MAGNET (Magnetically Controlled Capsule for Assessment of Gastric Mucosa in Symptomatic Patients): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MAGNET (Magnetically Controlled Capsule for Assessment of Gastric Mucosa in Symptomatic Patients) (NCT04724291), a na na study. The primary outcome is Number of Participants With Visualization of All Major Anatomic Regions in the Stomach With MCCE Based on 2 Reviewers.

2. Clinical Question

This is a feasibility question about visualization, not a comparative test of clinical outcomes. The intended assessment covered the lower esophagus, the gastroesophageal junction and Z-line, and 6 gastric landmarks: cardia, fundus, body, angularis, antrum, and pylorus. The primary outcome title defines the measure as the number of participants with visualization of all major anatomic regions, based on 2 reviewers.

The registry summary says participants had a standard indication for EGD and were willing to receive MCCE. That describes the intended study population; the record does not give further eligibility criteria or a demographic profile. It also describes secondary questions about patient preference compared with EGD and safety, including adverse-event encounters up to the 30 Day follow-up. Their numerical results are not reported in the registry record. The central question is therefore whether the capsule examination met a stated visualization benchmark in this study, while the posted information does not establish the observed rate or how it compares with EGD.

3. Trial Design

MAGNET was a completed, single-group device study sponsored by George Washington University. Its registry status is COMPLETED, and its phase and allocation are listed as NA. Masking is listed as NONE. Enrollment was 43. The recorded start date is 2021-02-10 and the primary completion date is 2022-06-10.

The intervention was named MAGNET and classified as a device. The arm description is “MAGNET + EGD”: capsule endoscopy followed by traditional endoscopy. The capsule is described as actively controlled by a clinician, unlike capsule endoscopes that move passively by gravity or peristalsis. The aim was to assess whether the examination could visualize stomach anatomy in people who had a standard indication for EGD and were willing to undergo the capsule examination.

Because the study is single-group, it does not provide a randomized comparison between MCCE and EGD. Performing both examinations in sequence does not, on its own, make the design a controlled comparison. The registry record does not report random assignment, a separate control arm, or masking of participants or clinicians. It also does not report a protocol for comparing findings from the two examinations.

The primary outcome was the number of participants with visualization of all major anatomic regions, based on 2 reviewers. Its timeframe is listed as 90min. The description states that each of 40 MCCE results was reviewed by at least 2 physician reviewers for documentation of the listed regions. That review description gives a count of examinations assessed, but the registry record does not explain why it differs from the enrollment figure or how any reviewer disagreements were handled.

The secondary outcomes concern patient preference compared with EGD and safety compared with EGD, with adverse-event encounters through the 30 Day follow-up mentioned for safety. The registry record does not report results for these outcomes. No analysis results are listed. Further detail about recruitment, participant characteristics, procedures for handling incomplete examinations, or the statistical analysis plan is 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: There weren't any significant events following participant enrollment, but prior to assignment of participants to an arm or group.

Overall Study

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Visualization of All Major Anatomic Regions in the Stomach With MCCE Based on 2 Reviewers, measured over 90min.

The primary endpoint counts participants whose MCCE examination documented all major anatomic regions specified in the registry description. The regions include the lower esophagus, the gastroesophageal junction and Z-line, and the 6 named gastric landmarks: cardia, fundus, body, angularis, antrum, and pylorus. The outcome title describes complete visualization across the regions, and the timeframe is 90min.

This endpoint is used to assess the technical feasibility and completeness of the examination. For a procedure intended to inspect anatomy, recording whether key areas were visualized is a direct way to describe image coverage. The registry description relates the assessment to established quality metrics for traditional endoscopy, stating a benchmark of >90% photo-documentation of pre-established regions. This is a stated criterion, not a reported result for MAGNET.

The description says each of 40 MCCE results was reviewed by at least 2 physician reviewers. However, the registry record does not report the number of participants who met the complete-visualization criterion, the denominator used in the posted outcome analysis, reviewer agreement, or a rule for resolving different assessments. The numerical endpoint result is not reported in the registry record. Without that result, the extent to which examinations met the stated criterion cannot be assessed from the posted information.

Even when reported, a visualization count would describe anatomical documentation, not by itself diagnostic accuracy, agreement with EGD, patient preference, or downstream clinical consequences. Those are distinct questions and require their own outcome data and analysis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count measure?

The primary outcome is a count of participants who met a complete-visualization condition. In general, a count becomes easier to interpret when paired with its denominator: together they show how many assessed participants met the condition and how many were assessed. The registry describes review of 40 MCCE results, but it does not report the primary count or clearly state the analysis denominator for that outcome. A rate, uncertainty interval, or comparison with a target therefore cannot be reconstructed from the registry record.

The outcome is binary at the participant level: each examination either meets the stated all-regions criterion or it does not, according to the endpoint definition. General analyses of binary outcomes can report the number meeting the criterion and the corresponding proportion, with a confidence interval to describe uncertainty. A confidence interval gives a range of values compatible with the data under the chosen method; it does not guarantee that the true value lies in that range. No such interval or primary outcome estimate is reported in the registry record.

Why does the design matter?

MAGNET is recorded as a single-group study with allocation listed as NA. The endpoint can therefore be described as an outcome observed in the enrolled study group, but the design does not create a randomized contrast between MCCE and EGD. EGD followed capsule endoscopy according to the arm description, but sequence alone is not a controlled comparison. A comparative claim would require a defined comparison and suitable analysis, neither of which is reported in the registry record.

General statistical interpretation also depends on the target population and how participants entered the study. The registry summary describes people with a standard indication for EGD who were willing to undergo MCCE. The record does not report enough information about recruitment or participant characteristics to assess how closely the enrolled group represents other patients. This matters because an observed feasibility result in one group may not automatically apply to groups with different characteristics or circumstances.

What do the reviewer assessments contribute?

The endpoint description says each of 40 MCCE results was reviewed by at least 2 physician reviewers. Multiple reviewers can provide more than one assessment of an examination, but the method used to combine those assessments affects the final participant-level classification. General reporting should clarify whether reviewers assessed examinations independently, whether they were masked to other findings, how disagreements were resolved, and how agreement was summarized. These procedures are not reported in the registry record. It is therefore not possible to assess the reliability of the classifications or determine whether the reviewers applied the complete-visualization criterion consistently.

The endpoint is based on documentation of specified anatomic regions. It should not be conflated with diagnostic accuracy. General diagnostic accuracy analyses require a defined reference standard and classification of findings, such as agreement or disagreement on specific conditions. The registry record does not report such an analysis for the primary outcome. It describes the regions to be documented and mentions EGD as part of the study, but does not provide paired diagnostic findings or an agreement statistic.

How should planning illustrations be read?

The registry record describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These assumptions describe planning illustrations, not the actual trial design: MAGNET is recorded as single-group, not as a two-arm randomized comparison. The registry record does not report the trial's own sample-size justification, and the illustrations should not be read as observed power.

In general, sample-size planning asks how many participants would be needed under specified assumptions to detect an effect with a chosen operating characteristic. The answer depends on the assumed effect, variability, analysis, and design. An illustration based on a fraction of an observed effect is conditional on those assumptions; it does not establish that a study had a particular probability of detecting an effect after the data were collected. The specific planning counts and the observed effect on which they rely are not reported in the registry record. No new sample-size calculation can be made from the posted primary outcome information because the outcome result itself is absent.

For a time-to-event outcome, general planning methods can instead use the total number of events as the main information quantity; the registry describes its time-to-event illustrations in those terms. The primary endpoint in MAGNET is a participant count, not a time-to-event outcome. The registry record does not indicate that this endpoint was analyzed using time-to-event methods.

What can be said about uncertainty and analysis?

General statistical reporting for a binary endpoint can include a point estimate and confidence interval, along with the analysis population and rules for missing or unevaluable examinations. A point estimate conveys the observed frequency, while its interval conveys sampling uncertainty under the chosen statistical method. Neither can be interpreted without knowing who was included and how outcomes were classified. The registry record lists 0 analyses and does not report an outcome estimate, confidence interval, or hypothesis test.

Over-dispersion is a general concern when observations vary more than a simple model assumes. For example, correlated observations or meaningful differences among participants can make a basic model understate uncertainty if those features are ignored. Here, the endpoint is defined at the participant level, while multiple physician reviewers assess examination documentation. The record does not report a model or a method for accounting for reviewer-level variation or dependence. It would be inappropriate to assume that over-dispersion occurred or that a particular adjustment was used.

Thus, the available statistical information is chiefly descriptive: the design, intended endpoint, review description, and safety counts. The registry record does not report enough outcome or analysis detail to evaluate precision, reviewer agreement, or a formal comparison with EGD.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 4 outcome measures. The named secondary outcomes concern patient preference compared with EGD and safety compared with EGD, including adverse-event encounters up to the 30 Day follow-up. The primary outcome concerns complete visualization of the specified anatomic regions. Numerical results for the preference and primary outcomes are not reported in the registry record; safety counts are posted separately.

When a study evaluates multiple outcomes or multiple statistical tests, multiplicity is a general consideration. Testing several hypotheses can increase the chance of at least one apparently notable result when each test is considered in isolation. Common approaches include identifying a primary endpoint in advance, defining a hierarchy for testing, or adjusting interpretation for multiple tests. The registry record does not report whether any multiplicity strategy was planned or used. It also lists 0 analyses, so no pattern of reported tests can be assessed.

Missing-data handling and analysis populations are not reported in the registry record. The enrollment figure is 43, while the primary endpoint description says each of 40 MCCE results was reviewed. The record does not explain this difference, state how many participants had evaluable examinations, or describe whether incomplete or unavailable outcomes were excluded, counted as failures, or handled another way. Those are materially different approaches for a binary endpoint, and the registry does not identify which, if any, was used.

The record also does not specify whether all enrolled participants, all participants who underwent MCCE, or another defined group formed the primary analysis population. The description of at least 2 reviewers per examination does not explain how reviewer assessments were combined or what happened when assessments differed. Without these details, the endpoint denominator and classification process cannot be independently interpreted. No missingness rate, sensitivity analysis, or analysis-population definition is reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry safety listing describes one group, “MCCE(Magnetically Controlled Capsule Endoscopy) & EGD.” It records 40 participants at risk, 0 serious adverse events, 0 other adverse events, and 0 deaths. These figures are counts for the listed group; they are not comparative estimates against a separate control group.

A zero count means that no event in the relevant listed category was recorded in the registry summary. It does not prove that the underlying event risk is zero. General interpretation of rare or uncommon events depends on the number of participants observed, duration and completeness of follow-up, event definitions, and how events were collected. The registry record does not report those details for the posted counts. It does mention adverse-event encounters up to the 30 Day follow-up as part of a secondary safety outcome, but does not provide further event-level information or a separate follow-up-completeness summary.

The count of 40 participants at risk is not the same as total enrollment of 43. The registry record does not explain the difference or state whether the safety denominator reflects a defined analysis population. It also does not list serious adverse-event terms. The figures should therefore be read narrowly as the posted counts and denominator, not as evidence that no safety events could occur or that safety has been established relative to EGD.

12. What the Result Does, and Does Not, Mean

The registry record documents a completed feasibility study designed to assess whether magnetically controlled capsule endoscopy could visualize a specified set of anatomic regions. It gives a concrete endpoint definition, describes review by at least 2 physicians, and states a photo-documentation benchmark of >90%. It also records 43 enrolled participants and a safety group of 40 at risk.

However, the numerical result for the primary visualization endpoint is not reported in the registry record. The posted information therefore does not show how many participants had complete visualization, whether the stated benchmark was met, or how precisely the result was estimated. The 40 reviewed MCCE results are a description of the assessments, not a result showing that all 40 met the endpoint.

The record also does not establish diagnostic accuracy or equivalence with EGD. The study is single-group, and although the capsule examination was followed by traditional endoscopy, no paired findings, agreement analysis, or randomized comparison is reported. Nor does the record report the numerical result for patient preference. These questions cannot be answered from the posted results described.

The safety summary records 0 serious adverse events, 0 other adverse events, and 0 deaths among 40 at risk in the combined MCCE and EGD group. That is a useful description of the recorded counts, but it does not show that risk is zero, define the completeness of follow-up, or compare safety between procedures.

Overall, the registry record specifies what the study intended to evaluate and gives limited descriptive safety information. It does not provide the primary outcome estimate or enough methodological detail to evaluate missing data, reviewer agreement, or statistical precision. The record should not be interpreted as establishing that MCCE does or does not meet the visualization benchmark, or as showing a comparative clinical benefit.

13. Why This Trial Matters Statistically

This study raises a statistical question that is common in early device evaluation: how should feasibility be defined and reported? MAGNET identifies a concrete criterion—documentation of all specified regions—and relates it to a stated photo-documentation standard. A clear endpoint makes the study question more interpretable than a general claim that visualization was adequate. The registry record also specifies that physician reviewers assessed the examinations, which makes the reviewer process part of the measurement rather than a minor operational detail.

The design is important to the scope of the conclusions. A single-group study can describe performance in the participants assessed, but it cannot by itself estimate a randomized difference between MCCE and EGD. When two procedures occur in sequence, the resulting observations still need a defined comparison method and relevant analysis. The registry record does not report such comparative results. This distinction helps prevent a feasibility measure from being read as evidence of equivalence or superiority.

Statistical interpretation also depends on transparent denominators and outcome reporting. The record gives enrollment of 43 and states that 40 MCCE results were reviewed, but does not explain the relationship between these figures or report the number meeting the primary criterion. Without the outcome count and analysis population, readers cannot assess the observed frequency or its precision. These are central elements for interpreting a binary feasibility endpoint.

The posted safety counts illustrate another general point: zero recorded events are descriptive, not proof of no risk. Their meaning depends on the population observed and completeness of follow-up, details not reported in the registry record. Taken together, the study's stated endpoint and design show why careful separation of feasibility, comparative performance, and safety claims matters statistically.

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 main limitation for interpreting the trial is that the primary visualization result is not reported in the registry record. Although the endpoint definition and review process are described, there is no count of participants meeting the criterion, denominator for the outcome analysis, or uncertainty estimate. It is therefore not possible to determine the observed level of complete visualization or its precision from the posted information.

The record reports enrollment of 43 and says each of 40 MCCE results was reviewed, but does not explain the difference. It does not identify the number of participants who underwent each procedure, the number with evaluable outcomes, or how incomplete examinations were handled. The endpoint description also does not state how at least 2 reviewers' assessments were combined or how disagreements were resolved.

The single-group design limits comparative interpretation. The arm description states that capsule endoscopy was followed by traditional endoscopy, but the registry record does not report a randomized comparator, paired diagnostic findings, an agreement analysis, or the numerical results of the preference outcome. The sequence alone does not provide evidence of comparative performance.

Further limitations are the absence of reported participant characteristics, detailed eligibility criteria, and analysis methods. The record lists 4 outcome measures and 0 analyses, but does not describe multiplicity handling or analysis populations. Safety information is limited to 0 serious adverse events, 0 other adverse events, and 0 deaths among 40 at risk; event definitions and completeness of follow-up are not reported. These gaps restrict interpretation of both the endpoint and safety counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: MAGNET (Magnetically Controlled Capsule for Assessment of Gastric Mucosa in Symptomatic Patients) — NCT04724291.
• Registry record last updated 2023-09-11; status last verified 2023-08.
• Results first posted 2023-09-11.
• 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.

18. Record Summary

MAGNET is a completed, single-group device study sponsored by George Washington University. Enrollment was 43. The registry lists no masking, phase NA, and allocation NA. The study dates are 2021-02-10 to 2022-06-10.

The intervention was magnetically controlled capsule endoscopy followed by traditional endoscopy. The primary outcome was the number of participants with visualization of all specified anatomic regions, based on 2 reviewers; the timeframe was 90min. The description says 40 MCCE results were reviewed by at least 2 physician reviewers. The numerical primary outcome result is not reported in the registry record.

The registry lists 4 outcome measures and 0 analyses. Safety figures record 0 serious adverse events, 0 other adverse events, and 0 deaths among 40 at risk in the MCCE and EGD group. The record does not report further analysis details or explain the difference between enrollment and reviewed examinations.