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 NMES in HF Patients to Improve Functional Recovery Following Hospitalization (NCT05338437), a randomized na study. The primary outcome is 6 Minute Walk Distance (6MW).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05338437 |
| Phase | NA |
| Condition | Heart Failure With Preserved Ejection Fraction |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Vermont Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
People hospitalized with heart failure with preserved ejection fraction (HFpEF). The study concerns functional recovery after discharge. The registry record does not give additional eligibility details or describe the characteristics of enrolled participants.
Intervention
Neuromuscular electrical stimulation (NMES) of the quadriceps, described as 45 minutes per session, 5 days per week. The study summary describes an at-home program continuing for 4 weeks following hospital discharge.
Comparator
A no-treatment control group. The registry record describes the trial as randomized and parallel, with no masking.
Primary question
How did six-minute walk distance change between hospital discharge, measured within 1 day, and 4 weeks after discharge in the NMES and control groups? This is a question about measured functional change over the stated follow-up interval. The registry record reports group summaries, but no statistical comparison of the groups.
3. Trial Design
The registry record describes a randomized, parallel-group trial with no masking. It lists 8 participants enrolled and a completed study. The condition is heart failure with preserved ejection fraction. The intervention is neuromuscular electrical stimulation of the quadriceps, compared with a no-treatment control. The study summary describes an at-home program intended to begin after hospitalization and continue for 4 weeks following discharge.
The primary outcome was change in six-minute walk distance, measured from hospital discharge within 1 day to 4 weeks after discharge. The outcome is expressed in feet. For that primary result, the registry lists 3 participants in the stimulation group and 4 in the control group. These outcome counts do not add to the listed enrollment of 8; the reason for the difference is not reported in the registry record. The outcome counts should therefore be read as the numbers contributing to the posted group summaries, not as a complete account of participant flow.
The record lists the study as completed, with a start date of 2022-02-07 and a primary completion date of 2023-09-30. It also lists 41 outcome measures and 40 posted secondary outcomes. Named secondary measures include the Short Physical Performance Battery, the Katz Index of Independence in Activities of Daily Living, the Lawton Instrumental Activities of Daily Living Scale, and items from the Medical Outcomes Short Form 36. The registry record lists no statistical analyses for the outcomes. Details such as allocation concealment, the randomization procedure, the protocol’s planned analysis, and the reasons for any difference between enrollment and outcome counts 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 | Neuromuscular Electrical Stimulation | Control |
|---|---|---|
| STARTED | 4 | 4 |
| COMPLETED | 3 | 4 |
| NOT COMPLETED | 1 | 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 | Neuromuscular Electrical Stimulation | Control | Total |
|---|---|---|---|---|
| Participants analysed | 4 | 4 | 8 | |
| Age, Continuous | years | 80 (72 to 89) | 75.5 (70 to 79) | 76.1 (70 to 89) |
| Sex: Female, Male: Female | Participants | 3 | 2 | 5 |
| Sex: Female, Male: Male | Participants | 1 | 2 | 3 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: United States | participants | 4 | 4 | 8 |
6. Primary Endpoint
The registry lists the primary outcome as 6 Minute Walk Distance (6MW), measured over Change from Hospital Discharge (Within 1 day) to 4-weeks post-discharge.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | feet |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is change in six-minute walk distance from hospital discharge, measured within 1 day, to 4 weeks after discharge. Participants walk around a standard course for 6 minutes, and the distance covered is recorded in feet. The registry description says this test was developed to assess cardiopulmonary fitness in people with lung and cardiac disease and has been validated in heart failure patients.
Walking distance is a functional measure: it captures how far a participant can walk during a set period rather than relying only on a report of symptoms or a laboratory measure. Assessing change between discharge and follow-up makes the endpoint relevant to the study’s focus on recovery after hospitalization. It does not, by itself, identify why a participant’s distance changed, and a group average cannot describe every participant’s experience.
The registry reports a mean change and the full range of observed changes for each group. The stimulation group’s mean change was 211.3 feet, with a full range from 75.0 to 384.0. The control group’s mean change was 61.5 feet, with a full range from -192.0 to 301.0. These are descriptive summaries. No standard deviation, confidence interval, or inferential comparison is reported for this endpoint in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome is descriptive. The registry reports a mean change in six-minute walk distance of 211.3 feet for the neuromuscular electrical stimulation group and 61.5 feet for the control group. The reported full ranges are 75.0 to 384.0 feet and -192.0 to 301.0 feet, respectively. The ranges overlap, and the control range includes both decreases and increases in walking distance. These group summaries show variation among the reported participant changes; they do not establish the size or uncertainty of a treatment effect.
The outcome counts are 3 in the stimulation group and 4 in the control group. Such small groups make descriptive summaries highly sensitive to the values of individual participants. A mean can move substantially when a single observation changes, and the full range gives only the lowest and highest values, not the distribution of values between them. The registry does not report standard deviations or other measures of spread beyond the ranges. It also does not report confidence intervals or a p-value for the primary comparison.
There are no posted analyses in the registry record. Consequently, the available statistics do not quantify the uncertainty around the difference between group outcomes or provide a formal test of a group contrast. The numerical contrast between the two reported means should not be treated as a calculated treatment effect or as evidence of statistical significance. No such contrast is calculated in the registry record. The primary outcome results are best read as the observed group-level summaries for the participants with outcome data.
The study’s randomized design is relevant to how a comparison could be interpreted, but randomization alone does not supply the missing analysis or its uncertainty. The record does not report the randomization method, allocation concealment, baseline outcome values by arm, or an adjusted analysis. It is also not reported why the primary outcome counts differ from the enrolled total. Without those details, the group summaries cannot show whether the observed changes reflect a treatment contrast, differences already present at discharge, chance variation, or other factors.
The listed secondary outcomes broaden the study’s measurement of function, independence, and health-related quality of life. However, the registry record reports no outcome analyses for them. The presence of multiple outcome measures also makes it important to know which outcomes and comparisons were planned as primary, how missing observations were handled, and whether any adjustment for multiple testing was intended. Those details are not reported. The primary result therefore offers a small descriptive account of walking-distance change, not a conclusive estimate of a group effect.
9. Statistical Methods Explained
What do the group summaries describe?
A mean is the arithmetic average of the participant values included in a group summary. Here, the reported means describe change in walking distance from discharge to four weeks after discharge. A positive value indicates an increase in distance over that interval, while a negative value indicates a decrease. The stimulation group mean is 211.3 feet and the control group mean is 61.5 feet. These means summarize the participants with posted outcome values; they are not individual results and do not show how many participants improved or declined.
The registry gives the full range for each group: the smallest and largest observed changes. For the stimulation group the range is 75.0 to 384.0 feet, and for the control group it is -192.0 to 301.0 feet. A range conveys the span of values but does not show the pattern of observations within it. It also does not indicate how precisely the group mean estimates a broader population mean. The registry does not report a standard deviation or another summary that describes the typical distance of observations from the mean.
What would an inferential comparison add?
An inferential comparison would estimate how compatible the observed group difference is with uncertainty from sampling. A confidence interval is a range of values constructed by a statistical procedure to express uncertainty around an estimate. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. A p-value, when calculated under a specified statistical model, describes how unusual data at least as extreme as those observed would be if a defined null hypothesis were true. Neither measure alone establishes clinical importance or removes concerns about trial design and data quality.
No confidence interval, p-value, or formal primary group comparison is reported in the registry record. The registry lists 0 analyses. Therefore, the means and ranges should not be read as an inferential result, and the numerical difference between the means should not be assigned a precision or significance that was not reported.
Why does the small outcome count matter?
The primary outcome summaries include 3 participants in the stimulation group and 4 in the control group. With so few observations, each participant’s value has substantial influence on the mean and on the range. Randomization is a method for reducing systematic differences between groups on average, but small randomized groups can still have important chance imbalances. The record does not report baseline walking-distance summaries or other baseline characteristics that would allow those features to be examined.
Small samples also limit the information available about the shape and variability of outcome distributions. A full range is especially dependent on the most extreme values and can change when one participant’s result changes. General statistical practice may use different methods depending on the outcome distribution and design; the analysis method for this endpoint is not reported in the registry record. No assumption about the distribution or a particular test should be inferred from the descriptive statistics alone.
What do the planning assumptions mean?
The planning illustration is described as using the observed effect, a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It is an illustration for planning, not evidence of the study’s achieved power. Sample-size calculations based on an observed effect are sensitive to that effect estimate, particularly when it comes from a very small sample. They do not replace a prospective design justification, and they do not show that the trial had a particular probability of detecting an effect.
The registry record does not report the trial’s own sample-size justification, the effect it was designed to detect, or a planned power target. The stated planning assumptions do not establish that those assumptions were used in the trial design. The normal approximation is an assumption for the illustration, not a statement that the outcome data follow a normal distribution. Any numeric planning target should be understood as a planning scenario rather than an observed trial result.
Why do outcome and analysis counts need context?
The record lists 8 participants enrolled, while the posted primary outcome summaries include 3 participants in one arm and 4 in the other. The reason for this difference is not reported in the registry record. The listed outcome counts therefore do not establish whether the remaining enrolled participant lacked a measurement, was excluded under a planned rule, or had another status. Those possibilities should not be guessed.
Likewise, randomized allocation does not reveal whether the reported summaries include all randomized participants, only participants with complete measurements, or another analysis population. The statistical analysis plan and analysis population are not reported. The record also does not specify how missing measurements, protocol deviations, or withdrawals were handled. These details affect the meaning of an estimate and the population to which it might apply.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 41 outcome measures and 40 posted secondary outcomes. The named secondary measures include physical performance, activities of daily living, instrumental activities of daily living, and multiple Medical Outcomes Short Form 36 items. This broad set of outcomes may describe different aspects of function and health-related quality of life, but the registry record lists no analyses for these outcomes.
When a study evaluates multiple outcomes or comparisons, the chance of at least one apparently unusual result can increase if each is tested separately at a conventional threshold. General statistical approaches can define a primary outcome in advance, control family-wise error, or use other procedures suited to the study’s aims. The registry record does not report a multiplicity strategy, a hierarchy for secondary outcomes, or which outcomes were prespecified for formal testing. Since there are no posted analyses, no correction or unadjusted testing results can be assessed.
The record does not describe missing-data methods, participant flow by analysis population, or whether the primary summaries are based on all randomized participants. Enrollment is 8, while the primary outcome counts are 3 and 4; the reason for the discrepancy is not reported in the registry record. There is also no reported account of withdrawals, exclusions, or incomplete measurements. It is therefore not possible to determine from the posted record how missing outcomes affected the estimates or whether an intention-to-treat population was used.
Details of interim analyses, protocol deviations, and the statistical analysis plan are not reported in the registry record. Their absence from the record should not be interpreted as evidence that a particular procedure was or was not used.
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 |
|---|---|---|---|
| Neuromuscular Electrical Stimulation | 0 | 4 | 0.0% |
| Control | 0 | 4 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Neuromuscular Electrical Stimulation | 0 of 4 |
| Control | 0 of 4 |
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 |
|---|---|
| Neuromuscular Electrical Stimulation | 0 of 4 |
| Control | 0 of 4 |
The registry reports serious adverse events for 0 of 4 participants at risk in the neuromuscular electrical stimulation group and 0 of 4 participants at risk in the control group. It reports other adverse events for 0 of 4 participants at risk in each group, and deaths for 0 participants in each group. No serious adverse-event terms are listed.
These are event counts in the recorded safety groups, not estimates of the probability of an event in a wider population. With 4 participants at risk per group, the absence of a reported event provides limited information about uncommon or less frequent harms. The safety denominators differ from the primary outcome counts, which are 3 in the stimulation group and 4 in the control group. The registry does not explain the difference. It also does not report additional details on the duration or completeness of adverse-event monitoring, event definitions, or severity categories beyond the listed serious and other adverse-event counts.
Accordingly, the posted figures describe what was recorded for these small groups during the study. They should not be interpreted as establishing that an intervention is free of risk or as a comparative safety analysis.
12. What the Result Does, and Does Not, Mean
The registry record provides a limited descriptive account of change in six-minute walk distance after hospitalization for HFpEF. The reported mean change is 211.3 feet among 3 participants in the neuromuscular electrical stimulation group and 61.5 feet among 4 control participants. The full ranges show that participant changes varied within each group. These observations describe the reported sample and follow-up interval.
The results do not establish whether the observed group summaries reflect a reliable difference attributable to the intervention. There is no reported inferential comparison, confidence interval, or p-value. With only 3 and 4 participants contributing to the primary summaries, the group means are particularly sensitive to individual values. The record also does not explain the difference between the enrolled total and primary outcome counts or report whether baseline walking distance differed between groups.
The trial’s randomized structure is part of its design, but the available summary statistics do not show the randomization procedure or provide an analysis that accounts for uncertainty. The record does not report an adjusted result, an analysis population, or missing-data methods. The posted secondary outcomes are also not accompanied by statistical analyses in the registry record. As a result, readers cannot assess whether other functional measures support, differ from, or add context to the primary descriptive findings.
These results should be interpreted as early, small-sample observations rather than a definitive estimate of efficacy or safety. The safety record lists no serious or other adverse events and no deaths among the recorded groups, but the safety groups each include 4 participants at risk. Such counts cannot rule out events that were not observed in a small study. The registry record does not report a sample-size justification or formal statistical plan, so it is not possible to determine the study’s intended precision or inferential objectives from the posted results.
13. Why This Trial Matters Statistically
This trial raises several statistical issues that are common in studies of recovery after hospitalization. The clinical question concerns change over a defined interval, so interpretation depends on both the baseline measurement at discharge and the follow-up measurement. Reporting change in walking distance makes that interval explicit, but the registry provides only the group summaries for change, not baseline distributions or an adjusted analysis. Those additional details would help readers understand the starting values and evaluate whether the change summaries reflect comparable groups.
The very small outcome counts make precision central. Means can be calculated for a small group, but the existence of a mean does not mean it is estimated precisely. The reported ranges illustrate variation, yet they do not quantify uncertainty around the group means or a contrast. Without confidence intervals or a statistical comparison, the apparent separation between the reported means cannot be distinguished from chance variation using the information in the registry record.
The gap between enrollment and primary outcome counts is also important. Clear participant flow and an explicit analysis population are needed to understand who contributed to the estimates and how incomplete outcomes were handled. The registry record does not report the reason for the count difference. That limits assessment of possible bias from missing outcome data.
Finally, the record lists many outcome measures but no statistical analyses. A prospective analysis plan can make clear which outcomes are confirmatory, how multiple comparisons will be handled, and which methods will address missing data and uncertainty. Those plans are not reported in the registry record. This trial is statistically informative as an example of why descriptive results, precision, participant flow, and prespecified analysis details all matter when interpreting small randomized studies.
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 most immediate limitation is the small number of participants included in the primary outcome summaries: 3 in the neuromuscular electrical stimulation group and 4 in the control group. These counts make the mean and range vulnerable to the values of individual participants and provide little information about the broader distribution of responses. The registry reports a full range but no standard deviation, confidence interval, or inferential comparison.
The enrollment count is 8, whereas the primary outcome counts total 7. The reason for that difference is not reported in the registry record. No participant-flow information explains whether the difference is due to missing measurements, withdrawal, exclusion, or another reason. The analysis population and missing-data handling are also not reported, limiting assessment of potential bias.
The registry identifies a randomized, parallel, unmasked design, but does not report the randomization procedure, allocation concealment, baseline characteristics, or baseline six-minute walk distance by group. Without these details, the extent to which groups were comparable at the start of follow-up cannot be assessed from the posted record. The record also does not describe adherence to the stimulation schedule or the completeness of follow-up.
Although multiple secondary outcomes are listed, no analyses are posted, and the statistical analysis plan and approach to multiplicity are not reported. The trial’s sample-size justification is not reported in the registry record. Consequently, the intended precision, planned effect, and analysis strategy cannot be evaluated from the posted information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: NMES in HF Patients to Improve Functional Recovery Following Hospitalization — NCT05338437.
- Registry record last updated 2026-06-10; status last verified 2025-04.
- Results first posted 2026-06-10.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes NCT05338437, a completed randomized, parallel-group study of neuromuscular electrical stimulation in people with heart failure with preserved ejection fraction. The intervention was quadriceps stimulation, described as 45 minutes per session, 5 days per week, compared with a no-treatment control. The study summary describes an at-home program continuing for 4 weeks after hospital discharge.
The primary outcome was change in six-minute walk distance, in feet, from discharge within 1 day to 4 weeks after discharge. The posted mean changes were 211.3 feet for 3 participants in the stimulation group and 61.5 feet for 4 control participants. The registry reports full ranges but no inferential analyses. It lists 8 participants enrolled, 41 outcome measures, and 40 posted secondary outcomes. The reason for the difference between enrollment and primary outcome counts, the statistical analysis plan, and missing-data methods are not reported in the registry record.