B3 Buddy for Securing Urinary Drainage Bag to Patient While Walking: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for B3 Buddy for Securing Urinary Drainage Bag to Patient While Walking (NCT06571058), a non-randomized na study. The primary outcome is Acceptability of Device.

2. Clinical Question

The study addresses a practical issue in ambulation with urinary drainage: keeping the bag below the bladder while walking. The registry describes workarounds such as hooking the bag into clothing pockets and evaluates a device intended to secure the bag during ambulation. The study's primary question is about acceptability, not a comparative estimate of clinical benefit or a test of whether the device improves urine flow.

Patients and clinicians had distinct experiences in the protocol description. Patients wore the device and walked; clinicians received instruction and used the device while assisting a patient. Because acceptability was assessed only for patients, the primary endpoint cannot be interpreted as a measure of clinician acceptability. Nor does the registry describe a separate patient outcome comparing walking with the device against walking without it.

3. Trial Design

The registry describes a completed, non-randomized, parallel study of the B3 Buddy urinary drainage bag securement device. The trial status is completed, and enrollment is listed as 41. The record gives a start date of 2023-07-27 and a primary completion date of 2023-11-17. The listed phase is NA. Ohio State University Comprehensive Cancer Center is identified as the sponsor.

The arms are Clinicians (B3 Buddy) and Patients (B3 Buddy). Patients received a short instructional session, wore the device to secure the urinary drainage bag, and walked approximately 90 feet before the bag was returned to its standard position. Clinicians received instruction, secured the bag to the patient using the device, assisted the patient with walking, and then removed the device and returned the bag to the standard position. The primary endpoint applied only to patients.

Allocation was non-randomized, masking was none, and the model was parallel. These features mean the arm descriptions should not be read as a randomized comparison of the same population receiving different assignments. The arms represent different roles and procedures. In particular, a comparison between clinician and patient results would not answer a treatment-effect question, and the primary endpoint was not measured in both arms.

The registry describes keeping the drainage bag below the bladder as standard of care to maintain urine flow and prevent urine from backing up into the bladder. The intervention was evaluated during walking, with the bag returned to its standard position afterward. The registry record does not report a separate control condition, a random allocation procedure, or masking beyond the listed design information. It also does not report the rationale for the enrollment target, detailed recruitment procedures, 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

Analysis population for the primary outcome, as defined in the registry: Acceptability of device was only measured for patient arm.

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 Acceptability of Device, measured over Up to 17 minutes.

The primary endpoint is the proportion of patients who find the device acceptable, measured with the Acceptability of Implementation Measure (AIM). The registry describes AIM as having 4 Likert items, each ranging from 1, for “completely disagree,” to 5, for “completely agree.” A higher number indicates greater acceptability. A patient's device use was classified as acceptable if at least 3 items were marked at 4 or higher.

The endpoint is a binary summary at the patient level: each patient is classified as meeting or not meeting the stated response rule, and the proportion meeting that rule is the outcome of interest. The registry states that the device would be considered acceptable if at least 70% of patient participants met the criterion. This threshold gives the feasibility assessment a prespecified benchmark in the record, but it is not itself an observed result.

Acceptability is useful in feasibility work because an intervention's practical use depends partly on whether intended users find it acceptable. It is distinct from efficacy, safety, ease of use, or a measured change in drainage. The endpoint does not directly quantify walking performance, urine flow, or patient or clinician experience beyond the defined questionnaire classification.

The timeframe is up to 17 minutes. The registry identifies the endpoint's unit as percentage of participants and its parameter as a number, with a 95% confidence interval. However, the actual patient count meeting the response rule, the observed percentage, and its confidence interval are not reported in the registry record. The endpoint definition can therefore be described, but its estimate and precision cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry record is limited. It identifies a primary endpoint, the measurement rule, a confidence-interval approach, and a planning framework for sample-size illustrations. It does not report statistical analysis results, the actual primary endpoint estimate, or a detailed analysis plan. The concepts below are general explanations of how these methods are ordinarily interpreted, not claims about analyses performed in this study.

What does a proportion measure?

The primary endpoint reduces questionnaire responses to a patient-level classification. A patient meets the stated acceptability rule when at least 3 of the 4 AIM items are marked at 4 or higher. The endpoint is then the proportion of patients meeting that rule. This is different from reporting an average item score: the classification rule focuses on how many patients cross a defined threshold, rather than the average response across items.

Converting responses into a binary classification makes the endpoint easier to compare with the stated benchmark of at least 70%. It also discards some detail. Patients just below and well below the response rule are both classified as not meeting it, while patients who meet it are grouped together despite possible differences in their item responses. The registry does not report item-level responses or an alternative summary of the questionnaire.

What does a confidence interval add?

In general, a confidence interval expresses statistical uncertainty around an estimated quantity. For a proportion, its width depends on features such as the number of observations and the distribution of responses, as well as the interval method. A narrow interval indicates greater precision under the method's assumptions; a wide interval indicates less precision. A confidence interval is not a guarantee about the true value, and it is not a substitute for examining how the outcome was defined or who was included.

The registry specifies a 95% confidence interval for the primary endpoint but does not report its limits or the proportion estimate. Consequently, the interval cannot be used to judge precision or to assess whether the observed data are consistent with the 70% criterion. The interval calculation method is not reported in the registry record.

What can the planning assumptions tell readers?

The record describes sample-size illustrations as planning calculations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For non-time-to-event outcomes, the planning quantities are participants per arm for 80% power or another stated power level; time-to-event calculations are described differently in the record. The numeric planning estimates are not reported in the registry record.

These are planning illustrations, not observed power. Observed power is not a useful replacement for an effect estimate and its uncertainty after data have been collected. A sample-size calculation can illustrate what a future study might require under its assumptions, but it does not establish that the current study was adequately powered, nor does it correct limitations in the design or reporting. In this study, the non-randomized arms represent different participant roles, so an equal-allocation calculation for a two-arm comparison would not make those arms a like-for-like control comparison.

Why does over-dispersion matter in general?

For count outcomes, over-dispersion means that observed variability exceeds what a simple model assumes. If it is ignored, standard errors can be too small and intervals or tests can appear more conclusive than warranted. This study's primary endpoint is a binary participant-level proportion, not a count outcome in the description, and the registry record does not report an over-dispersion analysis. This general concept should not be mistaken for a method used in this trial.

What limits statistical interpretation?

The registry reports no analyses, and the actual primary endpoint result is not reported in the registry record. There is therefore no basis to assess the observed effect, its precision, or a statistical test. The absence of an analysis result is not evidence that a result was null or that the endpoint failed to meet its benchmark. It means the record does not permit those conclusions. General statistical interpretation depends on the endpoint estimate, its uncertainty, the analysis population, and the methods used; those details are not available in the registry record.

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("Patients (B3 Buddy)")
n      <- c(21)
events <- c(21)
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  Patients (B3 Buddy)  21  21  100.0  83.9  100.0  84.5  100.0  84.6  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a multiplicity strategy. Multiplicity concerns the risk of false-positive findings when several outcomes, comparisons, time points, or analyses are examined. In general, a statistical plan may identify a primary outcome and specify how other tests will be handled. The registry names the primary acceptability endpoint, but does not report how any additional outcomes or analyses were prioritized or adjusted for. No analysis results are listed.

Missing-data handling is not reported in the registry record. The record does not say how incomplete AIM questionnaires, unanswered items, withdrawals, or other missing observations were treated. Because the primary outcome depends on the responses to several items, the approach to incomplete questionnaires could affect which patients can be classified under the stated rule. Without a reported missing-data method or completion information, the extent and possible influence of missing responses cannot be assessed.

The analysis population is also not reported in the registry record. It is not stated whether the primary endpoint was intended to include all enrolled patients, only patients who used the device, or another defined group. The registry states that acceptability was measured only for the patient arm, but does not describe the analysis set or explain how participant flow into the endpoint analysis was handled.

These omissions do not show that missing data or multiplicity problems occurred. They limit the ability to evaluate the reliability and completeness of the endpoint result, especially because the result itself is not reported. The number of analyses listed in the registry record is 0; no inferential results or accompanying analytic details are available for review.

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.

The registry safety record lists 0 serious adverse events, 0 other adverse events, and 0 deaths for the Clinicians (B3 Buddy) group, with 20 participants listed at risk. For the Patients (B3 Buddy) group, it lists 0 serious adverse events, 0 other adverse events, and 0 deaths, with 21 participants listed at risk. No top serious adverse-event terms are listed.

These figures describe what is recorded in the registry; they do not establish that no adverse events of any kind occurred or that the device has no risk. Zero recorded events can be difficult to interpret without details about event definitions, observation procedures, follow-up completeness, and the analysis population. Those details are not reported in the registry record.

The at-risk counts are safety-group denominators, not evidence that every participant completed every study procedure or endpoint assessment. The record does not give further information about exposure duration or safety surveillance. The safety counts should therefore be read as reported event counts for the listed groups, not as a precise estimate of the probability of harm or as a comparative safety analysis.

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

This study addresses the practical use of a device intended to secure a urinary drainage bag during walking. The registry defines patient acceptability using a questionnaire rule and states a benchmark of at least 70%. Those details describe what the study set out to assess. They do not reveal whether the benchmark was reached: the observed acceptability proportion and its confidence interval are not reported in the registry record.

The study's design also defines what its findings could address. The patient arm used the device and contributed to the acceptability endpoint; clinicians used the device while assisting patients. These are different roles, not treatment and control groups. The record does not describe a randomized comparison of device use against an alternative, so it cannot support a comparative treatment-effect interpretation.

The primary endpoint measures acceptability, not clinical efficacy. It does not directly show whether the bag remained below the bladder, whether urine flow changed, or whether walking became easier. The registry's background statement explains why securement and bag position matter, but the endpoint described is a questionnaire classification. No clinical outcome result is reported.

Likewise, the safety record's zero event counts are descriptive. They do not demonstrate absence of risk, particularly without further information on monitoring and follow-up. The record reports no statistical analysis results that could quantify uncertainty around either acceptability or safety.

Accordingly, the registry record supports a careful account of the feasibility question, device-use procedures, endpoint definition, and recorded safety counts. It does not support a conclusion about whether patients generally found the device acceptable, whether it improved clinical outcomes, or whether it was safer or more effective than another approach. Those questions require results and comparisons that are not reported in the registry record.

14. Why This Trial Matters Statistically

Feasibility studies can clarify whether an intervention and its assessment are practical enough to examine further. This trial focuses on securing a urinary drainage bag during walking, a setting in which patients and clinicians may have distinct needs. Its patient acceptability endpoint is relevant to implementation because a device intended for use during ambulation must be acceptable to the people expected to wear it.

Statistically, the endpoint definition illustrates why operational rules matter. The AIM responses are converted into a patient-level classification using a stated threshold, and the resulting proportion is judged against a stated benchmark. That makes the intended interpretation clear in principle. Reporting the observed proportion and confidence interval would be necessary to understand the estimate and its precision; neither is reported in the registry record.

The design also highlights the importance of identifying the right comparison. A parallel structure does not by itself imply a valid comparative trial. Here, patients and clinicians have different roles and procedures, and only patient acceptability is measured. Treating those arms as interchangeable comparison groups would misrepresent the study question.

The record further shows why feasibility evidence should be separated from clinical-effect evidence. Acceptability, safety-event counts, drainage outcomes, and comparative effectiveness are different quantities. The registry describes an acceptability measure and safety counts, but does not report outcome analyses establishing clinical benefit or comparative performance.

For readers assessing the evidence, the key statistical issue is the gap between a clearly defined endpoint and a missing endpoint result. The threshold and measurement rule make the planned question understandable, while the absence of an estimate, interval, and analysis details prevents assessment of what the study found. This distinction keeps interpretation tied to the registry record rather than to the device's intended purpose.

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 main limitation for statistical interpretation is that the primary endpoint result is not reported in the registry record. Although the endpoint definition, benchmark, timeframe, and confidence-interval measure are described, there is no observed patient proportion or interval to assess. No statistical analysis results are listed.

The design is non-randomized and has no like-for-like control comparison. The patient and clinician arms have different roles and procedures, and the primary endpoint was measured only among patients. As a result, differences between arms would not provide a direct comparative estimate of the device's effect.

The endpoint is an acceptability classification based on the AIM response rule. It does not directly measure bag position, urine flow, walking performance, or clinical outcomes. The record does not report the individual questionnaire responses, the number of completed questionnaires, or how incomplete responses were handled. Missing-data methods and the analysis population are not reported in the registry record.

Further details about recruitment, participant characteristics, adherence to the device procedure, follow-up, and the statistical analysis plan are not reported in the registry record. Safety figures are reported, but event definitions and monitoring details are not. The recorded zero event counts therefore have limited scope for characterizing safety.

Finally, the registry describes sample-size calculations as planning illustrations but does not report their numeric estimates. Such calculations cannot replace an observed effect estimate, and they should not be interpreted as observed power. Together, these limitations mean that the record documents the study's design and intended measures more fully than its statistical findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: B3 Buddy for Securing Urinary Drainage Bag to Patient While Walking — NCT06571058.
• Registry record last updated 2025-04-30; status last verified 2025-04.
• Results first posted 2025-04-30.
• 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

NCT06571058 is a completed, non-randomized, parallel feasibility study of the B3 Buddy urinary drainage bag securement device. The registry lists enrollment as 41 and identifies Ohio State University Comprehensive Cancer Center as sponsor. Patients wore the device while walking approximately 90 feet; clinicians used it while assisting patients. The primary endpoint was patient acceptability measured with the AIM response rule, with a stated benchmark of at least 70% and a timeframe of up to 17 minutes.

The registry record does not report the observed primary endpoint result, its 95% confidence interval, or statistical analysis results. It lists 0 serious adverse events, 0 other adverse events, and 0 deaths in each safety group. The design does not include a like-for-like randomized control comparison, and the record does not report missing-data methods, the analysis population, or a detailed analysis plan.