Computerized Vestibular Rehabilitation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Computerized Vestibular Rehabilitation (NCT03589859), a registered phase not stated study. The primary outcome is Vestibulo-ocular Reflex Gain Ratio.

2. Clinical Question

The research goal described in the record was to assess whether an interactive game could facilitate vestibular learning and whether the approach was feasible for people with vestibular impairment. These are related but distinct questions. The gain-ratio endpoint concerns motor learning in healthy volunteers; the registry specifically says that this experiment was not a treatment of impairment. The hypofunction group was described as testing feasibility, rather than as a control group for the healthy volunteers.

The registry’s rationale notes that vestibular disorders and balance problems can accompany conditions that affect veterans, and that the research aimed to develop a more engaging and adaptable rehabilitation tool. It also describes possible future features such as tracking progress and advancing exercises as function changes. Those longer-term goals are not themselves outcomes demonstrated by the primary measure. The registry record does not report a numerical gain-ratio estimate or interval, so the extent or precision of any measured change cannot be assessed from the primary outcome results reported in the record.

3. Trial Design

NCT03589859, titled Computerized Vestibular Rehabilitation, is recorded as completed. The registry lists an enrollment of 24 and identifies the sponsor as the VA Office of Research and Development. The study start date is 2018-12-01, and the primary completion date is 2022-11-30. These record-level details do not establish how many participants contributed data to each outcome or analysis.

The registry describes two groups with different purposes. Normal Volunteers were included for testing motor learning. The Vestibular Hypofunction group was included for testing the feasibility of the rehabilitation game. Because the groups had different stated roles, they should not be treated as interchangeable arms in a direct efficacy comparison. The record explicitly indicates that the study was not a randomized comparison and that allocation was not stated.

Interventions listed in the record are a VOR Test, a Computer Game, and a Nausea Scale. The primary endpoint was the Vestibulo-ocular Reflex Gain Ratio, a continuous measure reported as a mean with a 95% confidence interval. VOR measurements for gain were taken immediately before and after each approximately 30 minute training session; the pre- and post-training gains were then combined into the ratio. The registry record does not report the number of sessions, the sequence of activities, or further details of the allocation process.

The record lists two outcome measures and one analysis. It does not report a full statistical analysis plan, the analysis populations, or how the reported enrollment relates to the number analyzed for each measure. Therefore, the design can be described from the stated aims and recorded procedures, but details beyond those statements 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: This measure applied only to Group 1: healthy individuals with intact vestibular function

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 Vestibulo-ocular Reflex Gain Ratio, measured over VOR measurements to determine gain were performed immediately before and after each approximately 30 minute training session. Pre- and post-training gains were then combined in the VOR gain ratio to determine the training effect..

The primary outcome, Vestibulo-ocular Reflex Gain Ratio, measures the relation between head rotation and the eye movement elicited by it. VOR gain is estimated by fitting eye speed to the head speed that evokes it. The endpoint is the post-training gain divided by the pre-training gain, combining measurements taken immediately before and after each approximately 30 minute training session.

A gain ratio expresses change relative to the participant’s own pre-training gain. A ratio above unity would indicate that post-training gain was greater than pre-training gain; a ratio below unity would indicate the reverse. The registry describes normal gain as 1. For this motor-learning experiment, it says that increasing gain to a value above unity is better with respect to the training goal. It also cautions that this is not the same as better real-world visual function, for which a gain of 1 is the goal. The endpoint is therefore tied to the specific learning objective, not a general measure of clinical benefit.

The registry identifies this measure as applying only to Group 1, healthy individuals with intact vestibular function. It states that there is no threshold value for this kind of motor-learning experiment: the question is whether gain increased after training and, if so, by what percentage relative to the training goal. The registry record does not report the mean gain ratio or its confidence interval, so the magnitude and precision of the endpoint result are not available in the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary endpoint as a continuous measure summarized by a mean and a 95% confidence interval. The endpoint is the ratio of VOR gain after training to VOR gain before training. The following explanations are general statistical context; the registry record does not report the detailed analysis procedure used to obtain a primary-outcome estimate.

What does the mean describe?

A mean is a measure of the center of a set of numeric observations. For this endpoint, each observation represents a post-training gain relative to a pre-training gain. The mean gain ratio would describe the average relative change in the analyzed group, rather than the result for every individual. Participants can have different ratios, so a group mean alone does not show the spread of individual responses. The registry record does not report the mean or other distributional summaries for the primary endpoint.

What does a confidence interval add?

As a general explanation, a confidence interval communicates the uncertainty associated with an estimated quantity under a specified statistical procedure and its assumptions. It complements the point estimate: the estimate gives a central summary, while the interval indicates how precisely that summary has been estimated. A confidence interval is not a guarantee that individual observations fall inside its limits, and it does not show the range of possible effects for every person. The registry lists a 95% confidence interval as the primary outcome’s dispersion measure but does not report its limits. The method used to construct the interval is not reported in the registry record.

How should the ratio be understood?

The ratio compares post-training gain with pre-training gain. A ratio of 1 corresponds to no relative change between those measurements. A ratio above 1 indicates higher post-training gain, and a ratio below 1 indicates lower post-training gain. This is a general reading of the ratio and aligns with the registry’s description of the learning goal. The record emphasizes that a higher gain in this experiment is not equivalent to better real-world visual function: the stated real-world goal is a gain of 1. The endpoint therefore has to be interpreted in the context of the experimental training objective.

What does the study design imply for comparisons?

The registry says the study was not a randomized comparison and that allocation was not stated. It describes the Normal Volunteers group as testing motor learning and the Vestibular Hypofunction group as testing feasibility. Since the aims differ, a numerical difference between these groups would not automatically represent an intervention effect. The record does not describe a like-for-like control comparison, and it does not report an adjusted or unadjusted between-group estimate for the primary endpoint.

What can planning calculations establish?

As a general matter, sample-size planning calculations illustrate the number of participants that might be needed under chosen assumptions to detect a specified effect with a stated statistical approach. They do not show the observed result and are not observed power. The planning assumptions associated with this study use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. The planning illustration is based on the observed effect, rather than the trial’s own design. Its numerical outputs and the observed effect are not reported in the registry record, so no planning sample-size values or interpretation of their scale can be stated. These assumptions should not be mistaken for the trial’s analysis plan.

More generally, statistical interpretation depends on the analysis population, the handling of missing measurements, the model or calculation used, and the precision of estimates. Those details are not reported in the registry record. The reported outcome label and summary type identify the intended form of the primary result, but they do not establish which specific estimation method was used or whether any adjustment was applied.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures and one analysis. It does not state how many hypotheses were tested, whether the listed outcomes were analyzed using separate tests, or whether any multiplicity adjustment was planned. The registry record does not report a statistical analysis plan describing a hierarchy of outcomes or a rule for interpreting several analyses together.

As general statistical context, testing multiple outcomes or multiple hypotheses can increase the chance of at least one apparently unusual result when each test is interpreted on its own. Methods for addressing multiplicity can alter the criteria used to interpret results. Whether such methods were needed or used in this study cannot be determined from the registry record. The number of outcomes listed alone is not enough to infer the testing strategy.

The registry record does not report the analysis populations for the primary endpoint or the other outcome measure. It does not state how many participants contributed endpoint data, how missing observations were handled, or whether participants were excluded from any analysis. The listed enrollment of 24 is not a substitute for an analyzed denominator. It also does not establish that every enrolled participant completed every procedure or posted usable measurements.

As general statistical context, missing outcome data can affect both the precision and interpretation of an estimate, depending on how much is missing and why. Different handling methods rely on different assumptions. Since the registry does not describe missingness or its handling, the potential influence on the primary estimate cannot be evaluated from this record. Similarly, the record does not report whether the analysis followed an intention-to-treat, per-protocol, or other population definition. No such approach should be inferred from the study’s completion status or enrollment figure.

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 5% reporting threshold.

The registry lists serious adverse event counts as zero affected among 18 at risk in Normal Volunteers and zero affected among 6 at risk in Vestibular Hypofunction. It also lists other adverse event counts as zero affected among 18 at risk in Normal Volunteers and zero affected among 6 at risk in Vestibular Hypofunction. Deaths are listed as zero in each group. No top serious adverse event terms are listed.

These are the counts recorded in the registry, not proof that an event was impossible or that risk was absent. As general statistical context, observing no events in a group does not establish a true event rate of zero; the strength of any safety inference also depends on observation and ascertainment details. The registry record does not report the duration of safety follow-up, event-collection procedures, or further detail about how these counts were obtained. The at-risk figures are safety denominators and should not be assumed to be the number analyzed for the primary endpoint.

The safety counts do not answer the motor-learning question measured by the VOR gain ratio. They are descriptive adverse-event information, while the primary endpoint concerns change in a physiologic measure after training. The record does not report a comparative safety analysis.

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

The record describes a completed study intended to examine whether a computer game could facilitate vestibular motor learning and whether it could be used feasibly in a vestibular rehabilitation context. The primary endpoint was a post-training to pre-training VOR gain ratio in healthy participants with intact vestibular function. A separate group with vestibular hypofunction was included for feasibility testing.

The registry record does not report the numerical primary-outcome estimate or its 95% confidence interval. It therefore does not allow readers to judge the size or precision of the measured change from the record’s results. The record also does not report a numerical feasibility result. The study’s status as completed and its enrollment of 24 do not supply those missing outcome details.

The endpoint has a specific interpretation: an increase above unity is described as better relative to the motor-learning goal, while a gain of 1 is the stated goal for real-world visual function. The registry explicitly distinguishes this experiment from treatment of impairment. Therefore, the endpoint should not be taken as evidence on its own of improved daily visual function, reduced falls, better quality of life, or clinical effectiveness in people with vestibular disease.

The two groups also cannot be treated as a randomized treatment and control pair. The record says allocation was not stated and the study was not a randomized comparison; moreover, each group had a different stated purpose. The record does not establish that outcomes can be contrasted between them to estimate a causal effect.

In short, the registry supports a description of the study’s aim, endpoint, groups, and recorded adverse-event counts. It does not provide the numerical primary result or enough analysis detail to determine its statistical precision, assess missing-data effects, or draw a quantitative conclusion about motor learning. The study’s stated research aim should not be confused with evidence that the intended future rehabilitation tool achieves clinical benefit.

13. Why This Trial Matters Statistically

This trial is statistically notable for the distinction between a physiologic learning target and a patient-centered clinical outcome. VOR gain was measured before and after training and expressed as a ratio. The registry explains that moving above unity was considered better for the experimental training goal, while a gain of 1 is the goal for real-world visual function. That distinction is important: the direction of change in a mechanistic measure does not automatically have the same interpretation as change in everyday function.

The study also combines two purposes that should remain separate in interpretation. Normal Volunteers were included to test motor learning, and the Vestibular Hypofunction group to test feasibility. Since the record does not describe a randomized comparison and does not state allocation, the groups should not be treated as an intervention and control pair. Recognizing the role of each group helps prevent a descriptive group contrast from being read as a causal estimate.

Precision is central to interpreting a continuous endpoint. A mean gain ratio would summarize average change, while its confidence interval would indicate uncertainty around that estimate. The registry record specifies this summary format but does not report the estimate or interval. That gap limits quantitative interpretation: the study question and measurement are described, but the amount of observed change and its precision cannot be assessed from the registry results.

The record’s safety counts are also appropriately read as descriptive. Zero recorded serious and other adverse events in the listed risk groups is useful context, but without follow-up and ascertainment details it cannot establish absence of risk. Taken together, the study illustrates why endpoint meaning, group purpose, estimation uncertainty, and completeness of reporting all matter when interpreting a small feasibility and learning 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.

A central limitation of interpretation is that the registry record does not report the numerical mean for the primary VOR gain ratio or the endpoints of its 95% confidence interval. The direction, magnitude, and precision of the primary result therefore cannot be evaluated from the results recorded. The record also does not report a numerical result for feasibility.

The study was not a randomized comparison, and allocation was not stated. The groups had different purposes: motor-learning testing in Normal Volunteers and feasibility testing in Vestibular Hypofunction. Consequently, the record does not support treating the groups as a like-for-like control comparison. The available descriptions do not establish a basis for attributing a between-group contrast to the game.

The primary measure applied only to Group 1, healthy individuals with intact vestibular function. The record cautions that the experiment was not treatment of impairment and that the learning goal differs from the goal for real-world visual function. This limits the meaning that can be assigned to the endpoint beyond the stated motor-learning context.

The registry record lists an enrollment of 24, but it does not report the number analyzed for the primary outcome, the analysis populations, or the handling of missing data. It also does not report the detailed statistical analysis plan, the method used to construct the confidence interval, or whether any multiplicity adjustment was used. These omissions prevent assessment of several assumptions and analysis choices that can affect the interpretation of an estimate.

For safety, counts are recorded, but the duration of follow-up and event-collection procedures are not reported in the registry record. The absence of recorded events should therefore be read descriptively rather than as evidence that risk was absent. These reporting limitations restrict what can be concluded from the record; they do not by themselves establish that the study procedures were inadequate.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Computerized Vestibular Rehabilitation — NCT03589859.
• Registry record last updated 2024-11-26; status last verified 2024-10.
• Results first posted 2024-11-26.
• 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

NCT03589859, Computerized Vestibular Rehabilitation, is recorded as completed, with an enrollment of 24. The sponsor is the VA Office of Research and Development. The study’s stated goal was to assess game-based vestibular motor learning and feasibility.

The primary outcome was the mean Vestibulo-ocular Reflex Gain Ratio, with a 95% confidence interval. It applied to healthy individuals with intact vestibular function and compared VOR gain after training with gain before training. The Vestibular Hypofunction group was described as testing feasibility. The registry says the study was not a randomized comparison and does not state allocation.

The registry lists two outcome measures and one analysis, but does not report the numerical primary result, its confidence interval, analysis populations, or missing-data handling. Serious and other adverse event counts were zero in both listed groups, as were deaths. These safety counts are descriptive and do not replace the unreported primary outcome estimate.