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 Suturing for Primary Obesity Treatment (NCT01662024), a na na study. The primary outcome is Number of Participants With Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01662024 |
| Phase | NA |
| Condition | Obesity, Body Weight, Overweight |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Brigham and Women's Hospital |
| Results posted | Yes |
2. Clinical Question
Population
The record concerns people with obesity, body weight concerns, or overweight. It records enrollment of 20 participants. Further eligibility criteria, baseline characteristics, and the characteristics of the people who completed follow-up are not reported in the registry record.
Intervention
The intervention was an endoscopic gastric restrictive procedure using tissue approximation through an incisionless, per-oral approach. The record identifies the intervention as a device procedure and describes its purpose as restricting gastric size.
Comparator
There was no separate comparator group. The record describes a single-group study, with no randomized allocation and no like-for-like control comparison. The intervention group therefore cannot be contrasted with a concurrent control group in this record.
Primary question
The primary outcome was the number of participants with adverse events over 12 months. The record defines perioperative, postoperative, and delayed adverse events by when they occurred relative to the procedure. It also lists secondary outcomes concerning weight loss, durability, body mass index, and waist circumference, but does not report analyses for them.
In practical terms, the registry record describes a study collecting data on use of endoscopic gastric tissue approximation during a primary gastric restrictive procedure. It does not set up a randomized comparison to estimate how outcomes differ from another procedure or from no procedure. Its primary question is therefore descriptive: how many participants were recorded as having adverse events during the stated follow-up, under the outcome definitions in the record?
The trial’s brief summary presents gastric restriction as the rationale for the procedure and describes the endoscopic approach as incisionless and per-oral. That rationale is not itself evidence of a clinical benefit or of fewer complications. The listed secondary outcomes indicate additional areas the study intended to assess, but their definitions, numerical results, and analysis details are not reported in the registry record.
3. Trial Design
The registry record identifies NCT01662024 as the PROMISE Trial, with the official title Primary Obesity Multicenter Incisionless Suturing Evaluation. Brigham and Women’s Hospital is listed as the sponsor. The study is marked completed, with a start date of 2013-02 and primary completion in 2015-05. Enrollment was 20.
The design is recorded as a single-group study. Allocation is listed as NA, and masking is listed as none. The intervention was an endoscopic gastric restrictive procedure. No separate control arm or randomized allocation is described, so the design does not provide a concurrent like-for-like control comparison. The record lists phase as NA.
The stated primary objective was to collect data on use of the OverStitch Endoscopic Suturing System for gastric tissue approximation during primary gastric restrictive procedures. The description says the approach approximates tissue endoluminally, through an incisionless, per-oral route, to restrict gastric size. These are descriptions of the intended procedure and rationale, not reported comparative outcomes.
The primary outcome was the number of participants with adverse events, with a 12-month timeframe. The registry record defines perioperative events as those occurring during the procedure or post-procedure observation period; postoperative events as those occurring during the first three days after the procedure; and delayed events as those occurring on the fourth post-procedure day or afterwards. It also lists secondary outcomes for percent excess weight loss, durability, percentage of total body weight loss, BMI loss, and waist circumference loss.
Study eligibility criteria, detailed visit schedules, treatment implementation details, and participant disposition are not reported in the registry record. Nor are protocol-specific explanations of sample-size planning, interim analyses, or a statistical analysis plan reported. With a single group, the design can describe observed outcomes in the enrolled participants, but it cannot by itself separate procedure-related changes from other explanations or establish a comparative treatment effect.
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 | Endoscopic Gastric Restrictive Procedure |
|---|---|
| STARTED | 20 |
| COMPLETED | 15 |
| NOT COMPLETED | 5 |
Reasons for not completing this period:
| Reason | Endoscopic Gastric Restrictive Procedure |
|---|---|
| Pregnancy | 2 |
| Withdrawal by Subject | 3 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: Adults who are suffering from obesity with a Body Mass Index (BMI) of 30 - 35 kg/m\^2 seeking a minimally invasive alternative to bariatric surgery.
| Characteristic | Unit | Endoscopic Gastric Restrictive Procedure |
|---|---|---|
| Participants analysed | 20 | |
| Age, Continuous | years | 36.7 (34.4 to 39.0) |
| Sex: Female, Male: Female | Participants | 20 |
| Sex: Female, Male: Male | Participants | 0 |
| Initial Weight (kg) | kg | 90.4 (88.4 to 92.4) |
| Initial BMI (kg/m^2) | kg/m^2 | 33.4 (33.1 to 33.7) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events, measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with adverse events, measured over 12 months. It is a participant count: the outcome concerns whether participants experienced an event, rather than the total number of event episodes. The registry record does not provide a separate numerical breakdown by perioperative, postoperative, and delayed timing category.
The timing definitions matter because events in different periods may relate to different stages of the procedure and follow-up. The record classifies perioperative events as occurring during the procedure or post-procedure observation period, postoperative events as occurring during the first three days after the procedure, and delayed events as occurring on the fourth post-procedure day or afterwards. Those definitions make clear which time windows the record intends to distinguish, though the posted results do not give counts for each window.
Adverse-event outcomes are used to describe unwanted events observed during a study. A count can communicate how many participants were recorded as having events under the study’s definitions. It does not, by itself, establish the cause of an event, its severity, or how risk compares with another intervention. Those interpretations require details and comparisons beyond a count.
For this study, the reported primary outcome is an event count in a single group. The registry record reports no serious adverse events among 20 participants and reports 7 participants with other adverse events. It does not report event-level descriptions, severity grading for the other events, or a timing breakdown. The 12-month endpoint label should not be taken to mean that every participant had complete 12-month observation; follow-up completeness is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted safety figures describe participants in the endoscopic gastric restrictive procedure group. The record reports no serious adverse events among 20 participants and 7 participants with other adverse events among 20 at risk. These counts are descriptive for this enrolled group. Because the study has no comparator group, they do not estimate how event counts would differ under another procedure or under no procedure.
The distinction between serious and other adverse events is important in reading the record. A zero count for serious events means none were recorded in the reported group; it does not establish that serious events cannot occur. With 20 participants, uncommon events may not be observed even when they are possible. The record does not provide a confidence interval or a more detailed characterization of the event data, so precision beyond the counts cannot be assessed from the posted results.
The count of 7 participants with other adverse events should not be interpreted as 7 events: the primary outcome is the number of participants with adverse events, not the number of event episodes. The record does not report the event types, their severity, the number of events per participant, or their timing across the defined periods. It also does not report deaths; the death field is not populated with a numerical result. The registry record therefore does not support a conclusion about mortality.
The registry lists weight-related outcomes and durability as secondary outcomes, but no analyses are reported for them. In particular, the record does not give numerical results for percent excess weight loss, percentage of total body weight loss, BMI loss, waist circumference loss, or durability. Listing an outcome does not establish that a result was measured, analyzed, or favorable. The primary safety counts cannot substitute for those missing outcome results.
More broadly, an uncontrolled study can document what was recorded among its participants, but it cannot identify a counterfactual: what would have happened to those same participants under an alternative. Changes in weight, if measured, could have multiple explanations, and a single-group design does not provide a concurrent comparison to distinguish them. The registry record also does not report baseline values or follow-up distributions that would support interpretation of change.
The record marks the study completed and reports enrollment of 20, but it does not report how many participants contributed to each outcome or whether any were lost to follow-up. The count at risk is stated as 20 for the adverse-event group, but that alone does not clarify follow-up completeness over the full timeframe. The safest reading is therefore limited: these are reported event counts in the study group, with incomplete detail about event characteristics and no comparative estimate.
9. Statistical Methods Explained
What does a single-group design estimate?
In general, a single-group study describes outcomes among participants who receive the studied intervention. It can summarize what was observed in that group, but it does not provide a concurrent comparison with an alternative. A comparative treatment effect requires a contrast between outcomes under different treatment conditions. Without a control group, that contrast is unavailable from the study design described in the registry record.
This distinction is especially important when a study has an intended clinical rationale. A rationale explains why an intervention may be worth studying; it is not an outcome estimate. The PROMISE record describes gastric restriction as the procedure’s purpose and states that the study objective was to collect data on use of the endoscopic suturing system. The record does not report a controlled estimate of benefit, harm relative to another approach, or causal effect.
What does a participant count tell the reader?
For a count-of-participants endpoint, each participant is classified according to whether the specified event was recorded. The reported number is not necessarily the number of event episodes, since one participant may experience more than one event. The posted primary outcome is the number of participants with adverse events. It reports counts for serious and other adverse events, but does not give event-level descriptions or separate counts by timing category.
Counts are straightforward to read, but their precision depends on the amount of information behind them. In general, a result based on a small group can be compatible with a wide range of underlying event frequencies. A confidence interval expresses uncertainty around an estimate; the registry record does not report one for these adverse-event counts. No interval should be inferred from the counts alone in this explanation.
Why does the event definition matter?
Outcome definitions determine what qualifies for inclusion. Here, the registry record distinguishes perioperative events, postoperative events, and delayed events according to when they occurred relative to the procedure. These categories help organize safety observations by timing. However, the reported primary outcome does not include numerical results for each period, so the timing definitions cannot be used to infer when the reported events occurred.
There is also a difference between an adverse event and an event attributed to an intervention. In general, recording an adverse event does not, by itself, establish that the intervention caused it. The record does not provide event narratives or causal attribution details for the other adverse events. The counts should therefore be read as events recorded under the registry outcome, rather than as confirmed effects caused by the procedure.
What can be learned from the absence of a comparator?
A randomized comparison, when used, is designed to balance groups on average and support a between-group estimate. This record is not a randomized comparison: it describes a single group, with allocation listed as NA and masking as none. It does not report an active comparator or a control group. Consequently, comparisons with historical experience or external populations are not part of the reported analysis and should not be treated as though they were concurrent trial evidence.
Masking and allocation are separate design features. The record’s masking entry is none, while allocation is NA in the single-group design. The record does not report further details about how outcomes were assessed or whether any steps were taken to reduce assessment bias. It would be speculation to infer procedures beyond the entries in the registry record.
How should planning calculations be understood?
In general, power calculations describe the chance that a planned analysis will detect a specified effect under stated assumptions. They are planning tools, not evidence that a study found an effect. Any sample-size figures associated with this record are planning illustrations, not observed power and not the trial’s own design justification. The stated illustration assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect set as a stated fraction of an observed effect.
Those two-arm planning assumptions do not change the actual design described in the registry record, which is single-group. The record does not report a protocol sample-size justification, and the actual planned effect, if any, is not reported in the registry record. A planning calculation should not be interpreted as proof that the study was adequately sized for its endpoint or as evidence about the probability that the intervention works.
What is not available for further statistical assessment?
The registry record reports no analyses. It does not provide inferential estimates, confidence intervals, model specifications, adjustment variables, or a statistical analysis plan. No numeric analysis of the listed secondary outcomes is reported. Without those details, the posted results support a descriptive account of the event counts, but not reconstruction of a broader efficacy or safety analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists a primary adverse-event outcome and secondary outcomes concerning percent excess weight loss, durability, percentage of total body weight loss, BMI loss, and waist circumference loss. It reports seven outcome measures overall, but provides no analyses. Numerical results for the listed secondary outcomes are not reported in the registry record.
When a study evaluates multiple outcomes, multiplicity can arise because each additional statistical test creates another opportunity for a result to appear noteworthy by chance. In general, a prespecified approach to multiplicity can clarify how conclusions should account for multiple tests. The registry record does not report a multiplicity adjustment, a hierarchy among secondary outcomes, or a plan for interpreting multiple tests. No correction or unadjusted analysis should be assumed.
Missing-data handling is also not reported in the registry record. The record does not state whether any participants were lost to follow-up, how missing outcome values were handled, or whether an outcome was available for every enrolled participant. The adverse-event group lists 20 at risk, but this does not establish complete observation for the full 12-month timeframe.
Analysis populations are not described. The registry record does not specify an intention-to-treat, per-protocol, or other analysis population, nor does it report participant flow by outcome. The posted primary counts should therefore be interpreted as reported counts, without assuming a particular population definition or missing-data method. These omissions limit assessment of whether outcome availability or analysis choices could affect the reported results.
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 |
|---|---|---|---|
| Endoscopic Gastric Restrictive Procedure | 0 | 20 | 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 |
|---|---|
| Endoscopic Gastric Restrictive Procedure | 7 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Endoscopic Gastric Restrictive Procedure |
|---|---|---|
| Perioperative Nausea/Vomiting | Gastrointestinal disorders | 3 of 20 |
| Perioperative Abdominal Pain | Gastrointestinal disorders | 2 of 20 |
| Post-operative Abdominal Pain | Gastrointestinal disorders | 1 of 20 |
| Post-operative Nausea | Gastrointestinal disorders | 1 of 20 |
The safety record lists one group, Endoscopic Gastric Restrictive Procedure, with 20 participants at risk for serious adverse events and 0 affected. For other adverse events, it lists 20 at risk and 7 affected. These are counts of participants, not counts of event episodes. The record does not list deaths with a numerical value.
The absence of a recorded serious adverse event in this group is a descriptive observation, not proof that serious events are impossible. In general, a small study may not observe uncommon outcomes. No confidence interval or event-rate estimate is reported in the registry record, and none is calculated.
The other-adverse-event count does not show which events occurred, how severe they were, how many each participant experienced, or whether they were judged related to the procedure. The registry’s timing definitions distinguish perioperative, postoperative, and delayed events, but separate counts by those categories are not reported. The counts should be interpreted within these limits and should not be compared with an external rate as though the record included a control group.
12. What the Result Does, and Does Not, Mean
The result establishes that the registry record reports no serious adverse events among 20 participants and 7 participants with other adverse events among 20 at risk in the endoscopic gastric restrictive procedure group. It also establishes that the primary endpoint was defined as a participant count over a 12-month timeframe, with timing categories described for perioperative, postoperative, and delayed events.
These registry entries do not establish that the procedure is safe or unsafe in general. The study enrolled 20 participants and has no concurrent comparator. Its observed counts do not show how those outcomes compare with another procedure, usual care, or no intervention. The record does not provide event details, severity classifications for other events, or a timing-specific breakdown. It also does not report a confidence interval for the counts, so their precision cannot be quantified from the registry result.
The record’s description of the procedure’s purpose is not evidence that it achieved a particular amount of gastric restriction or weight loss. Although secondary outcomes for weight loss, durability, BMI, and waist circumference are listed, their numerical results and analyses are not reported. No conclusion about those outcomes can be drawn from their inclusion in the registry record.
More generally, an outcome observed after a procedure is not automatically caused by the procedure. A single-group design lacks the comparison needed to estimate what would have happened under an alternative. Differences over time, if any were measured, might reflect factors other than the procedure, and the record does not provide results that permit assessment of such changes.
The appropriate interpretation is consequently narrow and descriptive. The record documents the group size and adverse-event counts under the registry definitions. It does not establish comparative effectiveness, a causal safety effect, long-term durability, or results for the listed secondary outcomes. Those questions are not answered by the reported information.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the distinction between describing an outcome and estimating a comparative effect. A single-group study can record whether participants experienced events, but without a concurrent comparator it cannot show whether the observed count is higher or lower than it would have been under another approach. Keeping that distinction clear prevents descriptive safety figures from being mistaken for evidence of comparative benefit or harm.
It also demonstrates why endpoint definitions and reporting detail matter. The registry defines adverse events by timing and identifies the primary outcome as a count of participants with events. Yet the posted results do not give the event descriptions, severity details for other events, or timing-specific counts. Clear definitions are useful, but they do not replace reporting the outcome data needed to understand what was observed.
The record also lists several secondary outcomes without reporting analyses for them. A listed outcome is not a result. Statistical interpretation depends on whether measurements were collected, how they were analyzed, which participants contributed, and how multiple outcomes were handled. Those details are not reported in the registry record, so the listed weight-related outcomes cannot be interpreted quantitatively.
Finally, the sample-size planning assumptions should be distinguished from the trial design and its findings. Planning illustrations may describe hypothetical assumptions, but they do not show that a study had a particular probability of detecting an effect, and they do not provide a substitute for observed comparative data. The registry record’s single-group design and limited reported outcomes define what can be concluded: descriptive counts for the enrolled group, not a controlled estimate of treatment effect.
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 study’s single-group design is the central limitation for comparative interpretation. There is no randomized allocation or concurrent control group in the registry record. The reported adverse-event counts therefore cannot show how event occurrence would differ under another intervention or in the absence of the procedure.
The enrolled group comprised 20 participants. This limits the amount of information available for describing uncommon events, and the registry record does not report confidence intervals for the event counts. No broader population inference can be made from these counts alone.
Reporting is also incomplete for interpreting safety. The record does not describe the other adverse events, their severity, the number of event episodes, or whether events were considered related to the procedure. Although timing categories are defined, numerical results by category are not reported. A numerical result for deaths is not reported in the registry record.
Participant flow and follow-up completeness are not reported. The registry lists 20 participants at risk for the adverse-event categories, but does not state whether all participants were observed throughout the 12-month timeframe or whether any data were missing. Analysis populations and missing-data methods are also not reported in the registry record.
Finally, five secondary outcomes are listed, but no analyses are reported. Their definitions, measurement schedules, numerical results, and multiplicity approach are not reported. The record also does not report a protocol-specific sample-size justification or statistical analysis plan. These omissions prevent a fuller appraisal of outcome precision, analysis choices, and the relationship between planned and reported analyses.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Endoscopic Suturing for Primary Obesity Treatment — NCT01662024.
- Registry record last updated 2017-03-30; status last verified 2017-02.
- Results first posted 2017-03-30.
- 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
NCT01662024, the PROMISE Trial, is recorded as completed. Brigham and Women’s Hospital is listed as sponsor. The study began in 2013-02, reached primary completion in 2015-05, and enrolled 20 participants. Its design is single-group, with allocation listed as NA and masking listed as none.
The intervention was an endoscopic gastric restrictive procedure. The primary outcome was the number of participants with adverse events over 12 months. The record reports 0 serious adverse events among 20 at risk and 7 participants with other adverse events among 20 at risk. It lists secondary outcomes involving weight loss, durability, BMI, and waist circumference, but reports no analyses for those outcomes.
The registry record does not provide a concurrent comparator, detailed event descriptions, follow-up completeness, analysis populations, or a statistical analysis plan. The reported findings are descriptive counts for the study group and do not establish comparative effects.