Assessment of Safety and Effectiveness of Biodegradable Temporizing Matrix in the Treatment of Deep Burn Skin Injuries: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Assessment of Safety and Effectiveness of Biodegradable Temporizing Matrix in the Treatment of Deep Burn Skin Injuries (NCT02905435), a na na study. The primary outcome is BTM 'Take' Rate.

2. Clinical Question

3. Trial Design

This is a multi-center, single-arm, traditional feasibility study of Biodegradable Temporizing Matrix for deep burn skin injuries. The registry records the study as completed, with enrollment of 15. The recorded phase is NA. Allocation is NA, masking is none, and the model is single group. The sponsor is PolyNovo Biomaterials Pty Ltd.

The intervention is BTM, identified as a device. There is no randomized or concurrent control group in the registry record. The study can describe outcomes and safety events recorded in its BTM group, but its design does not support a direct treatment comparison. Differences between this group and people treated elsewhere would not be controlled by random allocation in this study.

The registry lists the study start as 2016-11-05 and primary completion as 2018-09-06. It describes the study as a preliminary assessment of safety and effectiveness. That feasibility purpose is important when reading the record: it is not a comparative trial, and the registry does not report a prespecified sample-size justification or a detailed statistical plan.

The primary outcome is a continuous measure of BTM take, defined for the intention-to-treat population. Its timeframe is at split skin graft application, typically 28-35 days after BTM application, with Day 0 also appearing in the timeframe description. The record lists 16 outcome measures, including secondary measures concerning infection, wound closure by body region and ease of use. Numerical results for those measures 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.

Before assignment: Only participants (or their legally authorized representatives) who provided written informed consent and who met the eligibility criteria were enrolled and had BTM applied to the study lesions. Participants (or their legally authorized representatives) who provided informed consent but who did not meet the eligibility criteria were excluded and did not have BTM applied.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intention to treat

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 BTM 'Take' Rate, measured over At time of application of split skin graft (SSG) (typically 28-35 days after application of BTM, Day 0).

The primary endpoint is BTM take rate, expressed as a percentage per subject. It represents the percentage of the total body surface area of BTM that had adhered at the time of skin grafting, divided by the percentage of total body surface area treated with BTM, then multiplied by 100. The description says the measure is calculated for each study lesion and averaged per participant.

The assessment is timed at application of a split skin graft. The registry describes this as typically 28-35 days after BTM application, and its timeframe also includes the wording Day 0. The endpoint is intended to quantify adherence at that treatment milestone, rather than to measure longer-term wound closure or a comparison with another intervention.

As a continuous measure, the endpoint can be summarized by a mean and a measure of spread. The registry specifies the mean and standard deviation. In general, a mean gives the average recorded value, while a standard deviation describes variation among values around that average. Neither statistic alone shows the distribution or range of individual outcomes.

The numerical mean and standard deviation for BTM take are not reported in the registry record. The endpoint definition therefore clarifies what was intended to be measured, but the posted record does not establish the observed average, variability, or precision of the result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry record is limited. The primary measure is continuous, and the specified summary is a mean with standard deviation. No numerical primary endpoint estimate or analysis is reported in the registry record. The explanations below describe general statistical concepts; they do not imply that a particular analysis was conducted for this trial.

What does a mean describe?

In general, a mean is an average across the observations included in an analysis. For this study, the endpoint definition says that values are calculated by study lesion and averaged per participant, and that the primary population is intention to treat. The mean would summarize the participant-level take-rate values if those values and the analysis were reported. Without the numerical mean, the registry record does not show the average BTM take observed in the study.

A mean can be informative but does not tell the whole story. The same average can arise from values that are closely grouped or widely dispersed. It can also be influenced by unusually high or low observations. The standard deviation is a descriptive measure of spread around the mean, not a measure of how certain the mean is. The registry specifies a standard deviation but does not report its numerical value.

How is a confidence interval different?

In general, a confidence interval gives a range of estimates compatible with the data under a specified statistical procedure. Its width reflects precision: a narrower interval indicates greater precision under that procedure, while a wider interval indicates less precision. An interval is not a guarantee that the true value lies within its bounds, nor does it correct for limitations in study design or measurement.

No confidence interval for the primary endpoint is reported in the registry record. A confidence interval cannot be reconstructed from the endpoint definition alone. It requires outcome data and an analysis method, neither of which is reported as a primary result. Thus, the precision of the primary estimate cannot be assessed from the posted record.

What does the single-group design allow?

In general, a single-group study can describe outcomes observed after an intervention, subject to how participants were selected, measured, and followed. With no concurrent comparison arm, the study cannot estimate a randomized between-group treatment contrast. A change over time, if measured, could reflect the intervention, the natural course of the condition, other care, or other influences. This study’s registry record describes no comparator, so a comparative effect is not available.

Allocation is recorded as NA and masking as none. Those entries do not establish further details about concealment, outcome assessment, or clinical procedures. Such details are not reported in the registry record. In general, lack of masking can matter when an outcome depends on judgment, but the record does not describe the assessment procedures enough to determine whether or how this affected measurement.

How should the safety counts be understood?

In general, an adverse-event count describes events recorded under the study’s definitions and observation procedures. A count of affected participants is not necessarily the same as a count of individual event episodes: one participant can experience more than one event. The record gives 6 serious-event-affected participants among 14 at risk and 14 other-event-affected participants among 14 at risk. It does not provide enough detail to infer the number of event episodes, timing, duration, severity grading beyond the serious classification, or causal relationship to BTM.

The listed serious-event percentages are registry entries. They should not be treated as comparative risks because the study has no control group. The record also lists 2 deaths, without providing a causal attribution in the registry record recorded. In general, safety interpretation depends on definitions, follow-up, ascertainment, and context; details not stated in the registry record cannot be assumed.

What do sample-size illustrations mean?

In general, a planning calculation estimates the sample size needed for a future study under stated assumptions about the effect to detect, variability, significance level, power, allocation, and analysis. Such calculations are not results from participants and do not show the power achieved by a completed study. The registry describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. For those illustrations, the effect to detect is a stated fraction of the observed effect. The registry does not report the study’s own sample-size justification.

Those planning assumptions describe a hypothetical two-arm design, whereas this study is recorded as single group. They should therefore be read as illustrations for planning, not as a reconstruction of the trial’s design or a statement about its evidential strength. Sample sizes for planning are not observed outcomes, and they are not observed power.

What analysis details are absent?

The registry record lists 16 outcome measures and 0 analyses. It does not report a statistical analysis plan, an inferential test for the primary endpoint, covariate adjustment, a missing-data method, or a confidence interval. The absence of these details means that readers cannot determine from the record whether results were adjusted, how incomplete measurements were handled, or how uncertainty was quantified. These omissions do not establish that no analysis occurred outside the registry; they mean that such analysis is not reported in the registry record.

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("Biodegradable Temporizing Matrix (BTM)")
n   <- c(12)
m   <- c(95.22)
sp  <- c(7.175)
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  Biodegradable Temporizing Matrix (BTM)  12  95.220  7.175  90.661  99.779

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 16 outcome measures, including the primary BTM take rate and secondary outcomes concerning infection, wound closure by body region, and ease of use. It lists 0 analyses. Numerical results for the primary and secondary outcomes, and any inferential procedures for them, are not reported in the registry record.

In general, multiplicity arises when several outcomes or statistical tests are examined. The more tests considered, the greater the chance that at least one result may appear notable by chance if each is interpreted separately. Statistical approaches can address this issue, but the registry record does not report a multiplicity procedure or a plan specifying which outcomes would receive confirmatory interpretation. No adjustment method should be inferred.

The primary population is described as intention to treat. In general, that principle aims to analyze participants according to their assigned group, but this study is single group and the record does not explain how the principle was operationalized. The registry enrollment is 15; the safety summaries report 14 at risk. The reason for this difference is not reported in the registry record. Nor does the record describe missing primary endpoint values, exclusions, withdrawals, or how any incomplete observations were handled.

These reporting gaps limit assessment of both outcome completeness and the reliability of any potential estimate. The registry does not report a numerical primary endpoint result, a missing-data analysis, or a comparison of analysis populations. It is therefore not possible to determine from the posted record how much data contributed to the primary endpoint or whether missingness could have influenced a result.

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: tracheostomy malfunction (14.3%), vascular pseudoaneurysm (7.1%), fusarium infection (7.1%), sepsis (7.1%), cellulitis infection right lower limb (7.1%).

The registry lists a BTM group with 14 participants at risk for serious adverse events and 6 affected. For other adverse events, it lists 14 at risk and 14 affected. It also lists 2 deaths. The reason that the safety denominator is 14 while enrollment is 15 is not reported in the registry record.

The serious-event terms listed are Tracheostomy malfunction, 14.3%; Vascular pseudoaneurysm, 7.1%; Fusarium infection, 7.1%; Sepsis, 7.1%; Cellulitis infection right lower limb, 7.1%; and Peritoneal haemorrhage, 7.1%. These entries describe the record’s reported safety information. They do not establish whether events were caused by BTM, and the registry does not provide a comparator group for estimating excess risk.

In general, a participant count and an event count are different quantities: a participant may have more than one event. The registry entries do not provide detail on event episodes, timing, or causal assessment. The figures should therefore be read as descriptive safety counts, not as a causal comparison or a complete account of each participant’s clinical course.

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

The registry record establishes that this was a completed, multi-center, single-arm feasibility study of BTM for deep burn skin injuries. It describes the primary endpoint as a participant-level mean of BTM adherence at split skin graft application and specifies an intention-to-treat population. It also records safety counts for the BTM group and lists secondary outcomes.

What the record does not establish is the numerical primary endpoint result. The mean BTM take rate and its standard deviation are not reported in the registry record. Without those values, readers cannot assess the observed average, its variability, or how precisely it was estimated. Numerical results for the listed secondary outcomes are also not reported.

The safety information is descriptive. The record reports 6 participants affected by serious adverse events among 14 at risk, 14 affected by other adverse events among 14 at risk, and 2 deaths. It does not establish that BTM caused these events. Because there is no concurrent comparator arm, the study cannot provide a randomized estimate of how safety or outcomes differ from another treatment.

In general, feasibility evidence can help characterize whether a study approach and its measurements can be used, while a single-group design can document observed outcomes in the group studied. Neither the design label nor safety counts alone demonstrate a treatment effect. The registry does not report the detailed feasibility criteria or numerical endpoint findings needed to judge the study against specific success thresholds.

The record also does not report a statistical analysis plan, missing-data handling, or multiplicity procedures. Those omissions limit how fully the analysis can be evaluated. Sample-size illustrations based on an observed effect, if considered, are planning scenarios rather than observed power or results from a comparative trial. The appropriate reading is therefore narrow: the registry documents the study’s design, endpoint definition, and selected safety counts, but does not provide enough outcome analysis to quantify effectiveness or comparative safety.

14. Why This Trial Matters Statistically

This study is statistically notable for the contrast between a clearly defined continuous primary endpoint and the limited numerical results reported in the registry. The definition specifies the unit, calculation, assessment time, summary measure, and intended population. Those details help clarify what the study aimed to measure, even though the result itself is not reported.

The design is also important. A multi-center feasibility study can collect experience across study sites, while a single-group design describes one intervention group without a randomized comparator. Statistical interpretation depends on that structure: counts and outcome summaries in one group do not yield a controlled estimate of comparative effect. This remains true regardless of how clearly an endpoint is defined.

The record’s safety entries illustrate why denominators and outcome definitions matter. Enrollment is 15, while the adverse-event summaries use 14 at risk. The record does not explain the difference. It reports affected-participant counts and selected serious-event terms, but does not provide a causal assessment or an event-level account. Readers therefore need to distinguish what is explicitly recorded from what cannot be inferred.

Finally, the record lists 16 outcome measures but no analyses. In general, multiple outcomes raise questions about which analyses were planned and how results should be interpreted together. A statistical plan and transparent outcome reporting would help readers evaluate those questions. Because such details and numerical outcome estimates are not reported in the registry record, the study’s statistical contribution in the posted record is principally its stated design and measurement framework, rather than a quantified estimate of BTM take or a comparative treatment effect.

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 study has no concurrent control group, and allocation is recorded as NA. As a result, its registry record cannot support a randomized comparison of BTM with another treatment. The single-group design also makes it difficult to distinguish outcomes associated with the device from other influences on healing or safety.

The primary endpoint is defined, but its numerical mean and standard deviation are not reported in the registry record. This prevents assessment of the observed take rate, variability, and precision. Numerical results for the secondary outcomes are also not reported. Although the record lists 16 outcome measures, it lists 0 analyses and does not report a statistical analysis plan.

The registry reports enrollment of 15, while 14 participants are listed as at risk in each adverse-event category. The reason for this difference is not reported in the registry record. The record does not explain whether the difference reflects eligibility, follow-up, data availability, or another reason, so none should be assumed. Missing primary outcome data and their handling are also not reported.

The safety summaries give affected-participant counts, selected serious-event terms, and deaths, but do not provide details on timing, event-level counts, causal assessment, or the completeness of safety follow-up. The record also does not describe how outcomes were assessed across centers or whether assessors were masked; masking is recorded as none, but further assessment procedures are not reported.

These limitations are specific to what the registry record documents. They do not establish that additional procedures or analyses were absent from the conduct of the study; they mean that the posted record does not describe them. Together, the lack of a comparator, missing numerical outcome results, and limited analytic detail constrain interpretation of both effectiveness and safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Assessment of Safety and Effectiveness of Biodegradable Temporizing Matrix in the Treatment of Deep Burn Skin Injuries — NCT02905435.
• Registry record last updated 2021-06-08; status last verified 2021-05.
• Results first posted 2021-06-08.
• 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 identifies a completed, multi-center, single-arm feasibility study of Biodegradable Temporizing Matrix for deep burn skin injuries. Enrollment is recorded as 15. The primary endpoint is BTM take rate, a continuous percentage measure assessed at split skin graft application and summarized as a mean with standard deviation for an intention-to-treat population.

The numerical primary endpoint result and secondary outcome results are not reported in the registry record. The record lists 16 outcome measures and 0 analyses. Its safety entries report 6 serious-event-affected participants among 14 at risk, 14 affected by other adverse events among 14 at risk, and 2 deaths. The reason for the difference between enrollment and the safety denominator is not reported.

With no concurrent comparator and no numerical primary result, the posted record supports description of the study design, outcome definition, and recorded safety counts, but not a comparative treatment-effect estimate.