Virtual Reality Education Program to Reduce Anxiety During Radiation Therapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Virtual Reality Education Program to Reduce Anxiety During Radiation Therapy (NCT04029961), a randomized na study. The primary outcome is Intra- and Inter-arm Differences in Pre-post Intervention Changes in Anxiety Using the State Trait Anxiety Inventory (STAI) for Adults Scores.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group study comparing VR-based Education with Video Education. The official title describes it as a pilot study for developing and implementing a virtual reality-based radiation therapy education and anxiety mitigation program. The registry lists the phase as NA, allocation as randomized, and masking as none. Thus, the record describes a randomized comparison without masking; it does not state that participants, educators, or outcome assessors were masked.

The registry reports enrollment of 28. The study started on 2019-08-12, and the primary completion date is 2020-04-14. Its status is terminated. The reason for termination is not reported in the registry record. The record does not specify the allocation ratio or provide final randomized and analyzed participant counts by arm. Safety figures list 12 participants at risk in each group, but those figures do not establish the number included in the primary outcome analysis.

Participants received either video education on radiation therapy or VR-based education on radiation therapy. The study summary says self-evaluation questionnaires were used to assess information needs, anxiety, stress, preparedness, and satisfaction before and after education. The primary outcome description also refers to measurement directly following the first radiation therapy treatment. The record does not describe the randomization procedure, how study visits were scheduled, or whether the education groups differed in any other care or contact.

The registry lists 5 outcome measures and 5 analyses. Further details about the statistical analysis plan, including the specific model or test used for the primary comparison, are not reported in the registry record. The status and dates provide context for the study, but do not explain why it was terminated or whether all planned assessments were completed.

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: Of 28 consented participants, 26 were found eligible and randomized to an intervention. One participant was considered ineligible after consent after moving treatment out of state and one participant's participation in the study was cancelled due to the COVID-19 pandemic.

Overall Study

Reasons for not completing this period:

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.

Population: Only complete datasets were analyzed in this study. There was one participant in the VR arm for whom baseline measurements were collected, but not used in the final data analysis, as the patient was withdrawn due to a change in treatment course prior to completing the study.

6. Primary Endpoint

The registry lists the primary outcome as Intra- and Inter-arm Differences in Pre-post Intervention Changes in Anxiety Using the State Trait Anxiety Inventory (STAI) for Adults Scores, measured over Directly pre/post education (education appointment), directly following first radiation therapy (RT) treatment (first RT session).

The primary outcome is described as intra- and inter-arm differences in pre-post intervention changes in anxiety using State Trait Anxiety Inventory for Adults (STAI) scores. The STAI is a self-evaluation questionnaire with a trait anxiety scale and a state anxiety scale. Each scale ranges from 20 - 80, with higher scores representing higher anxiety. The outcome is continuous, and the registry identifies its summary measure as the mean with standard deviation.

The scheduled measurements are described as directly pre/post education at the education appointment and directly following the first radiation therapy treatment. The outcome description says the questionnaire was administered at three time points, but does not identify the precise timing of every administration or specify which STAI scale or combination of scales is the primary score for analysis. Those details are not reported in the registry record.

Repeated anxiety measurement can describe whether reported anxiety changes around education and the start of treatment, while a comparison between arms can assess whether the pattern of change differs between the education approaches. In general, self-reported anxiety is relevant to an education intervention because it captures participants’ own assessments rather than an observer’s rating. It remains a measure of reported anxiety, not a direct measure of treatment delivery or clinical outcome. No numerical primary outcome results are reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is a continuous score summarized by a mean and standard deviation. The registry describes a randomized, parallel-group comparison, but does not report the specific statistical model, test, adjustment strategy, or primary contrast used. The concepts below explain how such data are generally interpreted; they are not a claim about the analysis actually performed in this study.

What do the mean and standard deviation describe?

In general, a mean represents the average score in a group at a specified assessment time, or the average change if the analysis uses change scores. A standard deviation describes how spread out individual scores are around that mean. It describes variation among observations, not the precision of the mean itself. The amount of precision depends on the data and the analysis, and cannot be inferred from a mean alone.

For an anxiety scale, a group mean gives a broad summary of reported scores. It does not show every participant’s experience or indicate whether individual scores moved in the same direction. A mean change can also hide variation in individual change. The registry record supplies the scale ranges and the direction of scoring, but does not give numerical group means or standard deviations.

Why distinguish within-arm change from the between-arm comparison?

In general, a within-arm analysis compares measurements from the same group across time. A between-arm analysis compares outcomes across the randomized groups. The primary outcome title refers to both within-arm differences and between-arm differences in pre-post changes. The latter is the key contrast for evaluating whether changes differ between the two assigned education approaches.

Repeated measurements from the same participant are related: a participant’s scores at different times are not independent observations. Statistical methods for repeated measures account for that relationship in different ways. An analysis based on change scores, a repeated-measures model, or a comparison at a selected follow-up time can answer somewhat different questions and rely on different assumptions. The registry record does not state which approach was used, how correlations across assessments were handled, or which time point was designated for the primary contrast.

Randomization supports a comparison of assigned groups, but does not remove the need to describe the analysis population and missing observations. In general, the chosen population might be based on randomized assignment, treatment received, or availability of outcome measurements; these are not interchangeable definitions. The registry record does not report which population was used for the primary analysis.

How should uncertainty and statistical significance be read?

In general, a confidence interval conveys uncertainty around an estimated contrast. A narrow interval indicates greater precision than a wide interval, while an interval that spans values in different directions may leave the direction or size of the contrast uncertain. A p-value assesses compatibility of the observed data with a specified null hypothesis under a statistical model; it is not a measure of clinical importance, and it does not describe the probability that a hypothesis is true. No primary-outcome estimate, confidence interval, or p-value is reported in the registry record, so these features cannot be evaluated for this trial.

Statistical significance and practical importance are also distinct. A small difference can be estimated precisely, while a potentially important difference can remain uncertain when data are limited. The registry does not state a threshold for interpreting a meaningful STAI change, so a clinical-importance threshold cannot be applied from the record.

What do the planning assumptions mean?

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It describes the target effect as a stated fraction of the observed effect. These assumptions define an illustration for planning, not the trial’s own design justification. The record does not report the sample-size justification used when the trial was designed, or any numerical planning outputs in the registry record for this analysis.

Such illustrations are not observed power and should not be read as a retrospective test of whether the trial succeeded. In general, a planning estimate depends on the assumed effect, variability, allocation, and analysis method. Changing the assumed fraction of an effect changes the planning question. Here, the registry’s stated assumptions do not replace an analysis of the actual outcome data or quantify the precision of the primary comparison.

Why can multiple assessments complicate interpretation?

The record describes multiple STAI assessment times and lists 5 outcome measures and 5 analyses. In general, examining multiple outcomes or time points creates multiple opportunities to find an apparently notable result. A prespecified analysis plan can clarify which contrast is primary and how additional analyses are interpreted. The statistical plan and any method for handling multiplicity are not reported in the registry record. It is therefore not possible to determine from the record whether the reported analysis, if any, followed a prespecified hierarchy or adjusted for multiple comparisons.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 5 outcome measures and 5 analyses. The primary anxiety outcome description includes multiple assessments: the STAI was administered at three time points, with timing described around education and the first radiation therapy treatment. Testing several outcomes, time points, or contrasts can increase the chance of a statistically notable finding even when there is no single underlying effect. In general, a prespecified hierarchy or multiplicity adjustment can help define how such findings are interpreted. Neither a hierarchy nor an adjustment method is reported in the registry record.

The registry does not report numerical results for the primary outcome in the registry record for this analysis, and it does not describe the results or analysis methods for the other outcomes. The record also does not state whether all planned analyses were conducted or identify any deviations from the original plan. As a result, the number of analyses listed does not reveal how many comparisons were tested or how their interpretation was controlled.

Missing data are especially relevant when repeated questionnaires are planned, because participants may have scores available at some assessments but not others. In general, complete-case analysis, imputation, and models using available repeated observations make different assumptions about missingness and can yield different estimates. The registry record does not report missing questionnaire counts, reasons for missingness, a method for handling missing data, or sensitivity analyses.

The registry also does not identify the primary analysis population or clarify whether the analysis followed randomized assignment. Without those details, the contribution of participants with incomplete assessments and the handling of participants who did not receive the assigned education cannot be determined. These omissions limit assessment of the risk of bias and the reproducibility of the outcome analysis.

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 safety record lists 0 serious adverse events and 0 other adverse events in the Video Education group, with 12 participants at risk. It also lists 0 serious adverse events and 0 other adverse events in the VR-based Education group, with 12 participants at risk. Deaths are listed as 0 in both groups, and no serious adverse event terms are listed.

These are recorded event counts, not proof that no unrecorded events occurred or that the groups have identical safety profiles. A zero count in a group does not by itself establish zero risk; interpretation depends on the observation period, completeness of reporting, and the way events were collected. The registry record does not give further information about event definitions, the duration of safety follow-up, or whether event collection was systematic.

The figures describe safety reporting, not the anxiety outcome. The at-risk counts in the safety record should not be treated as the number analyzed for the primary endpoint. The registry does not separately report primary outcome analysis counts by group, and the safety figures cannot resolve the missing numerical anxiety results.

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

The registry record establishes that a randomized, parallel-group pilot compared video education with VR-based education for breast cancer patients preparing for radiation therapy. It defines a primary anxiety outcome using the STAI and describes assessment around education and the first radiation therapy treatment. It also reports safety event counts for both groups. These are useful details about the study’s question and registered conduct.

The record does not report numerical primary outcome findings. There are no group means, changes, between-group estimates, confidence intervals, or p-values in the registry record for this analysis. It is therefore not possible to determine the direction, size, or precision of an anxiety difference from this record. The study description alone does not show that either education approach changed anxiety or that one approach was better than the other.

Even if an estimate were available, a change within one arm would not by itself show that the change was caused by that education approach or that it differed from the other arm. In general, the randomized between-group contrast is the relevant basis for comparing assigned strategies, interpreted with its uncertainty and the analysis assumptions. The registry does not report the primary contrast estimate or the method used to obtain it.

The absence of reported numerical results should not be converted into a conclusion of no effect. It means that the effect cannot be quantified from the registry record. Similarly, zero recorded adverse events in the safety figures does not establish an absence of all possible harms, particularly without further information about event collection and follow-up.

The study’s pilot designation and terminated status provide context, but the registry does not explain the reason for termination or report the sample-size justification. The record also lacks details about missing outcome data and the primary analysis population. These limitations leave substantial uncertainty about completeness and precision. The appropriate interpretation is therefore narrow: the registry describes a comparison and its planned anxiety measure, but does not report enough numerical outcome information to support a conclusion about the comparative anxiety results.

13. Why This Trial Matters Statistically

This trial raises a statistical question that is common in patient education research: whether an intervention changes a patient-reported outcome differently from an active educational comparison. The design is randomized and parallel-group, and the primary outcome title explicitly distinguishes changes within each arm from differences between arms. That distinction matters because improvement or worsening within one group does not establish a comparative effect.

The endpoint is assessed at multiple times around education and the beginning of radiation therapy. Those time points can reflect different parts of the patient experience, making timing and the chosen contrast central to interpretation. The registry record describes three questionnaire administrations but does not clarify the exact primary time-specific comparison or the analysis model. This highlights why outcome timing and prespecification are important parts of a statistical plan.

The pilot study also illustrates the difference between a planning illustration and evidence about the observed result. The registry describes planning assumptions, but a planning calculation does not reveal the precision of the outcome estimate or establish that the study was adequately powered. Those questions require outcome estimates and uncertainty measures, which are not reported in the record available for this analysis.

Finally, the registry’s lack of numerical primary results, missing-data details, and analysis-population information limits what can be learned from the registered record. These are not reasons to infer a particular result. They identify what is needed to assess a randomized comparison: the estimated between-group effect, its precision, the data contributing to the estimate, and the analysis decisions behind it. The study’s question is clear, while its comparative anxiety findings remain unquantified in the registry record.

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.

Several limitations specific to this trial affect interpretation. The registry identifies STAI as the primary anxiety measure but does not state whether the primary score uses the state scale, the trait scale, or both. Although the questionnaire is described as having two scales, the exact score used for the primary analysis is not reported. This makes it difficult to determine precisely which anxiety construct the primary result would represent.

The outcome description refers to three questionnaire administrations and gives timing around the education appointment and the first radiation therapy treatment. It does not map every administration to a specific time point or identify which assessment supplies the primary comparison. Because anxiety can vary with the timing of education and treatment, this missing detail limits interpretation of the intended change.

The registry does not report numerical outcome results, group-specific primary analysis counts, missing questionnaire counts, or the method used to handle missing data. It also does not identify the primary analysis population or state the model used for repeated measurements. These omissions prevent assessment of the estimate’s precision and the potential influence of incomplete follow-up.

The record lists the study as terminated but does not report why. It does not provide the sample-size justification or explain whether the planned analyses were altered. The safety record provides event counts and at-risk counts, but further details about event collection and follow-up are not reported. Together, these limits mean that the registry describes the study question and design more fully than it describes the evidence needed to evaluate the comparative anxiety outcome.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Virtual Reality Education Program to Reduce Anxiety During Radiation Therapy — NCT04029961.
• Registry record last updated 2021-05-10; status last verified 2021-04.
• Results first posted 2021-05-10.
• 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.

18. Record Summary

NCT04029961 is a randomized, parallel-group study comparing video education with VR-based education about radiation therapy for breast cancer patients preparing for treatment. The official title describes a pilot study. The registry reports enrollment of 28, a start date of 2019-08-12, a primary completion date of 2020-04-14, and terminated status. The reason for termination is not reported in the registry record.

The primary outcome concerns pre-post changes in anxiety measured with the STAI. Its two scales range from 20 - 80, with higher scores representing higher anxiety. The registry describes three questionnaire administrations and identifies the outcome as a mean with standard deviation. Numerical primary outcome results and the statistical analysis method are not reported in the registry record.

Safety figures list no serious or other adverse events and no deaths in either group, with 12 participants at risk per group. The record lists 5 outcome measures and 5 analyses, but does not report details of multiplicity handling, missing data, or the primary analysis population.