Chitosan Dressings to Facilitate Safe Effective Debridement of Chronic Wounds & Minimize Wound Bacterial Re-colonization: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Chitosan Dressings to Facilitate Safe Effective Debridement of Chronic Wounds & Minimize Wound Bacterial Re-colonization (NCT01035944), a randomized na study. The primary outcome is Demonstrate That Debridements Using HemCon Dressings at Bedside Can be Performed Safely Without Excessive Bleeding; Compare Levels of Bacterial Load Between Debrided Wounds Treated With HemCon Dressings vs. Wounds Treated With Gauze & Saline Dressings..

2. Clinical Question

The registry describes two care settings: debridement in an operating room and debridement at bedside. The arm descriptions distinguish HemCon dressing from control dressing within each setting. They describe planned groups of 20 patients for each treatment in the operating-room sub-study and the bedside sub-study. Those planned group sizes are not evidence that the intended enrollment was achieved in every arm.

The primary outcome record specifies assessment at 2 days and 5 days after debridement. It combines a safety question about excessive bleeding with a comparison of bacterial load. These are related to wound care but are distinct outcomes: bleeding concerns the procedure's safety, while bacterial load concerns wound colonization after debridement and dressing use.

The registry says that zero participant data were analyzed for the primary outcome because the study was terminated early and was unable to reach enrollment milestones. As a result, the clinical question is recorded, but the posted results do not provide an estimate of the treatment comparison for bleeding or bacterial load.

3. Trial Design

This was a randomized, parallel-group device study comparing HemCon chitosan-based dressings with gauze and saline dressings. Masking is listed as none. The registry lists the study phase as NA and the condition as wound debridement. HemCon Medical Technologies, Inc is named as the sponsor.

The design includes operating-room and bedside settings, with a HemCon and a control arm described for each. The operating-room sub-study concerned dressings used following debridement in that setting. The bedside sub-study compared HemCon dressings with control dressings following bedside debridement. The intervention record names HemCon Dressings and HemCon ChitoGauze; the comparison intervention is gauze and saline dressings.

The registry lists enrollment of 37. The arm descriptions state that 20 patients were planned for each treatment in each setting, but the study was terminated early because enrollment milestones could not be reached. The registry does not report how participants were allocated across the four listed arms or explain how the enrollment figure relates to the planned group sizes. No further details of the randomization procedure are reported in the registry record.

The study started in 2010-02, and the listed primary completion date is 2012-03. Its status is terminated. Those dates and the termination status provide context for interpreting the absence of primary-outcome findings: the record describes a planned comparison but does not report analyzed participant data for that outcome.

There is no reported description of concealment of allocation, the sequence-generation method, or the reason for choosing the planned enrollment. The registry record also does not provide a detailed statistical analysis plan. These omissions limit the ability to assess how the planned randomization and analysis were intended to work beyond the design labels and arm descriptions.

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

Analysis population for the primary outcome, as defined in the registry: Zero participant data were analyzed. Study was terminated early; unable to reach enrollment milestones.

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 Demonstrate That Debridements Using HemCon Dressings at Bedside Can be Performed Safely Without Excessive Bleeding; Compare Levels of Bacterial Load Between Debrided Wounds Treated With HemCon Dressings vs. Wounds Treated With Gauze & Saline Dressings., measured over 2 days and 5 days after debridement..

The primary outcome concerns whether bedside debridement using HemCon dressings can be performed safely without excessive bleeding and how bacterial load compares between wounds treated with HemCon dressings and wounds treated with gauze and saline dressings. The registry specifies measurement at 2 days and 5 days after debridement. It does not define a numerical threshold for excessive bleeding or describe how bacterial load was measured in the outcome record.

These measures address different aspects of the study question. Bleeding is a safety outcome related to debridement. Bacterial load is a wound-related outcome intended to inform whether bacterial re-colonization differs between dressing groups after the procedure. The outcome description also refers to bedside use, while the study arms include operating-room and bedside settings. The registry does not clarify how the primary outcome was to be analyzed across those settings or whether each setting had a separate primary comparison.

Such outcomes are used to evaluate both procedural safety and the biological question motivating dressing use. However, an endpoint definition alone is not evidence of an effect. The registry states that zero participant data were analyzed for the primary outcome because the study ended early after it could not reach enrollment milestones. No results for bleeding or bacterial load are reported, so the endpoint cannot support a treatment-effect estimate in this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does randomization contribute?

In general, randomization assigns participants to treatment groups using a chance-based process. Its statistical purpose is to reduce the risk that treatment groups differ systematically in factors that affect outcomes. It does not make groups identical, and it cannot compensate for missing outcome data. In this trial, the registry labels allocation as randomized, but the sequence-generation and allocation-concealment procedures are not reported in the registry record. The record also does not describe the implementation of randomization across the operating-room and bedside settings.

What does the parallel design mean?

In general, a parallel-group design compares groups assigned to different interventions over the study period. The registry identifies HemCon and control arms in both care settings. A meaningful treatment comparison would require a clear account of the population included, the outcome definition, and the analysis used. The record does not report a primary-outcome analysis or clarify whether the setting-specific comparisons were to be combined or kept separate.

How should an outcome estimate be read?

In general, an effect estimate describes the observed difference or contrast between groups for an outcome. A confidence interval describes the uncertainty around an estimate under the assumptions of the statistical model. Narrower intervals generally indicate greater precision, while wider intervals indicate less precision. Neither an estimate nor an interval establishes clinical importance by itself. In this record, no primary-outcome estimate or confidence interval is reported because zero participant data were analyzed for that outcome.

What would a significance test tell readers?

In general, a significance test evaluates how compatible the observed data are with a specified null model, given the test's assumptions. A p-value is not the probability that a treatment works, and a non-significant result does not establish equivalence. The registry does not report a primary-outcome p-value or a statistical analysis plan. Thus, there is no test result to interpret for bleeding or bacterial load.

Why do outcome definitions matter?

Statistical analysis depends on knowing what was measured and how it was summarized. The primary outcome describes excessive bleeding and bacterial load at 2 days and 5 days after debridement, but the registry does not define excessive bleeding, identify the bacterial-load measurement method, or specify the form of the outcome data. For example, a continuous measure, a categorical classification, and a count require different summaries and may call for different models. Those details are not reported in the registry record, so it is not possible to assess whether a particular analysis would have been appropriate.

What is over-dispersion, in general?

Over-dispersion occurs when observed variability in count data is greater than a model assumes. If a count outcome such as bacterial load or a count of events were analyzed with a model that understates variability, standard errors and confidence intervals could be too small, making uncertainty appear lower than it is. This is a general statistical consideration, not a reported feature of this trial. The registry does not describe the primary outcome's data distribution or an analysis model, so whether over-dispersion was relevant is not reported in the registry record.

What do planning calculations mean?

In general, sample-size planning explores how much information a future study might need under stated assumptions about the effect, variability, significance level, allocation, and desired power. A planning illustration is not an observed treatment result and must not be described as observed power. The registry's stated illustration assumptions include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as a fraction of an observed effect. The record does not establish that these assumptions formed the trial's original design or statistical plan. Since no primary-outcome participant data were analyzed, such planning assumptions cannot supply the missing clinical result.

For this study, the key distinction is between the design that was intended and the analysis that is reported. The record supplies design labels, arm descriptions, outcome timing, and a termination explanation. It does not report the primary data, the statistical model, or the inferential results. General statistical methods can explain what those elements would mean, but they cannot reconstruct results that the registry does not report.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome description includes a safety question about excessive bleeding and a bacterial-load comparison, with assessment specified at 2 days and 5 days after debridement. The study also lists a secondary outcome concerning cost efficacy, hemostasis, and patient comfort in bedside and operating-room care. These multiple outcomes and assessment times create potential multiplicity: when several hypotheses are considered, the chance of at least one apparently positive finding can increase if no adjustment or prespecified hierarchy is used.

The registry does not report a multiplicity strategy, such as a hierarchy of outcomes or an adjustment to account for multiple comparisons. It also does not report a statistical analysis plan. Therefore, readers cannot determine which comparisons were intended to be confirmatory, how results across settings and time points would have been handled, or whether any adjustment was planned. This uncertainty is separate from the absence of primary-outcome data.

The registry reports zero participant data analyzed for the primary outcome and lists zero analyses. It does not describe missing-data methods or an analysis population, such as an intention-to-treat or per-protocol population. The reason recorded for the lack of primary analysis is early termination after enrollment milestones could not be reached. The record does not explain whether any collected primary-outcome measurements were incomplete, or how missing observations would have been handled had an analysis been conducted.

In general, missing-data methods rely on assumptions about why data are absent and how that absence relates to treatment and outcome. Those assumptions cannot be assessed without a reported analysis population and information about missingness. Here, the registry does not provide that information. Accordingly, no claim about the robustness of a treatment comparison to missing data or multiplicity is supported by the record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 1% reporting threshold.

Most frequent non-serious adverse event terms

The registry records serious and other adverse events separately for each named arm. For serious adverse events, it lists 0 affected among 14 at risk in the HemCon Operating Room arm, 0 among 14 in Control Operating Room, 0 among 5 in HemCon Bedside, and 0 among 4 in Control Bedside. These are the recorded counts and denominators; they are not a primary-outcome analysis of bleeding after debridement.

For other adverse events, the record lists 2 affected among 14 at risk in HemCon Operating Room, 1 among 14 in Control Operating Room, 1 among 5 in HemCon Bedside, and 2 among 4 in Control Bedside. The registry does not list serious adverse-event terms, and deaths are not reported in these group entries.

These counts should not be interpreted as proof of equal safety or as a comparison adjusted for differences between groups. The record does not explain how the adverse-event analysis relates to enrollment of 37 or to the planned group sizes. It also does not provide event descriptions for the other adverse events in the listed summaries. Most importantly, the primary outcome record says that zero participant data were analyzed. The adverse-event entries therefore should be read as the safety counts recorded in the registry, not as a complete answer to the primary question about excessive bleeding or bacterial load.

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

The registry establishes that a randomized, parallel-group study of HemCon chitosan-based dressings versus gauze and saline dressings was planned for chronic-wound debridement. It identifies operating-room and bedside settings, specifies a primary question about excessive bleeding and bacterial load, and gives assessment times of 2 days and 5 days after debridement. It also records that the study was terminated early because enrollment milestones could not be reached.

What the record does not establish is whether HemCon dressings changed bleeding, bacterial load, cost efficacy, hemostasis, or patient comfort. The primary-outcome record states that zero participant data were analyzed. There is consequently no treatment-effect estimate, confidence interval, or primary-outcome test result to use when judging the direction, size, or precision of a difference.

This lack of findings should not be interpreted as evidence of no difference. A study that does not report an analyzed outcome cannot demonstrate equivalence or rule out a meaningful benefit or harm. Likewise, the adverse-event entries do not answer the primary endpoint question; they are recorded counts in separate safety categories, without a reported analysis connecting them to the primary bleeding measure.

The enrollment figure of 37 does not change that interpretation. Enrollment is not itself an outcome result, and the arm descriptions' planned group sizes do not establish that those sizes were reached. The registry does not reconcile those figures or report a primary-outcome analysis population. The termination status is therefore central to understanding why the intended clinical comparison remains unanswered in the posted results.

The record is useful for identifying the intervention, comparator, setting, intended outcomes, and the reason the study did not reach its enrollment milestones. Its statistical meaning is limited: it documents the design and safety counts, but it does not provide analyzed evidence from the primary outcome that could resolve the study's clinical question.

13. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the difference between a registered research question and an answer supported by analyzed outcomes. A randomized design can be intended to support a credible comparison, but that design cannot produce an effect estimate when the primary outcome has no analyzed participant data. In this record, early termination and failure to reach enrollment milestones are not background details; they explain why the central comparison is absent.

The record also makes clear why planned group sizes should not be confused with observed enrollment. The arm descriptions state plans for 20 patients in each treatment group within each setting, whereas the listed enrollment is 37. The registry does not explain the relationship between these entries. Without analyzed group-specific outcome data, neither the planned allocation nor the enrollment figure establishes the information available for estimating treatment effects.

There is a further interpretive distinction between safety counts and the primary outcome. Adverse-event entries can provide descriptive information, but they do not replace a prespecified analysis of bleeding or bacterial load. Readers need to know which outcome was measured, how it was defined, and how groups were compared before drawing statistical conclusions. Several of those details are not reported in the registry record.

Finally, the record shows why absence of a statistical finding is not a finding of no effect. Without an estimate and its uncertainty, the direction and precision of a comparison cannot be judged. The most defensible statistical reading is that the trial's intended questions remain unresolved in the posted results, rather than that the study demonstrated a particular benefit, harm, or equivalence.

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 primary limitation is the absence of analyzed participant data for the primary outcome. The registry attributes this to early termination and inability to reach enrollment milestones. No result for bleeding or bacterial load is reported, so the central comparison cannot be estimated or evaluated for precision.

The registry lists enrollment of 37, while the arm descriptions state planned group sizes of 20 patients for each treatment within the operating-room and bedside sub-studies. The record does not reconcile the enrollment figure with those plans, report final enrollment by arm, or explain the difference between planned and recorded enrollment. The registry also does not provide an analysis population for the primary outcome.

Important operational and statistical details are not reported in the registry record. These include the randomization method, allocation concealment, definitions of excessive bleeding, the bacterial-load measurement method, the outcome summary measure, the statistical model, handling of multiple outcomes and assessment times, and missing-data procedures. Without these details, readers cannot assess the planned analysis beyond the broad outcome description.

The adverse-event entries provide counts for serious and other adverse events but do not include event terms for the serious category or deaths. The registry does not explain how those entries relate to all enrolled participants or to the absent primary-outcome analysis. They should therefore be interpreted narrowly as recorded safety summaries rather than as a complete account of trial safety or evidence about the primary endpoint.

The status is terminated, and the listed primary completion date is 2012-03. The registry does not report further results that resolve the study question. Together, these limitations mean that the record is informative about the intended design and its early termination but not about the comparative primary-outcome effects of the dressings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Chitosan Dressings to Facilitate Safe Effective Debridement of Chronic Wounds & Minimize Wound Bacterial Re-colonization — NCT01035944.
• Registry record last updated 2014-07-01; status last verified 2014-05.
• Results first posted 2014-06-09.
• 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.

18. Record Summary

NCT01035944 was a randomized, unmasked, parallel-group device study sponsored by HemCon Medical Technologies, Inc. It compared HemCon chitosan-based dressings with gauze and saline dressings after chronic-wound debridement in operating-room and bedside settings. The registry lists enrollment of 37 and describes plans for 20 patients per treatment group within each setting.

The primary outcome concerned excessive bleeding and bacterial load, assessed at 2 days and 5 days after debridement. The study was terminated early because enrollment milestones could not be reached. The registry states that zero participant data were analyzed for the primary outcome. It records adverse-event counts by arm, but no primary-outcome comparison, estimate, confidence interval, or p-value is reported. The clinical question therefore remains unanswered in the posted results.