Virtual Reality to Improve Social Perspective Taking: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Virtual Reality to Improve Social Perspective Taking (NCT03927612), a randomized na study. The primary outcome is Change From Pre-intervention on the Virtual Reality Perspective Taking Scale.

2. Clinical Question

The study is concerned with whether experiencing an interaction from a virtual counterpart's point of view is associated with a different immediate change in a measure of perspective taking than repeating the interaction from the same perspective. The outcome is a score intended to indicate how well participants understand the virtual counterpart's perspective. The registry describes a higher change score as indicating greater improvement in perspective taking in the virtual environment.

The registry's brief summary also describes anticipated psychological and neurobiological effects, including brain function related to imagining another person's pain. Those anticipated effects describe the study's rationale; the primary outcome result is the scale's change score. The record lists three outcome measures, but it does not post secondary outcome results. Thus, the reported primary comparison addresses the scale-based question, not every psychological or neurobiological question raised in the study description.

3. Trial Design

The registry classifies the study as randomized, triple masked, and parallel. A randomized design assigns participants to study groups by chance, in principle reducing the influence of systematic differences in who receives each condition. A parallel design means the registry presents distinct groups receiving the alternate-perspective or control-perspective condition. The record does not describe the precise randomization procedure or which parties were masked, so those details are not reported in the registry record.

The registry records an enrollment of 90 and a completed study. The primary outcome results list 23 participants in the Alternate Perspective group and 22 in the Control Perspective group. The serious-adverse-event record lists 24 participants at risk in each group. These are separate reported counts for the outcome and safety results; the record does not explain their relationship, and no explanation should be inferred from these figures.

The intervention descriptions distinguish the conditions by the perspective used when participants experienced the VR interactions again. The Alternate Perspective group experienced them from the virtual counterpart's perspective; the Control Perspective group experienced them again from the same perspective. Both are described as virtual reality conditions. The registry labels the interventions as devices and does not provide further detail about session procedures or implementation.

The primary outcome was assessed before and after the intervention on the same day. The registry identifies the primary outcome timeframe as 1 Day. It does not report the trial's original sample-size justification, the planned statistical model, or further protocol details about the analysis. The design labels and outcome description establish the broad comparison, but they do not supply all details needed to reconstruct how the trial was conducted or analyzed.

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: Families underwent clinical interview to establish child's psychiatric diagnoses (required disruptive behavior disorder without autism spectrum disorder or current depression for assignment to group). Participants also underwent baseline surveys, practice VR (also used to assess presence of VR sickness for exclusion criteria), and baseline MRI scan. Enrolled participants were not randomized if they did not meet inclusion criteria or discontinued participation prior to the intervention visit.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Children aged 9-12 with a disruptive behavior disorder

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: While all participants completed the study, data from one participant in the Alternate Perspective arm was not included in analysis due to inability to follow instructions and two participants in the Control Perspective were not included (one failure to follow instructions; one equipment malfunction).

6. Primary Endpoint

The registry lists the primary outcome as Change From Pre-intervention on the Virtual Reality Perspective Taking Scale, measured over 1 Day.

The primary endpoint is change from pre-intervention on the Virtual Reality Perspective Taking Scale. The scale gives a 0-100 score intended to reflect the degree to which participants understand the perspective of their virtual counterpart. It is derived from the Perspective Taking subscale of the Interpersonal Reactivity Index. The outcome description states that a higher change score indicates greater improvement in perspective taking in the virtual environment.

Change is used to express how the score differs between the pre-intervention and post-intervention assessments, which the registry says were completed twice on the same day. Comparing the groups' mean change scores therefore addresses whether average short-term score changes differed between the two assigned perspectives. It does not, by itself, establish how participants perform in settings outside the virtual environment or whether any change persists beyond the listed timeframe.

The endpoint is a continuous measure, and the registry reports group means and standard deviations. The Alternate Perspective group mean change was 16.3, with a standard deviation of 27.9; the Control Perspective group mean change was -10.4, with a standard deviation of 26.3. The posted mean difference is 26.7. These values describe the reported scale outcome and its spread; the scale's stated direction gives the positive change scores a specific interpretation, but the score remains a measure of the outcome defined in the registry.

7. Results Posted in the Registry

• Alternate Perspective: mean 16.30 versus -10.40 on control; difference 26.70 (95% CI 10.86 to 42.54), standardized effect d = 0.98; z-test p = <0.001.

8. Statistical Interpretation

9. Statistical Methods Explained

The registry presents a continuous primary outcome as a mean change score for each group and a mean difference between the groups. The comparison includes a confidence interval and an unadjusted p-value. The detailed statistical procedure used by the sponsor is not reported in the registry record. The concepts below explain how these types of statistics are generally interpreted; they do not identify an unreported analysis method.

What does a mean change describe?

General explanation: a mean is the arithmetic average of observations. For a change outcome, each participant's post-intervention measurement is compared with that participant's pre-intervention measurement, and the group mean describes the average of those changes. A mean can summarize the center of a group while concealing differences among individual participants. Here, the reported means are 16.3 for Alternate Perspective and -10.4 for Control Perspective. The scale description says that a higher change score represents greater improvement in perspective taking in the virtual environment.

A mean difference compares the two group averages. The registry posts a mean difference of 26.7 and specifies the group means as -10.4 for Control Perspective and 16.3 for Alternate Perspective. The positive direction is consistent with a larger average change in the Alternate Perspective group on this scale. It does not imply that each participant's outcome followed the group-average pattern. The standard deviations, 27.9 and 26.3, describe how spread out the individual change scores are around their respective group means.

What does the confidence interval add?

General explanation: a confidence interval communicates uncertainty about an estimated quantity. The interval for the posted mean difference extends from 10.86 to 42.54. It presents a range of values compatible with the data and the method's assumptions, rather than a guarantee that the true value lies within the particular interval. A narrower interval would indicate greater precision; a wider one would indicate more uncertainty about the size of the difference. The interval's endpoints allow readers to assess both the direction and plausible magnitude of the estimated contrast.

The registry also reports standard errors of 5.607 for the control group mean and 5.818 for the alternate-perspective group mean. In general, a standard error describes the estimated sampling variability of a statistic, rather than the spread of individual observations. It is therefore conceptually different from a standard deviation. The outcome standard deviations describe participant-level variation, while standard errors concern uncertainty in estimated group means. The registry does not give enough detail to establish how these standard errors or the interval were calculated.

How should the p-value be read?

The reported unadjusted p-value is <0.001. General explanation: a p-value measures how incompatible the observed result, or a more extreme result, is with a specified null hypothesis under the assumptions of a statistical test. It is not a probability that the null hypothesis is true, a measure of effect size, or a measure of the chance that the finding will replicate. The word unadjusted indicates that the displayed p-value is not presented as adjusted for multiple comparisons. Whether an adjustment was planned or used elsewhere is not reported in the registry record.

The p-value and confidence interval answer related but different questions. The p-value summarizes evidence against a null value under a test, while the interval emphasizes uncertainty in the estimated difference and its plausible scale. Neither replaces examination of the outcome definition, group sizes, variability, and analysis assumptions. Statistical evidence is also distinct from evidence about clinical importance, durability, or outcomes not measured by the primary scale.

Why does variation matter?

General explanation: variability among participants affects how precisely group means and differences can be estimated. With greater participant-level spread, the group mean may be less precise for a given sample size. The reported standard deviations show appreciable variation in both groups, so the group averages should not be treated as descriptions of every participant. The registry does not report individual scores or distributional plots in the record details, so the shape of the score distributions cannot be assessed from the summary statistics alone.

General explanation: over-dispersion refers to variability greater than a model's assumed variance structure allows. It matters because a model that understates variability may produce standard errors that are too small and confidence intervals that are too narrow. The primary endpoint is reported as a continuous measure with means and standard deviations; the record does not state that an over-dispersion problem was identified or that a model requiring a particular variance structure was used. This concept is relevant generally, not a claim about an observed analysis issue in this trial.

Which analysis choices remain unclear?

The registry identifies the trial as randomized and the outcome as a mean, but it does not report the full statistical analysis plan, the exact test or model behind the comparison, any covariate adjustment, or the missing-data method. It also does not state whether the primary result used an intention-to-treat, per-protocol, or another analysis population. These details can affect interpretation and reproducibility. The posted comparison can be described as reported, while the unreported procedures should remain unknown rather than reconstructed from the result alone.

10. Confidence Intervals and Precision

The posted mean difference is 26.7, with a confidence interval from 10.86 to 42.54. The interval communicates uncertainty about the magnitude of the average contrast between the two groups. Its lower and upper endpoints are both on the positive side of zero, which is consistent with the positive posted estimate and the reported p-value of <0.001. The interval does not mean that all plausible values are equally likely, and it is not a range of individual participant outcomes.

Precision should be considered alongside the group sizes and score variability. The primary outcome results list 23 participants in the Alternate Perspective group and 22 in the Control Perspective group. The group standard deviations are 27.9 and 26.3, respectively. These standard deviations describe variation in participants' change scores, not uncertainty in the mean difference itself. The interval combines information about the estimate and its uncertainty under the method used, but the exact interval-construction procedure is not reported in the registry record.

The interval is informative about the scale of the statistical contrast, but it does not establish how important that contrast is in practical terms. The registry does not report a threshold for a meaningful change on this scale, and the confidence interval cannot supply such a threshold. Nor does it address how long a change might last: the primary assessment is described as occurring on the same day as the intervention. Precision for this endpoint should therefore not be mistaken for precision about long-term outcomes or other measures.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size planning figures are participants per arm, not total events. They are planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers detecting a stated fraction of the observed effect: 100%, 75%, or 50%. The registry does not report the trial's original sample-size assumptions or justification, so these figures should not be treated as the study's original design targets.

For 100% of the observed effect, the illustration gives 17 participants per arm for 80% power and 22 participants per arm for 90% power. For 75% of the observed effect, it gives 29 participants per arm for 80% power and 39 participants per arm for 90% power. For 50% of the observed effect, it gives 65 participants per arm for 80% power and 87 participants per arm for 90% power.

In plain terms, the 80% power column gives the estimated number of participants in each arm for a design with an 80% chance of detecting the specified effect under the stated assumptions; the 90% column describes the corresponding planning target for a 90% chance. Smaller effects require more participants to detect under the same assumptions, as the illustrations indicate. These are planning illustrations, not observed power. They do not tell how much power the completed trial had, and they are not evidence that the study was designed around the observed difference.

A sample-size curve, when read alongside these figures, represents how the planned number of participants changes with the effect size under the stated assumptions. It is a design aid rather than an additional trial result. Its interpretation depends on the same assumptions and should not be extended to unreported design choices, such as a planned allowance for missing observations.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 26.700; pooled standard deviation σ = 27.130.
2. n = 2 × (1.96 + 0.842)² × 27.130² / 26.700² = 16.2, rounded up to 17 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 26.7                      # observed difference in means
sigma <- 27.1303957231188                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(3927612)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 17 (80% power), 22 (90% power)
 75% of observed effect: n per arm = 29 (80% power), 39 (90% power)
 50% of observed effect: n per arm = 65 (80% power), 87 (90% power)
power.t.test: 17.2 
Simulated power at n = 17 per arm: 0.790 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures and posts a primary outcome result, but no secondary outcome results are posted. The primary measure is identified as change from pre-intervention on the Virtual Reality Perspective Taking Scale. The registry record does not report whether the trial had a prespecified hierarchy for outcomes, how many statistical tests were planned, or whether any multiplicity adjustment was part of the analysis plan. The displayed p-value is unadjusted. Without the full analysis plan, it is not possible to determine whether and how the family of planned tests was addressed.

Multiplicity matters generally when several hypotheses are tested: the chance of at least one apparently unusual result can increase as the number of tests grows. Adjustment approaches can control that risk, but they may also affect precision or the threshold used for interpretation. This general consideration does not establish that a particular adjustment was required or omitted in this trial. The record does not provide enough information about the planned testing strategy to make that determination.

The registry does not report how missing primary outcome data were handled, whether all randomized participants contributed to the displayed means, or whether any participants were excluded from an analysis. It also does not report an intention-to-treat or per-protocol designation for the primary comparison. These are important analysis-population details: different rules for retaining or excluding participants can change the population represented by an estimate. The posted group counts alone do not explain why the outcome results list 23 and 22 participants while the safety record lists 24 at risk in each group.

Further information about missingness, exclusions, imputation, and analysis populations is not reported in the registry record. The result can be interpreted as the comparison posted for the reported outcome counts, while the influence of unreported handling decisions remains unknown. No conclusion about selective reporting or bias can be drawn from these omissions alone.

14. 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 serious-adverse-event record lists 24 participants at risk in each group. It reports zero participants affected by serious adverse events in Alternate Perspective and zero in Control Perspective. The record also lists zero participants affected by other adverse events in each group and zero deaths in each group. No top serious-event terms are listed.

These are counts recorded for the listed groups and denominators. A count of zero means no event was recorded in that category in the registry results; it does not prove that an event is impossible or that the intervention is free of risk. With no further information about event definitions, collection procedures, follow-up, or reporting, the safety figures should be read narrowly as the posted counts. The registry record does not provide additional detail for interpreting event severity beyond the serious and other categories.

The safety denominators differ from the participant counts attached to the primary outcome results. The record does not explain that difference, so the safety counts should not be substituted for the outcome analysis counts or used to infer why participants may not appear in both summaries.

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

The primary result describes an observed difference in same-day change on a virtual-environment perspective-taking scale between the two randomized groups. The Alternate Perspective group had a mean change of 16.3, while the Control Perspective group had a mean change of -10.4. The registry posts a mean difference of 26.7, with a confidence interval from 10.86 to 42.54 and an unadjusted p-value of <0.001. In the scale's stated direction, these results indicate a larger average improvement in the Alternate Perspective group on this measured outcome.

That interpretation is limited to the outcome and time frame recorded. The scale is a 0-100 score derived from a perspective-taking subscale and is intended to represent understanding of a virtual counterpart's perspective. The primary measurement was made before and after the intervention on the same day. The result does not establish whether the score difference persists, transfers to everyday social interactions, or corresponds to changes in other psychological or neurobiological measures.

A statistically notable group contrast is not itself a measure of practical importance. The registry does not report a threshold defining meaningful change on this score. The confidence interval communicates uncertainty about the estimated average difference, and the standard deviations show that individual change scores varied. Group averages do not establish that each participant benefited or that each participant's experience resembled the group mean.

The record describes a randomized, triple-masked, parallel study, but it does not report all details of implementation and analysis. In particular, the statistical plan, missing-data handling, and analysis population are not reported in the registry record. These omissions limit how fully readers can assess the analysis. The posted primary result is therefore best read as a quantitative comparison for the specified scale and same-day assessment, rather than a general claim about treatment effects or outcomes beyond those measured.

16. Why This Trial Matters Statistically

This trial illustrates how a clearly defined continuous endpoint can support a direct comparison between randomized groups. The scale's direction is stated in the registry, the measurement timing is described, and the result includes group means, standard deviations, a mean difference, a confidence interval, and an unadjusted p-value. Taken together, these statistics help distinguish the estimated average contrast from the variability among participants and the uncertainty around the estimate.

It also shows why statistical significance and precision should be read together. The p-value is reported as <0.001, while the confidence interval gives a range from 10.86 to 42.54 for the mean difference. The interval helps readers consider the potential size of the contrast rather than relying on a threshold alone. At the same time, the standard deviations of 27.9 and 26.3 signal that individual change scores were variable, so the group-level summary cannot stand in for each participant's outcome.

Planning illustrations based on the observed effect can clarify how sample-size needs change when the effect targeted for detection is smaller. They are not a substitute for the original design rationale, which is not reported in the registry record, and they do not establish the power of the completed study. This distinction is important when interpreting sample-size displays after results are available.

Finally, the record demonstrates the value of separating what was measured from what the study hoped to investigate. The primary result concerns a same-day score in a virtual environment; the brief summary describes broader psychological and neurobiological aims. Clear statistical interpretation keeps those questions distinct and makes explicit where the registry does not provide analysis details, secondary results, or longer-term evidence.

17. 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 primary endpoint is a scale-based change measured on the same day as the intervention. The registry does not report later assessments, so persistence of the observed difference cannot be evaluated from this primary result. The scale is explicitly framed as perspective taking in the virtual environment; transfer to real-world behavior or broader social functioning is not established by the posted score.

The primary outcome results include 23 participants in Alternate Perspective and 22 in Control Perspective, whereas the safety record lists 24 at risk in each group. The record does not explain the difference. It also does not report whether all randomized participants were included in the outcome analysis, how missing measurements were handled, or why the displayed outcome counts have these values. This leaves uncertainty about the analysis population and the possible influence of missing data.

The registry identifies randomization and triple masking, but does not report the allocation procedure, which parties were masked, or how masking was maintained. The statistical analysis plan, model or test used for the comparison, covariate adjustments, and multiplicity strategy are also not reported in the registry record. These missing details limit independent assessment of the analysis choices.

The record lists three outcome measures but posts no secondary outcome results. The brief summary anticipates psychological and neurobiological effects, but the primary result alone does not answer those broader questions. The registry also does not state a threshold for a meaningful change in the scale, limiting interpretation of practical importance. These are limits on what can be concluded from the registry record, not evidence that any specific unreported procedure or outcome occurred.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Virtual Reality to Improve Social Perspective Taking — NCT03927612.
• Registry record last updated 2023-06-28; status last verified 2023-06.
• Results first posted 2023-06-28.
• 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.

21. Record Summary

The registry record describes a completed, randomized, triple-masked, parallel study sponsored by Indiana University. It lists an enrollment of 90 and compares Alternate Perspective virtual reality training with a Control Perspective condition in children aged 9-12 with a disruptive behavior disorder. The primary outcome is change from pre-intervention on the Virtual Reality Perspective Taking Scale, assessed on the same day.

The primary outcome results list mean changes of 16.3 for Alternate Perspective and -10.4 for Control Perspective. The posted mean difference is 26.7, with a confidence interval from 10.86 to 42.54 and an unadjusted p-value of <0.001. The registry does not post secondary outcome results or detailed analysis-plan information. Safety results list zero serious adverse events, zero other adverse events, and zero deaths in each group, with 24 participants at risk in each group.