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 Open, Prosp, Rand. Invest. Evaluating Pain With Mepitel One vs.Bridal Veil and Staples on Split Thickness Skin Grafts (NCT01365273), a randomized phase 4 study. The primary outcome is VAS Score for Pain Before Dressing Removal.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01365273 |
| Phase | Phase 4 |
| Condition | Deep Partial Thickness Burn, Full Thickness Burns |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 43 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Molnlycke Health Care AB |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerned people with deep partial-thickness or full-thickness burns requiring skin grafts. The registry summary describes an intended enrollment of approximately 40 subjects across 4-5 centres in the US; recorded enrollment was 43. For the primary endpoint, the stated analysis population included subjects who received post-randomization treatment and provided some data for that endpoint. The registry does not give further participant characteristics in the record.
Intervention
The intervention was Mepitel One, described in the record as a device and dressing. Its primary endpoint was pain before dressing removal at visit 6, day 7. The record does not provide additional procedural details about use of the dressing.
Comparator
The comparator was Bridal Veil fixed over the graft with staples, described as standard of care. The comparison therefore concerns two approaches to covering or securing the graft, with pain assessed before dressing removal. The record does not report further details about how the procedures were standardized across centres.
Primary question
The primary objective was to compare pain at dressing change for Mepitel One versus Bridal Veil with staples on deep partial-thickness or full-thickness burns requiring skin grafts. Pain was recorded on a Visual Analogue Scale, or VAS, described as spanning 0 for no pain to 100 for the most intense pain imaginable. The posted arm summaries are medians of 4.0 for Mepitel One and 11.0 for Bridal Veil and staples. No primary-endpoint hypothesis test or confidence interval is reported in the registry record, so the summaries alone do not establish the precision or statistical significance of the between-arm comparison.
3. Trial Design
This was a Phase 4, open, randomised investigation with a parallel-group model. Participants were assigned to Mepitel One or to Bridal Veil with staples. The registry describes the latter as standard of care and the former as a device dressing. The brief summary says subjects would be equally randomised, while the primary-endpoint summaries include 20 participants in the Bridal Veil and staples arm and 17 in the Mepitel One arm. Recorded overall enrollment was 43. These figures describe enrollment and endpoint summaries, respectively; the registry does not explain the difference in their denominators.
The study was open, with no masking. This matters for an outcome based on a participant-reported pain scale: participants knew their assigned dressing, and the record does not describe masking of people collecting or assessing the outcome. Awareness of treatment can influence subjective reporting or assessment, although the registry data do not establish whether that occurred in this study.
The record gives a start date of 2011-02 and a primary completion date of 2011-12, and lists the study status as completed. The summary describes a planned multicentre investigation in the US. The registry does not report site-specific enrollment, the number of centres that actually recruited, or details of allocation concealment. The method used to generate the random sequence and the procedures used to implement randomization are not reported in the registry record.
The primary outcome was pain before dressing removal at visit 6, day 7. The analysis population is described as all subjects who received post-randomization treatment and provided some data for the primary endpoint, labelled an ITT analysis in the record. The registry does not provide a fuller account of how participants with missing endpoint data were handled or whether analyses were conducted under other population definitions. No inferential analyses are posted in the 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.
Overall Study
| Stage | Bridal Veil and Staples | Mepitel One |
|---|---|---|
| STARTED | 22 | 21 |
| Compl. Pts, Not Evaluable for Pain. | 2 | 4 |
| COMPLETED | 20 | 20 |
| NOT COMPLETED | 2 | 1 |
Reasons for not completing this period:
| Reason | Bridal Veil and Staples | Mepitel One |
|---|---|---|
| Lost to Follow-up | 1 | 0 |
| Protocol Violation | 0 | 1 |
| Physician Decision | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: All subjects to post-randomization treatment and that provided some data for the primary endpoint were included in the ITT analysis.
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 | Bridal Veil and Staples | Mepitel One | Total |
|---|---|---|---|---|
| Participants analysed | 22 | 21 | 43 | |
| Age, Continuous | years | 42.3 (SD 16.0) | 38.0 (SD 18.0) | 40.15 (SD 17) |
| Sex: Female, Male: Female | Participants | 3 | 5 | 8 |
| Sex: Female, Male: Male | Participants | 19 | 16 | 35 |
6. Primary Endpoint
The registry lists the primary outcome as VAS Score for Pain Before Dressing Removal, measured over At visit 6, day 7.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the VAS score for pain before dressing removal at visit 6, day 7. The registry describes the VAS as a 100 mm scale, anchored at 0 for no pain and 100 for the most intense pain imaginable. A participant indicates the intensity of pain along this continuum; the resulting score represents a subjective report at the time specified by the study.
Pain is relevant to this comparison because the stated objective was to compare pain at dressing change between the dressing approaches. Measuring before removal gives a defined moment for the assessment, rather than asking about pain over an unspecified period. The record does not report whether additional pain assessments were collected at other times or how any such assessments were used.
The registry identifies the endpoint parameter as a median and the dispersion measure as a standard deviation. For Bridal Veil and staples, the median was 11.0 with a standard deviation of 21.0, based on 20 participants. For Mepitel One, the median was 4.0 with a standard deviation of 20.1, based on 17 participants. These summaries describe the reported endpoint values within each arm; they do not, on their own, quantify uncertainty around the difference between arms.
A median can describe the central position of participant scores, while a standard deviation describes spread around a mean and is more conventionally paired with a mean. Their use together is what the registry reports, but the record does not explain the choice of summary or provide additional distributional information. No confidence interval or test result for this endpoint is reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary-endpoint summaries show a median pain score of 4.0 for Mepitel One and 11.0 for Bridal Veil and staples at visit 6, day 7. The corresponding standard deviations were 20.1 and 21.0. The endpoint analysis included 17 participants in the Mepitel One arm and 20 in the Bridal Veil and staples arm. These are descriptive summaries of the observed scores in the stated analysis population.
The lower posted median in the Mepitel One arm is a descriptive contrast, not a complete estimate of the treatment effect. The registry does not report a between-arm estimate with a confidence interval, a hypothesis test, or a p-value for the primary endpoint. The available summaries therefore do not show how precisely the arms differ, nor whether a formal statistical analysis judged the contrast compatible with chance variation. No conclusion about statistical significance can be drawn from the medians alone.
Dispersion is substantial in both arms as represented by the reported standard deviations. However, the record gives no participant-level scores, distribution plots, or other summaries that would show the shape of the data, the presence of outliers, or how the VAS scores were distributed. Because the endpoint is reported as a median but paired with a standard deviation, readers should retain the registry's stated summaries rather than infer a distribution or reconstruct an unreported analysis.
The posted endpoint denominators are not the same as the recorded enrollment, and the safety denominators differ from the primary-endpoint denominators. These figures refer to distinct reported populations and should not be treated as interchangeable. The registry defines the endpoint analysis population as subjects receiving post-randomization treatment and providing some primary-endpoint data, but does not explain why other enrolled or randomized participants are absent from those summaries.
The study was open, and pain is a subjective outcome. Awareness of assignment could potentially affect a participant's report or the conduct of an assessment; this is a general methodological consideration, not evidence that reporting was biased in this trial. The record does not describe masking, standardized assessment procedures beyond the specified timing and scale, or an analysis intended to account for possible reporting effects.
Overall, the registry supports a descriptive statement about the observed medians and their reported variability. It does not support a precise inferential comparison, a claim about clinical importance, or a conclusion that one approach is superior. The sponsor's own analysis does not appear as a posted inferential result in the registry record, and no recalculated comparison is identified for this endpoint.
9. Statistical Methods Explained
Random allocation is intended to make treatment groups comparable, on average, with respect to factors that could affect an outcome. In a parallel-group study, each participant is assigned to a group and outcomes are assessed within that assignment. Randomization does not guarantee identical groups, especially in a modest-sized trial, and the record does not report the sequence-generation or allocation-concealment methods. It says that assignment was random and planned to be equal between the arms.
What does the median describe?
The median is the middle of the ordered observations and is often useful when an outcome may be skewed or contain extreme scores. It describes a typical position in the observed distribution without being pulled as strongly by unusually high or low values as the mean can be. The registry reports medians of 11.0 for Bridal Veil and staples and 4.0 for Mepitel One. Those summaries do not reveal the distribution of individual scores or the uncertainty in a comparison between groups.
The registry also labels the dispersion as standard deviation. Standard deviation measures spread around the mean and is typically interpreted alongside a mean. A median and standard deviation can both be reported, but the pair does not by itself specify a complete distribution or provide a direct uncertainty interval for a difference in medians. The record does not explain this reporting choice or give additional distributional summaries. It would be inappropriate to infer a standard error, confidence interval, or test statistic from these summaries without assumptions and a specified method.
Why does uncertainty matter?
A confidence interval is a statistical range describing uncertainty around an estimated quantity under a particular analysis method. In general, it helps readers distinguish an estimate's direction and size from its precision. A narrow interval indicates greater precision under the method; a wide interval indicates less precision. No confidence interval for the primary comparison is reported in the registry record, so the precision of the between-arm contrast cannot be assessed from an interval.
A hypothesis test evaluates data against a specified null hypothesis using an analysis model and assumptions. A p-value, when reported, describes how unusual the data would be under that null model; it is not the probability that a treatment effect is real, and it does not measure clinical importance. The registry posts no analysis for this endpoint, no test result, and no p-value. The observed medians should therefore remain descriptive rather than being interpreted as a statistically confirmed difference.
What does over-dispersion mean in general?
Over-dispersion occurs when observed variability is greater than a statistical model expects. In general, ignoring over-dispersion can make uncertainty estimates too small and tests too optimistic. Whether over-dispersion is relevant depends on the outcome and analysis model. The registry does not identify an inferential model for the primary endpoint, so no claim can be made about whether over-dispersion was assessed or affected a result in this trial. The reported standard deviations show variability in the arm summaries, but they do not diagnose a model problem on their own.
The sample-size material is described as a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It considers effects defined as stated fractions of the observed effect. Such an illustration is not evidence of the trial's original design rationale and is not observed power. Planning estimates depend on assumptions about the target effect and analysis; they do not replace an observed treatment-effect estimate or its uncertainty. The trial's own sample-size justification is not reported in the registry record.
The registry's description of the primary population uses an ITT label but limits inclusion to subjects who received post-randomization treatment and posted some data for the primary endpoint. In general, an intention-to-treat approach aims to analyze participants according to randomized assignment, regardless of treatment received. The description in this record does not establish that all randomized participants were included. The full analysis population, handling of missing scores, and any sensitivity analyses are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 3 outcome measures, but only the primary endpoint is described in the results summarized for this analysis. No secondary outcome results are posted. The record does not report a multiplicity procedure, such as an adjustment to account for testing several outcomes or comparisons. Without a stated analysis plan and posted tests, it is not possible to assess how multiplicity was handled or whether it affected interpretation.
The primary endpoint population is described as all subjects who received post-randomization treatment and provided some data for the endpoint. The registry labels this an ITT analysis. That description does not fully explain how missing endpoint data were treated, whether participants were analyzed according to randomized assignment, or what happened to those without a recorded score. The reason for any missing observations, the number missing by arm, and any imputation or sensitivity analyses are not reported in the registry record.
Recorded enrollment was 43, while endpoint summaries are based on 20 participants for Bridal Veil and staples and 17 for Mepitel One. The registry does not explain the relationship between these counts or provide a participant-flow account sufficient to trace exclusions, withdrawals, or missing measurements. The safety figures use different at-risk denominators, which should be read as safety-population counts rather than as replacements for the endpoint denominators.
Missing data can matter when the likelihood of having an observed score is related to treatment or outcome. This is a general concern, not proof that missingness biased this trial's results. Without details on missingness and the analysis approach, the potential influence of unavailable pain scores cannot be evaluated. Methods for multiplicity, missing data, interim analyses, and prespecified statistical testing are not reported in the registry record.
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 |
|---|---|---|---|
| Bridal Veil and Staples | 0 | 22 | 0.0% |
| Mepitel One | 0 | 21 | 0.0% |
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 |
|---|---|
| Bridal Veil and Staples | 0 of 22 |
| Mepitel One | 0 of 21 |
The registry reports serious adverse events in 0 of 22 participants at risk in the Bridal Veil and staples group and 0 of 21 participants at risk in the Mepitel One group. It also reports other adverse events in 0 of 22 and 0 of 21 participants at risk, respectively. These are the posted counts and denominators; they are separate from the primary-endpoint analysis populations.
A zero count means that no events of the specified category were recorded among the listed participants at risk in that group. It does not establish that an event is impossible or that the groups have identical safety profiles. With no events recorded, the registry figures do not quantify the range of event rates compatible with the observations. No safety comparison or uncertainty interval is reported.
The deaths field is not populated for either group, so death counts are not reported in the registry record. The record also provides no serious-event terms, which means the nature of any such events cannot be characterized from the posted results. The zero counts should not be extended to outcomes or follow-up periods that the registry does not specify.
These figures are best read as a narrow account of recorded adverse events among the stated at-risk denominators. They do not replace a full safety assessment, and they do not indicate whether participants outside those denominators were monitored or how long safety follow-up lasted. Such details are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The result describes pain scores before dressing removal at visit 6, day 7 among participants included in the registry's primary-endpoint analysis. The Mepitel One arm had a median of 4.0, compared with 11.0 for Bridal Veil and staples. The respective standard deviations were 20.1 and 21.0. These figures show the reported arm-level summaries, but they are not a complete statistical comparison.
The record does not report a confidence interval, inferential test, or p-value for the primary endpoint. Without those results, the precision of the contrast and its compatibility with random variation cannot be assessed using the posted record. The results also do not establish whether any observed contrast would be important to patients or clinicians. The registry provides no threshold for a clinically meaningful difference.
The study was open and pain was measured using a subjective scale. General concerns about awareness of treatment and outcome reporting apply, but the record cannot show whether those concerns affected these scores. The score distributions and participant-level data are not reported, so it is not possible to judge how the medians relate to the full range of responses.
Nor do the posted results establish that either dressing approach causes a particular level of pain. Randomization is a design feature intended to support comparisons, but interpretation also depends on implementation, complete outcome ascertainment, and analysis. The registry does not provide enough information to verify those aspects in detail. The distinction between enrollment, endpoint, and safety denominators should also be maintained rather than assuming that each outcome includes the same participants.
The appropriate reading is therefore limited: the registry reports lower median pain in the Mepitel One arm in this endpoint summary, alongside substantial reported within-arm variability. It does not provide the inferential or contextual information needed to make a definitive comparative claim. Absence of posted analyses is not evidence that no analysis was performed outside the registry; it means that such an analysis is not reported in the registry record.
13. Why This Trial Matters Statistically
This trial raises a useful statistical distinction between an observed difference in group summaries and an inferential conclusion. The medians describe what was recorded among the analyzed participants, but a treatment comparison also needs an estimate of uncertainty and a clearly specified analysis. The registry posts neither a confidence interval nor a test result for the primary endpoint. Readers can see the direction of the descriptive contrast but cannot judge its precision from the registry record.
The endpoint also illustrates why the choice and pairing of summary measures matter. Pain scores can vary between participants, and the registry reports a median together with a standard deviation. Those statistics convey different aspects of data, and they do not directly yield a comparison's uncertainty. Distributional details and a stated inferential method would help clarify how the endpoint was analyzed.
Open assessment is another relevant design feature. Randomization can help balance characteristics between groups, but knowledge of assignment may still matter for subjective outcomes. This is a general consideration for pain measurement, not evidence that the observed reports were biased. The registry does not report measures used to address that possibility.
Finally, the record distinguishes endpoint and safety denominators, while its participant-flow and missing-data details are limited. That makes careful attention to analysis populations important. These are common issues in trial interpretation: enrollment alone does not identify the number contributing to a particular endpoint, and zero recorded events do not convey the full uncertainty around safety. The trial is statistically informative as an example of how descriptive results, reporting completeness, and inferential evidence are distinct.
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 leaves important details unavailable for interpreting this trial. It does not report the random-sequence generation method, allocation concealment, or the procedures used to maintain consistency across centres. Although the study is described as open and randomised, those details would help readers assess how assignment was implemented.
The primary endpoint is reported using medians and standard deviations, but no rationale for that combination is given. There are no participant-level observations, additional distribution summaries, confidence intervals, or inferential test results in the registry record. As a result, the precision and statistical interpretation of the arm contrast cannot be evaluated from the posted endpoint results.
The registry describes an ITT population as participants who received post-randomization treatment and had some endpoint data. It does not provide enough detail to determine how all randomized participants were handled, why the endpoint denominators differ from recorded enrollment, or whether missing data were imputed or examined in sensitivity analyses. The missing-data reasons and participant flow are not reported in the registry record.
Because the trial was open and the outcome was self-reported pain, awareness of assignment is a possible source of measurement influence in general. The record does not describe masking, standardized participant instructions, or safeguards against assessment differences. This limitation does not establish that bias occurred.
The safety summaries report zero serious and other adverse events among their respective at-risk groups, but deaths are not reported and no event terms are listed. Follow-up duration for safety and the detail of safety ascertainment are not reported in the registry record. The absence of posted secondary analyses, multiplicity methods, interim-analysis information, and the trial's own sample-size justification further limits assessment of the planned statistical framework.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Open, Prosp, Rand. Invest. Evaluating Pain With Mepitel One vs.Bridal Veil and Staples on Split Thickness Skin Grafts — NCT01365273.
- Registry record last updated 2014-02-13; status last verified 2012-08.
- Results first posted 2012-09-14.
- 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.
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18. Record Summary
NCT01365273 is a completed, Phase 4, open, randomised, parallel-group investigation sponsored by Molnlycke Health Care AB. The comparison was Mepitel One versus Bridal Veil with staples for grafts on deep partial-thickness or full-thickness burns. Recorded enrollment was 43; the registry lists a start date of 2011-02 and a primary completion date of 2011-12.
The primary endpoint was VAS pain before dressing removal at visit 6, day 7. The posted medians were 4.0 for Mepitel One and 11.0 for Bridal Veil and staples, with standard deviations of 20.1 and 21.0, respectively. The endpoint summaries included 17 and 20 participants, respectively. No inferential comparison is posted for this endpoint.
Serious and other adverse-event counts were 0 in each arm, with at-risk denominators of 21 for Mepitel One and 22 for Bridal Veil and staples. Death counts are not reported in the registry record. The registry does not report methods for missing data, multiplicity, or the trial's own sample-size justification.