This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Effectiveness of KeraStat Gel for Improved Cosmesis of Partial Thickness Burns (NCT03564795), a randomized na study. The primary outcome is Improved Cosmesis.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03564795 |
| Phase | NA |
| Condition | Partial-thickness Burn |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 14 |
| Arms in the primary outcome | n/a |
| Lead sponsor | KeraNetics, LLC |
| Results posted | Yes |
2. Clinical Question
Population
People with partial-thickness burns who had eligible wounds for the study. The registry record lists 14 enrolled participants. Its brief summary describes a planned 30-subject trial, while the enrollment field records 14.
Intervention
KeraStat Gel applied to an eligible burn and covered with a secondary dressing. Participants were instructed to change the dressing and re-apply the gel according to its instructions for use; the registry description is truncated before the full instructions are stated.
Comparator
Silver sulfadiazine applied to another eligible burn and covered with a secondary dressing. The registry describes this as the institutional standard of care and says participants were instructed to change the dressing and re-apply the treatment according to institutional instructions; the description is truncated.
Primary question
At one year after the burn, how did the cosmetic assessment of healed wounds compare between wounds treated with KeraStat Gel and those treated with silver sulfadiazine? The registry identifies the Patient and Observer Scar Assessment Scale (POSAS) as the assessment, but does not report comparative scores or an analysis.
This is a within-subject comparison: the registry says each subject received both treatments, with eligible burns assigned to the respective treatment arms. That structure makes the wound the treatment-specific unit while allowing both treatments to be represented within a participant. The record does not describe how many eligible burns each participant contributed, or how randomization was carried out when participants had more than one eligible wound.
The primary outcome is listed as “Improved Cosmesis,” assessed using POSAS one year post burn. The scale includes patient and observer assessments. The registry also lists pain during dressing change as a secondary outcome, but does not provide its results. The central clinical research question is therefore about comparative scar appearance, not a reported finding that one treatment produced better cosmesis.
3. Trial Design
The registry describes a randomized, controlled, parallel-group trial with no masking. Its brief summary also calls the design within-subject: each participant received both KeraStat Gel and silver sulfadiazine on eligible burns. The two descriptions can be read together as randomized treatment assignment at the wound level within participants, but the record does not provide enough detail to establish the randomization procedure or allocation unit beyond the arm descriptions.
The listed interventions are KeraStat Gel and silver sulfadiazine. Each arm description says the assigned wound was treated and covered with a secondary dressing. Participants were instructed to change dressings and re-apply the assigned treatment. The registry’s text for both arm instructions is truncated, so further details are not reported in the registry record.
The record lists 14 participants enrolled and describes the intended study in the brief summary as a 30-subject trial. The study status is terminated. The reason for termination, the number completing follow-up, and the number assessed at the one-year endpoint are not reported in the registry record. The listed start date is 2018-08-31 and the primary completion date is 2023-03-31. The phase is listed as not applicable.
The sponsor is KeraNetics, LLC. Masking is listed as none. No detailed protocol, randomization method, allocation concealment procedure, or prespecified analysis plan is reported in the registry record. These omissions limit the ability to assess how the planned within-subject comparison was implemented and analyzed. The posted record does not include primary-outcome analysis results, so the design description alone cannot establish the direction or precision of any treatment contrast.
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: Total Started = 14. Each participant in the study received both treatment options (2 wounds per patient - one got treated with KeraStat Gel, one got treated with Silver Sulfadiazine).
Overall Study
| Stage | All Participants |
|---|---|
| STARTED | 14 |
| KeraStat Gel-treated: | 14 |
| Silver Sulfadiazine-treated: | 14 |
| COMPLETED | 3 |
| NOT COMPLETED | 11 |
Reasons for not completing this period:
| Reason | All Participants |
|---|---|
| Withdrawal by Subject | 3 |
| Lost to Follow-up | 6 |
| Physician Decision | 2 |
Analysis population for the primary outcome, as defined in the registry: Each subject received both KeraStat Gel and Silver Sulfadiazine.
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.
| Characteristic | Unit | All Participants |
|---|---|---|
| Participants analysed | 14 | |
| Age, Categorical: <=18 years | Participants | 1 |
| Age, Categorical: Between 18 and 65 years | Participants | 13 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 38.07 (SD 16.9) |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 13 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 |
| Race (NIH/OMB): White | Participants | 11 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Improved Cosmesis, measured over One year post burn.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary outcome is “Improved Cosmesis,” assessed one year post burn using the Patient and Observer Scar Assessment Scale (POSAS). The record describes two components: a Patient Scale and an Observer Scale, each made up of six items. Each item is scored on a 10-point range, with 10 indicating the worst possible state and 1 indicating normal skin. The six patient items are summed as a Total Patient Score, ranging from 6 to 60. The six observer items are summed as a Total Observer Score, also ranging from 6 to 60. Those totals can then be combined as a Total POSAS Score, ranging from 12 to 120.
These assessments capture cosmetic features of the healed wound from both the participant’s perspective and an observer’s perspective. In general, a structured scale can make assessments more consistent and communicate the construct being measured in a way that a broad label such as “cosmesis” cannot. The POSAS description also gives the direction of scoring: values nearer 1 represent normal skin, whereas values nearer 10 represent worse findings for an item.
The registry lists the primary outcome as a mean score with standard deviation, but does not report the observed scores, group means, variability, or a treatment comparison. It also does not state which POSAS summary was selected as the single primary analysis among the patient, observer, and combined scores. The outcome description mentions several related scores, and the registry indicates that its primary outcome has several categories or time points and was not reduced to one comparison. No treatment-effect estimate for cosmesis is reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a trial designed to compare KeraStat Gel-treated wounds with silver sulfadiazine-treated wounds within participants. It records 14 enrolled participants and a terminated study. Although the brief summary describes a 30-subject trial, enrollment is recorded as 14. The record does not state why enrollment differed from that description or why the study was terminated.
Most importantly for interpreting efficacy, no primary-outcome results or analyses are reported. There are no posted POSAS group means, standard deviations, treatment contrasts, confidence intervals, or p-values. Consequently, the record does not establish whether the observed cosmetic scores favored either treatment, how large any difference was, or how precisely it was estimated. This is an absence of reported comparative results, not evidence that the treatments had identical outcomes.
The outcome was intended to be assessed one year post burn. The registry does not report how many participants or wounds reached that assessment, whether all POSAS components were collected, or how any incomplete assessments were handled. The number enrolled cannot be assumed to equal the number analyzed at follow-up. The record also does not report whether the patient, observer, and combined POSAS scores were analyzed separately or whether a particular score was designated for the principal treatment comparison.
In general, an estimate of a treatment difference is more informative when accompanied by a confidence interval, which describes a range of values compatible with the data under the analysis assumptions. A p-value, when reported, addresses a different question about compatibility with a specified null model; it does not convey the size or practical importance of an effect by itself. Neither type of inferential result is reported for the primary outcome in this record.
The posted safety figures list no affected participants for serious adverse events or other adverse events in either treatment group, and no deaths. These counts are descriptive registry entries. They do not provide a comparative estimate of safety, and the lack of listed events should be interpreted in light of the recorded enrollment and the fact that the study was terminated.
The trial’s within-subject structure could support a comparison that accounts for the fact that two wounds from the same participant may be more alike than wounds from different participants. However, the analysis method is not reported. Without treatment-specific outcome data and a stated analysis, the treatment contrast and its uncertainty cannot be reconstructed from the registry record.
9. Statistical Methods Explained
The record describes a continuous primary measure summarized as a mean and standard deviation. The endpoint is a POSAS score, with lower item scores representing findings nearer normal skin and higher scores representing worse findings. The registry identifies the assessment time as one year post burn. It does not post the score data or a treatment-effect estimate, so the methods below explain how such data are generally interpreted rather than describing an analysis reported for this trial.
What does a mean score describe?
In general, a mean is the arithmetic average of the measured values in a group. It provides a summary of the group’s score level but does not show how scores are distributed among participants or wounds. A standard deviation describes the spread of observations around the mean. A small or large standard deviation is meaningful only in relation to the scale and the observations; it is not a measure of uncertainty in the estimated mean itself.
For POSAS, the scale description includes patient, observer, and combined totals. These are related but distinct perspectives on scar appearance. A mean for one total would not automatically describe the other totals. The registry does not identify which score or scores were used in a primary comparison, and it does not report any means or standard deviations. No numerical treatment contrast can therefore be interpreted from the posted record.
Why does the within-subject design matter?
In general, when each participant receives both treatments on different eligible wounds, the comparison can use information from both wounds in the same participant. This paired structure can account for shared participant characteristics that may influence both wound assessments. The analysis should preserve the pairing: treating every wound as independent could understate uncertainty if outcomes from the same participant tend to be related.
That advantage depends on having an appropriate analysis and enough information to identify the pairs. The registry’s brief summary says the study is within-subject, and the primary outcome description says each subject received both treatments. However, the record does not explain the statistical method, how multiple eligible burns were handled, or whether the analysis accounted for participant-level clustering. It also does not state whether randomization was performed separately for each wound or by another procedure.
What does a confidence interval add?
In general, a confidence interval expresses uncertainty around an estimated contrast. It helps readers assess which treatment differences are compatible with the data and the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, though precision does not by itself determine whether a difference matters clinically. The registry does not report a confidence interval for POSAS or any other primary-outcome estimate.
A p-value, in general, measures how unusual data at least as incompatible with a specified null hypothesis would be if that hypothesis and the model assumptions held. It does not give the probability that a treatment is effective, nor does it express the size of a contrast. No p-value or test result for the primary outcome is reported in the registry record. The record also does not give the analysis model, the null hypothesis, or whether any estimate was adjusted for other variables.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a model assumes. If a model understates variability, its standard errors can be too small and its confidence intervals too narrow. The issue is most often relevant to count or binary outcomes analyzed with models that impose a particular variance structure. The listed primary outcome is continuous, summarized by a mean and standard deviation; the registry does not report a model or any assessment of over-dispersion. It is therefore not possible to say whether this issue arose in the trial’s analysis.
What do the sample-size assumptions mean?
The record describes a planning illustration based on the observed effect, with 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. In general, such calculations explore how a hypothetical design’s participant requirement changes with the effect size and assumptions used. They are planning illustrations, not observed power and not evidence that the trial was adequately powered.
No sample-size illustration values or observed treatment effect are reported in the registry record. The planning description also does not report the trial’s own sample-size justification. The brief summary’s 30-subject description and the enrollment entry of 14 do not, by themselves, establish the planned statistical power or the reason enrollment ended at that level.
No recalculated estimate is reported for this record. The posted information does not include the summary statistics needed to perform a simple unadjusted recalculation. More broadly, without outcome values and an analysis method, a reader cannot reproduce or evaluate a primary treatment-effect estimate from the registry entry.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies a primary outcome with several related POSAS scores: a patient total, an observer total, and a combined total. It also indicates that the primary outcome has several categories or time points and was not reduced to one comparison. The stated assessment time is one year post burn. The record does not clarify which score was the principal endpoint for testing or whether all the described scores were analyzed.
In general, testing several outcomes or comparisons can increase the chance of finding an apparently notable result by chance. Statistical plans may address this through a prespecified hierarchy, adjustment, or other strategy. No multiplicity strategy, testing hierarchy, or adjustment is reported in the registry record. Because no primary-outcome analyses are posted, it is not possible to determine how multiple scores or comparisons were treated.
Missing-data methods are also not reported. The registry does not state how many participants or wounds had one-year POSAS assessments, whether any assessments were incomplete, or how missing items or follow-up measurements were handled. It does not report whether an analysis included only complete assessments or used another approach. These details matter because the analyzed set and the method for handling incomplete outcomes can affect the estimate and its uncertainty.
The record gives no analysis populations, such as an intention-to-treat population or a per-protocol population, and no participant flow for the primary analysis. Enrollment is recorded as 14, but that does not establish the number with outcome data or the number included in an analysis. No analysis plan or interim-analysis information is reported in the registry record. The absence of these details prevents assessment of the prespecified statistical approach and of how closely any analysis followed it.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| KeraStat Gel-treated Wound | 0 | 14 | 0.0% |
| Silver Sulfadiazine-treated Wound | 0 | 14 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| KeraStat Gel-treated Wound | 0 of 14 |
| Silver Sulfadiazine-treated Wound | 0 of 14 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| KeraStat Gel-treated Wound | 0 of 14 |
| Silver Sulfadiazine-treated Wound | 0 of 14 |
For the KeraStat Gel-treated wound group, the record lists 14 at risk for serious adverse events and 0 affected; it also lists 14 at risk for other adverse events and 0 affected. Deaths are listed as 0. For the silver sulfadiazine-treated wound group, it lists 14 at risk for serious adverse events and 0 affected, 14 at risk for other adverse events and 0 affected, and deaths of 0.
These figures describe the entries in the registry record. They are not a statistical comparison of safety between treatments. The record does not provide event descriptions, follow-up duration for safety reporting, or detail on how adverse events were collected or attributed. The study enrolled 14 participants and was terminated; the record does not state how many completed follow-up. Thus, the zero counts should be read as no affected participants listed in these registry entries, not as proof that no adverse events could occur.
The trial used a within-subject design, with treatment assigned to wounds in participants who received both treatments. The safety groups are named by treated wound, and the record lists 14 at risk in each. The registry does not explain whether the same participant could contribute to both group counts for safety, nor does it describe any statistical method for comparing adverse events. These descriptive counts cannot establish a comparative risk estimate.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, controlled study was registered to compare KeraStat Gel with silver sulfadiazine for cosmesis of healed partial-thickness burns. It describes a within-subject approach in which participants received both treatments on eligible burns, with POSAS assessment planned one year post burn. It also records 14 enrolled participants and a terminated study.
It does not establish the comparative cosmetic outcome. No POSAS scores, group summaries, treatment contrasts, confidence intervals, or p-values are reported. Therefore, the record cannot show whether the cosmetic assessments differed between treatments, in which direction any observed difference went, or how precisely such a difference was estimated. Missing results should not be interpreted as a finding of no difference.
The registry describes multiple POSAS summaries and a secondary pain-during-dressing-change outcome, but does not report analysis results for either. It also does not report the number with one-year outcome data, the analysis population, how missing assessments were handled, or the statistical method used for the within-subject comparison. These gaps prevent readers from evaluating the robustness of a treatment estimate or the uncertainty around it.
The listed safety entries report no affected participants for serious or other adverse events in either group and no deaths. Those entries are descriptive and should not be taken as a definitive comparative safety conclusion. Enrollment, termination, and incomplete reporting constrain what can be inferred from them.
In general, a registry description of a research question and design is different from a complete report of results. A treatment-effect conclusion requires outcome data and an analysis that reflects the design, along with enough information to judge precision and potential bias. Those elements are not reported for the primary outcome in this registry record.
13. Why This Trial Matters Statistically
This trial is statistically notable for its within-subject design. When participants receive both treatments on different wounds, the comparison can use each participant as their own reference. In general, that approach may reduce the influence of participant characteristics shared across the two wounds. It also requires an analysis that respects the relationship between observations from the same participant; otherwise, the precision may be misrepresented.
The registry gives a clear example of why design descriptions and results must be considered separately. It names the clinical question, interventions, endpoint, and intended assessment time, but does not report the primary outcome analysis. A registered design cannot by itself answer whether the score distributions differed or how uncertain a treatment contrast would be.
The outcome also has several components: patient, observer, and combined POSAS scores. These summarize different perspectives, and the choice among them matters for a statistical interpretation. The record does not reduce the outcome to a single comparison or state how multiple scores were handled. Without that information, the target estimand—the precise treatment contrast intended to be estimated—is unclear from the posted results.
Finally, enrollment is recorded as 14, while the brief summary describes a 30-subject study, and the status is terminated. These registry entries make the absence of follow-up and analysis details especially important to interpreting what was learned. They do not explain why the study ended or what outcomes were collected; those details are not reported in the registry record. Statistically, this record illustrates the limits of drawing conclusions from a trial description when estimates, uncertainty, and analysis decisions are not available.
14. 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 registry record lists 14 enrolled participants, whereas its brief summary describes a 30-subject trial. The study is marked terminated, but the reason for termination and the number who completed the planned follow-up are not reported in the registry record. The record does not say how many participants contributed one-year POSAS assessments or how many wounds were assessed.
The primary outcome description includes patient, observer, and combined POSAS totals. The record does not identify one of these as the single primary comparison, and it notes that the primary outcome has several categories or time points and was not reduced to one comparison. No treatment-specific results or analysis are reported. Accordingly, neither the direction nor the precision of a cosmetic comparison can be assessed.
Although the study is described as randomized and within-subject, details of the randomization procedure and analysis method are not reported. The record does not explain how multiple wounds within a participant were handled or whether participant-level dependence was accounted for. Masking is listed as none; the record does not provide further detail on who assessed the POSAS outcomes.
Missing-data handling, analysis populations, multiplicity procedures, interim analyses, and the statistical analysis plan are not reported in the registry record. The reason for the difference between the brief summary’s 30-subject description and recorded enrollment of 14 is also not stated. These are limitations of the available record; they do not establish how the trial was conducted beyond what is explicitly listed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effectiveness of KeraStat Gel for Improved Cosmesis of Partial Thickness Burns — NCT03564795.
- Registry record last updated 2024-08-01; status last verified 2024-07.
- Results first posted 2024-08-01.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes a randomized, controlled, within-subject comparison of KeraStat Gel and silver sulfadiazine for partial-thickness burns. The primary outcome is cosmetic assessment using POSAS one year post burn. The record lists 14 enrolled participants, no masking, and a terminated study; the brief summary describes a 30-subject trial.
The POSAS outcome includes patient, observer, and combined scores, but no primary-outcome results or analyses are reported. The record also does not report the analysis method, missing-data handling, analysis populations, or reason for termination. Safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each treatment group, with 14 at risk listed for each group.
Because comparative outcome estimates and their uncertainty are not reported, the registry record does not establish a difference in cosmesis between treatments.