | Participants | 0 | 1 | 1 |
| Sex: Female, Male: Female | Participants | 13 | 9 | 22 |
| Sex: Female, Male: Male | Participants | 16 | 12 | 28 |
| Region of Enrollment: United States | participants | 29 | 21 | 50 |
6. Primary Endpoint
The registry lists the primary outcome as Percent Change From Baseline in Dysphagia Score in Patients With Eosinophilic Esophagitis (EE), measured over 60 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percent Change |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is percent change from baseline in dysphagia score in patients with eosinophilic esophagitis, assessed at 60 days. The registry describes a score ranging from being able to eat a normal diet with no dysphagia to being unable to swallow anything, with intermediate levels corresponding to the ability to swallow some solid foods, only semi-solid foods, or liquids only. The record does not state the formula used to convert baseline and follow-up scores into percent change.
A dysphagia score is used to represent swallowing difficulty in an ordered, clinically interpretable form. Tracking change from baseline is intended to describe how the measure changes over follow-up rather than reporting a follow-up score alone. General statistical caution applies: a score with ordered categories does not automatically have equal distances between adjacent categories, and a percent-change summary depends on how the score is coded and transformed. The registry does not explain these choices or state whether the posted values are means, medians, or another summary.
The posted values are 69.0 for Group A and 79.0 for Group B, with the unit recorded as Percent Change. The record does not provide dispersion, confidence intervals, or a statistical test for this endpoint. It also does not report an analysis population definition. Therefore, the values describe the recorded group results but do not, on their own, quantify the precision of the estimated changes or establish the size and uncertainty of a between-group effect.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports a primary endpoint value of 69.0 Percent Change for Group A, which received routine care and esophageal dilation, and 79.0 Percent Change for Group B, which received standard care only. These are the posted arm-level values for change from baseline in dysphagia score at 60 days. The registry does not report an estimable two-arm comparison for this endpoint. It is therefore not possible to interpret the values as a tested difference between treatment strategies or to assess whether any apparent numerical separation is compatible with chance variation.
No standard deviations, standard errors, confidence intervals, or p-values are reported for the primary endpoint. Without an uncertainty measure, readers cannot assess how precisely the group values estimate the underlying outcomes. The record also does not specify the statistical summary represented by each value or how the percent-change calculation was made. The direction and meaning of the numerical values should therefore be interpreted cautiously rather than assumed from the label alone.
The arm counts attached to the outcome are 17 and 14. They identify the counts associated with the posted results, but the registry does not explain whether these are randomized participants, participants with observed endpoint data, or participants included under another analysis definition. The recorded enrollment is 50, and the record does not reconcile enrollment with the endpoint counts. Missing outcomes and the handling of missing data are not reported in the registry record.
The trial's stated clinical motivation includes prevention of food impaction and improvement in swallowing. The reported primary endpoint addresses dysphagia-score change; the registry does not provide a posted result for food impaction prevention. A secondary outcome is listed for immunological assessment into the etiology of eosinophilic esophagitis, but the record does not supply a result for that outcome.
Accordingly, the posted results allow a descriptive reading of the recorded endpoint values, but not an inferential conclusion about a treatment effect. The registry does not report enough information to establish the magnitude, precision, or statistical significance of a contrast between groups. That absence is not evidence that the groups were equivalent or that there was no effect; it means the registered results do not support those conclusions.
9. Statistical Methods Explained
The registry identifies randomized allocation and a parallel-group design. In general, random allocation is intended to reduce systematic differences between groups at the point of assignment, while a parallel design assigns participants to a strategy that is followed alongside the comparator strategy. These design features support a comparative question, but they do not by themselves establish that the reported outcome comparison is unbiased or precise. Details about sequence generation, allocation concealment, and the identity of masked parties are not reported in the registry record.
What can the arm values tell us?
The primary outcome values are reported separately for the dilation group and the standard-care-only group. An arm-level value describes the outcome summary in that group; a treatment comparison requires a defined contrast between groups and information about its uncertainty. The registry's analysis listing reports no analyses, and it flags the endpoint as not estimable for a two-arm comparison. There is therefore no sponsor-reported comparative estimate, confidence interval, or hypothesis-test result to interpret.
The endpoint is a percent change from baseline in an ordered dysphagia score. General statistical interpretation depends on how the score is summarized and transformed. For example, a percent-change measure can be sensitive to the baseline value and to the calculation used when baseline scores are near the scale's boundary. The registry does not state the calculation formula, the summary statistic, or how score distributions were handled. Those details matter because different choices can produce values with different interpretations.
Why does uncertainty matter?
General statistical principle: a confidence interval describes a range of estimates compatible with the observed data and the method's assumptions. Its width conveys precision; a narrow interval indicates more precise estimation than a wide interval. No confidence interval or other dispersion measure is posted for the primary endpoint. Consequently, the recorded values cannot be used to judge precision or to determine whether a comparative estimate would exclude no difference.
A p-value, when reported, addresses how compatible data are with a specified null hypothesis under a statistical model. It does not measure the size or clinical importance of an effect. No p-value is reported for the primary comparison, and no test procedure is described. Neither a significant nor a non-significant result can be inferred from the arm values alone.
Why might an analysis not be estimable?
The record marks this endpoint as not estimable for a two-arm comparison because it is a count-other type endpoint. That is a registry-level explanation, not a full account of the underlying data or analysis. It does not state whether the issue arose from the outcome's format, incomplete information, or another limitation. The record does not include an alternative model or an adjusted analysis. No cause should be inferred beyond the stated limitation.
General statistical principle: estimates of group differences require both an outcome definition and enough information to characterize variation within groups. For outcomes that are counts or other nonstandard summaries, methods may need to account for features such as skewness or over-dispersion, where variability exceeds what a simple model assumes. This trial's primary outcome is recorded as a percent-change measure, and the record does not report a distributional model or any assessment of its assumptions. These general considerations do not imply that a particular model was used in this trial.
How should the planning illustrations be understood?
The registry's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustration is described as detecting a stated fraction of the observed effect. No resulting participant-per-arm values are present in the record. These assumptions do not establish the trial's original design rationale or show that the study was planned using the observed effect. The sample-size justification and the trial's own statistical plan are not reported in the registry record.
General principle: a planning calculation asks how much information a future study might need under chosen assumptions. It is not an observed power calculation and does not measure how likely the completed trial was to detect an effect. Any planning illustration based on an observed result is especially dependent on that result and its uncertainty. In this record, the lack of an estimable comparative result and the absence of a reported uncertainty measure limit the interpretation of any such planning exercise.
The registry does not report interim analyses, prespecified analysis methods, adjustment for baseline values, or sensitivity analyses. These omissions prevent a detailed assessment of how the endpoint was intended to be analyzed and how robust the posted values are to analytic choices. They should not be filled in by assuming customary methods.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary dysphagia-score outcome and one secondary outcome, an immunological assessment into the etiology of eosinophilic esophagitis. It records two outcome measures overall. The posted information does not provide results for the secondary outcome, nor does it describe a multiplicity strategy for interpreting results across outcomes. The statistical analysis plan and any hierarchy of hypotheses are not reported in the registry record.
General statistical principle: when multiple outcomes or multiple comparisons are tested, the chance of at least one apparently notable result can increase unless the analysis accounts for multiplicity or establishes a prespecified hierarchy. This does not show that such adjustment was required or performed in this trial; the record does not say. No family-wise or other multiplicity adjustment is reported, and no unadjusted or adjusted p-values are posted for the primary outcome.
The registry does not define the analysis population for the primary endpoint. It does not state whether participants were analyzed according to randomized assignment, treatment received, or availability of outcome data. The counts accompanying the arm values are 17 and 14, while the recorded enrollment is 50; the record does not explain the relationship among these figures.
Missing-data frequency, reasons for missingness, and handling methods are not reported in the registry record. There is no description of imputation, exclusion rules, or sensitivity analyses for missing outcomes. Without those details, readers cannot evaluate whether the endpoint values represent all assigned participants or a subset with recorded measurements, or assess how missing data may have affected the results.
These reporting gaps do not establish that missing data or multiplicity affected the findings. They mean the registry record does not provide the information needed to evaluate those issues or reconstruct the planned analysis.
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 |
|---|---|---|---|
| Group A Receives Routine Care and Esophageal Dilatation | 0 | 17 | 0.0% |
| Group B Receives SOC Only | 0 | 14 | 0.0% |
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 |
|---|---|
| Group A Receives Routine Care and Esophageal Dilatation | 0 of 17 |
| Group B Receives SOC Only | 0 of 14 |
The registry reports zero serious adverse events among 17 participants at risk in Group A and zero among 14 participants at risk in Group B. It also reports zero other adverse events among 17 participants at risk in Group A and zero among 14 participants at risk in Group B. No serious adverse-event terms are listed. The record does not report death counts for either group.
These figures describe events recorded in the registry for the stated groups and at-risk counts. They do not show that the chance of an adverse event was zero. An observed count of zero can occur even when an event remains possible, and the precision of a safety estimate depends on the amount and completeness of follow-up. The registry does not provide confidence intervals, follow-up duration for safety, event definitions, or detail about how adverse events were collected.
The absence of listed serious-event terms should be read as no terms reported in this record, not as proof that no clinically relevant safety issues occurred. Likewise, the zero counts for other adverse events do not establish equal safety between groups. The registry does not provide a statistical comparison of safety outcomes, and its posted counts do not establish whether the groups differ in risk.
12. What the Result Does, and Does Not, Mean
The results record provides a descriptive endpoint value for each group: 69.0 Percent Change for routine care with dilation and 79.0 Percent Change for routine care alone. The outcome is change from baseline in dysphagia score at 60 days. These values are the available primary endpoint results, but the registry does not report a statistical comparison, an uncertainty estimate, or the precise summary and calculation behind them.
The values do not establish that either strategy produced a better outcome. The record does not report a treatment-effect estimate with uncertainty, a test result, or a prespecified threshold for interpreting a clinically meaningful change. Without those elements, the numerical ordering of the group values cannot support a conclusion about the direction, magnitude, or reliability of a difference.
The study's stated aim also concerns food impaction and swallowing. The posted primary endpoint addresses dysphagia-score change, but no result for prevention of food impaction is given. The registry lists an immunological secondary outcome without reporting its result. These questions therefore remain unanswered by the posted results.
The safety counts show zero serious and zero other adverse events recorded in each group, among the stated at-risk counts. They do not prove an absence of risk or demonstrate that safety is the same between strategies. The record does not provide precision estimates for those counts or enough follow-up detail to interpret them as comprehensive safety evidence.
In short, the registry supports a limited description of the study design, endpoint values, and reported adverse-event counts. It does not provide the comparative analysis needed to judge whether the groups differed, how precisely any difference was estimated, or whether the results are robust to missing data or analytic choices. Lack of an interpretable comparison is not evidence of equivalence, no effect, or a positive effect.
13. Why This Trial Matters Statistically
This trial asks a comparative question that is clinically and statistically distinct from asking whether dysphagia scores changed within each group. The intervention group received dilation alongside routine care, while the comparator group received routine care alone. A treatment-effect question requires a between-group contrast, because changes observed in either group may reflect factors beyond the additional procedure. The registry reports arm-level endpoint values but does not provide an estimable comparison.
This distinction is important for interpreting results. A pair of group summaries can look different numerically without revealing whether the underlying difference is precise or compatible with chance variation. In this record, no confidence interval, standard error, or p-value accompanies the endpoint values. The data therefore do not support a formal inference about the comparative effect.
The outcome also illustrates the importance of transparent measurement definitions. Dysphagia is represented by an ordered score, and the primary endpoint is described as percent change from baseline. The registry provides score categories but not the calculation used to derive percent change or the statistical summary represented by the reported values. Clear definitions help readers understand what a result measures and whether its scale supports the intended interpretation.
Finally, the record highlights the role of complete reporting. The enrollment figure, endpoint counts, analysis population, missing-data handling, and statistical plan are not reconciled or described in enough detail to reconstruct the analysis. Safety counts are available, but their precision and follow-up context are not. These gaps do not determine the underlying study findings; they limit what can be concluded from the registry record. A transparent comparative estimate with uncertainty and clear population definitions would be needed to evaluate the central statistical question.
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 for interpreting the posted results is that the registry does not report an estimable two-arm comparison for the primary endpoint. The arm-level values, 69.0 and 79.0 Percent Change, have no accompanying dispersion measure, confidence interval, or test result. The record does not identify the statistic represented by each value or specify the formula used to calculate percent change from the dysphagia score.
The primary outcome population field is blank, and the analysis population is not defined. The record gives an enrollment of 50 and endpoint counts of 17 and 14 but does not explain how these figures relate. It does not report whether outcome data were missing, why data might be missing, or how missingness was handled. The impact of these issues cannot be assessed from the registry information.
The official title mentions a sham comparison, but the intervention and arm descriptions do not explain a sham procedure. The record identifies single masking without saying who was masked or describing masking procedures. Randomization is reported, but sequence generation and allocation concealment are not described. These details limit assessment of potential bias and the practical separation between the assigned strategies.
The registry does not report a statistical analysis plan, sample-size justification, interim analyses, adjustment for baseline values, or sensitivity analyses. It also does not report results for food impaction prevention or the listed immunological secondary outcome. For safety, counts are reported without follow-up duration, event-collection detail, or uncertainty estimates. These are limitations of the available registry record and do not establish that the trial lacked procedures or analyses that were not recorded there.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of the Efficiency of Esophageal Dilation on Patient With Eosinophilic Esophagitis — NCT00880906.
- Registry record last updated 2017-11-06; status last verified 2017-10.
- Results first posted 2014-05-26.
- 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
NCT00880906 is a completed prospective, randomized, parallel-group study with single masking, sponsored by Vanderbilt University. The registry records enrollment of 50 and compares routine care with esophageal dilation against routine care without dilation. Both arm descriptions include steroid and proton pump inhibitor therapy.
The primary endpoint is percent change from baseline in dysphagia score at 60 days. The reported values are 69.0 for the dilation group and 79.0 for the standard-care-only group. The record states that a two-arm comparison is not estimable and reports no uncertainty estimates or analysis result.
Serious adverse-event counts are zero in both groups, as are other adverse-event counts; the record does not report death counts. It lists an immunological secondary outcome but provides no result for it. The registry does not describe the analysis population, missing-data methods, or statistical plan, and does not explain the relationship between enrollment and the primary-outcome counts.