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 Non-invasive Vagus Nerve Stimulation (nVNS) in Pediatric Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (NCT03772717), a na na study. The primary outcome is Nerve Conduction Study - Distal Latency.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03772717 |
| Phase | NA |
| Condition | Chronic Inflammatory Demyelinating Polyneuropathy |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 2 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Emory University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned participants with chronic inflammatory demyelinating polyneuropathy (CIDP) in a pediatric setting. The registry lists an enrollment of 2. The primary outcome record says participants withdrew before completing any follow-up study visits, so the posted record does not contain follow-up measurements for that outcome.
Intervention
The intervention was non-invasive vagus nerve stimulation (nVNS), used as an adjunct to standard-of-care treatment. The study description requested stimulation two times per day, at least five days per week. The device named in the arm description is VitalStim 400; participants were also to continue standard-of-care medication.
Comparator
This was a single-group study, with allocation listed as NA. The registry describes nVNS together with standard care, not a separate control group. Standard care is part of the intervention description rather than a like-for-like comparison arm, so the record does not support a comparative treatment effect estimate.
Primary question
The primary outcome was nerve conduction study distal latency, measured in milliseconds at baseline, Month 12, and Month 24. The measurement concerns the time taken for an electrical impulse to travel to the receiving site. The intended question was whether this continuous nerve-conduction measure could be followed during nVNS use alongside standard care. The registry’s primary outcome population description says participants withdrew before completing follow-up visits; no endpoint values or analysis results are reported.
The study also listed TNF-α and IL-1β as secondary outcomes. The record does not give their results. Since no follow-up outcome values or analysis results are posted, the record cannot establish a change over time, nor distinguish any change associated with nVNS from changes associated with standard care or other influences.
3. Trial Design
The registry describes an interventional, single-group study of non-invasive vagus nerve stimulation in pediatric CIDP. Enrollment is listed as 2, allocation as NA, and masking as NONE. The study was sponsored by Emory University. Its recorded start date is 2022-02-22, primary completion date is 2022-06-30, and status is TERMINATED. The reason for termination is not reported in the registry record.
The intervention combined nVNS with standard-of-care treatment. Participants were requested to use nVNS two times per day, at least five days per week, and were to be followed for two years. The arm description names the VitalStim 400 device and says participants would continue their standard-of-care medication. The record does not describe a separate untreated or standard-care-only group.
A single-group design can describe observed measurements in the participants who contribute data, but it does not by itself provide a concurrent comparison for separating intervention-associated change from other influences. Because allocation is listed as NA and there is no separate control arm described, this study is not a randomized comparison. Its design should not be read as a head-to-head test of nVNS against standard care.
The primary outcome was distal latency from a nerve conduction study, with measurements planned at baseline, Month 12, and Month 24. The registry lists eight outcome measures but reports zero analyses. Its primary outcome population description states that participants withdrew before completing any follow-up study visits. The record therefore contains no reported follow-up primary outcome results with which to describe the planned trajectory. The protocol’s statistical analysis plan, including any specific approach for within-participant comparisons, is 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 | Non-invasive Vagus Nerve Stimulation (nVNS) |
|---|---|
| STARTED | 2 |
| COMPLETED | 0 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Non-invasive Vagus Nerve Stimulation (nVNS) |
|---|---|
| Withdrawal by Subject | 2 |
Analysis population for the primary outcome, as defined in the registry: Participants withdrew from the study prior to completing any follow-up study visits.
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 | Non-invasive Vagus Nerve Stimulation (nVNS) |
|---|---|---|
| Participants analysed | 2 | |
| Age, Categorical: <=18 years | Participants | 2 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| 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 | 1 |
| Race (NIH/OMB): More than one race | Participants | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Nerve Conduction Study - Distal Latency, measured over Baseline, Month 12, Month 24.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | ms |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was nerve conduction study distal latency, reported in milliseconds. A nerve conduction study uses electrodes placed on the skin: one stimulates a nerve and a receiving site records how electrical impulses travel along it. Distal latency is the time for the impulse to travel to the receiving site. It is a continuous measurement, and the registry identifies the planned summary as a mean with standard deviation.
Latency is used in nerve conduction testing because it describes a measurable aspect of electrical impulse transmission along a peripheral nerve. As a general statistical point, a continuous endpoint retains the scale of the measurement, allowing its distribution and change over time to be described rather than reducing it to a yes-or-no category. The registry scheduled measurements at baseline, Month 12, and Month 24, which would permit descriptive assessment over time if follow-up measurements were available.
The primary endpoint record does not report observed latency values. It states that participants withdrew before completing any follow-up study visits. Consequently, the posted record cannot show the baseline-to-follow-up pattern for this endpoint, estimate a mean change, or describe the precision of an estimated change. The rationale for selecting distal latency as the primary endpoint is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a small, single-group study of nVNS used alongside standard-of-care treatment in pediatric CIDP. Enrollment is listed as 2, and the study status is TERMINATED. These design and status details are essential context for interpreting what the posted results can establish. There is no separate control group, and the record lists allocation as NA and masking as NONE.
The central interpretive limitation is that the primary endpoint has no reported follow-up values. The primary outcome population description says participants withdrew before completing any follow-up study visits. Thus, the planned distal-latency measurements at baseline, Month 12, and Month 24 do not appear as an analyzed series of results. The record does not provide a mean, standard deviation, change estimate, confidence interval, or test result for the primary endpoint. No analyses are listed.
That absence does not indicate that distal latency was unchanged, nor that it improved or worsened. It means the registry record does not present results with which to characterize the endpoint. Similarly, the study’s planned use of nVNS alongside standard care does not permit attribution of an unreported outcome to nVNS. In general, a single-group observation cannot separate intervention-associated change from the course of the condition, standard care, measurement variation, or other influences without additional design or analysis information.
The listed secondary outcomes are TNF-α and IL-1β, but their values and analyses are not reported in the registry record. The record lists eight outcome measures overall and zero analyses. It does not state which outcomes, if any, were collected before withdrawal, how missing measurements were handled, or whether any analyses were planned but not posted. Those details should not be inferred from the planned outcomes alone.
The safety record lists serious adverse events in the nVNS group, with 2 at risk and 1 affected; it lists 0 affected by other adverse events and 0 deaths. The serious event term is “Tingling, numbness, and pain in limbs,” listed as 50.0%. These figures describe the registry’s recorded safety information; they do not establish that the device caused the reported event. The record does not report additional detail on event timing, clinical course, or attribution.
Overall, the posted record is informative about the intended intervention, scheduled endpoint, study design, termination status, and limited safety counts. It does not provide an efficacy estimate, a comparative result, or a quantified treatment effect. The missing outcome data and absence of analyses mean that conclusions about the primary endpoint or secondary biomarkers cannot be drawn from this record.
9. Statistical Methods Explained
The registry characterizes the primary endpoint as a mean of a continuous measure, with standard deviation as its dispersion summary. These terms describe how a set of measurements may be summarized; they do not imply that usable measurements or a calculated summary are posted. In this record, no primary endpoint values or analyses are reported.
For a continuous endpoint such as distal latency, a mean describes the arithmetic center of observed measurements. A standard deviation describes how spread out individual measurements are around that mean. These summaries answer different questions: the mean describes the central value, while the standard deviation describes variability among measurements. Neither can be interpreted as a result for this study without reported observations. The registry does not report an endpoint mean, standard deviation, or estimated change.
A confidence interval is a statistical range intended to express the uncertainty around an estimate under a specified method. In general, narrower intervals indicate greater precision, while wider intervals indicate less precision. A confidence interval is not a guarantee that the true value lies within the interval, and it does not repair limitations in the design or data. No confidence interval for the primary outcome is reported in the registry record, so there is no interval-based precision estimate to interpret.
For repeated measurements, an analysis could describe how values change within participants over time. Such an analysis requires relevant observations and a stated approach to the dependence between measurements from the same participant. The primary endpoint schedule lists baseline, Month 12, and Month 24, but the registry says participants withdrew before completing follow-up visits. The record does not report a repeated-measures model, a method for estimating change, or a completed analysis. It would not be appropriate to infer which method would have been used.
The design is single-group, with allocation listed as NA and masking as NONE. As a general design principle, an observed change in a single group does not isolate the contribution of an intervention. A concurrent comparator can help account for changes that might also occur without the intervention; no separate comparator group is described. The study therefore does not provide a randomized treatment contrast. The record does not report an adjusted or unadjusted treatment-effect estimate.
Statistical significance and clinical importance are also distinct ideas. A significance test, when used, evaluates data relative to a specified statistical model and null hypothesis. The registry reports zero analyses and no test results, so there is no reported p-value to interpret. Even when a test is statistically significant, that alone does not describe the size or practical importance of an effect. Conversely, a non-significant result does not establish that no effect exists. Neither type of conclusion is available from the posted primary outcome record.
Over-dispersion is a general concern for count outcomes when the observed variability exceeds what a chosen count model expects. A model that fails to accommodate over-dispersion can yield uncertainty estimates that are too optimistic. This concept is not a reported analysis feature for the primary endpoint, which is continuous, and the registry does not report a count-outcome analysis. No particular modeling choice should be attributed to the study.
Multiplicity refers to the statistical complications that can arise when many outcomes or hypotheses are tested. If each test is interpreted separately without considering the number of tests, the chance of at least one apparently unusual result can increase. The registry lists eight outcome measures, including TNF-α and IL-1β as secondary outcomes, but it reports zero analyses. It does not report a hierarchy of hypotheses, an adjustment procedure, or another strategy for addressing multiplicity. Thus, no multiplicity-adjusted result can be interpreted.
Missing data methods are choices for handling measurements that were not observed. In general, methods differ in the assumptions they make about why values are missing and what unobserved values might have been. The primary endpoint record says participants withdrew before completing follow-up visits, but the registry does not describe a missing-data method, reasons for withdrawal, or the availability of baseline measurements. No imputation, sensitivity analysis, or analysis population should be presumed.
The registry includes a general planning-illustration description based on an observed effect, with assumptions about significance level, allocation, and an approximation. Such planning illustrations are not observed power and cannot substitute for outcome results. The actual design described for this study is single-group, not an equal-allocation comparison between two arms; the record does not report the trial’s own sample-size justification. No planning estimate should be treated as a finding about this study’s outcomes.
In general, methods should be matched to the design, endpoint scale, available observations, and analysis question. Here, the registry’s stated outcome type and schedule are known, but the analysis methods and endpoint results are not reported. The appropriate interpretation is therefore descriptive: the planned statistical summaries cannot be reconstructed from the posted record, and no unreported method or result should be inferred.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists eight outcome measures and names TNF-α and IL-1β as secondary outcomes. The primary outcome is nerve conduction study distal latency. The record reports zero analyses, and it does not state how the primary and secondary outcomes were ordered for inference, whether any outcomes were exploratory, or whether multiplicity was addressed through a formal adjustment. Without reported analyses, there are no outcome-specific estimates or tests to interpret, adjusted or otherwise.
Multiplicity matters because interpreting many statistical tests as if each were the only test can increase the chance of at least one apparently notable finding. General approaches include defining a primary hypothesis in advance, controlling a family-wise error rate, or treating secondary analyses as exploratory. The registry record does not report which, if any, approach was planned or used. These general possibilities should not be mistaken for the study’s methods.
Missing outcome data are particularly important for the primary endpoint: the registry says participants withdrew before completing any follow-up study visits. It does not report whether baseline distal-latency measurements were collected, the reasons for withdrawal, or any method for handling missing values. The record also does not report an analysis population definition, imputation method, or sensitivity analysis. Without these details and observed results, the potential influence of missing measurements cannot be quantified.
The registry’s description of withdrawal does not support assuming that unobserved outcomes would resemble observed outcomes, nor does it support any particular missing-data mechanism. The statistical consequences depend on information not reported in the registry record. No complete-case, intention-to-treat, per-protocol, or other analysis population should be attributed to this study on the basis of the posted information.
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 |
|---|---|---|---|
| Non-invasive Vagus Nerve Stimulation (nVNS) | 1 | 2 | 50.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Non-invasive Vagus Nerve Stimulation (nVNS) | 0 of 2 |
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 |
|---|---|
| Non-invasive Vagus Nerve Stimulation (nVNS) | 0 of 2 |
Most frequent serious adverse event terms
| Event term | Organ system | Non-invasive Vagus Nerve Stimulation (nVNS) |
|---|---|---|
| Tingling, numbness, and pain in limbs | Nervous system disorders | 1 of 2 |
Serious events with the highest arm-level rate: tingling, numbness, and pain in limbs (50.0%).
The registry safety figures list 2 at risk for serious adverse events in the nVNS group and 1 affected. It lists 2 at risk for other adverse events and 0 affected, with 0 deaths. The serious adverse event term recorded is “Tingling, numbness, and pain in limbs,” with 50.0% listed for that term. These are the safety counts and term as recorded, not an estimate of comparative risk.
The affected count describes participants recorded with an event, not necessarily the number of separate event episodes. The registry record does not give details about timing, duration, severity beyond the serious-event classification, clinical course, or whether the event was judged related to nVNS, standard care, or another cause. A recorded event during a study does not by itself establish causation.
Because this is a single-group record with no separate comparator, the safety figures cannot be interpreted as a comparative safety result. The record also does not describe how events were actively collected or define the observation period for the displayed counts. These limitations make the figures descriptive and narrow in scope; they should not be treated as a complete estimate of safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a study of nVNS alongside standard-of-care treatment was registered for pediatric CIDP, with distal latency as the primary endpoint and TNF-α and IL-1β among its secondary outcomes. It also records an enrollment of 2, a single-group design, and a TERMINATED status. These registry entries describe the study and its planned measurements, not evidence of a treatment effect.
The record does not report primary endpoint values or analyses. Its primary outcome population description states that participants withdrew before completing any follow-up study visits. Consequently, the posted information cannot establish whether distal latency changed, how large any change might have been, or how precisely it could be estimated. It also cannot establish results for the listed secondary biomarkers.
The absence of follow-up results is not evidence that the endpoint remained stable, and it is not evidence that it changed. It is a lack of reported outcome information. Similarly, the planned schedule of baseline, Month 12, and Month 24 measurements does not demonstrate that those measurements were collected or analyzed.
The single-group design does not provide a concurrent control for estimating the contribution of nVNS separately from standard care or other influences. The posted record therefore cannot support a comparative claim about nVNS versus standard care. The safety counts describe recorded events but do not establish that the intervention caused them.
In practical statistical terms, this registry entry offers context about the intervention, intended follow-up, outcome selection, and safety reporting, but not an interpretable estimate of benefit or harm. The reason for termination, analysis plan, sample-size justification, and handling of missing observations are not reported in the registry record. Any conclusion beyond the recorded design and limited safety information would go beyond what the posted results establish.
13. Why This Trial Matters Statistically
This study matters statistically because its record illustrates the difference between a planned outcome and an analyzed outcome. Distal latency was specified with a measurement unit and follow-up schedule, but the primary outcome description says participants withdrew before completing follow-up visits. Without reported endpoint values or analyses, the measurement plan cannot be converted into an estimate of change or its uncertainty.
The record also demonstrates why study design shapes interpretation. A single-group study can document observations among participants who contribute measurements, but it cannot provide the same kind of direct comparison as a randomized controlled design with a separate comparator. Here, the registry lists allocation as NA, masking as NONE, and no separate control group. The intervention was to be used alongside standard care, which further limits what could be attributed to nVNS even if outcome changes had been reported.
The small listed enrollment and the absence of analysis results make precision a central concern. A numerical estimate without uncertainty can be misleading, but this record does not report an estimate or interval at all. It also does not provide the trial’s own sample-size justification. Planning calculations, where included in trial materials, are distinct from observed power and cannot replace the missing outcome analysis.
Finally, the safety record shows why event counts need context. The listed serious event term and affected count are descriptive; they do not determine causality or comparative risk. Taken together, the record is a useful example of how design, missing follow-up, analysis reporting, and safety context constrain the claims that can be made from a clinical study.
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 direct limitation is the lack of reported follow-up results for the primary endpoint. The registry states that participants withdrew before completing any follow-up study visits, and it reports zero analyses. It therefore does not provide the planned distal-latency summaries or results for the scheduled follow-up assessments. The record does not report whether baseline endpoint measurements were available.
The listed enrollment is 2, and the study is single-group. There is no separate comparator described, so the design does not support a like-for-like comparison or a treatment-effect estimate against standard care alone. Masking is listed as NONE. These features limit causal interpretation independently of the missing outcome data.
The study status is TERMINATED, but the reason for termination is not reported in the registry record. The registry also does not report the statistical analysis plan, the trial’s sample-size justification, any interim analyses, or an approach to missing data. It does not specify an analysis population or report whether outcomes were collected before withdrawal.
Eight outcome measures are listed, but no analyses are reported. The record does not explain how secondary outcomes were prioritized or whether multiplicity was addressed. The two named secondary outcomes, TNF-α and IL-1β, have no reported results. The available safety information is limited to the listed counts and serious event term; event timing, duration, attribution, and collection details are not reported.
These limitations mean the record can describe study conduct as registered and the safety entries as posted, but it cannot support estimates of efficacy, comparative safety, or precision for the primary outcome.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Non-invasive Vagus Nerve Stimulation (nVNS) in Pediatric Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) — NCT03772717.
- Registry record last updated 2023-07-14; status last verified 2023-06.
- Results first posted 2023-07-14.
- 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 record describes a terminated, single-group study of non-invasive vagus nerve stimulation alongside standard-of-care treatment for pediatric CIDP. Enrollment is listed as 2; allocation is NA and masking is NONE. The recorded start date is 2022-02-22, and the primary completion date is 2022-06-30.
The primary outcome was nerve conduction study distal latency in milliseconds, scheduled at baseline, Month 12, and Month 24. The primary outcome population description says participants withdrew before completing any follow-up study visits. The registry lists eight outcome measures and zero analyses; it does not report primary or secondary outcome results.
The safety record lists 1 affected by a serious adverse event among 2 at risk, the term “Tingling, numbness, and pain in limbs” at 50.0%, 0 affected by other adverse events, and 0 deaths. The reason for termination and the statistical analysis plan are not reported in the registry record.