Irritation and Sensitization of Chlorhexidine Gluconate (CHG) Cloth: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Irritation and Sensitization of Chlorhexidine Gluconate (CHG) Cloth (NCT02224625), a randomized phase 3 study. The primary outcome is Grading Scale for Visual Evaluation of Skin Condition.

2. Clinical Question

In practical terms, the research question concerns how skin condition was graded after products were applied over a defined study schedule. The registry describes an irritation period involving 21 days of patching and a sensitization schedule involving 21 days of patching, 14 days of rest, and a subsequent patch. The planned assessment used an eight-point categorical scale, with grades ranging from no irritation to a strong reaction spreading. The listed primary outcome is a mean score with a full range, but the corresponding results are not reported in the registry record.

Because participants received more than one product at a time, product observations may be connected within participants rather than representing fully separate groups. The registry record does not provide the allocation of participants to each product, the pairing structure, or a reported analysis accounting for that structure. The central clinical question can therefore be described, but the magnitude and precision of any product differences cannot be evaluated from the posted results.

3. Trial Design

The study is listed as randomized, parallel, and single-masked. Its official title describes it as randomized and observer-blinded. The record does not clarify who was masked or how masking was maintained, so the masking designation should not be interpreted more specifically than the registry states. The study is listed as Phase 3, and the enrollment is 249.

The study compares skin responses to a finished test product and other products, including a vehicle cloth, a chlorhexidine gluconate solution, saline, and SLS. The record describes the vehicle cloth as containing excipients on cloth, saline as 0.9% sodium chloride, and SLS as a positive control intended to produce mild irritation. Participants received more than one product at a time. How products were distributed across participants and application sites is not reported in the registry record.

The primary outcome is the Grading Scale for Visual Evaluation of Skin Condition. The registry describes irritation assessment over 21 days of patching in 39 participants and sensitization assessment over 35 days in 249 participants. The sensitization schedule consisted of 21 days of patching, 14 days of rest, and a subsequent patch. SLS was not tested for sensitization. A reviewer assigned a score based on the appearance of treated areas at each visit.

The registry lists Medline Industries as sponsor, Surgery as the condition, and the study status as completed. The listed start is 2014-08 and primary completion is 2015-06. These record details describe the trial’s registration and schedule, but do not establish how long each participant was observed beyond the stated outcome timeframes.

The registry record reports one outcome measure and no analyses. It does not report outcome scores, comparisons, confidence intervals, or p-values. It also does not report a sample-size justification, allocation details, or a statistical analysis plan. The design can thus be described from the registered features, while the planned inferential approach and the results cannot be reconstructed from 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.

Before assignment: Participants received up to 5 products simultaneously on their skin. SLS was only used in the Irritation study (39 subjects) as a positive control.

Irritation

Reasons for not completing this period:

Sensitization

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants received more than one product at a time.

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.

Population: Participants in the Sensitization study received the following 4 products ( 2% CHG cloth, Vehicle cloth, DynaHex and Saline). Participants in the Irritation study received the same 4 products in addition to SLS.

6. Primary Endpoint

The registry lists the primary outcome as Grading Scale for Visual Evaluation of Skin Condition, measured over 21 Days for Irritation (N=39). 35 Days for Sensitization (N=249).

The primary outcome is a reviewer’s visual grade of skin condition at treated areas. The registry describes an eight-point categorical scale, reported as scores ranging from 0-7. Grade 0 indicates no irritation; the higher grades describe increasingly prominent findings, ending with a strong reaction spreading. This scale is used to characterize visible skin responses during the product application schedules.

The outcome covers two related but distinct assessments. Irritation was assessed during 21 days of patching in 39 participants. Sensitization was assessed during a 35-day schedule in 249 participants, consisting of 21 days of patching, 14 days of rest, and a subsequent patch. The record states that SLS was not tested for sensitization. A reviewer assigned scores to treated areas at each visit.

A visual grading scale can make observations more structured than an unstandardized description, and a repeated assessment schedule can capture changes over time. However, the grades are ordered categories, not measurements with guaranteed equal spacing between adjacent scores. A mean can summarize scores, but by itself it may conceal how scores are distributed across grades, visits, treated sites, or participants. The registry identifies the outcome parameter as a mean and its dispersion as a full range, but does not report the resulting values.

The outcome therefore indicates what the study intended to assess, not what was observed. The actual grades, their distribution, and any comparison between products are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study’s primary endpoint is an ordinal visual grade. Ordinal means that the categories have an order, but the distance between neighboring categories is not necessarily equal. Here, the scale ranges from 0-7. The definitions describe skin findings from no irritation through increasingly notable appearances to a strong reaction spreading. A reviewer assigned a grade to treated areas at each visit.

What does a mean score convey?

A mean score compresses several observations into one summary. It can be convenient for comparing groups or describing an overall level, but it has limitations for ordered categories. It treats the numeric labels as if their spacing can be summarized arithmetically. That may obscure whether most observations fell in one category or whether a small number of higher grades affected the average. The registry also specifies a full range as the dispersion measure, which can describe the lowest and highest observed values. Neither the mean nor the range is reported in the registry record, and a range alone would not show the frequency of each grade.

For a fuller interpretation of an ordinal outcome, distributions across categories and the number of observations contributing to each summary can be informative. Repeated measurements could also be described by visit or treated area. These are general statistical considerations; the registry record does not report whether such summaries were planned or performed.

Why might repeated observations matter?

The assessment schedule involved observations at visits, and the study description says participants received more than one product at a time. Observations from the same participant can be related. If a person has several treated sites or repeated scores, those measurements are not necessarily independent in the way observations from unrelated participants might be. Statistical methods that account for clustering or repeated measures can represent this dependence. Ignoring dependence can make uncertainty appear different from what it would be under an appropriate model. This is a general concern, not a claim about the analysis used in this study. The analysis approach is not reported in the registry record.

The registry labels the study parallel and randomized, but does not report the product allocation structure in enough detail to determine how participant-level or site-level comparisons were organized. The phrase that participants received more than one product at a time makes it particularly important not to assume that each product group consists of distinct, independent participants. The exact within-participant structure and its treatment in analysis are not reported.

How should uncertainty be assessed?

An estimate describes the observed outcome or contrast, while a confidence interval describes the range of values compatible with the data under a specified statistical method and its assumptions. A narrow interval generally indicates greater precision than a wide interval, but interpretation depends on the endpoint, model, and study design. A p-value, when used, measures how unusual data at least as incompatible with a specified null model would be under that model; it does not measure the probability that a hypothesis is true. These are general explanations. The registry record does not report estimates, confidence intervals, or p-values for the primary outcome.

Without an endpoint estimate and its uncertainty, the magnitude and precision of product differences cannot be assessed. The record’s lack of reported analyses should not be interpreted as evidence that products were equivalent or that no differences occurred. Equivalence or non-inferiority conclusions require an appropriate design, analysis, and prespecified margin; those details are not reported in the registry record.

What role do the product controls play?

The vehicle cloth provides a comparison involving the cloth’s excipients, while saline is another listed product. SLS is described as a positive control intended to produce mild irritation. A positive control can help establish whether an assessment procedure captures the kind of response it is intended to detect. This is a general role, not a reported finding from this study. The registry notes that SLS was not tested for sensitization, so it cannot serve as a sensitization comparison in the stated outcome schedule.

DynaHex (2% CHG) is listed separately from the 2% CHG Cloth and is described as a chlorhexidine gluconate 2% solution. These products should not be treated as identical formulations based only on the shared active ingredient description. The record does not report a formal contrast or an analysis of their relative scores.

What can planning calculations establish?

Sample-size calculations are planning tools that link a target effect, assumptions about variability and allocation, and a chosen statistical procedure to a prospective sample-size estimate. They do not establish that an effect was observed, and a retrospective calculation based on an observed effect does not constitute observed power. General planning illustrations should not be confused with trial design justification. The registry record does not report the trial’s sample-size justification or statistical analysis plan. It also does not report the primary outcome values needed to evaluate an observed effect.

Overall, the statistical concepts most relevant to this study are the interpretation of an ordinal mean, the distribution of scores, dependence from repeated or multiple product assessments, and uncertainty around product comparisons. The registered outcome description allows these issues to be identified, but the missing scores and analysis details prevent an assessment of how they were addressed.

10. Multiplicity, Missing Data and Analysis Populations

The study’s outcome description includes more than one assessment context: irritation over 21 days of patching and sensitization over 35 days. It also refers to treated areas being graded at each visit and lists several products. This creates the potential for multiple comparisons or repeated outcome summaries. When many comparisons are considered, the chance of a seemingly notable result arising by chance can increase unless the analysis plan addresses multiplicity. This is a general statistical concern.

The registry record does not report a multiplicity adjustment, a hierarchy of comparisons, or which comparisons were designated as primary beyond the listed outcome measure. It does not report a statistical analysis plan, analysis populations, missing-data methods, or how participants with incomplete assessments were handled. These details are not reported in the registry record.

Missing data can affect interpretation if the availability of scores is related to participants’ observed skin responses or other characteristics. General approaches include describing the amount and pattern of missingness and explaining how analyses account for it. No such information is reported. The enrollment of 249 does not establish that every participant contributed a score at every visit or for every product.

The record states that participants received more than one product at a time, but does not report the precise allocation or analysis population for each product. This limits assessment of whether product comparisons accounted for paired or clustered observations. The absence of these details is a reporting limitation, not evidence that the trial did or did not use a particular method.

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 0% reporting threshold.

Most frequent non-serious adverse event terms

The adverse-event listing reports zero serious adverse events affected in each of the five product groups. For other adverse events affected, the recorded counts are 5 for 2% CHG Cloth, 0 for Vehicle Cloth, 15 for DynaHex (2% CHG), 0 for Saline, and 1 for Sodium Lauryl Sulfate (SLS). The corresponding at-risk counts are 249 for the first four groups and 39 for SLS.

These counts should be read as registry-recorded group figures, not as a direct comparison of risk between products. Participants received more than one product at a time, and the record does not explain whether counts represent unique participants across groups, how events were defined, or how related observations were handled. The counts therefore should not be added or converted into comparative measures.

The record lists deaths as null rather than providing a numerical death count. A null entry is not a reported zero. The adverse-event information also does not describe the specific other events in the registry record. These safety counts are separate from the missing primary visual skin-condition scores, and they cannot fill that gap.

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

The record describes a randomized study of a 2% CHG cloth and other products, with visual assessment of skin condition during irritation and sensitization schedules. It specifies the scoring scale, the assessment periods, the stated participant counts, and adverse-event figures. These details show what the study was designed to evaluate and what parts of its record can be described.

However, the registry record does not report the primary outcome scores, the full range of observed scores, or analyses comparing products. Without those results, readers cannot determine the observed level of irritation or sensitization, whether scores differed between products, or how precise a difference estimate might be. The absence of reported results is not evidence that there was no effect or that products were equivalent.

The listed adverse-event counts provide a separate, limited description. Zero serious adverse events affected are recorded for each listed group, while other adverse-event counts are reported by product. The record does not provide enough detail to establish comparative safety from those counts, and the death entries are null rather than numerical zeros.

More generally, results from a study of visual skin grades depend on how the ordinal scores are summarized, how repeated observations are handled, and how uncertainty is quantified. Those considerations matter especially because participants received more than one product at a time. The record does not report enough analysis detail to determine how these issues were addressed.

The appropriate interpretation is therefore bounded: the registered design and outcome definition can be described, and the posted adverse-event counts can be quoted. The magnitude, direction, and precision of the primary product comparisons are not reported in the registry record. No conclusion about a treatment’s clinical effect should be inferred from the study title, its completed status, or its outcome definition alone.

13. Why This Trial Matters Statistically

This study raises statistical issues that are common in evaluations of skin responses. The endpoint is a graded visual assessment rather than a direct continuous measurement. Its ordered categories have clinical descriptions, but adjacent numeric labels do not necessarily represent equal increments. Reporting only a mean can therefore leave important features of the score distribution unclear.

The study also involved multiple products and states that participants received more than one product at a time. Such a design can create related measurements within a participant. The analysis needs to reflect the structure of the observations if product comparisons are to have appropriate uncertainty. The registry record does not report the allocation structure or the statistical methods used, so readers cannot judge how dependence was addressed.

The separate irritation and sensitization schedules also illustrate why endpoint timing and population matter. The irritation assessment is described for 39 participants over 21 days of patching, while sensitization is described for 249 participants over 35 days. SLS was not tested for sensitization. These are distinct assessment contexts, and the participant count and schedule for one should not be assumed to apply to the other.

Finally, the record demonstrates the difference between registering a research question and reporting an interpretable result. It supplies a clear description of the visual scale and study schedules, but not the outcome values or inferential analyses. Those missing elements prevent readers from evaluating effect size and precision, which are central to statistical interpretation.

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 principal limitation for interpreting efficacy-related or skin-response comparisons is that primary outcome values are not reported in the registry record. There is no reported mean score, full range, category distribution, product contrast, confidence interval, or p-value. Consequently, the direction and magnitude of any difference cannot be assessed.

The record does not report how participants were allocated across products or how the fact that participants received more than one product at a time was handled analytically. It does not report whether repeated scores from visits or treated areas were treated as dependent observations. These omissions make it difficult to evaluate the comparability and statistical precision of product contrasts.

The record identifies a mean and full range for an ordinal scale, but does not report the underlying distribution of grades. Means may not fully convey the pattern of categorical responses. The record also does not provide details about missing scores, participant flow by assessment, or the analysis population.

The study is listed as single-masked, while its official title describes observer blinding. The record does not specify who was masked or the procedures used to maintain masking. It also does not report a sample-size justification, a statistical analysis plan, multiplicity handling, or an interim analysis plan. These items are not reported in the registry record and should not be inferred.

For safety interpretation, the record reports counts of serious and other adverse events affected by group but does not provide event descriptions in the registry record. The death entries are null. Participants received more than one product at a time, so the group counts should not be assumed to be independent or directly comparable without further detail.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Irritation and Sensitization of Chlorhexidine Gluconate (CHG) Cloth — NCT02224625.
• Registry record last updated 2017-03-09; status last verified 2016-03.
• Results first posted 2016-05-30.
• 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

NCT02224625 is a completed randomized study titled Irritation and Sensitization of Chlorhexidine Gluconate (CHG) Cloth. The registry lists a parallel design, single masking, Phase 3, enrollment of 249, and Medline Industries as sponsor. The stated condition is Surgery. The listed start is 2014-08, and primary completion is 2015-06.

The primary outcome is a reviewer-graded visual evaluation of skin condition on a scale ranging from 0-7. The record describes a 21-day irritation assessment in 39 participants and a 35-day sensitization assessment in 249 participants. Participants received more than one product at a time; SLS was not tested for sensitization.

The registry record does not report primary outcome scores or statistical analyses. It lists zero serious adverse events affected in each product group and other adverse-event counts of 5, 0, 15, 0, and 1 across the listed groups. Death entries are null. The numerical effect and precision of product comparisons are not reported in the registry record.