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 Prospective Evaluation of Budesonide for Prevention of Esophageal Strictures After Endotherapy (NCT02069847), a non-randomized phase 2 study. The primary outcome is Dysplasia in Barrett Esophagus (BE).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02069847 |
| Phase | Phase 2 |
| Condition | Esophageal Stricture |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 90 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
Patients undergoing radical endoscopic mucosal resection or endoscopic submucosal dissection for advanced premalignant esophageal lesions or superficial esophageal cancers. The registry identifies esophageal stricture as a condition of interest, but does not give fuller eligibility details in the registry record.
Intervention
Oral budesonide after endoscopic treatment. The intervention description specifies 1mg twice a day for a total of 8 weeks following endoscopic submucosal dissection or endoscopic mucosal resection.
Comparator
The record describes a control group assembled retrospectively from subjects who underwent endoscopic submucosal dissection or endoscopic mucosal resection. Because allocation is listed as non-randomized, this is not a randomized, like-for-like comparison.
Primary question
The stated hypothesis is that oral budesonide prevents esophageal stricture formation after endoscopic treatment. The registered primary outcome, however, counts participants by Barrett esophagus dysplasia category at 3 months: non-dysplastic, low-grade dysplasia, high-grade dysplasia, or T1a early esophageal adenocarcinoma. The rate of esophageal stricture is listed as a secondary outcome.
This distinction matters when interpreting any reported result. The study’s clinical motivation concerns preventing strictures, but the primary endpoint is a classification of Barrett esophagus dysplasia. These outcomes describe different aspects of participants’ status. A dysplasia-category count should not be treated as a direct measure of stricture prevention, and a stricture rate should not be substituted for the registered primary endpoint.
The registry record does not report numerical results for either outcome. It therefore does not establish from the posted results whether dysplasia categories or stricture rates differed between the prospective budesonide group and the retrospective control data.
3. Trial Design
This is a phase 2 study listed as completed, with a non-randomized allocation, no masking, and a single-group model. The record lists enrollment as 90. Its intervention description is prospective: participants receive budesonide after endoscopic treatment. The control description instead specifies retrospective collection of data from people who underwent endoscopic submucosal dissection or endoscopic mucosal resection.
That structure is important. The registry’s “single-group” model and its separate description of retrospective control data do not amount to randomized assignment. Participants were not allocated at random according to the listed design. Differences between the prospective treated group and retrospective records could reflect differences in who was included, how care was delivered, or how outcomes were measured. The registry record does not report enough detail to assess or adjust for such differences.
The study began in 2014-02, and primary completion is listed as 2019-01-11. The record identifies Mayo Clinic as the sponsor. It describes budesonide as a drug intervention and gives the regimen as 1mg twice a day for a total of 8 weeks after endoscopic submucosal dissection or endoscopic mucosal resection.
The primary outcome is the number of participants in Barrett esophagus dysplasia categories at 3 months. The rate of esophageal stricture is listed as a secondary outcome. The registry record does not report the actual outcome values, the analysis populations, the detailed statistical methods, or how the prospective cohort was matched or compared with retrospective controls. It also does not report a sample-size justification for the trial’s design. The planning assumptions associated with sample-size illustrations are not a substitute for a documented prospective design justification.
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 | Esophageal Stricture, Budesonide | Control Group |
|---|---|---|
| STARTED | 22 | 68 |
| COMPLETED | 22 | 68 |
| NOT COMPLETED | 0 | 0 |
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 | Esophageal Stricture, Budesonide | Control Group | Total |
|---|---|---|---|---|
| Participants analysed | 22 | 68 | 90 | |
| Age, Continuous | years | 72.7 (SD 10.6) | 67.9 (SD 10.3) | 70.2 (SD 10.3) |
| Sex: Female, Male: Female | Participants | 4 | 10 | 14 |
| Sex: Female, Male: Male | Participants | 18 | 58 | 76 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: United States | participants | 22 | 68 | 90 |
6. Primary Endpoint
The registry lists the primary outcome as Dysplasia in Barrett Esophagus (BE), measured over 3 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants according to Barrett esophagus dysplasia status at 3 months. The listed categories are non-dysplastic, low-grade dysplasia, high-grade dysplasia, and T1a early esophageal adenocarcinoma. The registry description defines these in terms of the presence and extent of cell changes and includes noninvasive cancer as T1a early esophageal adenocarcinoma.
In general, a categorical endpoint can describe how participants are distributed across clinically distinct states at a stated follow-up time. Reporting categories separately preserves information that would be lost if all categories were collapsed into a single yes-or-no outcome. The registry record does not explain why this endpoint was selected as primary or how category assignments were determined.
The clinical hypothesis concerns prevention of esophageal stricture after endoscopic treatment, but the primary endpoint is dysplasia status. Stricture rate appears as a secondary outcome. These outcomes are related to the broader clinical setting but measure different events; results for one would not, by themselves, answer the other question.
No numerical counts for the primary endpoint categories at 3 months are reported in the registry record. Without those counts, the posted results do not permit an assessment of the distribution of dysplasia status or its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a prospective budesonide intervention and retrospective control data, but it does not report numerical results for the primary endpoint or the secondary stricture outcome. Consequently, no effect estimate or uncertainty interval for either outcome can be interpreted from the posted results. The stated hypothesis is not itself evidence that the hypothesis was supported.
The primary endpoint is the number of participants in Barrett esophagus dysplasia categories at 3 months. The registry record gives the categories and their definitions, but not the observed count in each category. The secondary outcome is the rate of esophageal stricture, but its observed value is also not reported. The safety information is separate from these efficacy outcomes: the listed adverse-event group has 0 serious adverse events, 11 participants with other adverse events, and 0 deaths among 22 at risk. Those figures do not supply the missing outcome results.
The design also limits what a comparison could establish. The allocation is non-randomized, the model is listed as single-group, and the control data are described as retrospective. Even if outcome values were reported, a difference between groups would not automatically be attributable to budesonide. A non-randomized comparison can be affected by differences in participant selection, baseline characteristics, clinical practice, or outcome ascertainment. The registry record does not report enough information to determine how these concerns were handled.
Precision cannot be assessed without outcome estimates and measures of uncertainty, such as confidence intervals. In general, a confidence interval describes a range of values compatible with the data and the specified statistical method; it helps distinguish a relatively precise estimate from one with substantial uncertainty. No such interval for the primary or secondary outcome is reported in the registry record.
The record lists enrollment as 90, whereas the adverse-event listing reports 22 at risk for its group. These are different reported quantities and should not be treated as interchangeable. The registry record does not explain the relationship between the enrollment figure and the safety denominator, or identify the number included in each efficacy analysis.
Accordingly, the posted information supports a description of the study’s question, design, endpoint definitions, and limited safety counts. It does not support a conclusion about the size, direction, or precision of an effect on dysplasia status or stricture formation.
9. Statistical Methods Explained
The registry identifies a count-based primary outcome: participants classified into Barrett esophagus dysplasia categories at 3 months. It also lists the rate of esophageal stricture as a secondary outcome. The record reports that two outcome measures and two analyses are present, but does not describe the specific statistical procedures used for those analyses. The analysis plan, including any covariate adjustment or handling of repeated measurements, is not reported in the registry record.
What does a participant count represent?
In general, a count of participants in an outcome category records how many people met that category definition during the specified assessment. It is not necessarily a count of every event experienced by those people. For the primary endpoint, the listed categories describe dysplasia status, rather than a count of stricture episodes. The record does not report the numerical category counts or explain how participants with missing or ambiguous assessments were classified.
For a binary outcome, a participant is typically classified as having or not having an event under a defined outcome rule. In general, comparing such outcomes requires clarity about the event definition, the denominator, and the analysis population. Those details matter because counts alone do not convey the amount of uncertainty, and denominators can differ across outcomes or analyses. The registry record does not provide the efficacy denominators or enough detail to determine the event rules used for the stricture outcome.
Why does the study design matter to the analysis?
Random allocation is one way to make comparison groups more similar, on average, with respect to measured and unmeasured characteristics. This study is listed as non-randomized. Its control description refers to retrospective data, while the budesonide intervention is described prospectively. In general, that structure can make groups differ in ways other than treatment exposure. Statistical adjustment can address some measured differences, but it cannot guarantee removal of bias from unmeasured factors. The registry record does not report whether adjustment was used, which factors were considered, or how the retrospective controls were selected.
No masking is listed. In general, knowledge of treatment assignment can influence care, outcome assessment, or reporting, depending on the outcome and how it is measured. The registry record does not describe whether outcome assessors were independent or whether any procedures were used to limit assessment bias.
How should uncertainty be understood?
In general, an estimate summarizes the observed data, while a confidence interval communicates its statistical uncertainty under a specified model and procedure. A narrow interval usually indicates greater precision than a wide interval, but neither an interval nor a point estimate can correct problems created by a biased comparison or incomplete outcome data. The registry record does not report an effect estimate or confidence interval for the primary endpoint or the stricture outcome.
Over-dispersion is a general concern when count data vary more than the statistical model assumes. If a model assumes less variability than is present, its uncertainty estimates may be too small. Whether over-dispersion is relevant depends on the outcome structure and model. The registry record does not identify a count model or provide sufficient outcome data to assess this issue. The primary endpoint is described as counts of participants across categories, which should not be confused with a rate of repeated events.
What do the sample-size assumptions mean?
The registry describes sample-size calculations as planning illustrations based on the observed effect, not as the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These calculations are not observed power and do not demonstrate that the study was adequately powered. The registry record does not report the trial’s own sample-size justification or enough information to evaluate its design rationale.
Overall, the registry supports a general account of the endpoint and design, but not a reconstruction of the statistical analysis. Details about tests or models, confidence intervals, adjustment, analysis populations, and missing-data handling are not reported in the registry record. These omissions limit independent interpretation and reproducibility.
10. Multiplicity, Missing Data and Analysis Populations
The record identifies a primary endpoint and a secondary outcome, and reports two outcome measures and two analyses. It does not describe how the analyses correspond to the outcomes, whether there were additional comparisons, or whether any multiplicity procedure was planned. Multiplicity refers, in general, to the increased chance of a false-positive finding when several hypotheses are tested. Whether that issue arose in these analyses cannot be determined from the registry record.
Missing-data methods are not reported in the registry record. The record does not state how missing 3-month dysplasia assessments or missing stricture information were handled, whether participants were excluded from particular analyses, or whether any sensitivity analyses were performed. In general, missingness can affect estimates when the people without observed outcomes differ systematically from those with observed outcomes.
Analysis populations are also not described. The registry lists enrollment as 90 but gives 22 at risk in the adverse-event group. It does not report the numbers assessed for the primary or secondary efficacy outcomes, the number with complete follow-up, or the criteria used to include participants in each analysis. The difference between the listed enrollment and safety denominator cannot be resolved from the registry record.
Because the allocation is non-randomized and the control data are retrospective, information on group eligibility, baseline characteristics, outcome ascertainment, and statistical adjustment would be important for interpreting any comparison. Those details, as well as a prespecified statistical analysis plan, are not reported in the registry record. The absence of those details does not establish that no procedures were used; it means they cannot be evaluated from the posted information.
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 |
|---|---|---|---|
| Esophageal Stricture, Budesonide | 0 | 22 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Esophageal Stricture, Budesonide | 0 of 22 |
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 |
|---|---|
| Esophageal Stricture, Budesonide | 11 of 22 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Esophageal Stricture, Budesonide |
|---|---|---|
| Dysphagia | Gastrointestinal disorders | 7 of 22 |
| Dilation | Gastrointestinal disorders | 4 of 22 |
The registry lists one adverse-event group, titled “Esophageal Stricture, Budesonide,” with 22 participants at risk. It reports 0 serious adverse events, 11 participants with other adverse events, and 0 deaths. No serious adverse-event terms are listed.
These figures describe the listed group only. The record does not provide a corresponding retrospective control safety group, so the counts do not support a between-group safety comparison. The adverse-event denominator of 22 should not be read as the overall enrollment of 90; the registry record does not explain the relationship between them.
In general, an observed count of zero for a reported category does not prove that the event is impossible or that risk is absent. Interpretation depends on the number monitored, the observation period, event definitions, and completeness of reporting. The adverse-event listing does not state a timeframe for these counts or provide uncertainty estimates. The meaning of “other” adverse events is not further specified in the registry record.
These safety counts should therefore be read as a limited registry summary, not as a complete characterization of comparative safety or of all events in the study.
12. What the Result Does, and Does Not, Mean
The registry record makes the clinical hypothesis clear: oral budesonide was studied for prevention of esophageal stricture after endoscopic treatment of advanced premalignant lesions or superficial esophageal cancers. It also describes the intervention regimen and identifies a secondary outcome of stricture rate. Those details explain the study’s clinical focus, but they are not outcome evidence.
The posted results do not report numerical values for the primary dysplasia endpoint or the secondary stricture outcome. The record therefore does not show how many participants fell into each dysplasia category, how often strictures occurred, or how precisely either outcome was estimated. No conclusion about the direction or magnitude of an effect can be drawn from the outcome information in the registry record.
The design is non-randomized, and the control group is described as retrospective. In general, comparisons made under this design may reflect differences between groups as well as any treatment effect. The registry record does not report methods that would allow readers to assess the extent of this concern. The results cannot be interpreted as if participants had been randomly assigned to comparable groups.
The adverse-event figures report 0 serious adverse events, 11 participants with other adverse events, and 0 deaths among 22 at risk in the listed group. These counts are limited to the reported group and do not constitute a comparison with controls. They also do not replace the missing efficacy results.
In general, a registry record is useful for identifying the planned clinical question, outcome definitions, and reported study information. A fuller assessment of treatment effects requires outcome estimates, their uncertainty, analysis details, and clear information about participant flow and missing data. Those elements are not reported for the efficacy outcomes in this registry record.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of why a clinical hypothesis and a registered primary endpoint need to be read separately. The stated hypothesis concerns prevention of esophageal stricture, while the primary endpoint counts participants across Barrett esophagus dysplasia categories at 3 months. The registry lists stricture rate as a secondary outcome. Keeping these outcomes distinct prevents one measure from being treated as evidence about another.
The study also illustrates the interpretive consequences of a non-randomized design. The budesonide cohort is described prospectively, while control information is collected retrospectively. In general, this design can be vulnerable to differences in participant selection, clinical practice, and assessment between groups. The registry record does not report enough detail to establish how these issues were addressed.
Reporting limitations are consequential. Numerical efficacy results, uncertainty estimates, analysis populations, missing-data methods, and detailed statistical procedures are not reported in the registry record. Without these elements, readers cannot assess the size or precision of any effect, reproduce the analysis, or judge how robust a comparison might be.
The sample-size assumptions are explicitly described as planning illustrations based on the observed effect, rather than the trial’s own design. This distinction matters because a planning calculation does not demonstrate that an analysis had a particular probability of detecting an effect. It should not be mistaken for observed power.
Together, these features make the record useful for understanding the proposed question and the limits of the posted information. They also show why transparent outcome reporting and clear documentation of methods are essential to statistical interpretation.
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 direct limitation is that numerical results for the primary dysplasia endpoint and the secondary stricture outcome are not reported in the registry record. There are no posted outcome estimates or uncertainty intervals with which to judge magnitude or precision. The clinical hypothesis therefore cannot be evaluated from the efficacy results listed in this record.
The design is non-randomized, and the comparator is described as retrospectively collected data. This raises the general possibility of differences between groups unrelated to the intervention. The record does not report comparator selection criteria, baseline characteristics, matching, adjustment, or outcome-assessment procedures, so the extent of this risk cannot be assessed.
The primary endpoint and the stated clinical hypothesis concern different outcomes: dysplasia categories at 3 months and stricture prevention, respectively. The registry does not explain the rationale for choosing the primary endpoint or provide information about how dysplasia categories were assigned. This limits assessment of how directly the primary endpoint addresses the clinical question.
Participant accounting is incomplete in the posted information. Enrollment is listed as 90, while 22 participants are reported at risk in the adverse-event group. The record does not explain this difference or give efficacy analysis denominators, follow-up completeness, or participant flow. Missing-data methods and analysis populations are not reported.
Finally, the registry does not report a detailed statistical analysis plan, methods for handling multiple analyses, or the trial’s own sample-size justification. The planning assumptions are described as illustrative calculations based on the observed effect, not as the study’s design. These limitations prevent a thorough assessment of statistical reliability and generalizability from the registry record alone.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Prospective Evaluation of Budesonide for Prevention of Esophageal Strictures After Endotherapy — NCT02069847.
- Registry record last updated 2020-06-16; status last verified 2020-05.
- Results first posted 2020-06-16.
- 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
This completed phase 2 study, sponsored by Mayo Clinic, evaluated oral budesonide after endoscopic mucosal resection or endoscopic submucosal dissection. The listed regimen was 1mg twice a day for a total of 8 weeks. The study is described as non-randomized, unmasked, and single-group, with retrospective control data also described in the record. Enrollment is listed as 90.
The primary endpoint counts participants in Barrett esophagus dysplasia categories at 3 months. Esophageal stricture rate is listed as a secondary outcome. The registry record does not report numerical results for either efficacy outcome. Safety information for the listed budesonide group reports 0 serious adverse events, 11 participants with other adverse events, and 0 deaths among 22 at risk.
The posted record establishes the study’s clinical question and some design details, but does not provide enough outcome or analysis information to estimate the effect or its precision.