Evaluation of the Performance of the CleanC System-Israel: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of the Performance of the CleanC System-Israel (NCT02387268), a na na study. The primary outcome is Percentage Subjects With Post Procedure Cleansing Level as Measured by the Boston Bowel Preparation Scale (BBPS) Adequate Cleansing-(BBPS>1 ).

2. Clinical Question

In statistical terms, the central question is whether participants undergoing colonoscopy with the CleanC system met the stated cleansing threshold during the procedure’s withdrawal phase. The device’s stated purpose is to support cleaning when the colon is poorly prepared. This study can describe outcomes among participants treated with the system, but without a separate comparison group it cannot estimate a treatment contrast against an alternative.

3. Trial Design

The registry record identifies the study as “Evaluation of the Performance of the CleanC System-Israel” and gives the official title as “Evaluation of the Performance of the ‘CleanC’ System.” It lists Motus GI Medical Technologies Ltd as sponsor. The study status is completed, with a start date of 2015-05 and primary completion in 2015-06. Enrollment is listed as 10.

The design is single-group. The intervention is the CleanC system, described as a device, and the arm description specifies standard colonoscopy using that system. Masking is listed as none, allocation as NA, and phase as NA. No randomized allocation or separate control arm is described. The record’s design notes also identify the study as not a randomized comparison and caution that arms are not a like-for-like control comparison.

The device is intended to facilitate intra-procedural cleaning of a poorly prepared colon through irrigation and evacuation of irrigation fluid and feces. That stated purpose gives context for the cleansing endpoint, but it does not establish that all enrolled participants had a poorly prepared colon or specify how poor preparation was determined before the procedure. Those details are not reported in the registry record.

The primary outcome concerns adequate cleansing according to the Boston Bowel Preparation Scale (BBPS), measured during the colonoscopy procedure withdrawal phase, described as 10 min in average. The record also lists the percentage of participants in whom the cecum was reached as a secondary outcome, and indicates 3 outcome measures. It lists 0 analyses. Detailed procedures for recruitment, eligibility, outcome assessment, analysis populations, and statistical testing are not reported in the registry record.

Because the study has no separate comparison group, its design is suited to describing recorded outcomes in the CleanC group, not to isolating the effect of the device from other influences. Even a reported proportion would need to be interpreted as an observation in this study group rather than as a comparative estimate.

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.

6. Primary Endpoint

The registry lists the primary outcome as Percentage Subjects With Post Procedure Cleansing Level as Measured by the Boston Bowel Preparation Scale (BBPS) Adequate Cleansing-(BBPS>1 ), measured over During the colonoscopy procedure withdrawal phase (10 min in average).

The primary endpoint is the percentage of participants with post-procedure cleansing rated adequate by the BBPS, with adequacy defined in the endpoint title as a score greater than 1. The assessment is placed during the colonoscopy procedure withdrawal phase, described as 10 min in average. The record specifies a 95% confidence interval as the endpoint’s dispersion measure, but does not report the observed percentage or interval.

The BBPS scale description runs from 0 to 3 for a colon segment. A score of 0 indicates that solid stool prevents the mucosa from being seen. A score of 1 indicates that some mucosa is seen but other areas are obscured by staining, residual stool, or opaque liquid. A score of 2 describes minor residual staining, small stool fragments, or opaque liquid while the mucosa is seen well. A score of 3 describes the entire mucosa as seen well with none of those residual materials.

A threshold-based percentage is useful because it expresses how often participants met a defined cleansing criterion, rather than reporting only a scale description. It can make the endpoint’s clinical meaning more direct, while the underlying scale retains distinctions in cleansing quality. The registry record says the scale wording was finalized after feedback from three colleagues experienced in colonoscopy. It does not report how scores were assigned, whether assessments were independently reviewed, or how missing assessments were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes the primary endpoint as a percentage of participants and specifies a 95% confidence interval for dispersion. It does not state the statistical method used to calculate that interval, any hypothesis test, or an adjusted analysis. The concepts below are general explanations of how such statistics are commonly interpreted; they do not identify methods used in this study unless the registry record explicitly says so.

What does a percentage represent?

For a binary endpoint, a percentage summarizes the share of participants classified as having the outcome. In this study, the outcome is meeting the stated BBPS threshold for adequate cleansing. The percentage depends on both the number classified as meeting the criterion and the number whose outcome is included in the calculation. The registry record does not report either the primary outcome count or its analysis denominator, so no percentage can be reconstructed from the recorded details.

A binary outcome simplifies a scale into a threshold decision. That can make a result easier to communicate, but it also discards detail: scores on either side of the threshold may differ in their underlying cleansing quality, while the binary classification treats them as distinct outcome categories. The BBPS scale description preserves that underlying context, but the primary endpoint is specified as a percentage above the threshold.

What does a confidence interval communicate?

General explanation: a confidence interval describes the statistical uncertainty around an estimated quantity under the assumptions of the method used to calculate it. For a percentage, the interval helps readers understand how much uncertainty remains about the underlying proportion in a broader population. A narrow interval indicates greater precision under the method’s assumptions; a wide interval indicates less precision. An interval does not remove uncertainty about the study design, measurement quality, or representativeness of the participants.

The registry record names a 95% confidence interval as the dispersion measure for the primary endpoint. It does not provide the interval’s lower or upper limit, the observed percentage, or the calculation method. The stated interval type alone cannot tell readers the precision of the endpoint estimate.

Why does a single-group design matter?

General explanation: a single-group study estimates outcomes within the group that received the intervention. Without a separate control group, it does not directly estimate a difference between intervention and control outcomes. A result may be influenced by participant selection, procedural circumstances, measurement practices, or other factors. Randomization in a comparative study can help balance factors between groups; the registry record does not describe randomization and identifies the study as not a randomized comparison.

Accordingly, a proportion meeting the cleansing threshold would describe the CleanC group, not the change attributable to CleanC relative to a comparator. The design does not support a like-for-like comparison, and the record does not identify an external reference rate for comparison.

What methods are not described?

The registry record lists 0 analyses. It does not report an analysis plan, a hypothesis test, an adjustment strategy, a method for handling missing outcomes, or an analysis population. It also does not describe whether the primary endpoint was assessed by a single endoscopist or by independent assessors. These details can affect how estimates are calculated and interpreted, but they cannot be inferred from the endpoint definition.

General explanation: analysis choices should be specified because different reasonable methods can produce different uncertainty estimates, particularly when the amount of information is limited or observations depart from the assumptions of a simple model. Over-dispersion is a general statistical concern when observed variability exceeds what a model assumes. It can make standard errors too small if ignored. The registry record does not report a model or indicate that over-dispersion was assessed, so this concept should not be read as a finding about this study.

How should planning calculations be read?

The record describes sample-size assumptions for planning illustrations: two-sided significance level 0.05, equal allocation between two arms, normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. Those assumptions describe planning calculations, not the design actually used in this single-group trial. The record does not report the resulting planning sample sizes or the observed primary effect needed to interpret such calculations.

General explanation: sample-size planning asks how much information a future study might need under specified assumptions. Such calculations are not observed power and do not establish that a completed study was adequately powered. Planning illustrations based on an observed effect are also conditional on that effect and on the calculation assumptions. They cannot substitute for the missing endpoint estimate, confidence interval, or a prespecified analysis plan.

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("CleanC")
n      <- c(9)
events <- c(8)
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  CleanC  9  8  88.9  51.8  99.7  56.5  98.0  55.5  97.5

11. Multiplicity, Missing Data and Analysis Populations

The registry record indicates 3 outcome measures and 0 analyses. It identifies a primary cleansing endpoint and lists the percentage of participants in whom the cecum was reached as a secondary outcome. Results for those outcomes are not reported in the registry record. The other outcome measures are not described in the recorded details.

Multiplicity concerns arise when several outcomes or statistical tests are examined. General explanation: the more tests considered, the greater the chance that at least one result may appear unusual by chance, unless the analysis plan addresses that issue. The record does not report a multiplicity strategy, a hierarchy of secondary outcomes, or any inferential test results. It is therefore not possible to determine whether multiplicity was considered or whether any adjustment was used.

Missing-data handling is also not reported in the registry record. The enrollment figure is 10, but the record does not state how many participants had an evaluable primary endpoint, whether any endpoint assessments were missing, or how missing observations were treated. The analysis population is not reported. Enrollment should not be assumed to equal the endpoint denominator.

These gaps matter because the estimate, uncertainty, and interpretation of a percentage depend on which participants are included and how missing assessments are handled. The record also does not describe exclusions, protocol deviations, or the population used for the safety counts. No conclusions about these analysis choices can be drawn from the listed outcome definitions alone.

12. Safety Results

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

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 registry record lists a CleanC safety group with 10 participants at risk for serious adverse events and 0 affected. For other adverse events, it lists 10 participants at risk and 1 affected. These counts describe the safety information recorded for the group; they do not identify the type, timing, severity, or relationship to the device of the other adverse event.

The record does not report deaths; the deaths field is null, which is not the same as a reported count of zero. No serious adverse event terms are listed. The safety figures should therefore be read narrowly: the record reports no participants affected by a serious adverse event in the listed group, and reports 1 participant with an other adverse event. It does not provide enough detail to characterize the event further.

Safety counts are descriptive. In a single-group study, these figures do not establish whether an event was caused by the device or whether event frequency differs from another approach. The registry record does not provide a comparative safety group or the additional detail needed for broader safety conclusions.

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

The registry record establishes that CleanC was evaluated as part of standard colonoscopy in a completed single-group study. It describes the device’s intended role in irrigating and evacuating fluid and feces from a poorly prepared colon, and defines a primary endpoint based on adequate cleansing using the BBPS. It also lists safety counts for the CleanC group.

The record does not report the primary endpoint percentage or its 95% confidence interval. Consequently, it does not establish how often participants met the cleansing threshold or how precisely that rate was estimated. It also does not report the secondary cecum-reaching result. The listed endpoint definitions are not outcome results, and the stated confidence interval type is not a numerical confidence interval.

Even if a cleansing percentage were reported, the single-group design would describe outcomes in the CleanC group rather than provide a direct estimate of the difference between CleanC and an alternative. There is no separate comparator listed, and the record identifies the study as not a randomized comparison. The available information cannot establish that the device caused an outcome or that its performance is better or worse than another method.

The safety record reports 0 participants with serious adverse events among 10 at risk and 1 participant with other adverse events among 10 at risk. These figures do not explain the nature or relatedness of the other event, and deaths are not reported. They should not be stretched into a broader safety claim.

Thus, the study record is informative about the question investigators intended to assess, the intervention, and the design constraints. It does not contain the outcome information required to judge the observed cleansing rate, its precision, or comparative performance. Conclusions beyond those boundaries are not supported by the registry record.

14. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the difference between defining an outcome and reporting an estimate for that outcome. The registry record gives a threshold-based primary endpoint, a scale description, and a confidence interval type, but it does not report the percentage or interval. Without those values, the main statistical question remains unanswered in the record.

The single-group structure is also central to interpretation. A percentage within the CleanC group can describe what was recorded among participants who received the system, but it cannot estimate a contrast against another approach without a comparator. This is an important distinction between an outcome description and evidence of a treatment effect.

The record further illustrates why enrollment is not interchangeable with the denominator for an endpoint. It lists enrollment of 10, but does not give the number analyzed for cleansing or explain missing data. A complete statistical report would make clear how participants entered the analysis and how uncertainty was calculated.

Finally, safety counts have limits when event descriptions and comparative data are absent. The listed figures can be stated accurately, but they do not provide context about event type or causality. Overall, the record allows readers to identify the study’s question and some design features while also showing how missing outcome and analysis details constrain interpretation.

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 limitations specific to this trial follow directly from the registry record. The study is single-group, with allocation listed as NA and masking as none. No separate comparator is listed, so the design does not support a direct comparative estimate. The record also identifies the study as not a randomized comparison and cautions that arms are not a like-for-like control comparison.

The primary result is not reported in the recorded details. Neither the percentage meeting the BBPS threshold nor its 95% confidence interval is available. The listed enrollment of 10 does not establish the primary endpoint denominator, because the analysis population and endpoint-specific missingness are not reported. The registry record lists 0 analyses.

Important details about the population and measurement are also absent. The condition is colorectal cancer screening, but participant eligibility criteria are not reported in the primary endpoint information. The record does not describe how poor preparation was identified, how BBPS ratings were assigned, or how endpoint assessments were handled when unavailable. It gives the withdrawal-phase timeframe as 10 min in average but does not provide further assessment procedures.

For safety, the record reports the affected counts but does not describe the other adverse event or report deaths. It does not provide comparative safety information. Together, these omissions prevent a detailed assessment of outcome precision, measurement procedures, missing data, or safety context. They do not change the stated study design, but they limit what can be concluded from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of the Performance of the CleanC System-Israel — NCT02387268.
• Registry record last updated 2017-09-20; status last verified 2016-02.
• Results first posted 2016-03-07.
• 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

The registry record describes a completed, single-group evaluation of the CleanC system sponsored by Motus GI Medical Technologies Ltd. It lists enrollment of 10, a start date of 2015-05, and primary completion in 2015-06. The device was used during standard colonoscopy and was intended to support intra-procedural cleaning of a poorly prepared colon.

The primary endpoint is the percentage of participants with adequate cleansing by the BBPS threshold, assessed during the colonoscopy withdrawal phase. The record specifies a 95% confidence interval but does not report the endpoint result or interval. It lists the cecum-reaching percentage as a secondary outcome and indicates 3 outcome measures and 0 analyses.

The safety record lists 0 participants with serious adverse events and 1 participant with other adverse events, with 10 at risk in each listing. Deaths are not reported. The absence of a comparator, outcome estimates, and analysis details limits interpretation of both performance and safety.