Non-pharmaceutical Motion Sickness Mitigation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Non-pharmaceutical Motion Sickness Mitigation (NCT04859868), a randomized na study. The primary outcome is Motion Perception.

2. Clinical Question

3. Trial Design

The registry record describes a randomized crossover study of non-pharmaceutical motion sickness mitigation. It lists healthy participants, an enrollment of 29, and Galvanic Vestibular Stimulation as the device intervention. The study is marked completed. Its recorded start date is 2021-03-12, and its primary completion date is 2022-08-30. The phase is listed as NA.

The listed conditions are GVS throughout the session, no GVS during the session, and GVS beginning mid-session. These descriptions identify the intended timing contrast, but they do not explain the precise stimulation magnitude or how it was assigned. The study summary also says it aims to evaluate GVS amplitude in relation to functional fitness task performance. Detailed procedures for those evaluations are not reported in the registry record.

Randomization can reduce systematic differences in how study conditions are assigned, while a crossover design can allow comparisons across conditions within participants. Those are general design features, not evidence that the record documents a particular sequence or analysis. The assignment method, order of conditions, washout intervals, handling of period effects, and any safeguards against carryover are not reported in the registry record. Masking is listed as none, so the record does not describe the study as blinded.

The registry lists Motion Perception as the primary outcome and Motion Sickness Questionnaire as a secondary outcome. It records two outcome measures and zero analysis entries. Thus, the design and intended measurements are described, but quantitative results are not available in the registry record for assessing the primary question.

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 29 participants were enrolled to receive all interventions, however the order the intervention was received was randomized. All subjects completed the first experimental visit. 2 subjects withdrew from the study prior to the start of the second experimental visit.

First Experimental Visit (1.5 Hour)

Second Experimental Visit (1.5 Hour)

Third Experimental Visit (1.5 Hour)

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 Motion Perception, measured over During the rotation of the chair, approximately 1 hr.

The primary endpoint is Motion Perception, recorded as a verbal report using a visual analog scale from 1 to 100 during rotation of the chair, approximately 1 hr. The record defines 1 as feeling no motion perception and 100 as feeling the maximum motion perception. It describes the measure as a score on a scale and identifies the planned summary as a mean with standard deviation.

As a general measurement principle, a participant-reported scale can capture perceived experience directly, which is relevant when the research question concerns motion perception. A mean describes the average reported score, while a standard deviation describes how dispersed scores are around that average. Neither statistic is available for the listed conditions in the registry record, so the endpoint's observed level and variability cannot be assessed.

The measure concerns perceived motion, not an objective measure of vestibular function or a direct count of motion-sickness symptoms. The record separately lists Motion Sickness Questionnaire as a secondary outcome, but does not report its results. It also mentions functional fitness task performance in the study summary; the specific outcome measure and results for that assessment are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a continuous primary outcome summarized as a mean and standard deviation. These summaries are appropriate descriptions for scores on a numerical scale, but they do not by themselves establish a difference between conditions. The registry record does not post condition-specific summaries or an inferential analysis for Motion Perception.

What does a mean describe?

In general, the mean is the arithmetic average of measured scores in a group or condition. It provides a measure of the central level of the observations, but does not reveal whether scores are tightly clustered or widely spread. A mean can also be influenced by unusually high or low observations. The registry describes the scale anchors, but does not provide observed means, distributions, or participant-level data.

Why report a standard deviation?

In general, the standard deviation describes the spread of observations around their mean. It is not the same as the uncertainty in the mean: the standard error and a confidence interval address precision of an estimate, and depend on the data and analysis. The record names standard deviation as the planned dispersion measure but reports no observed standard deviations for the primary outcome. Variability therefore cannot be evaluated from the posted results.

How would a crossover comparison be interpreted?

As a general statistical concept, crossover designs can compare conditions within the same participants. This may reduce the influence of stable characteristics that differ between people. However, observations from the same participant are related, so an analysis ordinarily needs to account for that dependence rather than treat every measurement as independent. Condition sequence, period, and carryover can also affect the contrast. The registry labels the model crossover but does not report the analysis method, condition order, washout procedures, or how these potential effects were handled. No specific model can therefore be attributed to this study from the registry record.

Randomized allocation is recorded, but the record does not explain how the sequence was generated, concealed, or implemented. Those details can inform assessment of allocation procedures. Masking is recorded as none. In general, lack of masking can matter for participant-reported outcomes because expectations or awareness may influence reports; this is a possible source of measurement bias, not evidence that bias occurred in this study.

What do an effect estimate and confidence interval add?

In general, an effect estimate expresses the magnitude and direction of a comparison, while a confidence interval describes the range of values compatible with the data and analysis at the stated confidence level. A p-value addresses compatibility with a specified null model, but does not convey the size or practical importance of an effect. These measures require an analysis result. The registry record contains no primary-outcome comparison, effect estimate, confidence interval, or p-value, so none can be interpreted for Motion Perception.

How should planning calculations be read?

In general, sample-size calculations are planning illustrations rather than observed results. The stated illustration approach uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it describes effects to detect as fractions of an observed effect. Those assumptions do not constitute the trial's own design justification. The registry record does not report a sample-size justification or a primary-outcome effect estimate from which to assess a planning illustration. Such calculations should not be treated as observed power or evidence that the study detected an effect.

Finally, analysis choices should reflect the study structure and outcome. A mean-based analysis may be reasonable for a continuous scale under suitable assumptions, but the registry record does not give score distributions or diagnostics. If measurements were more variable than a model assumes, uncertainty estimates and tests could be unreliable; general methods can account for over-dispersion where relevant. There is no evidence in the registry record that over-dispersion was assessed or that any particular adjustment was used. With no posted analysis, the appropriateness of the statistical method cannot be evaluated.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies Motion Perception as primary and Motion Sickness Questionnaire as secondary, and records two outcome measures. The study summary also describes evaluating timing, magnitude, and functional fitness task performance. The registry record does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment for testing multiple outcomes or contrasts. Without that information, the impact of multiple testing on any inferential results cannot be assessed. No primary-outcome analysis is posted, so there are no reported tests to interpret in light of multiplicity.

Missing-data handling is not reported in the registry record. The record does not state how incomplete scale responses, missed sessions, withdrawals, or unavailable measurements were handled, nor does it describe imputation or sensitivity analyses. In general, missingness can affect an estimate when the probability of missing data is related to the outcome or participant characteristics. The extent and consequences of missing data cannot be determined without outcome availability and analysis details.

Analysis populations are also not described. The registry record does not state whether analyses were based on all randomized participants, participants who completed particular conditions, or another defined population. In crossover studies, the handling of participants without measurements under every condition can affect which comparisons are represented. No analysis population or participant flow is reported, so the population underlying any estimate cannot be established from this 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.

For each listed condition, the registry records 29 participants at risk for serious adverse events and 0 affected; it also records 29 at risk for other adverse events and 0 affected. Deaths are recorded as 0 in each condition. The registry record lists no serious adverse-event terms.

These entries are counts as recorded, not a detailed safety analysis. The crossover design means the condition entries should not be added or treated automatically as independent groups; the record does not explain how participants contributed across conditions. The entries also do not describe event definitions, the observation period for safety reporting, ascertainment procedures, severity grading beyond the serious/other categories, or completeness of reporting. Those details are not reported in the registry record.

A recorded zero means that no affected participants are entered for that category and condition in the registry. It does not show that an event is impossible or establish the absence of risk. Without additional reporting detail and outcome analyses, these figures are best read as the registry's recorded adverse-event counts rather than a complete characterization of safety.

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

The registry record establishes that a randomized, unmasked crossover study was conducted in healthy participants to evaluate non-pharmaceutical motion sickness mitigation using GVS. It identifies timing conditions, a primary measure of Motion Perception during chair rotation, and Motion Sickness Questionnaire as a secondary outcome. The study is marked completed, but completion status is not a result.

The record does not report primary-outcome values, condition comparisons, effect estimates, confidence intervals, or p-values. It therefore does not show whether GVS was associated with a change in reported motion perception, nor how precise any such estimate might be. The secondary outcome is named but has no posted result. The study summary's aim concerning GVS amplitude and functional fitness task performance likewise has no corresponding analysis result reported in the registry record.

These limitations distinguish a study's question from its answer. Registration details can explain what was intended to be measured and how the study was labeled, but without outcome data they cannot establish the size, direction, or reliability of an effect. The adverse-event entries record zero affected participants for the listed categories, but do not by themselves establish that there was no risk or that reporting was complete.

Accordingly, the registry record supports a description of the design and stated outcomes, not a conclusion about efficacy, lack of effect, or comparative performance. Any such conclusion would require reported outcome data and analysis details that are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically notable because its registered question connects intervention timing and magnitude with subjective motion perception, while using a crossover design. In general, crossover designs can make within-participant comparisons possible, which may be useful when responses vary substantially between people. That potential advantage depends on a clearly specified sequence and an analysis that accounts for repeated measurements and possible period or carryover effects. Those details are not reported in the registry record.

The primary endpoint is a participant-reported scale with stated anchors, making the intended construct and direction of the scale interpretable. However, a well-described endpoint does not replace the need for observed data. Because the registry record contains no primary-outcome analysis, it offers no estimate of how reported motion perception varied among conditions and no information about precision.

The record also illustrates why design labels should not be mistaken for complete methodological reporting. Randomization and crossover are useful descriptors, but they do not specify sequence generation, handling of missing measurements, analysis populations, or statistical models. The absence of those details limits assessment of how an eventual contrast would be obtained and interpreted.

For clinical researchers and biostatisticians, the distinction between a completed study and a reported result is important. The record documents a completed study and the intended outcome framework, yet leaves the central quantitative question unanswered in its posted results. This makes the study informative about the registered measurement and design, but not about the magnitude or precision of any GVS-related outcome difference.

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 principal limitation of the registry record for interpreting this trial is the absence of posted primary-outcome results. No condition-specific Motion Perception means or standard deviations, comparative estimate, confidence interval, or inferential test is reported. The record contains zero analysis entries. As a result, neither the direction nor precision of an outcome contrast can be assessed.

Methodological detail is limited. Although the study is labeled randomized and crossover, the assignment sequence, condition order, washout procedures, handling of period or carryover effects, and crossover analysis are not reported in the registry record. Masking is listed as none. The record does not describe the sample-size justification, analysis populations, missing-data procedures, or multiplicity strategy.

The population description is limited to healthy participants, with enrollment recorded as 29. Eligibility criteria, participant characteristics, and the number contributing data to each outcome or condition are not reported in the registry record. The study summary refers to GVS timing and magnitude and to functional fitness task performance, but detailed outcome definitions and results for those aims are not reported. Motion Sickness Questionnaire is named as a secondary outcome, without posted results.

Safety entries record zero affected participants in each listed category and condition, but event definitions, observation windows, ascertainment, and completeness are not described. These limitations restrict both interpretation of the outcome evidence and assessment of how broadly any eventual findings might apply.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Non-pharmaceutical Motion Sickness Mitigation — NCT04859868.
• Registry record last updated 2023-09-28; status last verified 2023-09.
• Results first posted 2023-09-28.
• 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

NCT04859868, titled Non-pharmaceutical Motion Sickness Mitigation, is recorded as a completed randomized crossover study sponsored by Mayo Clinic. It lists healthy participants, enrollment of 29, no masking, and Galvanic Vestibular Stimulation as the device intervention. The recorded start date is 2021-03-12, and primary completion is recorded as 2022-08-30.

The primary outcome is Motion Perception, a verbal visual analog scale from 1 to 100 measured during chair rotation for approximately 1 hr and summarized as a mean with standard deviation. Motion Sickness Questionnaire is listed as a secondary outcome. The registry record contains no primary-outcome analysis results and zero analysis entries. Adverse-event entries record zero affected participants and zero deaths for each listed condition, with limitations in event-reporting detail.