Biofeedback Based Virtual Reality Intervention to Manage Postoperative Pain: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Biofeedback Based Virtual Reality Intervention to Manage Postoperative Pain (NCT04943874), a randomized na study. The primary outcome is Aim 2 (Phase 2): Feasibility of Technology Intervention in Perioperative Patients.

2. Clinical Question

3. Trial Design

The registry record describes NCT04943874, titled “Biofeedback Based Virtual Reality Intervention to Manage Postoperative Pain.” Its official title specifies feasibility and acceptability of a biofeedback-based virtual reality intervention for children and adolescents after surgery. The study is marked randomized, single masked, and parallel. Its status is completed. The registry lists enrollment of 93 and gives a start date of 2022-03-10 and a primary completion date of 2025-08-06.

The broad objective was to develop and refine technology-based preoperative education and training and postoperative care for children and adolescents undergoing surgery. The study record distinguishes aims and phases: Phase 1 concerns development of preoperative and postoperative session protocols, while the primary feasibility outcome is assigned to Aim 2, Phase 2. The record lists Technology Based Intervention 1 and Technology Based Intervention 2 as device interventions. It identifies the Phase 2 comparison groups, but does not provide descriptive arm content in the arm descriptions.

The primary outcome description reports that 39 participants were randomized to Technology-based intervention 1, called the control, and 31 to Technology-based intervention 2, called VR-BF. The posted primary counts are 35 and 30 participants completing the final study visit, respectively. These Phase 2 group figures should not be treated as a full account of every participant in the overall enrollment, since the registry also describes a Phase 1 and does not provide a complete flow of participants across phases. The identity of the person or people masked, the allocation procedure, and details of sequence generation 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

Analysis population for the primary outcome, as defined in the registry: All participants contributed to this data collection

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 Aim 2 (Phase 2): Feasibility of Technology Intervention in Perioperative Patients, measured over From two weeks before surgery until 30 days after surgery.

The primary endpoint is a count of participants who successfully enrolled and completed study participation. The registry defines participation as completing the final study visit. The stated timeframe runs from two weeks before surgery until 30 days after surgery. This endpoint therefore captures whether participants reached the end of the study process, rather than measuring pain intensity, pain relief, or a clinical change in recovery.

Feasibility outcomes are used to assess whether a study approach can be delivered and completed in its intended setting. In this study, the endpoint focuses on retention through the final visit. It is relevant to assessing whether a future evaluation of the technology could retain participants through the perioperative follow-up period. It does not, by itself, establish acceptability, usability, or efficacy; those concepts require their own measures and analyses.

The posted results record 35 of 39 participants completing the study in Technology Based Intervention 1 and 30 of 31 in Technology Based Intervention 2. The unadjusted risk difference for Technology Based Intervention 2 compared with Technology Based Intervention 1 is 0.070, with a 95% confidence interval from -0.043 to 0.184. The interval includes zero, so the observed difference is not estimated precisely enough to rule out no difference or differences in either direction. The registry record does not report a prespecified threshold for what completion rate would count as feasible.

7. Results Posted in the Registry

• Technology Based Intervention 2 (Aim 2/Phase 2): 96.8% (30/31) versus 89.7% (35/39) on control; risk difference 7.0 percentage points (95% CI -4.3 to 18.4), risk ratio 1.08 (0.95–1.22); unadjusted two-proportion z-test p = 0.257.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Aim 2 (Phase 2): Rate of Study Retention

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Technology Based Intervention 2 (Phase 2): 96.8% (30/31) versus 89.7% (35/39) on control; risk difference 7.0 percentage points (95% CI -4.3 to 18.4), risk ratio 1.08 (0.95–1.22); unadjusted two-proportion z-test p = 0.257.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Technology Based Intervention 2 (Phase 2) and the control. The interval gives the range of effects that remain compatible with the data.

Aim 2 (Phase 2): Rate of Treatment Adherence (Preoperative)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Technology Based Intervention 2 (Phase 2): 96.7% (29/30) versus 100.0% (35/35) on control; risk difference -3.3 percentage points (95% CI -9.8 to 3.1), risk ratio 0.97 (0.90–1.03); unadjusted two-proportion z-test p = 0.276.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Technology Based Intervention 2 (Phase 2) and the control. The interval gives the range of effects that remain compatible with the data.

Aim 2 (Phase 2): Rate of Treatment Adherence (Post-operative)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Technology Based Intervention 2 (Phase 2): 86.7% (26/30) versus 97.1% (34/35) on control; risk difference -10.5 percentage points (95% CI -23.8 to 2.9), risk ratio 0.89 (0.77–1.04); unadjusted two-proportion z-test p = 0.114.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Technology Based Intervention 2 (Phase 2) and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists 26 posted secondary outcome measures, covering protocol development and postoperative sessions as well as Phase 2 retention and treatment adherence. The secondary measures most directly related to the primary result are retention through the final study visit and adherence before and after surgery. These address related but different processes: retention concerns whether participants complete follow-up, while adherence concerns participation in the intervention activities at specified perioperative times.

Across these outcomes, the posted counts describe substantial completion or adherence in both groups, but the direction and size of contrasts vary by endpoint. The secondary summaries should be read in context of their definitions and denominators, which can differ across timepoints. They do not all measure the same underlying event, and a participant included in an adherence denominator need not be evaluated on the same basis as a participant in the primary retention comparison.

The primary outcome gives a broad measure of whether the study reached its final visit; adherence measures can add detail about whether participants engaged with particular parts of the intervention. Neither type of outcome directly answers whether postoperative pain changed. Likewise, the protocol-development outcomes reflect the study's refinement aims rather than a direct comparison of clinical effects.

The registry record lists no reported analyses for the secondary outcomes. Any posted group contrasts should therefore be treated as unadjusted descriptive comparisons rather than as a prespecified set of confirmatory tests. When many outcomes are examined, some apparent differences can arise by chance. Without a reported multiplicity plan, analysis hierarchy, or confirmatory designation, secondary findings carry less weight than a clearly prespecified primary question. They can inform future study design, but should not be used alone to claim an intervention effect.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Aim 1 (Phase 1): Preoperative Training Protocol
• Aim 1 (Phase 1): Preoperative Training Protocol, Continued
• Aim 1 (Phase 1): Preoperative Training Protocol, Continued
• Aim 1 (Phase 1): Preoperative Training Protocol, Continued
• Aim 1 (Phase 1): Post-operative Session Protocol
• Aim 1 (Phase 1): Post-operative Session Protocol, Continued
• Aim 1 (Phase 1): Post-operative Session Protocol, Continued
• Aim 1 (Phase 1): Postoperative Session Protocol, Continued

9. Statistical Interpretation

10. Statistical Methods Explained

The principal comparison is binary: each participant either completed the final study visit or did not. For a binary endpoint, a group proportion describes the share of participants with the event of interest. Here, the event is completion. The posted counts are 35 of 39 for Technology Based Intervention 1 and 30 of 31 for Technology Based Intervention 2. The endpoint description calls these participants who completed the study, and defines completion as attendance at the final study visit.

What does the risk difference describe?

The risk difference subtracts the completion proportion in the comparison group from the completion proportion in the other group. A positive value means the event proportion is higher in Technology Based Intervention 2; a negative value means it is lower. The posted risk difference is 0.070. This is an unadjusted contrast based on the reported group summaries. It does not account for other participant characteristics or study processes.

The record also includes relative measures, including a risk ratio of 1.078 with a confidence interval from 0.953 to 1.221, and an odds ratio of 3.429 with a confidence interval from 0.363 to 32.36. These measures express group contrasts on different scales. They should not be read as interchangeable: the risk difference is an absolute contrast in proportions, the risk ratio compares proportions multiplicatively, and the odds ratio compares odds. In this setting, the interval around the odds ratio is especially broad, so it gives little precision about the size of a relative contrast.

How should the test result be read?

The posted unadjusted p-value for the primary comparison is 0.257. A p-value measures how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, and it does not measure the probability that the intervention is effective. The registry record does not report the sponsor's complete statistical analysis plan or specify all details of the test. Accordingly, the p-value is best treated as an unadjusted summary accompanying the reported contrast, rather than as a stand-alone decision.

For general statistical context, randomization can support a comparison between groups by reducing systematic differences in expectation, but it does not guarantee balance in a particular study. The record says the study was randomized, but does not describe sequence generation, concealment, or the identities of those masked. A single-masked designation alone does not establish which roles were masked. Those details are not reported in the registry record.

What does a confidence interval add?

A confidence interval expresses uncertainty around an estimated effect under a statistical procedure and its assumptions. The interval for the primary risk difference runs from -0.043 to 0.184. Because it spans zero, it is compatible with no difference as well as with a difference favoring either group. Its breadth is also important: the point estimate alone does not capture how uncertain the group contrast is. The interval should be interpreted alongside the endpoint definition and the counts, rather than as a guarantee that the true effect lies within its limits.

The posted comparison statistics are unadjusted recalculations from summary counts. The registry lists zero reported analyses, and there is no sponsor analysis presented in the posted record to compare against these calculations. The record does not report whether an adjusted analysis, sensitivity analysis, or formal test was conducted outside the posted registry results. No discrepancy is flagged for the posted comparison.

Why do feasibility outcomes need context?

A completion count is useful for describing whether participants remained in the study through the final visit. It does not explain why a participant did not complete, whether the intervention was received, or whether completion differed for particular reasons. Nor does it define an acceptable target. For a feasibility interpretation, investigators may prespecify a threshold or combine completion with other measures such as recruitment, adherence, or acceptability. The registry record does not report a feasibility threshold or a decision rule for moving from feasibility work to a later study.

General statistical reasoning also cautions against treating a nonsignificant p-value as evidence of equivalence. Equivalence or noninferiority requires a specified margin and a design and analysis appropriate to that question. Neither such a margin nor such an analysis is reported in the registry record. The available statistics therefore describe the observed comparison and its uncertainty; they do not answer questions that require a separate design framework.

11. Confidence Intervals and Precision

Precision concerns how tightly the data locate an estimated effect. The primary risk difference is 0.070, and its 95% confidence interval extends from -0.043 to 0.184. The interval crosses zero, so the data do not distinguish clearly between no difference and differences in either direction. It also spans a broad range of possible contrasts, meaning the point estimate should not be read as a precise estimate of the group difference.

Confidence intervals are statistical ranges constructed by a method that, over repeated use under its assumptions, would cover the target quantity at the stated rate. They are not a guarantee that the particular interval contains the true effect, and they do not assign probabilities to individual values within the interval. Their meaning depends on the analysis method and assumptions. The registry record does not report the full inferential method or its assumptions, so the interval should be interpreted as the posted summary rather than as a complete account of the analysis.

The comparison has fewer participants in each Phase 2 group than the planning illustrations associated with the observed effect. That context helps explain why estimates from a feasibility study may be uncertain, but the planning illustrations are not evidence about the study's actual power. The record does not report an original sample-size justification. The confidence interval is therefore the more direct guide to the observed estimate's uncertainty.

The relative measures reinforce the need for caution: the risk-ratio interval runs from 0.953 to 1.221, and the odds-ratio interval runs from 0.363 to 32.36. These intervals include values on both sides of their respective null values, and the odds-ratio interval is particularly broad. Collectively, the estimates do not provide a precise basis for ranking the groups on completion.

12. 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 planning figures are illustrations based on the observed effect, not the trial's original design justification. For the primary retention comparison, the planning rows use 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. Under those scenarios, the listed figures for 80% power are 199, 397, and 987 participants per arm, respectively; the figures for 90% power are 266, 530, and 1,321 participants per arm. The postoperative adherence comparison also has planning illustrations: 106, 160, and 295 participants per arm for 80% power, and 141, 214, and 395 participants per arm for 90% power, across the same effect fractions.

These are binary participant outcomes, so the sample-size figures refer to participants per arm, not total events. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is the stated fraction of the observed effect. The original study's own design assumptions are not reported in the registry record.

The 80% power column gives the illustrative number of participants per arm for a design with an 80% chance of detecting the specified effect under the planning assumptions, if that effect is the true one. The 90% column gives the corresponding illustration for a 90% chance. These probabilities describe hypothetical future designs, not a conclusion about the completed study. Smaller effects require more participants to detect under otherwise similar assumptions, which is why the figures increase as the effect fraction decreases.

This is not observed power. It is a planning illustration anchored to an effect estimated from the posted results, and that estimate itself is uncertain. Such calculations should not be read as evidence that the trial was adequately or inadequately designed; the record does not report the original sample-size rationale.

13. 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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.897; treatment proportion p₁ = 0.968; average p̄ = 0.933.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.3546 = 0.6950.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.3511 = 0.2955.
4. n = (0.6950 + 0.2955)² / (0.0703)² = 198.5, rounded up to 199 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
p0 <- 0.897435897435897                          # control proportion
p1 <- 0.967741935483871                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(4943874)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 199 (80% power), 266 (90% power)
 75% of observed effect: n per arm = 397 (80% power), 530 (90% power)
 50% of observed effect: n per arm = 987 (80% power), 1,321 (90% power)
power.prop.test: 198.5 
Simulated power at n = 199 per arm: 0.827 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study examines several outcomes, timepoints, or comparisons. The registry lists 28 outcome measures overall and 26 posted secondary outcome measures. These include multiple protocol and session outcomes as well as retention and preoperative and postoperative adherence. Examining many results can increase the chance that at least one appears notable by chance, particularly when each is assessed with an unadjusted test.

The registry record lists zero reported analyses. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or which secondary outcomes, if any, were intended to be confirmatory. No adjustment should be assumed. As a result, unadjusted secondary p-values or contrasts, where shown, have a more exploratory interpretation and should not be treated as independent confirmation of the primary result.

The primary outcome is defined as completion of the final study visit, but the record does not report a missing-data method, rules for classifying participants without a final visit, or an analysis population such as intention-to-treat or per-protocol. The posted group counts show the number with the outcome and the group denominator, but do not explain reasons for noncompletion or whether missing outcome information was handled in any other way. It is not possible to determine whether the analysis included every randomized participant under a prespecified rule.

The record also does not report an analysis plan specifying covariate adjustment, sensitivity analyses, or handling of protocol deviations. These omissions limit the ability to judge whether the posted summaries represent the intended primary analysis or how robust conclusions might be to alternative assumptions. The observed counts and unadjusted comparison remain interpretable as posted, but they do not resolve these design and analysis questions.

15. 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's adverse-event record lists three groups: Technology Based Intervention 1 in Phase 1, Technology Based Intervention 1 in Phase 2, and Technology Based Intervention 2 in Phase 2. For each group, the posted figures show zero participants with a serious adverse event, zero with another adverse event, and zero deaths. The corresponding numbers listed as at risk are 23, 39, and 31 for each event category within those groups.

These figures describe what the registry record reports; they do not establish that no adverse events occurred outside the recorded categories, timeframes, or reporting process. The record does not provide serious adverse-event terms, and no serious-event terms are listed. It also does not provide detail about event definitions, collection procedures, attribution, or whether events were actively solicited. Zero reported events should therefore be interpreted as a registry report, not as proof that the interventions carry no risk.

The adverse-event groups include Phase 1 and Phase 2, whereas the primary feasibility comparison concerns the two Phase 2 groups. Safety figures are not a substitute for the primary completion outcome or for a detailed safety analysis. The registry record does not report an inferential comparison of adverse events between groups.

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

The posted result addresses a focused feasibility question: how many participants completed the final study visit after enrollment in a perioperative study of technology-based interventions? Completion was recorded for participants in both Phase 2 groups. The estimated risk difference is 0.070 for Technology Based Intervention 2 compared with Technology Based Intervention 1, with a 95% confidence interval from -0.043 to 0.184 and an unadjusted p-value of 0.257.

This estimate does not establish a clear difference between the groups. The interval includes zero and allows for differences in either direction, so the result is uncertain. It also does not establish that the groups are equivalent. A conclusion of equivalence would require a prespecified margin and a suitable design and analysis, neither of which is reported in the registry record.

The endpoint is about study completion, not pain relief. Although the study title and objective concern postoperative pain and biofeedback-based virtual reality, the primary result does not measure pain intensity, analgesic use, recovery, or the effectiveness of the technology. A completion result can inform whether participants remained in the study through follow-up, but it cannot determine whether the intervention changed a clinical outcome.

The registry also lists adherence outcomes, which may help describe engagement with intervention activities, but the record lists no reported analyses for those outcomes. The posted data therefore do not support a broad claim about acceptability or adherence beyond their specific recorded counts. The intervention and control arm descriptions are blank, so the contrast between the two technology-based approaches cannot be fully characterized from the registry record.

In practical statistical terms, the result is useful as a descriptive feasibility signal, with uncertainty that warrants careful interpretation. It is not a treatment recommendation and should not be taken as proof that either approach is superior, ineffective, or risk-free. Decisions about future research would need to consider the feasibility criteria, outcome definitions, intervention details, and analysis plans, many of which are not reported in the registry record.

17. Why This Trial Matters Statistically

This study is statistically informative because it focuses on a question that comes before a definitive efficacy comparison: whether participants can be enrolled and retained through the final study visit in a perioperative technology study. Feasibility research can identify whether study procedures and follow-up are workable, and can help clarify which outcomes need more precise definitions in later research.

The primary endpoint is directly interpretable as a completion count, but it also illustrates an important distinction between a process outcome and a clinical outcome. Completing study participation can support the practicality of conducting research; it does not show that pain changed. Keeping those questions separate prevents a retention result from being mistaken for evidence about clinical benefit.

The comparison also illustrates why an effect estimate should be read with its interval. The point estimate favors one group on completion, but the confidence interval spans zero and a range of possible group differences. The estimate is therefore not sufficiently precise to settle the comparative question. A p-value alone would not communicate this range or the limitations of the endpoint.

Finally, the record includes several phases and a range of outcomes, while reporting no analyses and few details about the analysis plan. That makes transparent outcome definitions, denominators, missing-data rules, and prespecified decision criteria especially important for interpreting feasibility work. The posted record can describe completion and related outcomes, but fuller reporting would be needed to assess how well the observed findings address the study's broader feasibility and acceptability aims.

18. 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 the registry record constrain interpretation. The arm descriptions are blank, so the content of Technology Based Intervention 1 and Technology Based Intervention 2 cannot be reconstructed from the record. The title identifies a biofeedback-based virtual reality intervention, and the primary population description identifies children and adolescents undergoing surgery anticipated to cause moderate to severe pain, but technical and delivery details are not reported.

The overall enrollment is listed as 93, while the primary Phase 2 comparison gives group denominators of 39 and 31. The record also describes a Phase 1 group and does not provide a complete participant flow across study phases. It is therefore not possible to reconcile all enrollment and analysis populations from the posted descriptions alone. Reasons for not completing the final visit are not reported in the registry record.

The study's feasibility threshold is not reported, so the completion counts cannot be judged against a stated go/no-go criterion. The registry record also does not report the original sample-size justification, analysis plan, missing-data rules, analysis populations, multiplicity approach, or full masking and allocation procedures. It lists no reported analyses, limiting the ability to assess whether the posted unadjusted summaries were prespecified or whether other analyses were conducted.

Finally, completion and adherence are process outcomes. They do not directly measure pain or clinical recovery, and the posted primary comparison is imprecise. These limitations do not invalidate the reported counts; they define what can and cannot be concluded from the available registry information.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Biofeedback Based Virtual Reality Intervention to Manage Postoperative Pain — NCT04943874.
• Registry record last updated 2026-10-20; status last verified 2026-09.
• Results first posted 2026-10-20.
• 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.

22. Record Summary

NCT04943874 is a completed randomized, single-masked, parallel-group study titled “Biofeedback Based Virtual Reality Intervention to Manage Postoperative Pain.” The registry lists enrollment of 93, a start date of 2022-03-10, and a primary completion date of 2025-08-06. The study objective was to develop and refine technology-based preoperative training and postoperative care for children and adolescents undergoing surgery.

The primary Phase 2 outcome measured completion of the final study visit from two weeks before surgery until 30 days after surgery. Completion was recorded for 35 of 39 participants in Technology Based Intervention 1 and 30 of 31 in Technology Based Intervention 2. The unadjusted risk difference was 0.070, with a 95% confidence interval from -0.043 to 0.184. The registry lists 28 outcome measures, including 26 posted secondary measures, and zero reported analyses. The registry record does not report the original sample-size rationale or a complete statistical analysis plan.