Hoarding Disorder Treatment With Virtual Reality: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Hoarding Disorder Treatment With Virtual Reality (NCT03828461), a na na study. The primary outcome is Change in Hoarding Symptom Severity as Measured by Saving Inventory-Revised (SI-R).

2. Clinical Question

3. Trial Design

The registry lists this as a completed, single-group study sponsored by Stanford University. The listed study start is 2020-07-01, and the primary completion date is 2021-12-17. Enrollment is listed as 13. The phase is recorded as NA.

The sole arm is named BITS + VR and is described as facilitated group therapy with behavioral practice over 16 weeks. The study summary describes the work as exploring a facilitated peer support group called Buried in Treasures and virtual reality decluttering practice. Details of the intervention beyond these descriptions are not reported in the registry record.

The study model is single group, allocation is listed as NA, and masking is listed as none. No separate comparison group is described. As a result, the design does not provide a concurrent control against which to distinguish changes during the intervention from changes that might occur for other reasons. This is a design limitation, not a finding about whether participants changed.

The record lists two outcome measures, including the primary SI-R change outcome and a secondary outcome concerning change in clutter level measured by the Clutter Image Rating Scale. It lists zero analyses. Actual outcome results, the analysis population, and details of how outcomes were handled are not reported in the registry record. The record also does not report the rationale for the enrollment target or a statistical analysis plan.

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:

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 Change in Hoarding Symptom Severity as Measured by Saving Inventory-Revised (SI-R), measured over Change from baseline to 16 weeks after treatment.

The primary endpoint is change in Hoarding Symptom Severity, measured with the Saving Inventory-Revised (SI-R), from baseline to 16 weeks after treatment. The registry identifies the outcome as a mean and the measure of dispersion as the standard deviation. The SI-R is described as a 23-item questionnaire with subscales for difficulty discarding, excessive clutter, and compulsive acquisition. Its total score ranges from 0 to 92; a total score higher than 41 is described in the registry as indicating significant difficulty with clutter.

The endpoint is intended to capture the measured difference in symptom severity between the baseline assessment and the assessment 16 weeks after treatment. In general, a change score places attention on how a measured outcome differs across two assessment times for the same study group. It does not, by itself, establish what caused that change. In a single-group study, observed change cannot be separated from other influences using a concurrent control group.

The registry also describes SI-R subscale ranges and thresholds: acquisition and difficulty discarding each range from 0 to 28, with scores greater than 13 indicating difficulty in the respective area; clutter ranges from 0 to 36, with a score greater than 15 indicating difficulty with accumulated clutter. These descriptions clarify how the instrument's scores are interpreted, but the registry does not report this study's scores or changes. The endpoint result and its precision are therefore not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change describe?

The primary outcome is continuous: it is a score on a scale, and the registry specifies a mean as the summary measure. In general, a mean represents the average of the values included in an analysis. For a change outcome, the values represent differences between assessments for the participants whose data are analyzed. A mean can give a concise account of the group's average change, but it does not show whether individual participants had similar or widely varying changes.

The registry names the standard deviation as the dispersion measure. In general, a standard deviation describes how spread out observed values are around their mean. It describes variability among measurements, rather than the precision of the estimated mean. Precision depends on the data and the analysis, and is commonly expressed with a confidence interval. No mean change, standard deviation, or confidence interval is reported in the registry record for this study.

What would a confidence interval add?

In general, a confidence interval communicates uncertainty around an estimate. A relatively narrow interval indicates greater precision under the method's assumptions; a wider interval indicates less precision. The interval does not resolve limitations of the design or establish that a change was caused by an intervention. In this record, a confidence interval for the primary outcome is not reported, so the precision of any change estimate cannot be assessed.

What does a p-value address?

In general, a p-value describes how compatible data are with a specified statistical model or null hypothesis, assuming that model and hypothesis. It is not the probability that a treatment works, nor does it measure the size or practical importance of an effect. A p-value also cannot replace an estimate and its uncertainty. The registry lists zero analyses and does not report a p-value for the primary outcome.

Why does the single-group design matter?

In a single-group study, a baseline-to-follow-up change describes the course of measured outcomes in that group. In general, a comparator group can help assess whether changes differ from those observed under another condition over the same period. Without a separate comparator, a change over time cannot be attributed to the intervention by comparison with concurrent control data. The registry lists no comparator and describes the study model as single group.

How should the planning illustration be read?

The registry describes a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. These are assumptions for a planning calculation, not a description of this single-group study's design. The illustration is not observed power and should not be read as evidence that a particular result was detected. The registry does not report the trial's own sample-size justification.

In general, sample-size calculations describe what a planned design might require under specified assumptions. They do not establish the reliability of a result after data collection, and an illustration based on an observed effect is especially distinct from a prespecified design rationale. The registry's assumptions describe a hypothetical two-arm comparison; they do not turn the study's single group into a controlled comparison.

What can be inferred from the listed analysis count?

The registry lists zero analyses. That means no statistical analysis results are available in the record for interpretation. It does not justify filling in an outcome estimate from the study description, enrollment, or adverse-event counts. The outcome measures specify what was intended to be measured; they do not reveal what participants scored or how those scores changed.

In general, interpreting a continuous endpoint requires knowing what observations entered the analysis, how missing observations were handled, and how the estimate and its uncertainty were calculated. A statistical model can also depend on assumptions about the data and study design. Those methodological details are not reported in the registry record. Accordingly, the available record supports explanation of the endpoint and general statistical concepts, but not reconstruction of an outcome analysis.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("BITS + VR")
n   <- c(9)
m   <- c(14.2)
sp  <- c(7.7)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  BITS + VR  9  14.200  7.700  8.281  20.119

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary SI-R change outcome and a secondary change outcome for clutter level measured by the Clutter Image Rating Scale. It lists zero analyses and reports no outcome results. A plan for handling multiple outcomes, including any adjustment or prioritization beyond identifying one as primary, is not reported in the registry record.

In general, multiplicity arises when several outcomes or statistical tests are considered. The more results examined, the more important it is to know which outcomes were designated primary and how the analysis plan addressed the resulting interpretive uncertainty. Naming one outcome as primary helps identify the main question, but does not reveal whether other analyses were planned or how their results would be interpreted. The record does not provide that detail.

Missing-data methods are also not reported in the registry record. The record does not state how incomplete assessments, withdrawals, or other unavailable outcome values were handled, or whether any imputation or sensitivity analysis was planned. In general, missing observations can affect both the amount of information available and the interpretation of an estimate, particularly if the availability of measurements is related to participants' outcomes.

The analysis population is not reported in the registry record. It is therefore not possible to tell which participants were included in any outcome analysis, whether the analysis used all enrolled participants, or how assessment completion was defined. The enrollment entry of 13 does not establish the number with usable outcome data. These omissions leave the intended outcome measures clear but the analysis procedures and their implications unspecified.

12. 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.

Most frequent non-serious adverse event terms

For the BITS + VR group, the registry lists 0 serious adverse events among 9 participants at risk, 7 other adverse events among 9 participants at risk, and 0 deaths. These are reported counts; they are not outcome-effect estimates and should not be interpreted as evidence about the primary SI-R change measure.

The registry does not list serious adverse event terms. It does not explain why the safety figures use 9 participants at risk when enrollment is listed as 13, or provide further detail about event definitions, timing, severity, or relationship to the intervention. Those details are not reported in the registry record.

In general, adverse-event counts describe events recorded under a study's reporting procedures. Without information about ascertainment and attribution, counts alone do not establish whether an event was caused by an intervention. The single-group design also provides no separate comparator for assessing how these counts compare with another condition. The figures should therefore be read as the safety counts posted for this group, with the limits of the registry detail in mind.

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

The registry record establishes that a completed, single-group study examined facilitated group therapy with behavioral practice and virtual reality decluttering practice. It identifies change in SI-R score from baseline to 16 weeks after treatment as the primary outcome and lists change in clutter level measured by the Clutter Image Rating Scale as a secondary outcome. It also gives the SI-R's score ranges and describes thresholds for difficulty in its total and subscale scores.

Those descriptions do not constitute outcome findings. The registry lists zero analyses and does not report observed changes, variability, confidence intervals, or statistical tests. Therefore the amount, direction, and precision of any outcome change are not reported in the registry record. The posted information cannot establish whether scores changed or how consistently they changed across participants.

Even if a before-and-after estimate were available, the single-group design would limit causal interpretation. In general, change over time in one group does not show what would have happened over the same period under a different condition. No comparator group is described, and no randomized allocation is reported. The design therefore does not provide a like-for-like control comparison.

The safety counts are separate from the symptom outcomes. They report serious adverse events, other adverse events, and deaths for the named group, but do not explain event attribution or the difference between the enrollment entry and participants at risk. These counts do not answer the primary endpoint question.

The appropriate reading is narrow: the record describes a study question, intervention, design, and planned outcome measures, alongside limited safety counts. It does not report the statistical results needed to quantify change or its uncertainty. Neither the intervention's effect nor the absence of an effect can be concluded from the outcome information in the registry record.

14. Why This Trial Matters Statistically

This study illustrates an important distinction between a clearly stated outcome and an interpretable result. The registry identifies the SI-R as the primary measure and specifies the assessment interval, while also describing a secondary clutter measure. Those details identify what the study sought to measure. Without posted outcome estimates or analyses, however, readers cannot assess the size or precision of any change.

The design also makes the role of comparison especially visible. A single-group before-and-after study can describe change within that group, but it cannot use a concurrent comparator to distinguish intervention-associated change from other influences. Statistical interpretation depends not only on the outcome scale and analysis, but also on how the design supports the question being asked.

The planning illustration offers another useful statistical distinction. Its assumptions describe a hypothetical two-arm calculation, whereas the registered study is single group. Planning quantities do not become evidence about observed outcomes, and they are not observed power. Keeping design, planning, and analysis separate helps prevent a hypothetical calculation from being mistaken for a trial result.

Finally, the registry shows why enrollment, analysis, and safety denominators should not be treated as interchangeable. Enrollment is listed as 13, while the safety figures use 9 participants at risk. The reason for that difference and the number included in any outcome analysis are not reported. These details matter because denominators define which observations a statistic describes. The record is therefore useful for understanding the study's structure and what information is missing, even though it does not report an outcome analysis.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The principal limitation of the available record is that it lists no statistical analyses and reports no primary or secondary outcome results. The primary endpoint's estimate, dispersion, and uncertainty are therefore unavailable. The registry does not report an analysis plan, the handling of missing outcome data, or the population included in any outcome analysis.

The registered design is single group, with allocation listed as NA and masking listed as none. No separate comparator is described. This limits the extent to which a change over time could be attributed to the intervention, even if such a change estimate were posted. The record does not describe a randomized comparison.

Enrollment is listed as 13, but the adverse-event counts list 9 participants at risk. The registry does not explain the difference or state how many participants contributed baseline and follow-up outcome data. This leaves the relationship among enrollment, safety follow-up, and outcome assessment unclear.

The intervention description is brief: facilitated group therapy with behavioral practice over 16 weeks, with the study summary mentioning a peer support group and virtual reality decluttering practice. Further details about the activities and their delivery are not reported in the registry record. The record also does not report a sample-size justification for the study; the stated planning illustration is described as separate from the trial's own design.

These limitations concern what can be learned from the registry record. They do not establish that additional information does not exist outside it, and they do not imply a particular study outcome.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Hoarding Disorder Treatment With Virtual Reality — NCT03828461.
• Registry record last updated 2024-04-01; status last verified 2024-03.
• Results first posted 2024-04-01.
• 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.

19. Record Summary

The registry lists NCT03828461 as a completed, single-group study sponsored by Stanford University, with enrollment of 13. The listed start date is 2020-07-01, and the primary completion date is 2021-12-17. The intervention is facilitated group therapy with behavioral practice over 16 weeks, described in the study summary alongside a Buried in Treasures peer support group and virtual reality decluttering practice.

The primary outcome is change in SI-R score from baseline to 16 weeks after treatment. A secondary outcome concerns change in clutter level measured by the Clutter Image Rating Scale. The registry lists zero analyses and does not report outcome results or an analysis plan. Safety figures for the BITS + VR group list 0 serious adverse events among 9 at risk, 7 other adverse events among 9 at risk, and 0 deaths. The reason that safety denominator differs from the enrollment entry is not reported in the registry record.