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 Evaluation of Pancreatobiliary Disorders in Patients With Altered Gastric Anatomy (NCT01238341), a registered phase not stated study. The primary outcome is Papilla or Duct-enterostomy Was Reached.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01238341 |
| Phase | Phase not stated |
| Condition | Pancreatobiliary Disease, Altered Gastric Anatomy |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 7 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Florida |
| Results posted | Yes |
2. Clinical Question
Population
Patients with altered gastric anatomy and pancreatobiliary disease who need ERCP. The registry describes the clinical setting but does not report further eligibility details or baseline characteristics.
Intervention
Endoscopic Retrograde Cholangiopancreatography (ERCP) with an overtube. The study evaluates use of the overtube to facilitate ERCP in patients with altered gastric anatomy.
Comparator
No control group or alternative procedure is described. Allocation is not stated, and the registry record does not present a like-for-like comparison between treatment groups.
Primary question
During the procedure, up to 3 hours, was the papilla or duct-enterostomy reached? The primary endpoint is recorded as the number of ERCPs meeting this procedural milestone.
The clinical question is about procedural access in a challenging anatomical setting, not a comparison of clinical outcomes between competing procedures. The registry describes patients with altered gastric anatomy who need ERCP for evaluation of pancreatobiliary disease, and identifies ERCP with an overtube as the intervention of interest. Its primary endpoint asks whether the papilla or duct-enterostomy was reached during the procedure.
Reaching the intended anatomical target is a procedural milestone. It is distinct from successful cannulation of the duct of intent, successful endoscopic therapy, or total procedure time, which are listed as secondary outcomes. Reaching the target alone does not establish that cannulation or therapy was successful, nor does it describe the overall clinical course.
The record does not report a comparator, random allocation, or numerical result for the primary endpoint. It therefore cannot answer whether use of the overtube changes the chance of reaching the target compared with another approach. The clinical question that can be identified is narrower: whether the intended site was reached during ERCP in this study population. The record’s descriptions establish the setting and endpoint, but do not provide enough outcome detail to quantify the answer.
3. Trial Design
This is a prospective evaluation of ERCP with an overtube in patients with altered gastric anatomy, as stated in the official study title. The registry lists the intervention as Endoscopic Retrograde Cholangiopancreatography (ERCP), a procedure, and describes a group of patients with altered gastric anatomy who need ERCP for evaluation of pancreatobiliary disease. Enrollment is 7. The sponsor is the University of Florida, and the status is COMPLETED.
The registry gives a start date of 2007-06 and a primary completion date of 2015-07. These dates describe the study record’s timing; they do not supply details about recruitment pace, follow-up, or when individual procedures took place. The primary endpoint timeframe is during the procedure, up to 3 hours.
The record does not describe a randomized allocation or a concurrent control group. Allocation is not stated, and the listed arm description is a treatment group rather than a like-for-like control comparison. Consequently, this should be read as an evaluation of a procedure in a specified clinical setting, not as evidence from a randomized comparison of alternative strategies.
The registry lists successful cannulation of the duct of intent, successful endoscopic therapy, and total procedure time as secondary outcomes. It reports 4 outcome measures and 0 analyses. A count of analyses in the registry is not a complete account of everything investigators may have examined; it indicates that no analyses are listed in this record. The registry does not report a protocol, a sample-size justification, or details of any statistical analysis plan.
Although the study status is COMPLETED, that status alone does not mean that every planned result is available in the record. In particular, the primary endpoint is named and defined, but its numerical outcome is not reported. The design can therefore be described from the registration details, while conclusions about observed procedural success remain limited by the available results.
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 | Altered Gastric Anatomy |
|---|---|
| STARTED | 7 |
| COMPLETED | 7 |
| NOT COMPLETED | 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 | Altered Gastric Anatomy |
|---|---|---|
| Participants analysed | 7 | |
| Age, Continuous | years | 59.3 (39 to 72) |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 1 |
| Region of Enrollment: United States | participants | 7 |
| Postsurgical anatomy: Roux-en-Y hepaticojejunostomy | participants | 2 |
| Postsurgical anatomy: Roux-en-Y gastric bypass | participants | 3 |
| Postsurgical anatomy: Roux-en-Y gastric bypass with hepaticojejunostomy | participants | 1 |
| Postsurgical anatomy: Billroth II gastrectomy w/ Braun enteroenterostomy | participants | 1 |
| Indications for Endoscopic Retrograde Cholangiopancreatography (ERCP): Biliary obstruction | participants | 5 |
| Indications for Endoscopic Retrograde Cholangiopancreatography (ERCP): Bile duct stones | participants | 1 |
| Indications for Endoscopic Retrograde Cholangiopancreatography (ERCP): Pancreatic leak | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Papilla or Duct-enterostomy Was Reached, measured over During procedure, up to 3 hours.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | ERCPs |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is “Papilla or Duct-enterostomy Was Reached.” It measures whether ERCP reached the intended anatomical target, with the outcome expressed as a number of ERCPs. The registry specifies the timeframe as during the procedure, up to 3 hours. It does not give a more detailed endpoint definition or explain how an attempt was classified if the target was not reached.
Procedural access is a relevant milestone because cannulation and endoscopic treatment depend on reaching the intended site. However, reaching the papilla or duct-enterostomy is not the same as successfully cannulating the duct of intent or completing endoscopic therapy. The registry lists those as separate secondary outcomes, preserving the distinction between access and subsequent procedural steps.
The endpoint is a count rather than a continuous measurement such as time. To interpret a count, readers would ordinarily need both the number meeting the criterion and the relevant number of ERCPs assessed. The record gives the unit but does not report the observed primary endpoint count or its denominator. Enrollment is 7, but enrollment should not automatically be treated as the number of procedures assessed for this endpoint.
The endpoint is useful for describing whether the procedure reached its intended target in this anatomical context. By itself, it does not measure clinical benefit, compare the approach with an alternative, or establish the success of later procedural steps. With no numerical primary result reported, its observed frequency cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry establishes that this was a completed prospective evaluation of ERCP with an overtube in patients with altered gastric anatomy and pancreatobiliary disease. Enrollment was 7. The primary endpoint was whether the papilla or duct-enterostomy was reached during the procedure, up to 3 hours. The record does not report the numerical result for that endpoint, so it does not establish how many ERCPs reached the target or how often that occurred among procedures assessed.
This missing result is central to interpretation. A clearly defined endpoint can indicate what the investigators intended to measure, but it cannot substitute for an observed outcome. Without the result and its denominator, readers cannot estimate the frequency of reaching the target from this record. Enrollment is not necessarily the same as the number of procedures contributing to the endpoint, and the record does not report whether every enrolled patient had an evaluable procedure.
The secondary outcomes are successful cannulation of the duct of intent, successful endoscopic therapy, and total procedure time. Their names indicate further aspects of procedural performance, but numerical results for them are not reported in the registry record. No conclusion about cannulation, therapy, or procedure duration follows from the endpoint definition alone.
There is no stated allocation and no control group described. Thus, the record does not provide a comparative effect estimate for overtube-assisted ERCP versus another procedure or approach. Even if a group outcome were reported, a single-group result would describe the experience in that group; it would not by itself identify what would have happened under an alternative strategy. Patient selection, anatomy, operator experience, and other circumstances could affect outcomes, but the registry does not provide details to assess them.
The registry lists 0 analyses. This means that no analyses are listed in the registry record; it should not be interpreted as proof that investigators conducted no analyses outside the record. No p-value, confidence interval, adjusted estimate, or statistical model result is reported. Accordingly, there is no inferential result to interpret as evidence for or against a difference.
For safety, the altered gastric anatomy group lists 7 at risk and 0 affected for serious adverse events, and 7 at risk and 0 affected for other adverse events. These are registry entries, not proof that no adverse event occurred in any setting or that the procedure has no risk. Deaths are not reported in the record. The safety entries should be read alongside the absence of detailed event descriptions and the limited cohort size.
Overall, the record identifies a specific procedural question and reports a limited set of safety counts, but does not provide the primary or secondary efficacy outcome values. The strongest interpretation is therefore about what was planned to be measured and what safety counts were recorded, rather than a quantified conclusion about procedural performance or comparative effectiveness.
9. Statistical Methods Explained
The registry record describes a count endpoint and several procedural outcomes, but lists 0 analyses. No statistical analysis plan, model, inferential estimate, or numerical primary outcome is reported. The explanations below describe general statistical concepts relevant to interpreting this kind of study; they are not claims about analyses conducted by the investigators.
What does a count endpoint describe?
A count records how many observations meet a defined condition. For this study, the condition is reaching the papilla or duct-enterostomy during ERCP. A count can be informative, but its interpretation depends on knowing how many procedures were assessed and how the endpoint was determined. A count without a denominator cannot show the frequency of the outcome. Here, the unit is ERCPs, but the observed count and the number assessed are not reported in the registry record.
Counts also differ from continuous measurements. Total procedure time, listed as a secondary outcome, would ordinarily be represented by a time value or a distribution of times. Whether the registry reports such a result cannot be determined from the outcome name; the numerical result is not reported. Successful cannulation and successful endoscopic therapy are additional procedural outcomes, not interchangeable descriptions of reaching the target.
What would a confidence interval mean?
In general, a confidence interval expresses the uncertainty around an estimate under a specified statistical method. For a proportion or rate, it helps show how compatible the observed data are with a range of underlying values. It does not guarantee that the true value lies in the interval, and it does not remove limitations such as a small or selected study population. No confidence interval for the primary endpoint is reported, and no numerical estimate is available from which to interpret one.
When an estimate is based on a limited number of observations, its uncertainty can be substantial. A point estimate alone would not show that uncertainty. Conversely, the absence of a reported interval is not evidence that the outcome is precise. Readers should distinguish an unreported uncertainty measure from a narrow interval or a precise estimate: the registry supplies neither for this endpoint.
Why does the absence of a comparator matter?
A comparative effect is based on outcomes under different strategies. A single group can describe observed outcomes in that group, but it does not supply the counterfactual outcome—what would have occurred for comparable patients under an alternative. Random allocation, when used and properly implemented, can help make groups comparable on average. This registry does not state allocation or describe a control group, so no randomized contrast can be interpreted.
Even a comparison in a nonrandomized study can be affected by differences between groups, including differences in the patients selected for each approach. The record does not report such a comparison, so adjustment or confounding cannot be evaluated. A procedural outcome in this group should not be framed as an effect attributable to the overtube relative to another method.
How should planning calculations be read?
Planning calculations are prospective illustrations of the sample size that might be needed under stated assumptions. They are not a description of observed outcomes, and they are not “observed power.” The registry’s planning assumptions specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; they also define the effect to detect as a stated fraction of the observed effect. These are assumptions for planning illustrations, not evidence that the study used two arms or randomized participants. The registry does not state that they formed the study’s original design or sample-size justification.
For a count outcome, the distributional assumptions matter. A simple model may assume that the variability follows the expected pattern for counts. If data vary more than that model expects, there is over-dispersion. In general, over-dispersion can make standard errors too small if it is ignored, leading to confidence intervals that are too narrow and tests that appear more decisive than warranted. The registry record does not report a count model or an assessment of dispersion, so readers should not infer that any particular method was used.
Planning results also depend on the effect used as a target. If that target is drawn from an observed effect, uncertainty in the observed effect can carry into the planning illustration. A planning result based on an optimistic effect can suggest a smaller study than would be needed for a more modest effect. No planning calculation should be mistaken for evidence that a study had adequate power, and no planning output replaces the missing primary result.
What can be inferred from the analysis listing?
The registry lists 0 analyses. That entry means analyses are not listed in the registry record; it does not establish that no analyses took place. Without specified methods and reported estimates, readers cannot check how endpoint observations were handled, whether results were adjusted, or how uncertainty was quantified. The appropriate statistical reading is to separate the protocol-level question and outcome definitions from results and analyses that are not reported.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures, including the primary endpoint and secondary outcomes for successful cannulation of the duct of intent, successful endoscopic therapy, and total procedure time. When several outcomes are assessed, the possibility of chance findings across multiple tests is a general statistical concern. A prespecified hierarchy, adjustment procedure, or clear distinction between confirmatory and exploratory outcomes can help readers interpret multiple results.
The registry record does not report a multiplicity strategy or identify a statistical testing hierarchy. It also lists 0 analyses, so there are no reported inferential results for which an adjustment can be evaluated. This absence does not prove that investigators did not consider multiplicity; it means that the record does not describe how it was handled.
Missing-data methods and analysis populations are also not reported in the registry record. The record does not say how missing or unevaluable procedures would be treated, whether all enrolled patients were included in each outcome analysis, or how exclusions were determined. Enrollment of 7 does not establish the denominator for the primary endpoint, whose unit is ERCPs.
These omissions limit reproducibility and interpretation. Readers cannot determine whether an outcome was analyzed according to an intention-to-treat, per-protocol, or another population definition, nor whether missing observations could have affected the results. Such details matter in general because different handling choices can lead to different estimates. No specific missing-data mechanism or analysis population should be assumed for this study.
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 |
|---|---|---|---|
| Altered Gastric Anatomy | 0 | 7 | 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 |
|---|---|
| Altered Gastric Anatomy | 0 of 7 |
For the group labelled Altered Gastric Anatomy, the registry lists 7 at risk and 0 affected for serious adverse events. It also lists 7 at risk and 0 affected for other adverse events. These are the recorded safety counts in the registry. They should be read as no affected participants recorded in these categories in this group, not as proof that the procedure has no risk or that no events occurred outside the registry’s reporting.
The deaths field is not populated with a numerical result; deaths are not reported in the registry record. The record does not provide event descriptions, timing, severity details beyond the serious/other categories, or information about how safety events were collected. Therefore, the zero affected entries have limited context.
Safety counts from a small cohort cannot establish that an uncommon event is absent. More generally, observing no recorded events does not imply that the underlying risk is zero, particularly when the number observed is limited. These counts should not be converted into a broader safety claim or used as a substitute for detailed adverse-event reporting.
12. What the Result Does, and Does Not, Mean
The result record identifies what the investigators intended to assess: whether ERCP reached the papilla or duct-enterostomy during the procedure, up to 3 hours. It also names secondary outcomes for cannulation, endoscopic therapy, and procedure time. However, the numerical primary and secondary outcome results are not reported in the registry record. The procedural performance of the approach therefore cannot be quantified from this record.
The registry describes a prospective evaluation in patients with altered gastric anatomy and pancreatobiliary disease, with enrollment of 7. It does not state allocation or describe a control group. Consequently, it cannot establish a comparative effect of ERCP with an overtube versus another approach. A study can describe what occurred in the group it evaluated, but comparison and causal attribution require additional design and outcome information.
Reaching the target is also only one step in the procedure. It does not itself establish successful cannulation, successful therapy, or a favorable clinical outcome. Those are distinct questions, and the registry lists cannulation and therapy separately as secondary outcomes. Their numerical results are not reported.
The safety record lists 0 affected for serious adverse events and 0 affected for other adverse events in the group, with 7 at risk in each category. These entries describe what was recorded; they do not establish that there is no risk. Deaths are not reported. A limited set of safety counts cannot replace event-level detail or a broader assessment.
Thus, the registry provides a description of the clinical question, intervention, endpoint, and limited safety reporting, but not a numerical efficacy result or a comparative estimate. Conclusions about the observed rate of reaching the intended site, or about how the procedure compares with alternatives, would go beyond what the registry record reports.
13. Why This Trial Matters Statistically
This study addresses a procedural question in patients with altered gastric anatomy, a setting identified in the registry as relevant to pancreatobiliary disease and ERCP. Statistically, the central issue is whether the endpoint is defined clearly enough to interpret and whether the record reports the observations needed to answer the question. The primary endpoint is named, its unit is ERCPs, and its timeframe is specified as during the procedure, up to 3 hours.
That definition distinguishes access to the papilla or duct-enterostomy from later procedural outcomes. The registry separately lists successful cannulation and successful endoscopic therapy, as well as total procedure time. Keeping these outcomes distinct is important: a milestone at one stage should not be treated as proof of success at another stage.
The record also illustrates why a completed study status and an outcome definition do not guarantee that results are available. The primary endpoint’s numerical value and denominator are not reported, and no analyses are listed. This leaves the intended measurement identifiable but prevents readers from estimating its observed frequency or assessing statistical uncertainty.
The absence of a stated allocation or control group matters as well. A group description can be useful for understanding feasibility in the studied setting, but comparative claims require a relevant contrast and adequate outcome reporting. The registry does not supply that contrast. Its safety counts are similarly descriptive and should not be generalized into a claim of no risk.
These features make the record a useful example of separating the clinical importance of a question from the strength of the statistical evidence available to answer it. Endpoint clarity, a reported denominator, complete outcome results, analysis methods, and a design suited to the intended comparison all contribute to interpretation. Where these are absent from a record, restraint is part of sound statistical reporting.
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 primary limitation for interpreting procedural performance is that the numerical result for “Papilla or Duct-enterostomy Was Reached” is not reported in the registry record. Although the endpoint unit is ERCPs and the timeframe is specified, neither the observed count nor the number of procedures assessed is given. Enrollment of 7 cannot be assumed to be the endpoint denominator.
The registry also does not report numerical results for the secondary outcomes of successful cannulation, successful endoscopic therapy, and total procedure time. It does not provide details of participant characteristics, eligibility criteria, anatomical subgroups, operator experience, or procedure-level variation. These omissions limit assessment of which patients and procedures the record represents and how broadly the findings might apply.
No comparator or allocation method is described. Allocation is not stated, so the record cannot support an interpretation based on randomization. Without a concurrent comparison group, observed outcomes would not by themselves show what would have occurred under another approach. The record also does not provide a statistical analysis plan, effect estimates, confidence intervals, p-values, or model details.
Missing-data handling, analysis populations, and multiplicity procedures are not reported. It is not possible to determine how unevaluable procedures would be handled or whether the populations contributing to different outcomes differed. The registry lists 0 analyses, which does not establish that no analyses were conducted, but leaves no analysis results available for evaluation.
Safety reporting is limited to affected and at-risk counts for serious and other adverse events; deaths are not reported. Event descriptions and collection details are absent. Taken together, these limitations mean that the record supports a description of the study question and limited safety entries, but not a full assessment of efficacy, comparative performance, or safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of Pancreatobiliary Disorders in Patients With Altered Gastric Anatomy — NCT01238341.
- Registry record last updated 2015-10-23; status last verified 2015-10.
- Results first posted 2015-10-05.
- 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
NCT01238341, “Evaluation of Pancreatobiliary Disorders in Patients With Altered Gastric Anatomy,” is a completed prospective evaluation of ERCP with an overtube. The registry identifies patients with altered gastric anatomy and pancreatobiliary disease, enrollment of 7, and the University of Florida as sponsor. The recorded start is 2007-06 and primary completion is 2015-07.
The primary endpoint is whether the papilla or duct-enterostomy was reached during the procedure, up to 3 hours, with the unit recorded as ERCPs. Secondary outcomes are successful cannulation of the duct of intent, successful endoscopic therapy, and total procedure time. Numerical results for the primary and secondary outcomes are not reported in the registry record. Allocation is not stated, and no control group is described.
The safety group lists 0 affected for serious adverse events and 0 affected for other adverse events, with 7 at risk in each category. Deaths are not reported. The registry lists 0 analyses and does not report the analysis plan, missing-data handling, or analysis populations. The record therefore defines a procedural question but does not provide a numerical outcome estimate or a comparative result.