Vestibular Intervention Via Portable Electrical Stimulator (VIPES): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vestibular Intervention Via Portable Electrical Stimulator (VIPES) (NCT04968197), a randomized na study. The primary outcome is Change in Balance Performance.

2. Clinical Question

The trial asks whether balance performance during testing differs when people with balance disorder receive stochastic vestibular stimulation (SVS) through the Vestibular Intervention via Portable Electrical Stimulator (VIPES) system, compared with testing without SVS. Its focus is a measured change in balance during the study, rather than a reported longer-term clinical outcome.

The trial is described as an effort to develop a vestibular intervention using a small, lightweight device and a comfortable electrode set on the back of the head. That description gives the study's rationale, but it is not evidence that balance improved. The record does not report outcome values, a treatment contrast, a confidence interval, or a statistical test for the primary question. It also does not state participant eligibility details beyond the condition of balance disorder. Consequently, the clinical question is identifiable, while the magnitude and precision of any difference between stimulation and control remain not reported in the registry record.

3. Trial Design

VIPES is listed as a randomized, unmasked crossover study sponsored by Mayo Clinic. Its status is completed, with enrollment of 23. The recorded start date is 2022-09-01 and the primary completion date is 2023-03-16. The intervention is a device, named the Vestibular Intervention via Portable Electrical Stimulator system.

In the SVS condition, participants performed standard clinical testing for balance and gait while wearing the device with stimulation active. The description specifies current levels from 0.2mA to 1 mA at 0.2 mA increments. The control condition involved the same stated types of testing without SVS. This within-participant arrangement is consistent with the registry's crossover classification: participants are assigned to conditions that can be compared within the same study rather than only as separate parallel groups. However, the record does not state the condition sequence, whether sequence assignment was balanced, or how much time elapsed between conditions.

The trial was unmasked. The record does not explain whether participants, assessors, or both knew which condition was active, and it does not report procedures to reduce expectations or measurement bias. A crossover design can make within-person comparisons useful because each participant contributes information under more than one condition. It also means that observations from a participant are related rather than independent. Any statistical analysis needs to reflect that structure, but the registry record does not identify the analysis model used.

The description of stimulation levels and the safety reporting categories are not identical in wording. The intervention description gives a range and increments, while adverse-event groups are named for the control condition and SVS conditions at 0.33 Milliamps (mA), 0.67 Milliamps (mA), and 1 Milliamps (mA). The record does not explain how those safety labels map to the testing levels or to the primary-outcome comparisons. The study's phase is recorded as NA. Its detailed protocol, condition-order procedures, and statistical analysis plan 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.

Before assignment: Total of 23 participants were enrolled to receive all interventions; however, the order the intervention was received was randomized. All subjects completed all study visits/interventions.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Change in Balance Performance, measured over Through study completion, approximately 1.5 hours.

The primary endpoint is titled “Change in Balance Performance.” It measures change in balance performance during testing using center-of-gravity sway, expressed in degrees per second. The description says that sway is assessed across tested levels of GVR amplitude and the control condition. The stated timeframe is through study completion, approximately 1.5 hours.

This is a continuous measure, and the record identifies the summary parameter as a mean with standard deviation. In general, a continuous measure can preserve more gradation in the observed response than a simple category such as improved or not improved. A mean describes the average value in a group or condition; a standard deviation describes the spread of individual measurements around that average. These summaries do not, by themselves, show the difference between conditions or how uncertain that difference is.

Center-of-gravity sway is used in the trial as a measured indicator of balance performance during clinical testing. In general, an objective measurement can support comparison across conditions, provided the measurement procedure is applied consistently. The registry record does not give further details about the measurement instrument, the exact calculation of change, the direction considered favorable, or how repeated readings were combined. It also does not report endpoint values or a statistical comparison. The endpoint is therefore described, but its observed result and precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized crossover design and a continuous primary outcome summarized by a mean and standard deviation. Those features indicate the broad statistical setting, but do not reveal the analysis actually conducted. The statistical analysis plan, model specification, and outcome results are not reported in the registry record.

What a crossover comparison involves

In general, a crossover study measures participants under more than one condition. This allows a comparison that uses information from the same participant across conditions, rather than treating all measurements as unrelated. Such measurements are usually correlated: a participant's readings tend to share features even when the condition changes. A suitable analysis therefore needs to represent the within-participant relationship. If that relationship is ignored, uncertainty can be estimated inappropriately.

The record names randomization but does not state how condition order was randomized, whether different sequences were used, or whether sequence was included in analysis. In crossover studies, order can matter if performance changes over time or if one condition influences measurements in a later condition. A washout interval is sometimes used to reduce carryover, but the registry record does not say whether one was planned or used. These are general design considerations, not claims about what happened in VIPES.

Means, spread, and contrasts

A mean summarizes the central value of a continuous measure. A standard deviation describes how much individual measurements vary around the mean. Neither quantity alone expresses the uncertainty in a comparison between conditions. To interpret a condition contrast, readers generally need an estimated difference, its confidence interval, and, where reported, a test result. A confidence interval gives a range of values compatible with the data and the statistical method; its width reflects precision. The record does not provide these outcome statistics.

The endpoint is called change in balance performance and is based on center-of-gravity sway in degrees per second. A clear analysis would need to define the baseline or reference used to calculate change, how measurements at different GVR amplitudes enter the comparison, and whether one contrast or several are estimated. Those operational details are not reported in the registry record. The stated mean and standard deviation do not fill in those missing definitions.

Multiple levels and multiplicity

The registry notes several categories or time points and says the primary outcome was not reduced to one comparison. General statistical practice treats multiple comparisons carefully because examining many contrasts can make apparently notable findings more likely by chance. Possible approaches include identifying a single primary contrast in advance, adjusting inference for multiple comparisons, or presenting estimates with clear exploratory labeling. The registry record does not say which approach, if any, was used. Without the separate outcome analyses, neither the number of tested contrasts nor their statistical handling can be evaluated.

Precision and sample-size planning

The record contains a description of a planning illustration based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It characterizes the illustration as planning rather than the trial's original design justification. The record does not report a sample-size justification for the trial itself. It also does not provide numerical illustration results in the information available for this analysis.

In general, a sample-size calculation estimates how much information a study might need under stated assumptions. It is not an observed result, and it is not “observed power.” An illustration based on an observed effect is especially dependent on the effect estimate and its uncertainty. The crossover design also differs from the equal-allocation, two-arm assumption described for the illustration. Therefore, that planning framework should not be mistaken for a reconstruction of the actual design or for proof that the enrollment was adequate to detect a meaningful difference.

Over-dispersion and model choice

General statistical models need to match the distribution and dependence structure of the data. Over-dispersion means that observed variability is greater than a model assumes; if ignored, standard errors may be too small and confidence intervals too narrow. The listed endpoint is continuous and summarized by mean and standard deviation, but the record gives no evidence that over-dispersion was evaluated or that any particular model was fitted. This is a general consideration, not a reported feature of the VIPES analysis.

Because there are no posted outcome estimates or analysis details, no recalculated comparison can be made from the record. In general, a recalculation from summary statistics would be unadjusted and would not replace a sponsor's own analysis if results disagreed. Here, no sponsor analysis is posted for the primary outcome, so there is no estimate to compare or recalculate. The statistical methods that generated the endpoint results, if any, are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome description refers to measurements across tested levels of GVR amplitude and a control condition. The registry also flags the outcome as involving several categories or time points and not reduced to one comparison. It does not report a multiplicity strategy, a hierarchy of contrasts, or which comparison was designated as the principal inferential test. Without separate estimates and methods, it is not possible to assess how the number of comparisons affected interpretation.

Missing-data methods are not reported in the registry record. The record does not state whether all enrolled participants contributed measurements in every condition, how incomplete testing was handled, whether any values were excluded, or whether imputation was used. Enrollment of 23 does not establish that 23 participants had usable observations for every endpoint contrast. In a crossover study, missingness in one condition can also affect the availability of a within-participant comparison.

The analysis population for the primary outcome is not specified. The record does not say whether analyses followed assigned condition sequences, included only participants who completed every condition, or used another population definition. These distinctions can affect which participants contribute to an estimate. They should not be inferred from the enrollment count or from the completed study status.

These reporting gaps limit appraisal of both the analysis and its precision. They do not establish that the study had missing observations or that multiplicity was mishandled; they mean those aspects are not reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry safety record lists four condition groups: control, 0.33 Milliamps (mA) SVS, 0.67 Milliamps (mA) SVS, and 1 Milliamps (mA) SVS. Each group lists 23 participants at risk. For every group, the recorded counts are zero serious adverse events, zero other adverse events, and zero deaths.

These figures describe what was recorded for the named groups. They do not provide a statistical comparison between conditions, and the record gives no confidence intervals or other uncertainty estimates for the event counts. Since the study is classified as crossover, participants may have contributed to multiple conditions. The at-risk counts should therefore not be added together or interpreted as independent groups of participants.

The registry record does not report event definitions, how adverse events were collected, the safety observation period, or whether events were assessed for relationship to the device. Zero recorded events in these summaries should not be taken to establish that an event could not occur, nor does the record support a comparative safety conclusion. The primary endpoint timeframe is approximately 1.5 hours, but the safety follow-up timeframe is not reported in the registry record.

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

The registry record establishes that VIPES was a completed randomized, unmasked crossover study involving 23 enrolled participants with balance disorder. It identifies SVS delivered through a portable electrical stimulator as the intervention, testing without SVS as the control condition, and center-of-gravity sway as the basis of the primary balance endpoint. These details describe the question and the framework used to investigate it.

What the record does not establish is whether the intervention condition produced a different measured balance response from control. No primary-outcome analysis, condition-specific result, effect estimate, confidence interval, or p-value is reported. The record's note that the outcome involved several categories or time points also means the result cannot be represented by a single comparison in the available information. The absence of a posted estimate is not evidence that the conditions were equivalent, and it is not evidence that one condition improved performance.

The safety summaries report zero recorded serious events, other events, and deaths across the listed condition groups, each with 23 at risk. These counts are descriptive and do not establish comparative risks or rule out events beyond the recorded observation. The crossover design also means that the same participant may appear in more than one condition's safety count.

More broadly, the study's stated aim and device description are not outcome findings. To interpret an effect, readers would need the measured results, a clearly defined contrast, an analysis that accounts for the crossover structure, and an estimate of uncertainty. Details about missing observations, condition order, and multiplicity would further inform the reliability of that interpretation. Those items are not reported in the registry record. The conclusions that can be drawn are therefore limited to the design, the endpoint definition, and the reported safety counts.

13. Why This Trial Matters Statistically

This trial is statistically notable because it uses a crossover design to study balance measurements under SVS and control conditions. In general, crossover designs can use within-participant comparisons, which may help distinguish condition-related variation from stable differences among participants. That advantage depends on appropriate handling of repeated measurements and on understanding sequence, time, and possible carryover effects. The registry record does not report those analytic details.

The endpoint is a continuous measure based on center-of-gravity sway, summarized as a mean and standard deviation. That creates a need to distinguish the average response from its variability and from the uncertainty in a condition contrast. A mean alone would not show whether individual responses were consistent, while a standard deviation alone would not establish whether conditions differed. The lack of posted outcome estimates makes these distinctions especially important: the statistical question is described, but its answer cannot be assessed from the registry record.

The outcome's multiple categories or time points also raise a general issue of multiplicity. A study may examine several contrasts, but interpretation depends on prespecification and transparent reporting of which ones are primary and how uncertainty is handled. The registry record says the outcome was not reduced to one comparison and gives no multiplicity approach. This prevents assessment of the inferential framework as well as the endpoint result.

Finally, the planning assumptions described in the record are not the same as the trial's own design justification or an observed analysis. Treating a planning illustration as evidence of study adequacy would confuse a hypothetical calculation with a trial result. VIPES therefore illustrates why clear reporting of crossover methods, outcome contrasts, missing-data handling, and uncertainty is essential for translating a completed study record into statistical evidence.

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 central limitation for interpretation is that the registry record does not report the primary-outcome analyses. Although the endpoint and its timeframe are described, there are no outcome values or estimates with which to judge the direction, magnitude, or precision of a difference. This prevents a substantive statistical conclusion about balance performance.

The record identifies a crossover design but does not give the condition sequence, allocation procedures beyond randomized assignment, or details about timing between conditions. It does not explain whether carryover or order effects were considered. Because repeated observations from the same participant are related, the missing analysis model is a consequential limitation for evaluating how comparisons were made.

The primary endpoint description includes several GVR amplitude levels and a control condition, and the registry notes that the outcome was not reduced to one comparison. It does not report which contrasts were prespecified, how multiplicity was addressed, or whether any analyses were exploratory. The protocol and statistical analysis plan are not reported in the registry record.

Participant characteristics beyond balance disorder are not reported in the registry record of the record. Nor are eligibility criteria, analysis population definitions, missing-data methods, or endpoint-specific completion counts. Enrollment of 23 does not show how many participants contributed complete outcome data.

The stimulation-level descriptions also differ in form: the intervention description gives a range from 0.2mA to 1 mA at 0.2 mA increments, while safety categories use labels of 0.33 Milliamps (mA), 0.67 Milliamps (mA), and 1 Milliamps (mA). The relationship between these labels and the primary-outcome comparisons is not explained. Finally, safety follow-up and event-collection procedures are not reported, limiting interpretation of the zero recorded event counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Vestibular Intervention Via Portable Electrical Stimulator (VIPES) — NCT04968197.
• Registry record last updated 2024-06-13; status last verified 2024-05.
• Results first posted 2024-06-13.
• 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.

18. Record Summary

VIPES (NCT04968197) is a completed randomized, unmasked crossover device study sponsored by Mayo Clinic, with enrollment of 23 and a condition of balance disorder. Its intervention is the Vestibular Intervention via Portable Electrical Stimulator system, delivering stochastic vestibular stimulation during balance and gait testing; the control condition involves testing without SVS.

The primary outcome is change in balance performance, measured as center-of-gravity sway in degrees per second across tested GVR amplitude levels and control. The stated timeframe is through study completion, approximately 1.5 hours. The registry record lists one outcome measure but no analyses. It does not report a primary-outcome estimate or statistical plan, and notes that the outcome's categories or time points were not reduced to one comparison.

Safety summaries list zero serious adverse events, zero other adverse events, and zero deaths in each named condition group, with 23 at risk in each. The record does not report the primary-outcome results, missing-data methods, analysis populations, or detailed crossover procedures.