Safety,Usability and Compliance of Using C-Scan System for Providing Information on Colonic Polypoid Lesions and Masses: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety,Usability and Compliance of Using C-Scan System for Providing Information on Colonic Polypoid Lesions and Masses (NCT03735407), a na na study. The primary outcome is Number of Incidence of Device and Procedure Related Serious Adverse Events (SAE).

2. Clinical Question

This is a safety and usability evaluation, not a test of comparative effectiveness. The record also lists non-compliance and satisfaction as secondary outcomes, but their numerical results are not reported in the registry record. The central interpretive issue is therefore the scope of the safety observation: a count from one study group can describe events recorded in that group, but cannot establish how the event experience compares with another procedure or with no procedure.

3. Trial Design

The registry describes a prospective, multicenter, single-arm safety study of the C-Scan System. It lists the study as completed, with enrollment of 45. The brief summary describes up to two centers located in the United States. The study start is listed as 2019-02-01 and primary completion as 2020-01-01. The phase is listed as NA, and masking is listed as none.

The single intervention is the C-Scan procedure, classified as a device intervention. The system comprises a capsule, tracking component, and viewing component. The arm description says participants at high or average risk for developing colorectal cancer who were scheduled for optical colonoscopy would undergo the procedure. In contrast, the brief summary calls the 45 participants healthy subjects. The registry record does not explain how these population descriptions relate to one another, so the study population should not be characterized more narrowly than the record allows.

There is one study group and no like-for-like control arm. Allocation is listed as NA, so this was not a randomized comparison. The study's stated purpose was to demonstrate system safety. Its primary objective was safety assessment, while its secondary objectives were participant compliance, participant satisfaction, and collection of data to improve the product's algorithm.

The primary outcome is a count of participants with device- and procedure-related serious adverse events over 6 Months. The description specifies adjudication by an Independent Physician Adjudicator. The adverse-event figures list 40 participants at risk for the event categories. The reason that this denominator differs from the enrollment of 45 is not reported in the registry record. The registry record does not report further details about recruitment, eligibility criteria, follow-up completion, or the statistical analysis plan.

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

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: High risk and average risk for CRC

6. Primary Endpoint

The registry lists the primary outcome as Number of Incidence of Device and Procedure Related Serious Adverse Events (SAE), measured over 6 Months.

The primary endpoint counts participants with a device- or procedure-related serious adverse event during the stated 6 Months timeframe. It is a participant count, rather than a measure of event severity over time or a comparison between treatment groups. The registry's outcome description says an Independent Physician Adjudicator would adjudicate these events, providing a stated process for deciding whether an event met the endpoint definition.

Safety outcomes are used to identify and describe harmful events associated with an intervention. A serious adverse event is an important safety category, but the endpoint's interpretation depends on its definition, the observation period, the number of participants actually followed, and how events are identified and adjudicated. The registry record does not provide further operational details about the serious-event definition or adjudication process.

The posted safety figures list 0 participants with serious events among 40 at risk. That count describes the recorded experience in this study group; it is not evidence that the possibility of serious events is absent. The registry record does not report an uncertainty interval for this outcome or explain why 40, rather than the enrollment of 45, appears as the number at risk. The result should therefore be read with the denominator and the limited scope of a single-group safety study in mind.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count measure?

A count-of-participants endpoint records how many people meet an event definition at least once during the stated observation period. It differs from an event count, which could count repeated events in one person more than once, and from a time-to-event measure, which incorporates when an event occurs. The primary outcome in this study is explicitly a participant count. Its posted result is 0 participants with serious adverse events among 40 at risk, over 6 Months.

Counts are easier to interpret when paired with the number of people observed and a clear event definition. The denominator indicates the group in which events could be detected. Here, the adverse-event figures list 40 at risk, while enrollment is 45. The registry record does not report why these numbers differ, whether all 40 contributed the full follow-up timeframe, or how incomplete observation was handled. Those details matter because an event can only be counted if it is captured and classified during observation.

Why does the study design matter?

A single-group study describes outcomes among people who receive the intervention, but does not directly estimate what would have happened to comparable participants under a different intervention or without the procedure. With no randomized comparator, differences from other settings cannot be attributed to the device using this study alone. Such a design can report observed safety events, but it does not support a treatment-effect comparison.

Randomization, when used, aims to make comparison groups comparable in expectation. This registry lists allocation as NA and the study model as single group, so there is no randomized allocation to interpret. Masking is listed as none. The record does not report other procedures intended to reduce bias in event identification or reporting beyond the stated Independent Physician Adjudicator for the primary endpoint.

What does adjudication contribute?

Adjudication is a process for reviewing events against specified criteria, often to determine whether an event qualifies for an endpoint or is considered related to an intervention. The outcome description says serious adverse events would be adjudicated by an Independent Physician Adjudicator. This indicates a planned review role, but the registry does not report the detailed criteria, reviewer procedures, or any adjudication results beyond the posted counts. These details are important when interpreting how consistently events were classified.

How should zero events be understood?

In general, observing no events in a study group does not show that the event cannot occur. A finite observation can be compatible with a range of underlying event risks, especially when events are uncommon. A confidence interval expresses uncertainty around an estimate under a specified statistical method. No confidence interval, hypothesis test, or other inferential result for the primary endpoint is reported in the registry record. Consequently, the posted count is best treated as a descriptive result rather than a precise estimate of risk for a broader population.

The adverse-event record also lists 13 participants with other adverse events among 40 at risk and 0 deaths among 40 at risk. These categories have different meanings. The registry does not list the terms for the other events, so their clinical nature, seriousness, and relationship to the device cannot be inferred from the count alone. The recorded serious-event result should not be interpreted as meaning that no adverse events of any kind occurred.

What role do planning calculations play?

In general, sample-size planning asks how many participants or events a future study might need to detect a prespecified effect under stated assumptions. Such illustrations are planning exercises, not observed evidence and not a measure of the probability that the completed study found a true effect. The registry describes an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is expressed as a fraction of the observed effect. These assumptions do not describe the actual single-group design, and the registry record does not report that they were the study's own design justification.

For binary outcomes, general planning methods depend on the event proportions anticipated in each comparison group and the effect considered meaningful. A single-group safety study does not provide a randomized two-arm contrast. Any planning illustration based on a hypothetical two-arm comparison should therefore be distinguished from the study's actual observed safety counts. The registry record does not report a sample-size justification for the enrolled group.

What analyses are reported?

The registry record reports no analyses. It does not provide a statistical analysis plan, inferential tests, confidence intervals, adjustments, or details of how missing observations were treated. The absence of a reported analysis is not evidence that no analysis was conducted; it means that analytical procedures are not available in the registry record for evaluation. The posted outcome counts can still be described, but they do not permit a fuller assessment of precision or robustness.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("C-Scan Procedure")
n      <- c(40)
events <- c(0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  C-Scan Procedure  40  0  0.0  0.0  8.8  0.0  8.8  0.1  8.6

11. Multiplicity, Missing Data and Analysis Populations

The study lists a primary safety objective and secondary objectives concerning compliance, satisfaction, and product-algorithm improvement. The registry also lists non-compliance rate and participant satisfaction as secondary outcomes. It does not report numerical results for those secondary outcomes, nor does it report a statistical analysis plan describing how they were to be analyzed.

When a study assesses multiple outcomes, multiplicity can arise because several statistical questions are considered. In general, conducting many hypothesis tests can increase the chance of at least one apparently notable finding by chance. Methods such as prioritizing a primary endpoint or adjusting statistical thresholds can address that issue, depending on the objectives. Whether any multiplicity strategy was planned or used is not reported in the registry record. The record reports no analyses, so there are no posted test results to interpret for multiplicity.

The registry lists 45 enrolled participants, while the adverse-event figures list 40 participants at risk. The reason for this difference is not reported in the registry record. The disposition of the other enrolled participants, the number completing follow-up, and the amount or handling of missing outcome data are also not reported. The completed status of the study does not by itself establish that all outcomes were observed for all enrolled participants.

The registry record does not define analysis populations, such as who was considered eligible for each outcome analysis, or state whether the posted safety counts include all participants who began the procedure. It does not report exclusions, withdrawals, or sensitivity analyses. These omissions limit the ability to assess whether the observed counts could be affected by incomplete follow-up or selective availability of outcome data. They also prevent assessment of whether the denominator was determined consistently with the primary endpoint's planned analysis population.

12. 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.

Most frequent non-serious adverse event terms

The C-Scan Procedure group lists 0 participants with serious adverse events among 40 at risk, and 0 deaths among 40 at risk. The primary outcome description concerns device- and procedure-related serious adverse events during 6 Months, with adjudication by an Independent Physician Adjudicator. These figures describe the posted safety observations, not a comparison against another procedure or an untreated group.

The record also lists 13 participants with other adverse events among 40 at risk. The event terms and further details are not reported in the registry record. This separate count means the zero serious-event figure should not be mistaken for a report of zero adverse events overall. The record does not explain the difference between the 45 enrolled participants and 40 at risk.

In general, zero observed serious events in a finite group does not establish that the underlying risk is zero. The registry record does not report a confidence interval or other precision estimate for the serious-event count. The figures are therefore most appropriately read as descriptive counts within the stated group and follow-up timeframe, with the limitations of the denominator and unreported follow-up details in mind.

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

The registry documents a completed, single-group safety study with 45 enrolled participants. Its posted adverse-event figures list no serious adverse events and no deaths among the 40 participants at risk in the C-Scan Procedure group. The record also lists 13 participants with other adverse events among 40 at risk. These observations describe the recorded experience in this study; they do not establish comparative safety against another procedure.

The result does not demonstrate that serious adverse events are impossible or that the device is free of risk. General statistical reasoning distinguishes an observed count from the underlying event risk: a study can observe no events while still leaving uncertainty about how often an event might occur in a broader population or with longer observation. No confidence interval or other precision estimate is reported in the registry record.

The figures also do not establish effectiveness, diagnostic accuracy, or benefit. Although the study title and objectives refer to structural information on colonic polypoid lesions and masses, the primary endpoint is a safety count. The registry does not report results for diagnostic performance. The stated secondary aims include compliance and satisfaction, but their numerical results are not reported in the registry record.

Interpretation is further limited by the single-group design, the absence of a control arm, and the difference between enrollment of 45 and 40 participants at risk in the safety figures. The reason for that denominator difference, the number completing follow-up, and the treatment of missing observations are not reported. The summary calls participants healthy subjects, while the arm description refers to people at high or average risk who were scheduled for optical colonoscopy. The record does not reconcile these descriptions.

Accordingly, the most defensible reading is narrow: the registry reports no serious adverse events among the participants listed as at risk, alongside a separate count of other adverse events. The data do not support conclusions about comparative risk, broader populations, unreported outcomes, or event rates beyond the study's observation.

14. Why This Trial Matters Statistically

This study illustrates why safety counts need their design and denominator alongside them. The primary outcome is a count of participants with serious adverse events, and the posted count is zero among 40 listed at risk. Without the denominator, follow-up context, and endpoint definition, a count alone would have limited meaning. Even with those details, a zero observed count is descriptive and does not establish that the underlying risk is zero.

The single-group design also sets a clear boundary on inference. The study can describe recorded events in people who underwent the C-Scan procedure, but it has no concurrent comparison group for estimating relative safety. A statistical test cannot create a valid randomized comparison where the design contains none. This distinction is important when a study's title or device purpose may lead readers to expect conclusions beyond the outcomes actually reported.

The record also shows how discrepancies in participant descriptions and denominators affect interpretation. The summary describes healthy subjects, while the arm description refers to people at high or average risk and scheduled for optical colonoscopy. Enrollment is 45, whereas the safety figures list 40 at risk. Since the registry does not explain these differences, readers cannot fully reconstruct the population contributing to the outcome or the completeness of follow-up.

Finally, stated secondary objectives are not interchangeable with reported results. Compliance and satisfaction were objectives, but numerical findings are not reported in the registry record. Separating the study's aims from its posted outcomes helps avoid treating an intended assessment as evidence of its result. The record is useful for identifying the planned safety question and the observed event counts, while leaving important questions about precision, follow-up, and other outcomes unresolved.

15. 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.

Several trial-specific limitations constrain interpretation. The study has a single group and no comparator, so its event counts cannot be used to estimate a difference in safety relative to another intervention. Allocation is listed as NA and masking as none. The record does not report other methods for limiting bias in event collection or reporting, apart from the stated adjudication role for serious adverse events.

The enrollment total is 45, but the adverse-event figures list 40 participants at risk. The registry record does not explain this difference or report the disposition of participants who are not included in that denominator. It also does not state how many completed the 6 Months timeframe, how missing outcome information was handled, or how the analysis population was defined.

The description of the population is not consistent across the registry record: the summary calls the participants healthy subjects, while the arm description refers to people at high or average risk for colorectal cancer who were scheduled for optical colonoscopy. The record does not reconcile the descriptions, report detailed eligibility criteria, or clarify which characterization best represents the enrolled group.

Further limitations include the absence of reported confidence intervals or other measures of precision for the primary outcome, and the absence of detailed event terms for the 13 participants listed with other adverse events. Numerical results for compliance and satisfaction are not reported. A statistical analysis plan, sample-size justification, and details of any interim analyses are not reported in the registry record. These gaps limit assessment of the planned analysis, completeness of reporting, and applicability of the safety observations beyond the participants listed at risk.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Safety,Usability and Compliance of Using C-Scan System for Providing Information on Colonic Polypoid Lesions and Masses — NCT03735407.
• Registry record last updated 2023-09-13; status last verified 2023-08.
• Results first posted 2023-09-13.
• 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.

19. Record Summary

NCT03735407 is a completed, prospective, multicenter, single-group safety study of the Check-Cap C-Scan System. The record lists enrollment of 45, no masking, and up to two United States study centers in the brief summary. The primary outcome is the number of participants with device- and procedure-related serious adverse events over 6 Months, with adjudication by an Independent Physician Adjudicator.

The C-Scan Procedure group lists 0 participants with serious adverse events among 40 at risk, 0 deaths among 40 at risk, and 13 participants with other adverse events among 40 at risk. The reason for the difference between enrollment and the safety denominator is not reported in the registry record. The summary's description of healthy subjects and the arm description's risk-based characterization are not reconciled.

The study's secondary objectives include compliance and satisfaction, but numerical results are not reported. There is no comparator arm, and the registry record reports no analyses or precision estimates for the primary safety result. The posted counts therefore describe the recorded safety experience in the study group without establishing a comparative effect.