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 Simple Non-invasive Breathing Device to Improve Pulmonary Flow Pusatility in Single Ventricle Post Fontan (NCT05634226), a na na study. The primary outcome is Change in Pulmonary Pulsatility Index.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05634226 |
| Phase | NA |
| Condition | Single-ventricle |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 15 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Tarek Alsaied |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes patients with single-ventricle conditions who have Fontan palliation. Enrollment was 15. Further eligibility details and characteristics of the enrolled participants are not reported in the registry record, so the population cannot be described more specifically from this record.
Intervention
The intervention was a hands-free oral-positive pressure device, identified as oPEP. The study summary describes participants being shown how to use it, using it after their clinical echocardiogram, and then being asked to use it at home 3-4 times a day for 10-15 mins before returning for another echocardiogram approximately 4 weeks later.
Comparator
This was a single-group study, not a randomized comparison. The planned comparison is within participants: the enrollment echocardiogram is compared with an echocardiogram after 4 week use of the device. There is no separate control group described in the registry record.
Primary question
The primary question is whether pulmonary artery pulsatility, measured by the Pulmonary Artery Pulsatility Index (PAPI), changes between enrollment and the echocardiogram after device use. The registry describes the measurement and timeframe, but the outcome values and estimated change are not reported in the registry record.
This design can describe changes observed over time among participants with measurements at both time points, if such paired results are available. Without a concurrent control group, however, a change cannot by itself establish that device use caused it. Other influences, including ordinary variation in measurements over time, cannot be separated from an intervention effect using a single-group comparison alone.
3. Trial Design
This is a completed pilot study with a single-group model. The registry lists enrollment of 15 and an oral-positive pressure device as the intervention. Allocation is listed as NA, and masking is listed as none. The record does not describe a randomized assignment or a separate control arm, so the design is best understood as a before-and-after assessment in the enrolled group rather than a controlled treatment comparison.
The study summary describes an enrollment echocardiogram, instruction in use of the device, and use after the clinical echocardiogram at the clinic appointment. Participants were then asked to use the device at home 3-4 times a day for 10-15 mins and return in approximately 4 weeks for another echocardiogram using the same measurements. The primary endpoint timeframe is described as the change between the enrollment echocardiogram and the echocardiogram after 4 week use of the device. Whether every participant completed both assessments is not reported in the registry record.
The study dates are listed as starting 2023-08-01 and reaching primary completion on 2024-01-31; its status is completed. The phase is listed as NA. The sponsor is Tarek Alsaied. These registry entries describe the study’s administrative design and timing, but do not supply a statistical analysis plan or outcome estimates.
The within-person structure can account for stable differences between participants when paired measurements are analyzed, because each participant’s later value is compared with their own enrollment value. It does not control for changes over time that would also have occurred without the device, nor for measurement variation or other time-varying influences. Consequently, any observed change would be descriptive of this group over the study period unless supported by additional evidence. The registry record does not report the primary outcome results, the number of paired observations, or whether analyses used all enrolled participants.
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 | Hands-free Oral-positive Pressure Device (oPEP) |
|---|---|
| STARTED | 15 |
| COMPLETED | 11 |
| NOT COMPLETED | 4 |
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 | Hands-free Oral-positive Pressure Device (oPEP) |
|---|---|---|
| Participants analysed | 15 | |
| Age, Continuous | years | 19.9 (SD 8.7) |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 13 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 15 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 15 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Pulmonary Pulsatility Index, measured over The change is between enrollment echocardiogram and echocardiogram after 4 week use of the device.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Ratio |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in Pulmonary Artery Pulsatility Index (PAPI), a ratio derived from pulmonary artery velocities measured by echocardiography with Doppler evaluation. The registry defines PAPI as (Systolic Velocity - Diastolic Velocity) /Mean Velocity. The stated timeframe compares the enrollment echocardiogram with an echocardiogram after 4 week use of the device.
PAPI expresses the difference between systolic and diastolic pulmonary artery velocity relative to mean velocity. As a ratio, it is intended to represent pulsatility in the measured pulmonary artery flow rather than simply reporting one velocity alone. The registry identifies the endpoint’s unit as a ratio and describes the primary outcome parameter as a mean, with standard deviation as the dispersion measure.
In general, an endpoint of this kind gives investigators a defined quantity to compare across measurement occasions. Using echocardiographic Doppler measurements makes the endpoint relevant to the study’s stated focus on flow pulsatility in the Fontan circuit. The registry summary also describes assessment of pulsatility in other parts of the circuit and aortic blood flow measurements, but the designated primary endpoint is change in PAPI.
The record does not report the enrollment or follow-up PAPI values, the mean change, its variability, or an uncertainty interval. Thus, the endpoint definition and planned comparison can be described, but the magnitude, direction, and precision of the observed change cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive limitation is that the registry record describes the primary endpoint but does not report its numerical results. There is no posted mean PAPI at enrollment or follow-up, no estimated mean change, and no reported confidence interval or test result. It is therefore not possible to state whether the measured index increased, decreased, or remained similar, or to assess how precisely any estimated change was measured.
The study is listed as completed, with enrollment of 15, but completion status is not itself evidence of a particular outcome. Likewise, the planned schedule of an enrollment echocardiogram and another examination after approximately 4 weeks describes the measurement plan, not the measurements actually obtained. The number of participants with usable paired measurements and the handling of incomplete measurements are not reported in the registry record.
Even if a before-and-after change were reported, its interpretation would be limited by the single-group design. A paired comparison can describe how values changed among participants who were measured at both times, but it cannot distinguish a device-related effect from temporal changes, measurement variability, or other influences that were not controlled by a concurrent comparison group. The absence of masking, listed as NONE, is another design detail to consider when interpreting an echocardiographic outcome; the registry record does not describe procedures to reduce measurement or assessment bias.
In general, an estimate should be read together with its uncertainty. A confidence interval describes a range of values compatible with the data and analysis under the method used; it does not show that all values in that range are equally likely or establish causation. No such interval is reported for this endpoint in the registry record. A p-value, if available, would address compatibility with a specified statistical model and null hypothesis, not the size or practical importance of a change. No primary-outcome p-value or analysis method is reported.
The record’s description of this study as a pilot is consistent with treating it as an exploratory assessment rather than a definitive controlled comparison. But the protocol’s objectives beyond the summary, the planned statistical analysis, and any criteria for interpreting a meaningful change are not reported in the registry record. Consequently, the available information supports description of the trial design and endpoint, but not a conclusion about the observed effect or its precision.
9. Statistical Methods Explained
The primary measure is continuous: PAPI is calculated from Doppler-derived pulmonary artery velocities and is recorded as a ratio. The registry specifies a mean as the outcome parameter and standard deviation as the dispersion measure. In general, a mean describes the center of a set of measurements, while the standard deviation describes how spread out individual values are around that center. Neither statistic is reported as an outcome value in the registry record for this study.
What does a paired comparison represent?
The endpoint timeframe compares an enrollment echocardiogram with an echocardiogram after 4 week use of the device. In a paired analysis, each participant’s measurement at one time is linked to that same participant’s measurement at the other time. The analysis can then estimate the average within-person change among participants with both measurements. This differs from treating the enrollment and follow-up observations as unrelated groups, because the paired approach retains the connection between measurements from the same person.
Pairing can be useful when stable participant characteristics contribute to different starting values: the comparison focuses on change within each person rather than differences between people. It does not, however, provide the protection against time-related influences that a concurrent control group may offer. A before-and-after difference may reflect the intervention, but also ordinary temporal variation, measurement variability, changes in other circumstances, or a combination of these. The single-group design cannot separate those explanations on its own.
How should uncertainty be considered?
In general, a confidence interval communicates uncertainty around an estimated quantity, such as a mean change. A narrower interval indicates greater precision under the assumptions of the analysis; a wider interval indicates less precision. The interval should be considered alongside the point estimate and the design, not as proof that an effect is causal. The registry record does not report a confidence interval for the primary endpoint, and it does not identify the inferential method used to calculate one.
A standard deviation and a confidence interval answer different questions. The standard deviation describes variability among measurements, whereas a confidence interval describes uncertainty in an estimate. The registry lists standard deviation as the dispersion measure, but no result-level standard deviation is reported. The record also does not report the distribution of individual changes, which would help readers understand whether a group mean reflects broadly similar changes or varied individual responses.
What analysis details are missing?
The statistical analysis plan is not reported in the registry record. In particular, the record does not specify whether the primary analysis was intended to use paired differences, how missing follow-up measurements would be handled, whether the analysis would adjust for any covariates, or what inferential test would be used. These details matter because they determine which participants and observations contribute to an estimate and how its uncertainty is calculated. The registry also does not state whether assumptions for a particular statistical method were assessed.
In general, continuous measurements can have unequal variability or a distribution that differs from the assumptions of a simple normal model. When observations are more variable than a model allows, standard errors can be understated and uncertainty can appear too small; this is one reason to assess model fit and distributional assumptions. This is a general statistical consideration, not a claim about the distribution of PAPI in this study. The registry record does not report diagnostics or alternative analyses.
The record lists two outcome measures and two analyses, but does not describe a multiplicity strategy or explain how those analyses relate to the primary endpoint. When multiple outcomes or tests are considered, the chance of at least one apparently unusual result can increase if each is interpreted independently. In general, a prespecified hierarchy or adjustment can help define how evidence across outcomes is interpreted. Whether such an approach was planned or used is not reported in the registry record.
How do the planning calculations fit?
The sample-size assumptions describe a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The assumed effect is expressed as a stated fraction of the observed effect; the corresponding rows are planning for a fraction of that effect. Such calculations are planning illustrations, not observed power and not evidence that the study had a particular probability of detecting an effect.
Those stated assumptions use equal allocation between two arms, while the trial is listed as single group with no randomized comparison. The two-arm planning framework therefore does not describe the trial’s actual design. The record does not report the trial’s own sample-size justification or explain how the planning illustration was intended to apply. No numerical planning result is needed to interpret the primary endpoint, and no planning calculation substitutes for the missing observed outcome estimate.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures and two analyses, but it does not describe how the primary and secondary outcomes were organized statistically. A multiplicity plan—such as a prespecified hierarchy for testing outcomes or an adjustment for multiple tests—is not reported in the registry record. In general, when several outcomes or analyses are examined, interpreting each test in isolation can make an apparently unusual result more likely to arise by chance. The importance of this issue depends on which outcomes were tested, how they were selected, and what conclusions were intended; those details are not reported.
The primary endpoint is identified as change in PAPI, while Aortic Valve VTI is listed as a secondary outcome. The registry does not provide results for either outcome or clarify whether the two analyses correspond exactly to these measures. No statistical analysis plan is reported, so the method used to estimate change, test hypotheses, or control multiplicity cannot be assessed.
Missing-data handling and analysis populations are also not reported in the registry record. It does not state how many participants completed the follow-up echocardiogram, how many had evaluable measurements at both time points, or how missing or unusable measurements would be treated. The record lists enrollment of 15, but that does not establish how many observations contributed to any outcome analysis. It also does not identify an intention-to-treat or other analysis population.
In general, missing follow-up measurements can affect an estimate if participants with missing data differ in relevant ways from those with complete measurements. The extent and direction of any such effect depend on the amount and pattern of missingness and on the assumptions of the analysis. Since those details are absent, the robustness of any outcome estimate cannot be evaluated from the registry record.
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 |
|---|---|---|---|
| Hands-free Oral-positive Pressure Device (oPEP) | 0 | 15 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Hands-free Oral-positive Pressure Device (oPEP) | 0 of 15 |
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 |
|---|---|
| Hands-free Oral-positive Pressure Device (oPEP) | 0 of 15 |
The registry reports safety figures for the hands-free oral-positive pressure device group. The number listed at risk is 15 for serious adverse events and 15 for other adverse events. The number affected is 0 for serious adverse events and 0 for other adverse events; deaths are listed as 0. These are the event counts recorded for the reported group.
Zero reported affected participants should be read narrowly: no serious or other adverse events are recorded as affecting participants in these registry figures. It does not establish that an adverse event is impossible or that there is no risk. In general, a study with limited enrollment may not detect uncommon events, and interpretation also depends on how events were defined, collected, and reported. Those monitoring and reporting details are not reported in the registry record.
The figures do not provide event descriptions beyond the absence of reported events, and no serious adverse event terms are listed. They also do not explain the observation period used for safety assessment or whether the listed at-risk group represents everyone who received the device. The record’s safety figures should therefore be treated as a concise report of recorded events, not as a comprehensive characterization of safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed single-group pilot study was designed to assess change in pulmonary artery pulsatility index after use of a hands-free oral-positive pressure device. It defines the primary measure, its Doppler basis, and the intended comparison between an enrollment echocardiogram and one after 4 week use. It also records enrollment of 15 and reports zero affected participants for both serious and other adverse events in the device group.
The record does not report the primary endpoint results. There is no estimated change, no measure of its uncertainty, and no result from which to assess direction or magnitude. The study’s completed status cannot fill that gap. Nor can the study objective or proposed mechanism be treated as evidence that the device changed flow pulsatility or cardiac output.
Even with outcome results, a before-and-after comparison in a single group would describe change over time rather than isolate a causal effect. Without a concurrent control group, a change could reflect the device or other time-varying influences. The record does not report enough information about the analysis population, missing measurements, or statistical methods to judge how an estimate would have been produced.
In general, statistical significance and clinical importance are not interchangeable. A p-value, if reported, would not alone establish the size, relevance, or cause of a change; an estimate and its uncertainty would also be needed. No threshold for a clinically important PAPI change is reported in the registry record. It is therefore not possible to assess whether any observed change would be meaningful to patients or clinicians.
The appropriate interpretation is limited to what the record documents: the study question, single-group design, endpoint definition, follow-up plan, and posted safety counts. The registry record does not provide outcome evidence to support a conclusion about the effect of device use.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how a pilot study can define a measurable physiologic question without establishing a controlled treatment effect. The registry specifies a continuous primary endpoint, PAPI, and a within-person comparison between enrollment and follow-up echocardiography. That makes the intended quantity of interest clear: change in a Doppler-derived ratio over the device-use period.
The single-group design also makes the limits of interpretation especially important. Repeated measurements can describe temporal change, but do not distinguish intervention effects from other influences over time. The lack of a separate comparator is therefore central when interpreting any before-and-after result—not a technical detail that can be resolved just by calculating a more precise mean.
The registry record further illustrates why a defined endpoint and completed status are not substitutes for posted results. It includes the endpoint formula, timing, enrollment, and safety counts, but does not report the estimated PAPI change or its uncertainty. Without those results, readers cannot assess the observed direction, magnitude, or precision of the primary outcome.
Finally, the record’s planning assumptions describe equal allocation between two arms even though the trial is listed as single group. This difference emphasizes the need to distinguish illustrative sample-size calculations from a study’s actual design and analysis. Such calculations are not observed power, and a planning framework that does not match the trial structure cannot be interpreted as a direct description of the trial’s evidence.
The statistical value of this record lies in clarifying the question and the limits of what is reported. It does not provide the outcome estimates needed to judge the study’s measured change.
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.
Several limitations specific to this study constrain interpretation. First, the registry lists a single-group design with no randomized comparison. The planned enrollment-to-follow-up comparison can describe within-group change, but cannot separate the device’s contribution from other changes over time. Masking is listed as none, and the record does not describe whether echocardiographic assessments were conducted or interpreted by assessors unaware of measurement timing.
Second, the primary endpoint results are not reported in the registry record. The mean change, variability, confidence interval, and test result are unavailable, as are the enrollment and follow-up values. The number of participants with paired measurements and the approach to missing data are also not reported. Enrollment of 15 should not be taken as the number analyzed.
Third, the record does not report the statistical analysis plan, outcome definitions beyond the PAPI formula, assessment procedures, or any threshold for a meaningful change. The record lists a secondary outcome, Aortic Valve VTI, but does not report its results or how it was handled in relation to the primary outcome.
Finally, the planning assumptions use an equal-allocation, two-arm framework, while the study is identified as single group. The registry does not explain this difference or report the study’s own sample-size justification. These limitations mean that the record supports a description of the intended study and reported safety counts, but not a quantitative assessment of the primary outcome or a causal conclusion.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Simple Non-invasive Breathing Device to Improve Pulmonary Flow Pusatility in Single Ventricle Post Fontan — NCT05634226.
- Registry record last updated 2025-02-10; status last verified 2025-01.
- Results first posted 2025-02-10.
- 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.
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18. Record Summary
The registry describes a completed pilot study of a hands-free oral-positive pressure device in patients with single-ventricle Fontan palliation. Enrollment was 15. The study is listed as single group, with allocation NA and masking NONE.
The primary endpoint is change in Pulmonary Artery Pulsatility Index, calculated from Doppler-derived pulmonary artery velocities. The stated comparison is between the enrollment echocardiogram and an echocardiogram after 4 week device use. The study summary describes home use 3-4 times a day for 10-15 mins and return in approximately 4 weeks.
The registry record does not report the primary or secondary outcome results, the number analyzed, or the statistical analysis plan. Safety figures list 0 affected participants for serious adverse events, 0 for other adverse events, and 0 deaths in the device group. These figures do not establish absence of risk.