Decision Making Tool for Firearm Storage: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Decision Making Tool for Firearm Storage (NCT06382194), a na na study. The primary outcome is Number of Participants With Any Improvement in Safe Firearm Storage (Adapted From the National Firearm Survey).

2. Clinical Question

3. Trial Design

The registry record identifies NCT06382194 as a single-group pilot titled “Decision Making Tool for Firearm Storage.” Its official title describes shared decision making for firearm safety among older adults with early changes associated with Alzheimer's disease or Alzheimer's disease-related dementias. The listed conditions are dementia, mild, and depression. The sponsor is the University of Washington.

The study has one intervention arm. Participants in that arm were to receive the decision aid and undergo research assessments. The record lists the intervention type as other and describes the study's purpose as testing feasibility and acceptability. Allocation is NA, and masking is NONE. Phase is listed as NA. These registry entries do not establish a randomized comparison; there is no control arm against which to contrast outcomes.

Enrollment is recorded as 5. The start date is 2024-04-10, and the primary completion date is 2024-10-09. The overall status is TERMINATED. The registry record does not report why the study was terminated, whether enrollment ended as planned, or whether all enrolled participants completed the assessments.

The primary outcome concerns any improvement in safe firearm storage at 4 weeks post enrollment. The record also lists outcomes for change in decisional conflict, change in firearm safe-storage knowledge, access to the intervention, and intervention acceptability. There are 5 outcome measures in total and zero analyses listed. The registry record does not report a protocol, a sample-size justification, or details of how feasibility and acceptability were to be judged.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: This is reporting the percentage of participants with an improvement in safe firearm storage.

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 Number of Participants With Any Improvement in Safe Firearm Storage (Adapted From the National Firearm Survey), measured over Assessed at 4 weeks post enrollment.

The primary endpoint is the number of participants with any improvement in safe firearm storage, assessed at 4 weeks post enrollment. The description says storage was initially recorded on an ordinal scale: 0=unlocked and loaded; 1=unlocked and unloaded; 2=locked and loaded; 3=locked and unloaded; and 4=removed from house. The primary endpoint turns the change from baseline to follow-up into a binary outcome: 0=no improvement and 1=any improvement.

This approach treats any upward movement on the scale as an improvement while grouping all such movements together. It also groups unchanged storage with no improvement. As a result, the endpoint can express whether a participant moved in a safer direction according to the scale, but it does not retain how large the change was or which storage state was reached. The registry record describes the primary measure as a percentage of participants with improvement, while its outcome unit is participants.

A binary count is straightforward to describe, but interpretation depends on knowing both the number with improvement and the number assessed. Neither primary outcome count nor follow-up denominator is reported in the registry record. Consequently, the endpoint's observed result and its precision cannot be evaluated from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a single-group study rather than a randomized comparison. In a single-group design, participants receive the intervention, and outcomes may be observed at baseline and follow-up. Without a concurrent control group, observed change cannot by itself separate a possible intervention-related change from other influences or ordinary variation. This is a general design consideration; the registry record does not report a causal analysis.

How the primary endpoint is constructed

The primary outcome starts with an ordered measure of firearm storage, ranging from 0=unlocked and loaded to 4=removed from house. The record says change from baseline to follow-up was dichotomized: 0=no improvement and 1=any improvement in safe firearm storage. In general, dichotomizing an ordered outcome simplifies reporting to a count of participants meeting a definition. It also discards distinctions among degrees of change and treats all participants classified as improved alike. Here, the definition captures any improvement on the ordered scale, not a specific storage method or threshold.

The stated outcome unit is participants, and the registry describes the population measure as the percentage with improvement. To interpret such a measure, readers would need the number meeting the improvement definition and the number assessed. The registry record reports neither primary outcome count nor follow-up denominator. No estimate can be reconstructed without inventing information, and no confidence interval can be assessed.

What precision and uncertainty would mean

In general, a confidence interval describes a range of values compatible with the observed data under a specified statistical method. Its width reflects uncertainty: more imprecise estimates have wider intervals. For a small study, a participant-count outcome can be sensitive to the status of each individual, so precision is particularly important. No confidence interval or other uncertainty estimate is reported in the registry record. These general principles do not supply an estimate for this study.

For count outcomes, the denominator also matters. A count of participants with improvement has a different interpretation depending on how many participants completed the follow-up assessment. Enrollment is recorded as 5, but that does not establish that all 5 contributed a primary outcome. The number assessed and the handling of incomplete observations are not reported in the registry record.

Planning assumptions are not trial results

The record describes sample-size planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those are planning assumptions, not evidence that the actual study used a two-arm design: the registered study is single-group. The record does not report its own sample-size justification. Planning illustrations are not observed power and do not show that the study detected an effect. The observed effect used for any such illustration is not reported in the registry record, so the illustration cannot be independently interpreted from these outcome details.

In general, a sample-size calculation asks how many participants a hypothetical design would require for a specified effect and statistical assumptions. It does not describe the number actually enrolled, guarantee a particular result, or establish the precision of a completed study. The registry's enrollment is 5; it should not be confused with a target derived from a planning illustration. The record does not provide the calculated participant requirements, so none can be stated.

Multiplicity and secondary outcomes

The registry lists 5 outcome measures: the primary storage-improvement outcome and secondary outcomes for change in the Low-Literacy Decisional Conflict Scale Score, change in Firearm Safe Storage Knowledge Questionnaire Score, the number of participants who access the intervention, and the mean Acceptability of Intervention Measure score. When a study evaluates multiple outcomes, general statistical practice considers whether the analysis plan accounts for the chance of false-positive findings across those outcomes. The registry record does not report a multiplicity strategy, and zero analyses are listed. It is therefore not possible to assess any adjustment or hierarchy of tests.

More broadly, the record does not specify the statistical test or model, the analysis population, the handling of missing observations, or the treatment of ordinal responses beyond the stated dichotomization for the primary endpoint. These omissions prevent replication or detailed appraisal of the intended analysis. They should be distinguished from statistical choices that might be reasonable in general: no unreported method can be attributed to this trial.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Intervention Arm")
n      <- c(3)
events <- c(1)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Intervention Arm  3  1  33.3  0.8  90.6  6.1  79.2  6.8  80.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 5 outcome measures, including the primary safe-storage improvement endpoint and secondary measures of decisional conflict, safe-storage knowledge, intervention access, and acceptability. Considering multiple outcomes can raise a multiplicity issue: in general, testing several outcomes can increase the chance of at least one apparently positive result by chance. The registry record does not report a testing hierarchy, adjustment method, or other multiplicity plan. It lists zero analyses, so there are no reported tests to evaluate.

Missing-data handling is also not reported in the registry record. The enrollment is 5, but the number with primary follow-up data is not given. The record does not describe whether participants missed assessments, how incomplete measures would be handled, or whether any imputation or sensitivity analysis was planned. It is not appropriate to assume that all enrolled participants contributed to every outcome.

The analysis population is not reported in the registry record. There is no stated rule about which participants would be included in the primary or secondary analyses. The record also does not identify an intention-to-treat, per-protocol, or other analysis population. With zero analyses listed, the posted information does not establish how these issues were handled in practice. Thus, the enrolled group, the group assessed at follow-up, and the group used for any outcome analysis cannot be assumed to be identical.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: injury related to home invasion (0.0%).

The adverse-event record lists 5 participants at risk in the intervention arm. It records 0 participants with a serious adverse event, 0 participants with other adverse events, and 0 deaths. The listed serious-event term, “Injury related to home invasion,” is recorded as 0.0%. These entries describe what is recorded in the registry; they do not establish that every possible event was assessed or captured.

The registry record does not report the adverse-event collection period, definitions, monitoring procedures, or whether event reporting was complete for all participants. The number at risk is 5, but the record does not state whether all participants had the same observation time. Zero recorded events in a small group should therefore be read as an absence of reported events in this record, not as proof that no event could occur or that the intervention has no safety risks.

The record also does not describe an adverse-event comparison with another group, because the study is single-group. These figures do not establish whether the decision aid changed safety outcomes. They are descriptive counts from the intervention arm and should be interpreted within the limited enrollment and the missing detail about event ascertainment.

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

The registry record supports a limited description: a single-group pilot of a decision aid about safe firearm storage enrolled 5 participants, was marked TERMINATED, and specified a primary endpoint based on any improvement at 4 weeks post enrollment. It also records no serious adverse events, other adverse events, or deaths in the intervention arm. These are design and registry-record details, not a complete account of efficacy or safety.

The primary outcome result is not reported in the registry record. No count of participants with improvement, follow-up denominator, estimate of uncertainty, or analysis is listed. The posted information therefore does not establish whether participants' storage practices changed, how often they changed, or how precisely any change was estimated. The secondary outcome results are also not reported.

The single-group design has no concurrent control. General statistical reasoning cautions that a pre-to-follow-up change, even if available, would not by itself show that the intervention caused the change. The record does not provide results that would support a conclusion about feasibility or acceptability, despite identifying those as the pilot's purpose.

Termination is a registry status, and the reason is not reported in the registry record. It should not be treated as evidence of benefit, lack of benefit, harm, or a particular operational problem. Likewise, the absence of recorded adverse events among 5 participants does not demonstrate the absence of risk. The appropriate interpretation is that the record describes a small terminated pilot with important outcome and analysis information missing; it does not answer whether the decision aid changed firearm storage or was acceptable to participants.

14. Why This Trial Matters Statistically

This trial matters statistically because its question is measured as change in an ordered storage scale but reported as a binary count of participants with any improvement. That transformation makes the endpoint easier to summarize, yet it removes information about the extent of change and the final storage state. Readers evaluating such an outcome need both the event count and the number assessed, along with an account of missing observations. Those details are not reported in the registry record.

The design also illustrates the distinction between pilot aims and comparative-effectiveness claims. The stated aim is feasibility and acceptability, and the study has one intervention group. A pilot may help assess whether an intervention and its assessments can be used, but the registry record does not report the corresponding outcomes. Nor does a single-group design offer a control-based contrast for attributing change to the decision aid.

Small enrollment makes transparent reporting especially important. With enrollment of 5, the status of each participant can have substantial influence on a count-based summary. Yet the registry record does not report the primary count, the follow-up denominator, an uncertainty estimate, or any analysis. Without these, neither the observed pattern nor its precision can be evaluated.

Finally, the record lists multiple outcomes but no analyses and no multiplicity plan. These gaps mean that readers cannot assess how outcomes were prioritized or whether missing data and multiple comparisons were addressed. The statistical importance of the record is therefore methodological: it highlights how design, endpoint construction, denominators, and transparent results are essential for interpreting a pilot, while leaving the substantive outcome question unanswered.

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 most direct limitation is that the primary outcome result is not reported in the registry record. Enrollment is 5, but there is no primary event count or follow-up denominator. The record also lists zero analyses and does not report effect estimates, confidence intervals, or statistical tests. This prevents assessment of both the observed result and its precision.

The study is single-group, with no concurrent comparator. Any baseline-to-follow-up change, if it had been reported, could not by itself isolate an effect of the decision aid. The status is TERMINATED, but the reason for termination and its implications for follow-up or data collection are not reported in the registry record.

The primary outcome reduces an ordered storage measure to any improvement versus no improvement. This loses information about how far a participant moved on the scale and which storage category applied at follow-up. The record does not report category-level results or details about the assessment process. Follow-up is specified at 4 weeks post enrollment, so the record does not establish longer-term outcomes.

Further limitations include unreported eligibility details, participant characteristics, missing-data procedures, analysis populations, outcome analysis methods, multiplicity handling, and sample-size justification. The registry lists secondary outcomes, but their results are not reported. Adverse-event counts are zero in the intervention group, yet the observation period and event-ascertainment procedures are not reported. These limitations constrain interpretation; they do not establish that any particular bias, missingness, or safety issue occurred.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Decision Making Tool for Firearm Storage — NCT06382194.
• Registry record last updated 2026-04-28; status last verified 2026-04.
• Results first posted 2026-04-28.
• 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.

19. Record Summary

NCT06382194 is a University of Washington, single-group pilot titled “Decision Making Tool for Firearm Storage.” Its official title concerns shared decision making for firearm safety among older adults with early changes associated with Alzheimer's disease or Alzheimer's disease-related dementias. The listed conditions are dementia, mild, and depression. The intervention is a decision aid. Phase and allocation are listed as NA, and masking is NONE.

Enrollment is 5. The study started on 2024-04-10, had a primary completion date of 2024-10-09, and is marked TERMINATED. Its primary endpoint is the number of participants with any improvement in safe firearm storage at 4 weeks post enrollment. Five outcome measures are listed, but zero analyses are recorded. Primary and secondary outcome results are not reported in the registry record.

The adverse-event entries list 0 serious events, 0 other events, and 0 deaths among 5 participants at risk. The record does not report the reason for termination, analysis details, missing-data handling, or the primary outcome count.