This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Transesophageal Echocardiography (TEE): A Novel Technique for Spinal Cord Imaging (NCT02415244), a registered phase not stated study. The primary outcome is Number of Thoracic Spinal Segments Successfully Visualized With TEE.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02415244 |
| Phase | Phase not stated |
| Condition | Spinal Cord, Epidural |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 75 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Kenichi Ueda |
| Results posted | Yes |
2. Clinical Question
The study asked whether transesophageal echocardiography (TEE) could identify structures within the vertebral foramen and what range of spinal segments could be visualized. Its registered primary outcome focused on the number of thoracic spinal segments successfully visualized within 30 minutes. The record describes counting short-axis views of thoracic spinal cord segments and surrounding structures in pediatric and adult patients.
Population
The study enrolled patients described in two groups: “Age 0 - 18” and “Age 18 plus.” The group descriptions identify pediatric and adult patients, respectively. The record does not provide further eligibility criteria or a more detailed description of the population for the primary outcome.
Intervention
The procedure under study was TEE, used to visualize spinal cord segments and surrounding structures. The record describes this as a prospective observational study, not as a randomized treatment assignment.
Comparator
No separate control procedure or randomized comparator is described. The pediatric and adult groups are age-based groups, not like-for-like control arms. The allocation method is not stated.
Primary question
How many thoracic spinal segments could be visualized with TEE within 30 minutes? The registry record specifies a median and inter-quartile range as the intended summary, but the numerical endpoint result is not reported in the registry record.
This is a question about visualization and the range of segments that can be seen, rather than a comparison of clinical outcomes between assigned treatments. The record’s aim is descriptive: to assess whether TEE can identify the relevant anatomy and to characterize the spinal segments visible with the technique. Because no numerical endpoint result or analysis is reported, the registry record cannot establish the observed extent of visualization or how precisely it was estimated.
3. Trial Design
NCT02415244 is registered as a completed prospective observational study titled “Transesophageal Echocardiography (TEE): A Novel Technique for Spinal Cord Imaging.” The listed sponsor is Kenichi Ueda. The registry record gives a start date of 2012-07 and a primary completion date of 2017-09-23. Enrollment is listed as 75.
The procedure of interest was TEE. The record describes two groups by age: “Age 0 - 18,” described as TEE visualization in patients age between 0 - 18, and “Age 18 plus,” described as TEE visualization in patients age 18 or greater. These are descriptions of the groups, not evidence of randomized allocation or a control condition. The record states that allocation was not stated and that the groups are not a like-for-like control comparison. The wording places age 18 in both descriptions; the record does not clarify how that boundary was handled.
The study is classified as “other” in the registry record and is not presented as a randomized comparison. Its stated purpose is to assess whether TEE can identify structures within the vertebral foramen and determine the range of spinal segments that can be visualized. The primary outcome concerns thoracic segments visualized within 30 minutes. It is specified as a median with an inter-quartile range, but no numerical outcome is reported.
The record lists one outcome measure and zero analyses. It does not report the statistical analysis plan, a sample-size justification, or an interim-analysis plan. The listed enrollment should therefore be read as the registered enrollment, not as evidence about a particular analysis population or the number of patients contributing data to the endpoint. Further details about recruitment, sites, eligibility criteria, or the conduct of imaging 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
| Stage | Age 0 - 18 | Age 18 Plus |
|---|---|---|
| STARTED | 50 | 25 |
| COMPLETED | 50 | 25 |
| NOT COMPLETED | 0 | 0 |
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.
| Characteristic | Unit | Age 0 - 18 | Age 18 Plus | Total |
|---|---|---|---|---|
| Participants analysed | 50 | 25 | 75 | |
| Age, Categorical: <=18 years | Participants | 50 | 0 | 50 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 19 | 19 |
| Age, Categorical: >=65 years | Participants | 0 | 6 | 6 |
| Age, Continuous | years | 5.0 (SD 4.8) | 52 (SD 20) | 20 (SD 25) |
| Sex: Female, Male: Female | Participants | 23 | 9 | 32 |
| Sex: Female, Male: Male | Participants | 27 | 16 | 43 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Thoracic Spinal Segments Successfully Visualized With TEE, measured over within 30 minutes.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | Thoracic segments |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of thoracic spinal segments successfully visualized with TEE within 30 minutes. The endpoint description says to count short-axis views of thoracic spinal cord segments and surrounding structures in pediatric and adult patients. It is a count intended to summarize how many segments could be seen during the specified observation period.
Such an endpoint is relevant to the study’s stated aim because the question concerns whether TEE can identify spinal structures and what range of segments is accessible to visualization. Counting the segments offers a descriptive measure of the extent of visualization, while the time limit defines the observation window. The record specifies the median and inter-quartile range, which are summaries suited to describing the center and spread of a measured distribution without requiring the mean to represent a typical observation.
The registry record does not report the median, inter-quartile range, participant-level observations, or the number contributing to the endpoint. It also does not report details such as how an image was judged successful, how an incomplete or uninterpretable view was handled, or whether the same assessment procedure was applied consistently across groups. Without the numerical result and those operational details, the endpoint definition can be described, but its observed value and measurement precision cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a descriptive visualization outcome but does not report its numerical result. It specifies the number of thoracic spinal segments successfully visualized within 30 minutes, summarized by a median and inter-quartile range. Since those summary values are absent, the observed extent of visualization and the spread of observations cannot be evaluated from the registry record. No estimate of precision for the primary endpoint is reported either.
This distinction matters: defining an outcome is not the same as reporting its value. A median would describe the central observation in the endpoint distribution, while the inter-quartile range would describe its middle spread. Neither can be interpreted because the relevant values are not reported in the registry record. The record also lists zero analyses, so it does not present an inferential comparison or an analysis supporting a conclusion about differences between age groups.
The study is observational. The pediatric and adult groups are not randomized comparators, and the record explicitly notes that they are not a like-for-like control comparison. Any differences between these groups, if reported elsewhere, would be descriptive unless supported by a suitable analysis addressing relevant differences between the groups. The registry record does not report adjusted estimates, an adjustment strategy, or an analysis plan. It therefore does not support attributing any difference in visualization to age or to another cause.
The record’s stated objective is to assess whether TEE can identify the structures within the vertebral foramen and to determine the range of spinal segments that can be visualized. The available registry entries establish the question, the procedure, the groups, and the endpoint definition. They do not establish the outcome of that assessment. In particular, the record does not show how often visualization was successful, how many segments were observed, or whether the findings varied across participants.
Planning calculations, where used, have a different purpose from reporting study outcomes. The stated calculation assumptions describe an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are not reported as the study’s own design assumptions. Planning sample sizes are not observed power, and they cannot substitute for the endpoint estimate or its uncertainty. Since the numerical endpoint result is not reported in the registry record, the observed effect underlying any such illustration cannot be assessed from these registry entries.
Overall, the registry record supports a limited interpretation: it documents a completed observational study designed to describe TEE visualization using a specified thoracic-segment count. It does not provide the numerical primary result or analyses needed to quantify the finding, assess its precision, or compare the groups. The absence of reported endpoint values is not evidence that visualization did or did not occur; it means the registry record does not report the result needed to make that assessment.
9. Statistical Methods Explained
The registry record identifies the primary outcome as a count and specifies a median with an inter-quartile range. It does not provide an inferential statistical analysis. Understanding what these summaries would mean helps distinguish the endpoint’s intended description from conclusions that cannot be drawn without its numerical result.
What does a median describe?
In general, the median is the central value after observations are ordered. It is often useful when a distribution is skewed or contains unusually high or low observations, because the median is less affected by extreme values than the mean. For this study, the median would describe the center of the recorded number of thoracic segments visualized. The registry record does not state the median value, so the central result cannot be interpreted.
What does an inter-quartile range describe?
In general, the inter-quartile range describes the spread of the middle half of a distribution, between its lower and upper quartiles. It complements a median by showing how much observations vary around the center. It is not a confidence interval: it describes variability among observations rather than the uncertainty around an estimated population value. The record specifies this measure of spread but does not report its endpoints. Therefore, neither the distribution’s central value nor its middle spread is available for interpretation.
How should the endpoint count be understood?
The endpoint is the number of thoracic spinal segments successfully visualized within 30 minutes. A count can be informative when the question concerns how many anatomical units meet a defined observation criterion. Its meaning depends on how “successfully visualized” is operationalized and how counts are recorded. The registry description refers to short-axis views of thoracic spinal cord segments and surrounding structure, but does not give further scoring rules. Such details are important for assessing reproducibility and understanding whether assessors could classify views consistently.
The time frame is part of the endpoint definition: the count pertains to visualization within 30 minutes. It does not, by itself, explain when that period began or how the observation was conducted. Those procedural details are not reported in the registry record. The record also does not specify whether multiple views or repeated assessments were handled in a particular way. These omissions limit assessment of the endpoint’s measurement process; they do not change the stated outcome definition.
What does an observational design imply?
In general, observational studies describe measurements without randomized assignment to competing interventions. A comparison between groups in such a study can reflect differences in characteristics or circumstances beyond the group label. Randomization is one method for balancing such factors on average, but the record does not describe randomized allocation. It says allocation was not stated and that the age groups are not a like-for-like control comparison. The two groups should therefore be read as descriptive categories rather than as treatment and control arms.
The record does not report an adjusted analysis or a model that accounts for differences between groups. Nor does it give an analysis plan from which the intended comparisons, assumptions, or handling of covariates could be assessed. The listing of one outcome measure and zero analyses means that no analysis results are presented in this registry record. It is not possible to infer which statistical tests, if any, were used outside the registry record.
How should planning calculations be separated from study results?
The record describes a planning illustration based on the observed effect. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For time-to-event settings, the described convention is a total number of events using Schoenfeld; for other settings, the convention is participants per arm.
These are planning assumptions, not evidence that the study was designed with those assumptions and not a report of observed power. In general, a planning calculation asks what sample size would be required under specified assumptions to detect a target effect with a chosen probability. Such an illustration depends on the effect used and other assumptions. It does not show that a completed study had that probability of detecting an effect, and it does not replace the effect estimate, its uncertainty, or a transparent account of the analysis.
Here, the numerical primary outcome result is not reported in the registry record, so the observed effect cannot be evaluated from the record. The stated planning framework can be described, but no conclusion about the adequacy of the actual enrollment or the precision of the primary estimate follows from it. The record also does not report a sample-size justification as part of the study’s own design.
What information would support a fuller statistical reading?
In general, interpreting a clinical study requires knowing the analyzed population, outcome data available, missing-data handling, and analysis methods. For an observational visualization study, clear group definitions and outcome-scoring procedures would also help assess comparability and measurement. The registry record does not report these details. Without the numerical outcome and the analysis information, statistical interpretation remains limited to the registered design and endpoint definition.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure and zero analyses. It does not report a multiplicity strategy, such as how inference would be controlled if several outcomes, subgroups, or comparisons were examined. With no analysis results listed, it is not possible to determine whether any multiplicity adjustment was used elsewhere or whether the primary outcome was treated as the sole inferential focus.
In general, multiplicity arises when many statistical questions are examined. Testing several hypotheses can increase the chance of obtaining an apparently unusual result by chance, so an analysis plan may define which outcomes and comparisons are primary and whether adjustment is appropriate. That general concern should not be mistaken for evidence that multiple analyses occurred in this study: the registry record lists zero analyses, and it does not provide an analysis plan.
Missing-data handling is not reported in the registry record. The record does not state whether all enrolled participants contributed to the primary outcome, how an unavailable or unreadable view was treated, or whether any observations were excluded. Consequently, the registered enrollment of 75 should not be assumed to be the endpoint analysis population. The number with usable outcome data and the reasons for any missing observations are not reported in the registry record.
The analysis population is also not described for the primary outcome. In general, a clearly defined analysis population identifies which participants contribute to an estimate and how departures from the intended measurement process are handled. The registry record does not specify this. It also does not report a statistical analysis plan, covariate adjustment, or procedures for handling incomplete observations. These omissions prevent assessment of whether the reported population, if results were available, would match the enrolled population or how missing information might affect interpretation.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Pediatric Group | 0 | 50 | 0.0% |
| Adult Group | 0 | 25 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pediatric Group | 0 of 50 |
| Adult Group | 0 of 25 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Pediatric Group | 0 of 50 |
| Adult Group | 0 of 25 |
The registry record reports safety counts separately for the pediatric and adult groups. In the pediatric group, 50 were listed as at risk for serious adverse events and 0 as affected; 50 were listed as at risk for other adverse events and 0 as affected; deaths were 0. In the adult group, 25 were listed as at risk for serious adverse events and 0 as affected; 25 were listed as at risk for other adverse events and 0 as affected; deaths were 0. No serious adverse-event terms are listed.
These are registry-reported counts, not estimates of the chance of an event under a controlled comparison. A zero affected count means that no events were recorded in the listed safety fields for the group; it does not establish that the underlying risk is zero. The record does not describe the duration or completeness of safety surveillance, event-collection procedures, or whether all participants were assessed in the same way.
The age groups are not randomized comparator groups, and the registry record says they are not a like-for-like control comparison. The counts therefore do not show comparative safety between assigned interventions. They also do not address events that may not have been captured or reported. The figures should be read narrowly as the safety information entered in the registry record, not as proof of absence of risk.
12. What the Result Does, and Does Not, Mean
The record documents a prospective observational study examining the use of TEE to visualize structures within the vertebral foramen. It defines a primary outcome based on the number of thoracic spinal segments successfully visualized within 30 minutes and specifies a median and inter-quartile range as the summary. Those details clarify what the investigators set out to measure.
What the record does not establish is the observed endpoint result. The median and inter-quartile range are not reported in the registry record, and no analyses are listed. As a result, the record cannot show the number of segments typically visualized, the variability in those counts, or how precisely either quantity was estimated. The missing numerical result should not be interpreted as a positive or negative finding.
The study’s age-based groups do not provide a randomized control comparison. The record explicitly says allocation was not stated and that the groups are not a like-for-like control comparison. Therefore, the design as registered does not support attributing group differences to age or to any cause without further information and appropriate analysis. The endpoint description alone cannot answer whether visualization differed between groups.
The safety entries report zero affected participants in the serious and other adverse-event fields for both groups, and zero deaths. These registry counts describe what was recorded; they do not establish that no risk exists or provide a controlled safety comparison. Details about the safety-monitoring period and event ascertainment are not reported in the registry record.
In general, a study’s statistical interpretation depends on both the outcome estimate and its uncertainty, along with a clear account of the population and analysis. Those elements are not available for the primary outcome in this record. Accordingly, the defensible conclusion is limited: the registry records the study’s objective, observational design, and endpoint definition, but does not report the numerical result needed to quantify its findings.
13. Why This Trial Matters Statistically
This study is statistically notable because its central question is one of measurement and visualization rather than a randomized comparison of treatments. The registered endpoint is a count of thoracic segments visualized within a defined time frame. That makes the quality and consistency of outcome measurement central to interpretation: readers need to know not only what was counted, but how successful visualization was determined and how consistently it was assessed.
The record does specify a median and inter-quartile range, a combination that describes both the center and spread of a distribution. This is a useful descriptive framework for a count whose distribution may not be well represented by a mean alone. However, selecting an appropriate summary does not substitute for reporting its values. Because the numerical endpoint result is not reported in the registry record, the intended descriptive approach cannot be used to assess the observed data.
The study also illustrates why age-group comparisons require caution. The groups are observational and are explicitly not described as like-for-like controls. Without random assignment or an analysis accounting for relevant differences, a group contrast would not by itself identify the reason for any difference. The registry record does not report such an analysis.
Finally, the record distinguishes planning assumptions from the study’s own design and outcomes. A planning illustration based on an observed effect is not observed power and does not reveal how precisely the primary outcome was estimated. Statistical interpretation depends on the actual outcome data, defined analysis population, and methods used. The registry record’s lack of endpoint values and analyses makes these limits especially important when drawing conclusions from the registered description alone.
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 this registry record is that it does not report the numerical result for its primary endpoint. Although the endpoint and its intended summary are specified, the median and inter-quartile range are absent. The record also lists zero analyses, leaving no reported inferential or descriptive analysis results to assess.
The study is observational, and the listed age groups are not like-for-like control groups. Allocation is not stated. This design does not support treating the groups as randomized arms, and the record does not describe an adjusted comparison that might address differences between them. The age descriptions also overlap at age 18: the pediatric group is described as “Age 0 - 18,” while the adult group is described as “Age 18 plus.” How that boundary was applied is not reported in the registry record.
The endpoint description does not give detailed criteria for a successful view or describe assessor procedures. The record does not state how unreadable images, incomplete visualization, or missing outcome observations were handled. It also does not identify the number of participants contributing to the endpoint analysis or define the analysis population. These gaps limit evaluation of measurement consistency and the extent to which the endpoint reflects the registered enrollment.
Other design and analysis details, including eligibility criteria, a statistical analysis plan, missing-data methods, multiplicity procedures, and any covariate adjustment, are not reported in the registry record. The recorded safety counts have no accompanying description of surveillance duration or event ascertainment. These are limits of what can be interpreted from the registry record; they do not establish how the study was conducted beyond the details it records.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Transesophageal Echocardiography (TEE): A Novel Technique for Spinal Cord Imaging — NCT02415244.
- Registry record last updated 2020-01-22; status last verified 2020-01.
- Results first posted 2019-10-23.
- 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.
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18. Record Summary
NCT02415244 is a completed prospective observational study of TEE for spinal cord imaging. Its stated aim is to assess identification of structures within the vertebral foramen and the range of spinal segments that can be visualized. Enrollment is listed as 75, with age-based pediatric and adult groups. The primary endpoint is the number of thoracic spinal segments successfully visualized within 30 minutes, summarized by a median and inter-quartile range.
The registry record does not report the endpoint’s numerical result and lists zero analyses. It states that allocation was not stated and that the groups are not a like-for-like control comparison. Safety entries record zero affected for serious and other adverse events in both groups and zero deaths. The record does not report the analysis population, missing-data handling, or statistical analysis plan. Accordingly, it documents the study question and design but does not provide the numerical primary result needed to judge the extent or precision of visualization.