Transmitted Light Tissue Thickness Analysis (TiLTT): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transmitted Light Tissue Thickness Analysis (TiLTT) (NCT02749201), a na na study. The primary outcome is Number of Patients With Transmitted Light Intensity to Gastric Wall Thickness).

2. Clinical Question

3. Trial Design

This is a completed, single-group device study registered as Transmitted Light Tissue Thickness Analysis (TiLTT), with the same official title. Maimonides Medical Center is listed as the sponsor. The registry lists morbid obesity as the condition and Gastrisail as the device intervention. Enrollment is recorded as 10.

The study start is listed as 2016-04 and primary completion as 2017-04. The phase is NA, allocation is NA, and masking is NONE. The model is SINGLE GROUP. These design entries do not describe a randomized comparison: no control arm or assigned alternative intervention is identified. The registry record itself flags that the arms are not a like-for-like control comparison.

The arm description names “Analysis” and describes light intensity and gastric wall thickness analysis. The record lists one outcome measure and no analyses. The primary outcome timeframe is intraoperative. Although its description uses the phrase “between the groups,” the record does not define groups that would support a between-group treatment comparison. It also does not provide further details of the study procedures, eligibility criteria, participant flow, or analysis population. Those details are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

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 Patients With Transmitted Light Intensity to Gastric Wall Thickness), measured over intraoperative.

The primary endpoint is recorded as the number of patients with transmitted light intensity to gastric wall thickness. Its unit is participants, its parameter is a count of participants, and the timeframe is intraoperative. The brief summary describes the study aim as assessing gastric wall thickness using transmitted light intensity. Taken together, these entries indicate that the registered outcome concerns a participant count related to transmitted light intensity and gastric wall thickness, rather than a reported continuous thickness measurement.

The registry does not explain the operational definition of a qualifying participant, the threshold or rule used to determine whether a participant met the endpoint, or how a count would be interpreted as evidence about thickness. Those details are not reported in the registry record. The endpoint description mentions “between the groups,” but the listed design is single group and no comparator groups are specified.

In general, a count endpoint summarizes how many participants meet a defined condition. Its usefulness depends on a clear definition of that condition and on knowing which participants were assessed. Here, no numerical primary endpoint result is reported, so the record does not allow readers to assess the observed count or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the endpoint count?

The primary outcome is specified as a count of participants, with an intraoperative timeframe. A count endpoint records how many participants meet a stated condition. In general, interpreting such an endpoint requires a clear rule for deciding who meets the condition, a defined set of participants assessed, and a report of the resulting count. The registry record does not specify the qualifying rule or report the primary count. It describes the aim as assessing gastric wall thickness using transmitted light intensity, but does not provide a numerical measurement or a method for relating the signal to thickness.

What kind of comparison is described?

The registered model is single group, and allocation is NA. No comparator arm or randomized assignment is described. The phrase “between the groups” appears in the primary endpoint description, but the record does not define groups for that comparison. In general, a between-group estimate requires identifiable groups and a defined outcome measured in each. Without those details and an analysis result, no contrast can be interpreted from the registry record.

The arm description names “Analysis,” rather than defining separate comparator arms. The record also notes that the arms are not a like-for-like control comparison. This distinction matters because a difference between groups, when groups are not comparable or are not defined, cannot be treated as a randomized treatment effect. The posted record does not provide a controlled comparison.

What analysis is reported?

The registry lists one outcome measure and zero analyses. It does not report a statistical test, model, estimate, confidence interval, or p-value for the primary endpoint. The statistical plan, including any prespecified analysis methods, is not reported in the registry record. It would be inappropriate to infer a test or model from the endpoint wording alone.

In general, a confidence interval communicates uncertainty around an estimate, while a test evaluates data against a specified null hypothesis under stated assumptions. Neither can be reconstructed from a participant count alone without the relevant outcome data and analysis definitions. No such result is posted for this endpoint.

How should planning illustrations be understood?

Any sample-size figures associated with this record are planning illustrations based on the observed effect, not the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. For non-time-to-event outcomes, such illustrations are described as participants per arm for a specified power level. They are not observed power and do not show that this single-group study was designed or conducted as a two-arm trial.

In general, a planning calculation asks how much information a proposed design might need under specified assumptions. It is not a substitute for a trial’s actual protocol or an analysis of observed results. Here, the registry does not report the trial’s own sample-size justification, and the single-group design does not supply a like-for-like two-arm comparison. The assumptions attached to planning illustrations should therefore be kept distinct from the registered design and from evidence about the endpoint.

Why does dispersion matter?

For outcomes that vary across participants, measures of variability help describe how spread out the observations are and how precisely an average or other estimate has been measured. This endpoint is specified as a participant count, and no dispersion estimate is listed. In general, over-dispersion matters when count data vary more than a statistical model expects; ignoring it can make uncertainty appear too small. The registry does not report a count model or enough outcome detail to assess whether over-dispersion is relevant to this analysis.

These general concepts explain what an analysis might need to address; they do not identify methods used in this study. The registry record does not report the statistical analysis plan or an analysis result.

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("Analysis")
n      <- c(10)
events <- c(10)
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  Analysis  10  10  100.0  69.2  100.0  72.2  100.0  71.5  99.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and no analyses. It does not describe a multiplicity strategy, such as how several outcomes or repeated statistical tests would be handled. With the posted information, it is not possible to determine whether multiple testing was planned or whether any adjustment was applied. The statistical plan is not reported in the registry record.

Missing-data handling is also not described. The record does not state whether endpoint data were missing, how missing assessments were defined, or whether any approach was used to address them. Enrollment is listed as 10, but the number with an evaluable primary endpoint is not reported. Enrollment alone should not be treated as the analysis population.

The analysis populations are not specified. The record does not say which participants were included in any endpoint analysis or whether exclusions were made. It also does not describe participant flow or the handling of protocol deviations. These omissions limit the ability to understand the completeness and representativeness of any result; no primary outcome result is posted to clarify them.

In general, multiplicity, missing data, and analysis-population definitions can affect how estimates and uncertainty should be interpreted. They are especially important when readers need to distinguish a prespecified primary analysis from additional exploratory analyses. For this record, the relevant procedures are not reported in the registry record, so no assumptions about them can be made.

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.

The registry records zero serious adverse events among 10 at risk in the Analysis group, zero other adverse events among 10 at risk, and zero deaths. These are the safety counts entered in the record. The serious-event listing has no top serious-event terms.

These entries describe what the registry reports, not a guarantee that no events occurred. The record does not describe event definitions, the observation period for safety reporting, how events were collected, or whether all participants had complete safety follow-up. Those details are not reported in the registry record. The timeframe for the primary endpoint is intraoperative, but the record does not state that this is the safety observation period.

In general, a zero recorded count means no events were entered for the specified category and denominator. It does not establish that the underlying risk is zero, particularly when the reporting process and follow-up are not described. The listed counts should therefore be read as registry-reported safety data, with the limits of the available reporting in mind.

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

The registry record establishes that TiLTT was registered as a completed, single-group device study sponsored by Maimonides Medical Center. It lists Gastrisail as the intervention, morbid obesity as the condition, enrollment of 10, and an intraoperative participant-count endpoint related to transmitted light intensity and gastric wall thickness. These entries describe the study’s registration and its stated aim.

The primary endpoint result is not reported in the registry record. There is no posted count, estimate of uncertainty, or analysis to show how the device assessment related to gastric wall thickness. The record therefore does not permit a judgment about the magnitude or precision of the endpoint finding. It also does not support a conclusion about diagnostic accuracy, agreement, or clinical benefit, because the relevant results and methods are not reported.

The single-group design and lack of a specified comparator mean that the record does not provide a randomized between-group treatment comparison. The endpoint wording mentions groups, but the registered design does not identify them. No causal contrast should be inferred from that phrase.

The safety entries report zero serious adverse events, zero other adverse events, and zero deaths in the listed group. Their interpretation is limited by the absence of detail on safety definitions and follow-up. Similarly, enrollment should not be confused with the number assessed or analyzed, which is not reported.

In general, a study’s stated objective, design, and results answer different questions. The registration describes what the study set out to assess and its broad structure; evaluation of performance requires outcome data and an analysis appropriate to the question. For this record, the objective and design are described, but the posted results do not provide the primary endpoint analysis needed to assess the stated aim.

14. Why This Trial Matters Statistically

This record is statistically notable because it combines a participant-count endpoint with a single-group design and an endpoint description that refers to “between the groups.” Careful reading keeps the stated endpoint separate from the study structure: no comparator groups are identified, and the record flags that the arms are not a like-for-like control comparison. This prevents the endpoint wording from being mistaken for a controlled treatment contrast.

The distinction between enrollment and an analysis population also matters. The registry lists enrollment of 10, but does not say how many participants contributed to the primary endpoint. Without that information, readers cannot assess endpoint completeness or connect the enrollment entry to an analysis denominator.

The record lists one outcome measure and no analyses, and it does not report the primary endpoint result. This makes the boundary between a registered objective and an evidentiary result especially important. A stated aim to assess gastric wall thickness using transmitted light intensity is not itself evidence about the observed relationship or the precision of an estimate.

In general, transparent reporting of endpoint definitions, participant flow, analysis methods, and uncertainty allows readers to judge what a study’s data can support. Their absence does not establish that an analysis was not conducted outside the registry, but those details are not reported in the registry record. The study illustrates why design labels, endpoint wording, and posted results need to be read together rather than treated as interchangeable descriptions of evidence.

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.

The registry record does not provide a numerical result for the primary endpoint. It also does not define the rule for counting a participant as meeting that endpoint, despite describing the outcome as a count involving transmitted light intensity and gastric wall thickness. This limits interpretation of what the endpoint represents and how it would be assessed.

The endpoint description refers to groups, but the registered model is single group and no comparator groups are described. The record itself cautions that the arms are not a like-for-like control comparison. Therefore, the registry does not establish a controlled comparison or provide the information needed to interpret a between-group effect.

Additional limitations arise from missing reporting details: participant characteristics, eligibility criteria, participant flow, numbers assessed, analysis populations, missing-data handling, statistical methods, and uncertainty estimates are not reported in the registry record. The safety entries lack details about event definitions and follow-up. These gaps limit assessment of both endpoint completeness and the scope of the safety counts.

The record lists enrollment of 10, but that entry does not establish the number with evaluable data. It lists one outcome measure and no analyses, and does not report the trial’s own sample-size justification. Planning illustrations based on an observed effect should not be confused with the registered design or observed power. These limitations concern what can be learned from the registry record; they do not establish what may have been collected or analyzed outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Transmitted Light Tissue Thickness Analysis (TiLTT) — NCT02749201.
• Registry record last updated 2021-06-23; status last verified 2021-06.
• Results first posted 2020-05-20.
• 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

Transmitted Light Tissue Thickness Analysis (TiLTT) is listed as a completed, single-group device study sponsored by Maimonides Medical Center. The registry records morbid obesity as the condition, Gastrisail as the intervention, and enrollment of 10. The start and primary completion entries are 2016-04 and 2017-04.

The stated aim is to assess gastric wall thickness using transmitted light intensity. The primary outcome is a participant count with an intraoperative timeframe. The record lists one outcome measure and no analyses, but does not report a numerical primary endpoint result, an uncertainty estimate, or the statistical analysis plan. It also does not specify a comparator group, despite wording in the endpoint description that refers to groups.

Safety entries list zero serious adverse events, zero other events, and zero deaths for the Analysis group. Details on safety definitions and follow-up are not reported in the registry record.