A Prospective, Open Label, Multicenter Trial for Evaluating the Efficacy of Treating and Managing Wounds in Elderly Population in Specialized Nursing Facilities Using RD1: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Prospective, Open Label, Multicenter Trial for Evaluating the Efficacy of Treating and Managing Wounds in Elderly Population in Specialized Nursing Facilities Using RD1 (NCT04577183), a na na study. The primary outcome is Number of Participants With Reduction in Wound Size.

2. Clinical Question

The study was prospective and multicenter, and its stated setting was specialized nursing facilities. The registry description says wound-care specialists, wound surgeons, or dermatologists would be involved in wound care. It also says a qualified physician would manage glycemic care for participants with diabetes. These details describe the intended care context; they do not establish what care each participant actually received or how consistently it was delivered.

3. Trial Design

The registry describes a prospective, open-label, multicenter study with a single group receiving the RD1 System. Masking is listed as none, and allocation is listed as NA. There is no randomized control group. The registry lists the study phase as NA, which does not establish a phase classification.

The registry description states that 60 subjects would complete the study, with enrollment to increase if participants were lost to follow-up or withdrew. The registered enrollment is 13, and the study status is terminated. These entries describe a substantial difference between the intended number completing and the recorded enrollment, but the reason for termination and the number who completed treatment or follow-up are not reported in the registry record. The description of 60 subjects is a stated target, not evidence that this number enrolled or completed the study.

Participants were to receive up to 16 RD1 applications. For a participant whose wound healed completely, the description calls for one confirmatory visit two weeks later or before discharge from the specialized nursing facility, whichever came first. The primary endpoint timeframe is 16 weeks. The registry does not report the schedule of assessments, the actual number of applications received, or how many participants had a confirmatory visit.

The start date is 2018-07-11, and the primary completion date is 2019-02-01. The sponsor is RedDress Ltd. Although the registry identifies prospective conduct and multiple centers, the number of sites and details of site-level procedures are not reported in the registry record. No protocol-level explanation of the design choices or sample-size justification is reported in the registry record.

Because the study has a single group and no masking, its design can describe outcomes recorded during RD1 treatment but cannot, by itself, separate treatment-associated change from other influences over time. The absence of a concurrent comparator is especially important when interpreting change in wound size, since the registry record does not provide a control trajectory.

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: Number of patients showed Percent of wound reduction in the intent to treat (ITT) population

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 Reduction in Wound Size, measured over 16 weeks.

The primary endpoint is titled Number of Participants With Reduction in Wound Size, with a unit of participants with Wound Size reduction. The description refers to the percent of wound reduction from baseline to end of treatment in the intent-to-treat population, and the timeframe is 16 weeks. This combines a count-based endpoint label with a description of percent change in wound size. The registry does not report a threshold defining what amount of reduction qualifies a participant as having reduction, nor does it specify how the wound-size measurement was obtained.

Counting participants who meet an outcome criterion can make a result easier to interpret as a proportion of a study group, while a continuous measure of percent change can preserve information about the size of each participant's change. Those are general features of these endpoint types; the registry record does not clarify which summary was ultimately intended or how the two descriptions were reconciled.

Wound size is relevant to the study's stated aim of evaluating wound treatment and management. A baseline-to-end comparison describes change during the observation period, but without a comparator group it cannot establish how much change would have occurred in the absence of RD1. The record does not report the observed endpoint count, percent reduction estimates, uncertainty intervals, or an inferential result. Consequently, the endpoint's numerical result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

The registered model is single group. In general, a single-group study can describe outcomes among participants exposed to an intervention during a defined observation period. If baseline and follow-up measurements are available, it can describe within-participant change. It does not directly estimate how those same participants would have fared under a different intervention or without the study treatment. A randomized concurrent comparator is one way to make that contrast, but none is recorded for this study.

For this reason, a change from baseline should be interpreted as an observed trajectory, not automatically as an effect caused by the intervention. Wound care, participant characteristics, the natural course of wounds, and other influences can contribute to change. These are general considerations for before-and-after studies; the registry record does not report how such influences were measured or addressed.

How should the primary outcome be understood?

The endpoint title describes the number of participants with wound-size reduction, while the endpoint description refers to percent reduction from baseline to end of treatment in the intent-to-treat population. A count endpoint requires a rule for classifying participants as having or not having reduction. The registry record does not report that rule or a threshold for qualifying as a reduction. A percent-change endpoint instead describes the amount of change relative to baseline. The record does not clarify whether the planned primary analysis was a participant count, a summary of percent change, or both.

In general, a binary summary can be straightforward to communicate but may discard information about the magnitude of change. A continuous summary can retain more information about the size of the change, but interpretation depends on measurement quality and how results are summarized. These general distinctions cannot resolve the endpoint ambiguity in the registry record.

What do uncertainty estimates add?

In general, a confidence interval gives a range of estimates compatible with the data and analysis under its assumptions. It helps readers judge precision: a less precise estimate has greater uncertainty. A confidence interval does not correct a weak design, missing observations, measurement problems, or confounding. No confidence interval or other uncertainty estimate for the primary endpoint is reported in the registry record, so its precision cannot be assessed.

A p-value, when reported, summarizes how incompatible the observed data are with a specified null model under the assumptions of the test. It is not the probability that a treatment works, and it does not measure the size or clinical importance of an effect. No primary endpoint p-value or test result is reported in the registry record. There is therefore no inferential result to interpret.

Why does over-dispersion matter in general?

For count data, a statistical model may assume a particular relationship between the mean and variability. Over-dispersion means the observed variability exceeds what a model assumes. If that extra variability is ignored, uncertainty can be understated and statistical conclusions can appear more precise than warranted. This is a general issue for count outcomes; the registered primary endpoint is a participant count, and no dispersion estimate or count-model analysis is reported. The record does not establish that over-dispersion was assessed or that a count model was used.

What can the planning assumptions tell readers?

The registered planning description states that sample-size illustrations use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. For time-to-event calculations, it describes a total number of events; for other calculations, it describes participants per arm. These are planning assumptions, not a report of the study's actual allocation, which is single group. Any sample-size scenarios are planning illustrations, not observed power. The registry does not report the protocol's sample-size justification, and no numerical planning results are included in the available record.

Observed power is not a substitute for estimating an effect and its uncertainty. In general, post hoc power calculations based on an observed estimate are largely a restatement of the estimate and its uncertainty. Planning calculations instead ask what sample size might be needed under specified assumptions. Because no primary observed effect is reported, the registry record does not allow readers to assess the effect used in any illustration or compare the illustration with a completed analysis.

What can be inferred from the posted analysis record?

The registry lists one outcome measure and zero analyses. This identifies an outcome but does not document a statistical analysis of it. The record does not report an analysis population size, summary statistic, effect estimate, confidence interval, p-value, model, or adjustment procedure. A reader therefore cannot verify how the endpoint was summarized or whether the analysis followed the intended definition. No sponsor analysis is available in the registry record to take precedence over a recalculation.

In general, interpretation should distinguish a measured outcome from an estimated treatment effect. A measured change is descriptive; an effect estimate requires a defined comparison and an analysis strategy appropriate to the design. For this study, the lack of a comparator constrains causal interpretation, while the absence of posted endpoint results prevents even a detailed descriptive assessment of the primary outcome.

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("RD1 System")
n      <- c(13)
events <- c(7)
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  RD1 System  13  7  53.8  25.1  80.8  29.1  76.8  28.9  77.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and zero analyses. It does not report a statistical analysis plan, any additional outcome analyses, or a multiplicity procedure. Multiplicity arises when multiple outcomes, time points, subgroups, or statistical tests are examined; in general, repeated testing can increase the chance of a nominally notable result arising by chance. The registry record does not provide enough detail to determine whether such testing occurred or how it would have been handled.

The primary endpoint description identifies an intent-to-treat population, but the registry does not report how that population was defined, how many participants were included in it, or how many had endpoint data. It also does not report the number who completed follow-up, whether all enrolled participants received treatment, or how participants who withdrew or were lost to follow-up were handled. The study description says enrollment would increase to compensate for losses or withdrawals, but the recorded enrollment is 13 and the study is terminated. The number of losses and the reasons for any missing outcomes are not reported in the registry record.

In general, missing outcome data can affect both the estimate and its uncertainty, particularly when the chance of missingness is related to participant outcomes. Common analytical approaches rely on assumptions about why data are missing; those assumptions should be stated and assessed where possible. No missing-data method, imputation approach, sensitivity analysis, or analysis-population rule is reported in the registry record. It is therefore not possible to determine whether missing data were present or how they may have affected the primary endpoint.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death (7.7%).

The registry lists 1 participant in the RD1 System group as affected by a serious adverse event, with 13 at risk. It lists 5 participants as affected by other adverse events, also with 13 at risk. The serious adverse event term shown is Death, at 7.7%, and the recorded number of deaths is 1. These are counts recorded for this study group.

These entries should be read descriptively. The record does not provide event narratives, timing, duration, severity beyond the serious classification, or an assessment of relatedness to RD1. It also does not provide a comparator group, so the figures cannot be used to estimate a difference in safety outcomes against another treatment or no treatment. The death entry does not, on its own, establish that RD1 caused the death.

Adverse-event counts are not interchangeable with the number of event episodes: the registry reports participants affected, and the record does not specify whether a participant could have had multiple events. The number of participants at risk is 13 for both categories. The registry does not report further details that would support a more complete clinical or statistical characterization.

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

The registry record establishes that a prospective, open-label, multicenter, single-group study of RD1 was registered for wound management in elderly people in specialized nursing facilities. It records enrollment of 13, a terminated status, and a primary endpoint concerning participants with wound-size reduction over 16 weeks. It also records limited adverse-event counts.

It does not establish the magnitude or direction of the primary outcome. The count of participants with wound-size reduction, the percentage change in wound size, and any uncertainty around those results are not reported in the registry record. Without those results, readers cannot determine how participants' wounds changed during the study or how consistent any change was across participants.

Even if a before-and-after change were available, the single-group design would not by itself establish that RD1 caused the change. A concurrent comparator would help distinguish changes associated with treatment from changes that might have occurred over the same period for other reasons. No comparator is recorded. Open-label conduct also means masking was not used; the registry does not report whether outcome assessment was independently blinded.

The intended completion count of 60 in the study description is not the same as the recorded enrollment of 13. The registry does not report the reason for termination or how many participants completed follow-up. These gaps limit assessment of the endpoint's completeness and the relationship between the planned and observed study conduct.

The safety counts are likewise not comparative evidence. One participant is recorded as having a serious adverse event, five as having other adverse events, and one death is listed. The registry record does not establish whether these events were caused by the device. The findings therefore support a limited account of the registered study and its recorded safety entries, not a conclusion about efficacy or comparative safety.

14. Why This Trial Matters Statistically

This trial is statistically notable because its registry record separates a clearly named clinical question from the evidence needed to answer it. It specifies wound-size reduction as the primary outcome and gives a 16-week timeframe, but does not report the observed outcome or an analysis. That distinction is fundamental: a prespecified measurement is not itself a result.

The design also illustrates the limits of uncontrolled before-and-after evidence. A single-group study can document change among enrolled participants, but it lacks a concurrent estimate of what would have happened under another care strategy. This limits causal interpretation even when outcomes are fully reported. Here, the absence of posted primary results adds a further barrier: neither the observed change nor its uncertainty can be assessed.

The enrollment of 13 should be considered alongside the stated aim for 60 subjects to complete the study. The registry lists the study as terminated but does not explain why or report completion and follow-up counts. Those details matter because the number and pattern of participants with available outcome data affect both the reliability and interpretation of a study estimate.

The record also makes the distinction between planning and evidence important. Sample-size calculations based on assumed effects are tools for planning, not proof of study precision or observed power. Without a reported endpoint estimate, the planning assumptions cannot be tied to an observed clinical result.

Finally, the safety entries demonstrate why counts need context. The registry lists serious and other adverse events and a death, but provides no comparator or detailed event information. These registry entries can identify what was recorded, while leaving attribution and comparative risk unresolved. The principal statistical lesson is that design, endpoint definition, completeness of follow-up, and transparent analysis all shape what a registry record can support.

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 largest trial-specific limitation is that the registry record contains no numerical primary outcome result or analysis, despite identifying wound-size reduction as the primary endpoint. The endpoint title and description also differ in emphasis: one refers to the number of participants with reduction, while the other refers to percent reduction from baseline. The record does not specify a threshold for classifying reduction or explain how the endpoint was summarized.

Enrollment was 13, while the study description states that 60 subjects would complete the study. The status is terminated, but the reason for termination, actual completion count, follow-up completeness, and number contributing endpoint data are not reported in the registry record. Those omissions make it impossible to assess attrition and its possible influence on the outcome.

The design is single group and open label, with no comparator and no masking. Thus, even a reported change could not be cleanly separated from other changes over time, and the registry does not say whether outcome assessment was blinded. The record does not report the number of participating centers, details of measurement procedures, or a statistical analysis plan.

The safety information is also limited to counts and a serious-event term. Event timing, clinical details, relatedness, and comparative safety information are not reported in the registry record. The device description is incomplete in the registry text, which also limits understanding of the intervention's operational details.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Prospective, Open Label, Multicenter Trial for Evaluating the Efficacy of Treating and Managing Wounds in Elderly Population in Specialized Nursing Facilities Using RD1 — NCT04577183.
• Registry record last updated 2024-12-02; status last verified 2024-11.
• Results first posted 2021-05-13.
• 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

NCT04577183 is a prospective, open-label, multicenter, single-group study sponsored by RedDress Ltd. The intervention is the RD1 System. The registry lists elderly people in specialized nursing facilities and wound conditions including diabetic foot ulcers, pressure ulcers, venous leg ulcers, trauma injuries, skin tears, and chronic ulcers. The start date is 2018-07-11, the primary completion date is 2019-02-01, and the status is terminated.

Recorded enrollment is 13. The study description states that 60 subjects would complete the study. The primary endpoint concerns the number of participants with wound-size reduction over 16 weeks, with a description referring to percent reduction from baseline to end of treatment in the intent-to-treat population. The registry lists one outcome measure and zero analyses. No numerical primary outcome result is reported in the registry record.

The RD1 group has 13 participants listed at risk for serious and other adverse events; 1 is listed as affected by a serious adverse event, 5 by other adverse events, and 1 death is recorded. The serious-event term is Death, at 7.7%. The registry does not provide event detail sufficient to establish causation or compare safety with another group.