Ultrasound Evaluation of Crohn's Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Ultrasound Evaluation of Crohn's Disease (NCT03235180), a na phase 4 study. The primary outcome is Change in Shear Wave Speed.

2. Clinical Question

3. Trial Design

The registry identifies NCT03235180 as a Phase 4, single-group study titled “Ultrasound Evaluation of Crohn's Disease.” Its stated purpose is to assess the effectiveness of a new ultrasound technology for evaluating Crohn's disease. The recorded enrollment is 9, and the study status is terminated. The record gives a start date of 2017-06-16 and a primary completion date of 2021-10-12; those entries do not, by themselves, explain why the study was terminated or how follow-up proceeded.

Allocation is recorded as NA, masking as none, and the model as single group. The arm is named Crohn's Disease Subjects. Its description says participants would receive bowel ultrasound exams using Ultrasound Elastography and Ultrasound Vascularity at baseline, 4 weeks, and 6 months. It also indicates that ultrasound exams would be performed first without contrast, but the remaining description is truncated. The precise sequence, contrast protocol, and role of the other listed interventions are not reported in the registry record.

The intervention list includes Sulfur Hexafluoride and Magnetic Resonance Enterography (MRE), as well as the two ultrasound devices. Their specific use in the study is not fully described in the available arm text. The primary endpoint is specified as change in shear wave speed between baseline and 6 months. The record lists two outcome measures but reports no statistical analyses. It does not report a protocol, statistical analysis plan, recruitment details, or reasons for termination. As a single-group study without a like-for-like control arm, its registry design does not support a randomized between-group treatment comparison.

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 Change in Shear Wave Speed, measured over baseline, 6 months.

The primary endpoint is change in shear wave speed, measured in KPa, from baseline to 6 months. The registry describes shear wave speed as a measure of small bowel stiffness and identifies the General Electric (GE) Logiq E9 Ultrasound Scanner as the measurement device. The endpoint is specified as a mean with standard deviation as its dispersion measure.

In general, a continuous measurement such as shear wave speed can describe a quantity along a scale rather than assigning each participant to a yes-or-no category. A change endpoint focuses on how measurements differ over time within the observed study group. It can be useful for describing whether and how measurements vary during follow-up, but interpretation depends on the underlying observations, the calculation method, and the amount of uncertainty around the estimate.

The registry record does not provide the baseline or follow-up means, the mean change, a standard deviation for the change, or a confidence interval. It also does not report how missing follow-up measurements, if any, were handled. Thus, the endpoint's clinical and statistical interpretation cannot be determined from the registry results: the stated measurement and time points are available, but the observed result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the record is limited. The primary endpoint is a continuous measure, specified as a mean with standard deviation, and the design is single group. The record lists two outcome measures and 0 analyses. It does not report an endpoint estimate, standard error, confidence interval, test statistic, p-value, or statistical analysis plan. The concepts below explain how such quantities are generally used; they are not descriptions of analyses reported for this study.

What does a mean describe?

In general, a mean is a summary of the central level of a continuous measurement in a defined set of observations. For a change endpoint, an analysis could summarize each participant's change over the stated interval and then describe the average change. The exact calculation and the participants included need to be specified to interpret that average. The registry identifies a mean as the endpoint parameter but does not report the mean change or define the analysis population.

What does a standard deviation describe?

In general, a standard deviation describes how dispersed individual measurements are around their mean. It is not the same as the uncertainty in the estimated mean. A large or small standard deviation describes participant-level variation in the analyzed observations; the uncertainty of an estimate also depends on how many usable observations contribute and on the analysis method. The registry specifies standard deviation as the endpoint's dispersion measure but does not report its value or clarify whether it refers to measurements at a particular time point or to changes.

How would a confidence interval help?

In general, a confidence interval gives a range of values compatible with an estimate under the assumptions of the statistical method. Its width communicates precision: a wider interval indicates greater uncertainty than a narrower interval, all else equal. An interval also helps readers distinguish the estimated magnitude from the uncertainty around it. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be assessed.

What would a significance test add?

In general, a significance test assesses how compatible the observed data are with a specified null hypothesis under a statistical model. A p-value is not the probability that the null hypothesis is true, and it does not measure clinical importance. It should be interpreted with an effect estimate and its uncertainty, not as a stand-alone verdict. The registry record reports no p-value or test for the primary endpoint, and the specific null hypothesis and test are not reported in the registry record.

Why does the design affect interpretation?

In general, a single-group follow-up analysis describes change in the observed group but cannot make the same controlled comparison as a randomized design with a separate comparator. Measurement changes over time can have multiple explanations. This does not invalidate descriptive summaries, but it restricts conclusions about what caused any observed change. Here, allocation is NA and the model is single group; no randomized control comparison is described.

What do the planning assumptions mean?

The registry's sample-size assumptions describe a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is stated as a fraction of the observed effect. Such an illustration concerns hypothetical future planning, not the observed power of the completed study. The record does not report a numerical planning result or the observed effect used as its basis. Its equal-allocation, two-arm framing also differs from the registered single-group design, so it should not be read as a description of this study's allocation or analysis.

For continuous outcomes, general planning calculations depend on assumptions about variability, the target effect, and the analysis. When observations are more variable than an assumed model allows, estimates and uncertainty can be affected; this is one reason model assumptions and dispersion matter. The record does not provide enough outcome data to assess variability or verify any such assumptions. No specific model, adjustment, or test is reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Crohn's Disease Subjects")
n   <- c(9)
m   <- c(8.42)
sp  <- c(4.07)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Crohn's Disease Subjects  9  8.420  4.070  5.292  11.548

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures, but it does not report a statistical analysis plan explaining which outcomes were primary or secondary for analysis beyond the named primary endpoint. It also reports 0 analyses. The handling of multiple outcomes or multiple tests is not reported in the registry record. In general, when several hypotheses are tested, the chance of at least one apparently unusual result can increase; methods for addressing this depend on the analysis plan and the purpose of the tests. No adjustment method or testing hierarchy is described.

Missing-data information is also absent. The registry record does not state whether all enrolled participants completed the baseline, 4-week, and 6-month assessments, whether any endpoint measurements were missing, or how missing measurements were handled. It does not report reasons for missingness, exclusions, or sensitivity analyses. These details matter because an analysis based only on participants with complete measurements may describe a different subset than intended if missingness is related to participants' measurements or circumstances. That is a general consideration, not an assertion that data were missing in this study.

The analysis population is not reported in the registry record. Enrollment is recorded as 9, but the number contributing to the primary endpoint and the rules for inclusion are not given. The record also does not identify an intention-to-treat, per-protocol, or other analysis population. Consequently, the completeness and representativeness of any endpoint analysis cannot be assessed from the registry entry.

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 reports serious adverse events among the Crohn's Disease Subjects group with 9 at risk and 0 affected. It also reports other adverse events with 9 at risk and 0 affected, and deaths with 0 reported. These are the counts recorded in the registry; they do not establish that no events occurred outside the record's defined collection or reporting process.

The registry entry does not provide a safety follow-up timeframe, event definitions, severity grading, attribution to an intervention, or further details about how adverse events were collected. It also does not describe whether participants completed all planned follow-up. Those omissions limit interpretation of the counts, especially for a study with a single group and no comparator. The counts should not be treated as a comparative estimate of safety or as evidence that any listed intervention caused or did not cause an event.

In general, an adverse-event count is easiest to interpret when the population at risk, observation period, event definitions, and completeness of follow-up are clear. The record provides at-risk and affected counts for the listed group but does not report those additional details. Thus, the safety figures are best read as registry-reported counts, not as a comprehensive assessment of risk.

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

The registry record establishes that a single-group study of ultrasound evaluation in Crohn's disease was registered, with enrollment recorded as 9 and status listed as terminated. Its primary endpoint was change in shear wave speed from baseline to 6 months, measured in KPa. It also records a plan for bowel ultrasound assessments at baseline, 4 weeks, and 6 months. These details describe the study's scope and intended measurements, not the outcome of those measurements.

The record does not report the observed primary endpoint result, an estimate of change, or a statistical analysis. As a result, it does not show whether shear wave speed changed, how large any change was, or how precise an estimate might be. The brief summary's stated purpose of assessing the effectiveness of a new ultrasound technology is not itself evidence of an effect. No conclusion about effectiveness can be drawn from the stated purpose alone.

The single-group design also places limits on what a change over time could establish. In general, an uncontrolled before-and-after observation describes what happened in the studied group but does not isolate the effect of an intervention from other explanations. The registry record does not describe a randomized comparator group, and its allocation is NA.

The safety counts document 0 serious adverse events among 9 at risk, 0 other adverse events among 9 at risk, and 0 deaths. Those counts must be interpreted within the reporting information available: the record does not specify the safety observation period or provide fuller collection and follow-up details. They do not amount to a comparative safety assessment.

In short, the registry supplies design, endpoint, and event-count information, but not results sufficient to estimate the primary outcome or judge its uncertainty. The reasons for termination and the extent of completed follow-up are not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a useful statistical distinction between registering an outcome and reporting its result. A registry can identify a measurement, its units, the intended time points, and a summary parameter without providing the observations needed to estimate an effect. Here, shear wave speed is specified as a mean with standard deviation, but the registry reports no endpoint estimate or analysis. Readers therefore can understand what was intended to be measured, but cannot assess the result or its precision.

The design also highlights why the comparison structure matters. Repeated measurements in one group can describe change over time, but they do not provide the same evidence as a randomized comparison with a control group. This distinction is important when a study purpose uses language about effectiveness: the design and reported analysis determine what conclusions can be supported, not the wording of the purpose alone.

The entry also illustrates the importance of transparent analysis details. The record lists two outcome measures yet no analyses, and it does not describe missing-data handling, an analysis population, or multiplicity procedures. Those details help readers understand how registered outcomes relate to reported results and how uncertainty was handled. Their absence does not explain why results are unavailable, but it leaves substantial questions open.

Finally, the sample-size assumptions describe a two-arm planning illustration, whereas the registered model is single group. Recognizing that difference prevents a planning calculation from being mistaken for the study's actual design or for observed power. More broadly, this record is a reminder that design descriptions, endpoint definitions, results, and planning assumptions serve different statistical purposes.

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 has several limitations specific to interpreting this study. Most importantly, it does not report the primary endpoint result or any statistical analysis. The stated endpoint is change in shear wave speed between baseline and 6 months, but no observed means, change estimate, standard deviation, confidence interval, or test result is included. This prevents assessment of both the direction and precision of the endpoint.

The arm description is incomplete. It identifies bowel ultrasound examinations with Ultrasound Elastography and Ultrasound Vascularity at baseline, 4 weeks, and 6 months, and begins to describe exams without contrast, but the remaining text is truncated. Although Sulfur Hexafluoride and MRE are listed as interventions, their roles in the study are not reported in the registry record. The exact measurement sequence and contrast procedures therefore cannot be fully characterized.

The record identifies the study as terminated but does not report the reason. It does not state whether participants completed the planned follow-up, how many contributed to the primary endpoint, whether measurements were missing, or how missing data were handled. The registered enrollment does not resolve these questions. No analysis population or statistical analysis plan is reported.

Because this is a single-group study without a like-for-like control comparison, any within-group change would have limited ability to distinguish intervention-related effects from other explanations. The available record also lacks details needed to interpret the safety observation period and event ascertainment. These limitations reflect information not reported in the registry record, rather than proof that a particular procedure or analysis was not performed.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Ultrasound Evaluation of Crohn's Disease — NCT03235180.
• Registry record last updated 2021-11-10; status last verified 2021-10.
• Results first posted 2021-11-10.
• 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

NCT03235180 is a Phase 4, single-group study titled “Ultrasound Evaluation of Crohn's Disease,” sponsored by Mayo Clinic. The registry records enrollment as 9 and status as terminated. The stated purpose is to assess a new ultrasound technology for evaluating Crohn's disease.

The listed interventions include Ultrasound Elastography, Ultrasound Vascularity, Sulfur Hexafluoride, and MRE. The primary endpoint is change in shear wave speed, measured in KPa, from baseline to 6 months. The registry describes this measure as an indicator of small bowel stiffness and names the GE Logiq E9 Ultrasound Scanner.

The record lists two outcome measures and 0 analyses. It does not report the primary endpoint result, the reason for termination, or details of missing-data handling and analysis populations. Safety counts are 0 serious adverse events among 9 at risk, 0 other adverse events among 9 at risk, and 0 deaths. The registry does not report a safety follow-up timeframe.