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 Endoscopic Peroral Myotomy for Treatment of Achalasia (NCT01405469), a na na study. The primary outcome is Treatment Success Defined as Symptom Relief 3 Months After Treatment Based on an Eckhardt Score ≤ 3.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01405469 |
| Phase | NA |
| Condition | Achalasia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 16 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Universitätsklinikum Hamburg-Eppendorf |
| Results posted | Yes |
2. Clinical Question
Population
The registry record describes adults older than 18 years with primary achalasia diagnosed using established methods, including contrast fluoroscopy, manometry, and esophagogastroduodenoscopy. The study enrolled 16 participants in a pilot group intended to evaluate feasibility and safety before studies of long-term efficacy.
Intervention
The intervention was peroral endoscopic myotomy, abbreviated POEM. The study was conducted as a single-group evaluation of this procedure for achalasia.
Comparator
No comparator arm is documented. Although the arm description mentions balloon dilatation, botulinum toxin injection, and Heller myotomy as possible treatments, the registry record does not describe these as assigned comparison groups in this study.
Primary question
The registered primary outcome concerns treatment success defined as symptom relief three months after treatment, using an Eckardt Score threshold of 3 or less. The registry record describes the score but does not report the resulting score distribution or the number of participants meeting that threshold.
Accordingly, the clinical question is how this pilot group was assessed after POEM, not whether POEM outperformed another treatment. A single-group study can describe outcomes among enrolled participants, but without a documented comparator it cannot isolate an intervention effect from other explanations for change. The record states that feasibility and safety were central aims; it does not report a comparative efficacy question.
3. Trial Design
This was a completed pilot study registered as NCT01405469, titled Endoscopic Peroral Myotomy for Treatment of Achalasia. The registry record identifies a single-group model and an enrollment of 16. Allocation is listed as NA, and masking is listed as none. The intervention recorded is peroral endoscopic myotomy. No randomized allocation or like-for-like control comparison is described.
The stated purpose was to investigate feasibility, safety, and efficacy of POEM for achalasia in a single-center European setting. The population description refers to adults with primary achalasia diagnosed by established methods. The record says the pilot was intended to precede studies evaluating long-term efficacy. That framing matters: this record describes an early, small, uncontrolled evaluation, rather than a confirmatory comparison between treatments.
The study began in 2010-11, had primary completion in 2011-06, and is marked completed. The sponsor was Universitätsklinikum Hamburg-Eppendorf. The record lists nine outcome measures, including the primary symptom outcome and secondary measures concerning lower esophageal sphincter pressure, reflux symptoms, procedure-related adverse events, medication, procedure duration, hospitalization, myotomy length, and treatment success.
The arm description mentions balloon dilatation, botulinum toxin injection, and surgical intervention as treatments patients might otherwise receive. However, the listed study intervention is POEM, and the trial model is single-group. Those alternative treatments should therefore not be treated as documented study comparators. Details such as a formal sample-size justification, specific eligibility criteria beyond the population description, and a statistical analysis plan are not reported in the registry record.
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.
Before assignment: 16 patients were included as per protocol, no patient was lost during follow-up over a 2 year period
Overall Study
| Stage | POEM Patients |
|---|---|
| STARTED | 16 |
| COMPLETED | 16 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Pilot study group to evaluate feasibility and safety of POEM procedure before initiating studies evaluating long-term efficacy.Patients with primary achalasia, diagnosed by established methods(contrast fluoroscopy, manometry, esophagogastroduodenoscopy(EGD)) and age greater than 18 years were included.
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 | POEM Patients |
|---|---|---|
| Participants analysed | 16 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 13 |
| Age, Categorical: >=65 years | Participants | 3 |
| Age, Continuous | years | 45 (SD 16.22) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 12 |
| Region of Enrollment: Germany | participants | 16 |
6. Primary Endpoint
The registry lists the primary outcome as Treatment Success Defined as Symptom Relief 3 Months After Treatment Based on an Eckhardt Score ≤ 3, measured over 3 months after treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Eckardt Score |
| Endpoint classification | Continuous Endpoint |
The registered primary outcome is titled treatment success defined as symptom relief three months after treatment based on an Eckardt Score of 3 or less. The score is described as assessing dysphagia, regurgitation, retrosternal pain, and weight loss. Higher symptom frequency and greater weight loss contribute more points; the stated scale runs from 0, indicating no achalasia symptoms, to 12, indicating the worst symptoms.
The registry record identifies the primary outcome measure as a mean, with standard deviation as its dispersion measure, and gives the timeframe as three months after treatment. A mean can describe the average symptom score in the study group, while the standard deviation describes how dispersed individual scores are around that average. The threshold of 3 or less expresses a different summary: the proportion of participants who meet a specified symptom-score criterion. The outcome title and measure therefore refer to related but distinct ways of presenting the score.
The record does not report the mean, standard deviation, individual score distribution, or number of participants meeting the threshold. It also does not report how missing three-month assessments, if any, were handled. Without those results, the endpoint definition explains what was intended to be assessed, but not what the observed symptom outcomes were.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an enrolled group of 16 participants and a primary symptom assessment planned for three months after treatment. It does not report a primary endpoint estimate. In particular, no mean Eckardt Score, standard deviation, confidence interval, or count meeting the threshold of 3 or less is included in the listed details. The record therefore does not support a numerical interpretation of symptom change or treatment success.
The primary outcome title uses the language of treatment success, but its registered summary measure is a mean score with standard deviation. These summaries answer different questions. A mean describes the group’s average score, whereas a threshold-based success measure counts participants on one side of a cutoff. Neither can be reconstructed from the other without additional participant-level or distributional information. The registry record does not report such information.
The study’s single-group design also limits interpretation. Any observed post-treatment score, if reported, would describe the enrolled group at that assessment; without a comparator, it would not establish what would have happened to similar participants under another treatment or without POEM. The registry record does not document randomization, a control group, or masking. This is consistent with the stated pilot purpose of examining feasibility and safety before longer-term efficacy studies, but it does not provide a controlled estimate of comparative benefit.
The record lists safety outcomes, including procedure-related adverse events, and reports serious and other adverse-event figures for the POEM group. Those counts describe events recorded among participants at risk; they do not by themselves establish whether an event was caused by the procedure. The record also does not report a death count. The listed serious-event terms include two ulcer descriptions, each with a stated 6.2% figure; the registry entry does not provide enough detail to determine how those terms relate to the participant-level count.
Overall, the posted information gives the study design, target symptom measure, and selected safety counts, but not the primary outcome results or a comparative treatment estimate. The status marked completed does not fill in those missing outcome details. Any conclusion about the direction or precision of symptom outcomes would require results that are not reported in the registry record.
9. Statistical Methods Explained
The primary outcome is a continuous score summarized by a mean and standard deviation. In general, a mean is the arithmetic average across measured participants. The standard deviation describes the spread of individual observations around that average; it is not the same as the uncertainty in the estimated mean. A confidence interval, when reported, expresses a range of values compatible with the data and the method used to calculate it. No mean, standard deviation, or confidence interval for the primary outcome is reported in the registry record, so its magnitude and precision cannot be assessed from these registry entries.
The score also has a threshold-based interpretation: a score of 3 or less defines treatment success in the outcome title. In general, a threshold turns a graded measure into a yes-or-no classification for each participant. That can be clinically interpretable, but it discards information about how far scores are from the threshold. A group mean and a count meeting a threshold are not interchangeable. The record lists the primary measure as a mean, but does not report either the group mean or the number meeting the threshold.
The Eckardt Score combines symptom frequency and weight loss. As described in the registry record, dysphagia, regurgitation, and retrosternal pain are scored according to how often they occur, while weight loss is also assigned points. The overall scale ranges from 0 to 12. In general, composite scores combine several features into one summary, which can simplify description but may conceal different patterns across components. Component-level results are not reported in the registry record.
The design is single-group, with 16 participants enrolled and no documented comparator. In general, a single-group follow-up can describe outcomes observed among those participants, but it cannot separate a treatment-associated change from changes that might occur over time or for other reasons. A comparator group provides a reference for such interpretation, especially when treatment allocation and outcome assessment are designed to reduce bias. Here, allocation is listed as NA and masking as none. The registry record does not describe a controlled comparison or an adjustment strategy.
The registry record lists nine outcome measures and one analysis. It does not report the specific statistical test or model, the analysis population, or a plan for handling repeated or missing measurements. General statistical practice distinguishes the population enrolled from the population contributing data to a particular analysis. If outcome data are unavailable for some participants, the number analyzed and the assumptions used to handle missingness can affect interpretation. Neither the amount of missing primary outcome data nor its handling is reported in the registry record.
The listed sample-size assumptions describe a planning illustration: two-sided significance level 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The registry record does not report the numerical planning targets or the underlying observed effect in the registry record. Such calculations are hypothetical planning exercises under their assumptions, not evidence that a study had a particular probability of detecting an effect. They are not observed power. Moreover, the stated two-arm planning assumptions do not describe the single-group structure documented for this trial.
In general, over-dispersion means that observed variability is greater than a statistical model assumes. When that occurs, uncertainty estimates from a model that assumes less variability may be too narrow, making results appear more precise than they are. The registry record does not report a model or dispersion assessment for the primary endpoint, so no claim about over-dispersion in this study can be made. More broadly, statistical methods can only be interpreted in context when the analysis population, outcome data, model, and uncertainty estimates are reported; these details are not reported in the registry record.
Multiplicity arises when several outcomes or comparisons are examined. In general, examining multiple outcomes can increase the chance of at least one apparently notable result by chance, and an analysis plan may specify how to account for that. This record lists nine outcome measures, but a multiplicity adjustment or prioritization plan is not reported in the registry record. The count of listed outcomes alone does not reveal which analyses were performed or whether any adjustment was used.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists nine outcome measures, including the primary symptom measure and several secondary measures. It also lists one analysis. The record does not describe a multiplicity strategy, such as adjustment for testing several outcomes, nor does it explain how the primary outcome was prioritized in analysis. In general, when multiple outcomes are tested, the chance of at least one result appearing notable by chance can increase. Whether that concern applies to any particular analysis depends on what was tested and how; those details are not reported in the registry record.
The registry record does not report the number of participants with primary outcome data at three months, whether any participants were lost to follow-up, or how missing values were handled. It does not identify an analysis population, such as all enrolled participants or only participants with an observed assessment. In general, these distinctions matter because the analyzed group may differ from the enrolled group, and assumptions about missing outcomes can affect estimates and their uncertainty.
No imputation method, sensitivity analysis, or approach to incomplete secondary outcomes is reported in the registry record. The absence of those details does not establish that data were missing or that a particular method was or was not used; it means the record does not describe the issue. As a result, the completeness and analysis basis of the endpoint results cannot be evaluated from the recorded information. The primary outcome results themselves are also not reported in the registry record.
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 |
|---|---|---|---|
| POEM Patients | 2 | 16 | 12.5% |
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 |
|---|---|
| POEM Patients | 1 of 16 |
Most frequent serious adverse event terms
| Event term | Organ system | POEM Patients |
|---|---|---|
| 1 cm superficial ulcer (Forrest III) | Gastrointestinal disorders | 1 of 16 |
| ulcer in the distal esophagus | Gastrointestinal disorders | 1 of 16 |
Most frequent non-serious adverse event terms
| Event term | Organ system | POEM Patients |
|---|---|---|
| treatment failure | Gastrointestinal disorders | 1 of 16 |
Serious events with the highest arm-level rate: 1 cm superficial ulcer (forrest iii) (6.2%), ulcer in the distal esophagus (6.2%).
The safety figures are recorded for the POEM group, with 16 participants at risk for serious adverse events and 2 affected. For other adverse events, 16 were at risk and 1 was affected. These are participant counts, not a comparison between treatment groups. The registry record does not report a comparator arm, so the figures cannot be used to estimate a difference in event risk between treatments.
The listed serious adverse-event terms are 1 cm superficial ulcer (Forrest III) and ulcer in the distal esophagus, each accompanied by a 6.2% figure. The registry record does not explain whether these terms refer to separate events, overlapping descriptions, or the same participant-level event. It is therefore important not to add the term-specific figures or infer an overall event rate from them. The serious-event count at the group level is reported separately.
The death count is not reported in the registry record. The available counts also do not state when events occurred, their duration, or whether investigators considered them related to the procedure. In general, an adverse event recorded after treatment is not automatically caused by that treatment. These entries describe reported safety events in this study group; the registry information does not establish causation or comparative safety.
12. What the Result Does, and Does Not, Mean
The study record documents a pilot evaluation of POEM in 16 participants with achalasia and specifies a symptom score intended for assessment three months after treatment. It also lists selected safety outcomes and reports serious and other adverse-event counts. This provides information about the study’s scope and the outcomes it set out to monitor.
The registry record does not report the primary endpoint results. It therefore does not show the group’s mean Eckardt Score, its variability, or the number of participants meeting the threshold for treatment success. The record also does not report a comparative estimate against another intervention. The completed status indicates that the study is marked completed, but does not itself supply missing outcome results.
Even if a post-treatment score were available, the single-group design would not establish how the outcome compares with another treatment or with the course participants might otherwise have experienced. The study was described as a pilot intended to evaluate feasibility and safety before studies of long-term efficacy. It should not be read as a randomized trial or as a controlled test of comparative effectiveness.
The safety counts describe events recorded among the POEM participants, but do not establish that the procedure caused those events. The registry record does not report a death count or enough detail to resolve how the listed ulcer terms correspond to individual events. These limits matter when interpreting safety information from a small, uncontrolled group.
Thus, the available information supports a description of the study design, outcome definitions, and selected adverse-event reporting. It does not support a conclusion about the size, precision, or comparative meaning of a symptom effect. Those questions require outcome estimates and analysis details that are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically instructive because its primary outcome title and its stated summary measure emphasize two different forms of reporting. The title defines success using an Eckardt Score threshold of 3 or less, while the registry record identifies a mean and standard deviation as the primary summary. A threshold-based count and a continuous-score mean answer related but distinct questions. Recognizing that distinction helps readers avoid treating the two summaries as interchangeable.
The record also illustrates what a pilot, single-group design can and cannot establish. With 16 participants and no documented comparator, results could describe the enrolled group and inform planning for later research, but they would not provide a controlled estimate of how outcomes differ between treatments. The stated intention to study feasibility and safety before long-term efficacy research fits that limited role.
Finally, the registry record demonstrates why outcome definitions alone are not enough to interpret a result. The score components and assessment timeframe are described, but the primary estimate, its variability, and the number meeting the threshold are not reported. Without these, readers cannot assess the magnitude or precision of the planned symptom outcome. The safety counts likewise require context about event timing, attribution, and overlap among event terms, which is not reported in the registry record.
These features make the record useful for understanding the study’s design and reporting boundaries. They also show why interpretation depends on the outcome data and analysis details, not only on the intervention name or completed status.
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 central limitation for statistical interpretation is that the primary outcome results are not reported in the registry record. The defined Eckardt Score endpoint has no reported mean, standard deviation, confidence interval, or count of participants meeting the success threshold. The size and precision of any symptom outcome therefore cannot be evaluated from the recorded information.
The study is described as single-group, with no comparator and no random allocation documented. Its findings, if available, would describe the enrolled group rather than provide a controlled contrast. The enrollment of 16 also means that any group summary would be based on a small pilot cohort; the record does not provide a sample-size justification or explain the precision intended for the primary estimate.
The endpoint wording leaves a reporting distinction to keep in mind: the title defines success by a cutoff, while the listed measure is a mean continuous score. The record does not report both forms of outcome or clarify how the threshold-based definition relates to the stated mean summary.
Further details are not reported in the registry record, including the analysis population, missing-data handling, statistical test or model, multiplicity approach, and whether outcome assessors were masked. Safety reporting is also limited: the death count is not reported, and the relationship between the two listed ulcer terms and the participant-level serious-event count is unclear. These gaps limit assessment of both outcome precision and safety context.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Endoscopic Peroral Myotomy for Treatment of Achalasia — NCT01405469.
- Registry record last updated 2019-10-15; status last verified 2019-10.
- Results first posted 2014-12-02.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01405469 is a completed pilot study of peroral endoscopic myotomy for achalasia. The record describes a single-group study with 16 enrolled participants, no masking, and no documented comparator. Its stated purpose was to investigate feasibility, safety, and efficacy in a single-center European setting before studies of long-term efficacy.
The primary outcome is defined as symptom relief three months after treatment using an Eckardt Score threshold of 3 or less; the measure is listed as a mean with standard deviation. The record describes the score but does not report the primary outcome results. It lists nine outcome measures and includes adverse-event counts for the POEM group. The study began in 2010-11, reached primary completion in 2011-06, and is marked completed. A formal sample-size justification, analysis plan, and key details about missing data are not reported in the registry record.