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 Diabetic Foot Ulcer Study Comparing Cytal Wound Matrix 1-Layer to Standard of Care (NCT03626623), a randomized na study. The primary outcome is Number of Wounds With Wound Closure.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03626623 |
| Phase | NA |
| Condition | Diabetes, Diabetic Foot, Diabetes Mellitus, Type 2 |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 15 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Integra LifeSciences Corporation |
| Results posted | Yes |
2. Clinical Question
Population
Participants with diabetic foot ulcers. The registry describes conditions including diabetes, diabetic foot, and type 1 and type 2 diabetes mellitus. It does not report further eligibility details in the record.
Intervention
Cytal Wound Matrix 1-Layer, applied according to the device instructions for use.
Comparator
Standard of Care (SOC), described as usual care from a licensed health care provider for diabetic foot ulcers or wounds.
Primary question
Whether the randomized groups differed in the incidence of complete wound closure, defined as 100% epithelialization, up to 12 weeks.
The clinical question is comparative: it concerns wound closure under the device intervention versus standard care, rather than closure in either group considered alone. Random allocation was used, but the trial was unmasked. The registry describes the study as prospective and controlled, and lists a parallel design.
The posted primary outcome is a count of wounds with closure, with wounds counted across participants. That count is not, by itself, a closure rate or an estimate of the probability that an individual participant’s wound closed. Interpreting it as a rate would require a clearly specified denominator and follow-up information for the relevant wounds. The record states that the study was terminated before all enrolled participants completed 12 weeks of follow-up, so the registered follow-up window was not completed for everyone.
The posted results therefore address the question only descriptively. They do not establish a precise comparison of closure rates, and they do not resolve whether the observed counts reflect a difference between interventions. A comparative estimate with uncertainty would be needed to assess the magnitude and precision of any difference.
3. Trial Design
NCT03626623 is listed as a randomized, controlled, prospective, parallel-group trial comparing Cytal Wound Matrix 1-Layer with Standard of Care (SOC) for diabetic foot ulcers. Allocation is recorded as randomized, and masking as none. The phase is listed as NA. Integra LifeSciences Corporation is the sponsor.
The registry records enrollment of 15 participants. The recorded start date is 2019-05-21, and the primary completion date is 2020-02-18. The trial status is TERMINATED. The registry states that the sponsor ended the study before completion and that all enrolled subjects did not complete 12 weeks of follow-up before termination. A reason for termination is not reported in the registry record.
The intervention description says the device was to be applied according to its instructions for use. SOC is described as the usual care a licensed health care provider would give for diabetic foot ulcers or wounds. The primary endpoint concerns complete wound closure up to 12 weeks, defined as 100% epithelialization. The record lists arm sizes of 4.0 for SOC and 9.0 for Cytal Wound Matrix 1-Layer for this outcome.
These design details do not establish how the study was planned or conducted beyond what is recorded. The randomization procedure, allocation concealment, eligibility criteria, treatment schedules, and detailed follow-up procedures are not reported in the registry record. The record also does not state why the arm sizes for the posted primary outcome differ from the overall enrollment. Those counts should therefore be read as the outcome-specific figures recorded, not as a complete account of participant flow.
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 | Standard of Care (SOC) | Cytal Wound Matrix 1-Layer |
|---|---|---|
| STARTED | 5 | 10 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 5 | 10 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated by sponsor prior to completion, all enrolled subjects did not complete 12 weeks follow-up prior to termination.
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 | Standard of Care (SOC) | Cytal Wound Matrix 1-Layer | Total |
|---|---|---|---|---|
| Participants analysed | 5 | 10 | 15 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 5 | 9 | 14 |
| Age, Categorical: >=65 years | Participants | 0 | 1 | 1 |
| Sex: Female, Male: Female | Participants | 0 | 1 | 1 |
| Sex: Female, Male: Male | Participants | 5 | 9 | 14 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 5 | 10 | 15 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Number of Wounds | Wounds | 5 | 10 | 15 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Wounds With Wound Closure, measured over up to 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | wounds |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of wounds with complete wound closure, assessed up to 12 weeks. Complete closure is defined in the registry as 100% epithelialization. The count is described as the total across all participants in each randomized group.
Closure is a clinically interpretable wound outcome: it records whether the wound reached the specified state of complete epithelialization during the study’s follow-up window. A count can describe how many wounds met that definition, but it does not alone express the chance of closure. To interpret closure as a rate or proportion, the number of eligible wounds at risk and the observation period for those wounds must also be clear. The registry reports an endpoint count and group sizes, but also states that all enrolled subjects did not complete 12 weeks before termination.
The posted values are 1 wound with closure in the SOC group and 1 in the Cytal Wound Matrix 1-Layer group. Those are descriptive counts, not a treatment-effect estimate. The registry does not report a confidence interval, a p-value, or an adjusted comparison for this endpoint. Nor does it report enough follow-up detail to determine from these counts alone how incomplete observation was handled. The endpoint is therefore relevant to the clinical question, but the posted result is limited in how precisely it can compare the randomized groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome reports 1 wound with closure in the SOC group and 1 in the Cytal Wound Matrix 1-Layer group. These are equal observed counts. They should not be read as evidence that the interventions have equal closure rates: the endpoint is presented as a count, and the registry does not provide a comparative estimate, uncertainty interval, or inferential test. In particular, the values do not convey how many wounds were observed for the full follow-up period in each group.
The outcome-specific arm sizes recorded are 4.0 for SOC and 9.0 for Cytal Wound Matrix 1-Layer, while overall enrollment is 15. The registry does not explain the relationship between those arm sizes and overall enrollment. The safety record has different at-risk counts, 5 for SOC and 10 for Cytal Wound Matrix 1-Layer. These figures refer to different posted outcome information and should not be treated as interchangeable denominators.
Follow-up is an important constraint. The registry says the study was terminated by the sponsor before completion and that all enrolled subjects did not complete 12 weeks of follow-up. The primary endpoint’s timeframe is up to 12 weeks, so incomplete follow-up may leave wound-closure status unobserved for some of the intended period. The record does not describe how incomplete follow-up was handled in calculating or presenting the endpoint.
No primary-outcome analysis is posted: the registry lists 0 analyses. Consequently, there is no reported effect estimate that quantifies a difference between groups, and no confidence interval or p-value with which to assess its precision or statistical compatibility with different possible effects. The raw counts can be described, but they cannot establish the size, direction, or precision of a comparative effect.
There are additional limits to interpretation. The trial was unmasked, and the record does not report the method used to assess closure or whether assessors were independent. The sample is limited in the sense that the registry records 15 enrolled participants, but the posted endpoint arm sizes are smaller and their relationship to enrollment is not explained. These circumstances make it especially important not to treat the descriptive outcome as a definitive answer to the comparative question.
The record’s secondary outcomes include wound size change, time to complete closure, recurrence, patient-reported measures, pain, activities of daily living, and adverse-event frequency. Although the record lists 14 secondary outcomes, it does not post analyses for them. The available primary counts and safety figures therefore offer only a partial description of the study, rather than a complete account of its planned clinical questions.
9. Statistical Methods Explained
The registry identifies a randomized, parallel-group design and posts descriptive outcome counts, but it does not report a statistical analysis plan or any outcome analyses. The explanations below describe general statistical concepts relevant to this type of trial; they do not claim that particular methods were used in NCT03626623.
What does randomization contribute?
In general, randomization assigns participants to study groups by chance. Its purpose is to reduce systematic differences between groups at the point of assignment, including differences that may not be measured. It does not guarantee that the groups will have similar characteristics, especially when enrollment is limited. Randomization also does not correct problems caused by incomplete follow-up, deviations from assigned treatment, or incomplete outcome assessment.
The registry records randomized allocation but does not describe the sequence-generation method, allocation concealment, or how assignment was implemented. Those details matter when assessing whether assignment could have been anticipated or influenced. Masking is recorded as none. In general, lack of masking can affect treatment delivery, outcome assessment, or decisions about follow-up. The record does not explain how complete wound closure was assessed or what safeguards, if any, were used to limit assessment bias.
What kind of result is a wound count?
A count records the number of events or observations meeting a definition. Here, the event is a wound reaching 100% epithelialization, and the posted primary values are counts of wounds across participants. A count is not automatically a rate. A rate or proportion requires a denominator that represents the wounds at risk or otherwise eligible for the outcome, and interpretation also depends on how long and how completely those wounds were observed.
In general, a comparative analysis could estimate a difference between groups in the probability of closure, or use another measure suited to the design and data. The choice depends on the unit of analysis, the number of wounds per participant, follow-up, and the analysis plan. If participants can contribute more than one wound, observations from the same participant may be related. Treating related wounds as independent can understate uncertainty. The registry says that the outcome count was totaled across participants, but does not report the number of wounds per participant or the statistical handling of multiple wounds.
Why does follow-up matter?
The endpoint is assessed up to 12 weeks, while the registry states that all enrolled subjects did not complete 12 weeks before termination. In general, an outcome that has not yet occurred by the end of observed follow-up is not necessarily equivalent to an outcome that will never occur. A simple count at a fixed assessment can be difficult to interpret if observation time varies or if some outcomes are unobserved. Time-to-event methods can account for differing observation times under specified assumptions, but they require information about event timing and censoring. The record does not post such an analysis for the primary endpoint.
Missing outcome information also matters because the reasons for missingness may be related to the outcome or to group assignment. A complete-case analysis, an imputation approach, or a sensitivity analysis can lead to different interpretations when assumptions differ. These are general options, not methods reported for this trial. The registry record does not report a missing-data strategy or an analysis population for the primary outcome.
How should uncertainty be described?
In general, a confidence interval gives a range of estimates compatible with the observed data under a specified statistical model and procedure. It conveys uncertainty around an estimate; it is not a guarantee that the true effect lies within the interval. For sparse counts, an interval may be wide, reflecting limited information. A p-value, when used, addresses compatibility between data and a specified null model; it does not express the probability that a treatment effect is true, nor does it describe the size of an effect.
No confidence interval or p-value is reported for the primary outcome, and the registry lists 0 analyses. The outcome counts therefore cannot be used to assess precision through an inferential result. The posted counts remain useful as a record of what was observed, but a count alone does not quantify uncertainty about the difference between interventions.
What can sample-size planning say?
In general, a sample-size calculation is a planning exercise based on assumptions about the effect to detect, variability or event frequency, statistical error rates, and design. The planning illustrations associated with the record are based on the observed effect, use a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is a stated fraction of the observed effect. Such illustrations are not the trial’s original design justification and are not observed power. They do not show that the trial had adequate power, and they do not resolve the uncertainty created by termination and incomplete follow-up.
The registry does not report the trial’s own sample-size justification, its prespecified analysis methods, interim analyses, or a statistical analysis plan. Those omissions prevent a reader from determining whether the posted outcome summaries follow an analysis plan established before results were known. No unreported model or test should be inferred from the design label or from the descriptive counts.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 14 secondary outcomes, including wound size change, time to complete wound closure, wound recurrence, quality-of-life measures, pain, activities of daily living, and adverse-event frequency. The primary outcome is the number of wounds with closure. Considering multiple outcomes can increase the chance that at least one result appears notable by chance when many statistical tests are conducted. General approaches include prespecifying a primary comparison, adjusting for multiple testing, or interpreting secondary findings as exploratory. The registry record does not report a multiplicity strategy or which secondary outcomes, if any, were intended to support confirmatory conclusions.
The record lists 0 analyses. It therefore does not provide estimates, uncertainty intervals, or p-values for the primary or secondary outcomes. With no posted analyses, the effect of any multiplicity adjustment cannot be assessed, and no secondary result can be interpreted as a demonstrated statistical finding.
Missing follow-up is material to the primary endpoint. The study was terminated by the sponsor before completion, and all enrolled subjects did not complete 12 weeks of follow-up. The record does not report the amount or pattern of missing outcome data, reasons for incomplete follow-up, a method for handling missing data, or sensitivity analyses. In general, these details matter because conclusions can depend on whether missingness is related to outcome status or treatment group.
The analysis population is not reported in the registry record. It is therefore unclear whether the posted outcome counts correspond to all randomized participants, participants with available assessments, or another defined group. The record also does not explain the relationship between overall enrollment of 15 and the primary-outcome arm sizes of 4.0 and 9.0. These are reporting gaps, not evidence of a particular analysis choice.
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 |
|---|---|---|---|
| Standard of Care (SOC) | 2 | 5 | 40.0% |
| Cytal Wound Matrix 1-Layer | 3 | 10 | 30.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard of Care (SOC) | 0 of 5 |
| Cytal Wound Matrix 1-Layer | 0 of 10 |
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 |
|---|---|
| Standard of Care (SOC) | 3 of 5 |
| Cytal Wound Matrix 1-Layer | 5 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | Standard of Care (SOC) | Cytal Wound Matrix 1-Layer |
|---|---|---|---|
| infection of target wound/ulcer | Infections and infestations | 0 of 5 | 2 of 10 |
| cellulitis of target wound/ulcer | Infections and infestations | 2 of 5 | 0 of 10 |
| chest pain | Cardiac disorders | 0 of 5 | 1 of 10 |
| elbow infection | Infections and infestations | 1 of 5 | 0 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Standard of Care (SOC) | Cytal Wound Matrix 1-Layer |
|---|---|---|---|
| new toe wound on target foot | General disorders | 1 of 5 | 1 of 10 |
| cellulitis, leg | Infections and infestations | 1 of 5 | 1 of 10 |
| flash burn, eye | Eye disorders | 0 of 5 | 1 of 10 |
| pneumonia | Respiratory, thoracic and mediastinal disorders | 0 of 5 | 1 of 10 |
| common cold | General disorders | 0 of 5 | 1 of 10 |
| wound recurrence (after closure) | General disorders | 0 of 5 | 1 of 10 |
| new wound on non-target limb | General disorders | 0 of 5 | 1 of 10 |
| thumb infection | Infections and infestations | 1 of 5 | 0 of 10 |
| infection of target wound | Infections and infestations | 0 of 5 | 1 of 10 |
Serious events with the highest arm-level rate: cellulitis of target wound/ulcer (40.0%), infection of target wound/ulcer (20.0%), elbow infection (20.0%), chest pain (10.0%).
The registry reports serious adverse events affecting 2 of 5 participants at risk in the SOC group and 3 of 10 at risk in the Cytal Wound Matrix 1-Layer group. It reports other adverse events affecting 3 of 5 at risk in SOC and 5 of 10 at risk in the device group. Deaths are recorded as 0 in each group. These are the registry’s safety counts; they are not a comparison adjusted for follow-up duration or other differences.
The listed serious-event terms include cellulitis of the target wound or ulcer at 40.0%, infection of the target wound or ulcer at 20.0%, elbow infection at 20.0%, and chest pain at 10.0%. The record does not explain the denominator or event-counting convention for these term percentages. They should not be treated as participant-level risks without that information.
The safety at-risk counts differ from the primary-outcome arm sizes. Safety figures and wound-closure figures refer to separate posted outcome information, and their denominators should not be substituted for one another. Because the study ended before all enrolled subjects completed 12 weeks, exposure and observation may also be incomplete. The registry does not report a comparative safety analysis, statistical uncertainty, or a detailed account of event timing and duration.
12. What the Result Does, and Does Not, Mean
The record documents a randomized comparison of Cytal Wound Matrix 1-Layer with standard care for diabetic foot ulcers, with complete wound closure defined as 100% epithelialization and assessed up to 12 weeks. It reports 1 closed wound in each group. Those counts describe the posted primary outcome, but they do not establish that the groups had the same closure rate or that either intervention had a particular effect.
A comparative conclusion requires more than a pair of counts. Readers need a clearly defined denominator, consistent follow-up, an estimate of the between-group effect, and a description of uncertainty. The registry does not report an analysis of the primary endpoint, confidence intervals, p-values, or details on how incomplete follow-up was handled. It also states that all enrolled subjects did not complete 12 weeks before termination.
The trial’s status and outcome reporting therefore constrain interpretation. Termination is not itself proof that the intervention was ineffective or harmful, and the posted results do not establish a reason for termination. Similarly, the absence of posted analyses is not evidence that the groups were equivalent. It means the registry record does not provide the inferential results needed to judge the magnitude and precision of a comparative effect.
The adverse-event figures are descriptive counts, not a complete assessment of comparative safety. The at-risk groups and event categories are reported, but the record does not provide a comparative analysis or enough detail to interpret the listed term percentages as individual risks. The figures should be read in the context of the study’s termination and incomplete follow-up.
Overall, the posted information documents the design, recorded outcome counts, and selected safety data. It does not support a precise estimate of the effect on wound closure, a conclusion about equivalence, or a broad conclusion about safety. Those limits concern the evidence reported in the registry record, not a general claim about the device or standard care.
13. Why This Trial Matters Statistically
This trial illustrates why a clinically meaningful endpoint and an interpretable statistical comparison are not the same thing. Complete wound closure is clearly defined as 100% epithelialization, and the registry records the number of wounds reaching that state. But the count alone does not tell readers the closure rate, how much follow-up each wound contributed, or how uncertain a between-group comparison would be.
It also highlights the importance of preserving the distinction between enrollment, outcome-specific group sizes, and safety denominators. The record lists 15 enrolled participants, primary-outcome arm sizes of 4.0 and 9.0, and safety at-risk counts of 5 and 10. Those numbers describe different parts of the record. Without an account of participant flow, they cannot be reconciled into a single denominator for every outcome.
Termination and incomplete follow-up affect how much information the study can provide. The endpoint was intended to cover up to 12 weeks, but the registry says that all enrolled subjects did not complete that follow-up. A statistical interpretation depends not only on the observed counts but also on outcome ascertainment, follow-up, missing-data handling, and a specified analysis. Those details are not reported in the registry record, and no analyses are posted.
Finally, the record shows why statistical transparency matters. A prespecified analysis plan, a clear analysis population, an effect estimate, and an uncertainty interval help readers distinguish a descriptive observation from evidence about a comparative effect. The posted record permits a factual account of the trial and its reported results, while leaving substantial uncertainty about the primary comparison.
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 main trial-specific limitation is early termination. The registry states that the sponsor terminated the study before completion and that all enrolled subjects did not complete 12 weeks of follow-up. The reason for termination is not reported in the registry record. Because the primary endpoint is assessed up to 12 weeks, incomplete follow-up limits the completeness of the outcome information.
The registry reports an enrollment of 15, but the primary-outcome arm sizes are 4.0 for SOC and 9.0 for Cytal Wound Matrix 1-Layer. The record does not explain the difference between these figures. The safety record separately lists 5 and 10 participants at risk. Without participant-flow details and outcome-specific analysis populations, these counts should not be combined or treated as equivalent denominators.
No primary or secondary analyses are posted. The record does not report an effect estimate, uncertainty interval, statistical test, missing-data method, or analysis population. It also does not report the trial’s own sample-size justification, a statistical analysis plan, or interim analyses. The reason for termination and detailed procedures for outcome assessment are not reported in the registry record.
The design is listed as unmasked. The registry does not describe how wound closure was assessed or whether the assessment process included safeguards against bias. It does not report baseline characteristics or enough detail to assess group comparability after randomization. The extent to which these gaps affect the result cannot be determined from the posted record.
These limitations restrict the conclusions that can be drawn from the descriptive counts and safety information. They do not demonstrate that the interventions differ, that they are equivalent, or that a particular mechanism explains the missing information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Diabetic Foot Ulcer Study Comparing Cytal Wound Matrix 1-Layer to Standard of Care — NCT03626623.
- Registry record last updated 2021-08-25; status last verified 2021-08.
- Results first posted 2021-02-15.
- 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
NCT03626623 is a randomized, unmasked, parallel-group trial comparing Cytal Wound Matrix 1-Layer with Standard of Care for diabetic foot ulcers. Integra LifeSciences Corporation is the sponsor. The registry records enrollment of 15, a start date of 2019-05-21, primary completion on 2020-02-18, and status TERMINATED.
The primary endpoint is the number of wounds with complete closure, defined as 100% epithelialization, up to 12 weeks. The posted counts are 1 for SOC and 1 for Cytal Wound Matrix 1-Layer. The registry states that the study was terminated before completion and that all enrolled subjects did not complete 12 weeks of follow-up. The outcome-specific arm sizes are 4.0 and 9.0, respectively.
The record lists 14 secondary outcomes and 0 analyses. It also reports safety counts, including serious adverse events affecting 2 of 5 at risk in SOC and 3 of 10 at risk in the device group, with 0 deaths in each group. The posted information is descriptive and does not include an inferential comparison of the primary endpoint.