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 Evaluation of the Antimicrobial Effectiveness of CHG/IPA (NCT04035161), a randomized phase not stated study. The primary outcome is Antimicrobial log10 Reductions From Baseline for Investigational Product and Reference Standard at 30 Seconds and 6 Hours Post-product Application.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04035161 |
| Phase | Phase not stated |
| Condition | Microbial Colonization |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 1935 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Becton, Dickinson and Company |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled healthy volunteers, with microbial colonization listed as the condition. The registry record reports enrollment of 1935. Its brief summary describes a planned minimum of 516 healthy volunteers at a single site. The record does not state how many participants contributed usable measurements to each outcome or analysis.
Intervention
The investigational product was applied to skin. The study description specifies abdominal and/or groin application sites and says each subject would receive two of the planned study products. The registry record does not explain the detailed assignment of products to sites or the measurement schedule for each participant.
Comparator
The primary outcome names the reference standard as the comparator for the investigational product. The outcome description identifies the reference standard as 60% v/v 1-Propanol. Active and negative controls are also listed among the interventions, but the primary outcome description excludes those controls.
Primary question
The primary question concerns mean log10 reductions in bacterial counts from baseline, measured at abdominal and groin sites at 30 seconds and 6 hours after product application. The registry record frames the measurements as addressing immediate and persistent antimicrobial activity against the reference standard. The estimates needed to answer how large the reductions were, and how precisely they were estimated, are not reported in the registry record.
3. Trial Design
The registry record describes a randomized, controlled study at a single site. Its design entries identify the allocation as randomized, the masking as single, and the model as parallel. The brief summary calls the study partially blinded. The record does not say which people were masked or describe the procedures used to maintain masking, so the masking designation cannot be interpreted more specifically.
The brief summary states that each subject would receive two of the planned study products on application sites of the abdomen and/or groin. The registry record also lists four intervention categories: investigational product, reference standard, active comparator, and negative control. Its arm descriptions state that skin would be prepared with the corresponding product. The relationship between receiving two products, the parallel-model designation, and the assignment of products to particular sites is not explained in the registry record.
The registry record reports enrollment of 1935 and describes a planned minimum of 516 in its brief summary. These figures describe different record entries; the registry record does not explain their relationship. It lists the study as completed, with a start date of 2019-04-17 and a primary completion date of 2019-12-24. The sponsor is Becton, Dickinson and Company.
Randomization is intended, in general, to reduce systematic differences between assigned groups, while masking can limit some forms of measurement or behavior bias. Those are general design principles, not evidence about how completely these protections operated in this study. The registry record does not report allocation concealment, a randomization procedure, allocation ratios, or the details of implementation.
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 were only treated if screening day baseline bacterial counts met the inclusion criteria. Participants were treated with 2 out of 4 study products (Investigational Product, Reference Standard, Active control and Negative Control) 1 on the left side of the body (both groin and abdomen), 1 on the right side of the body (both groin and abdomen).
Overall Study
| Stage | All Study Participants |
|---|---|
| STARTED | 1121 |
| Treated With Investigational Product | 609 |
| Treated With Reference Standard | 419 |
| Treated With Active Control | 609 |
| Treated With Negative Control | 605 |
| COMPLETED | 1121 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: This outcome includes test requirements outlined by Health Canada (HC) for an investigational product to demonstrate immediate and persistent antimicrobial activity against a reference standard, 60% v/v 1-Propanol. This outcome does not include negative and active control comparators. Analysis only includes participants with required treatment day baseline bacterial counts at each anatomical site at baseline and non-missing data at 30 seconds and 6 hours post-product application.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | All Study Participants |
|---|---|---|
| Participants analysed | 1121 | |
| Age, Continuous | years | 54.5 (SD 11.7) |
| Sex: Female, Male: Female | Participants | 205 |
| Sex: Female, Male: Male | Participants | 916 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1121 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 |
| Race (NIH/OMB): White | Participants | 1120 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: Romania | participants | 1121 |
6. Primary Endpoint
The registry lists the primary outcome as Antimicrobial log10 Reductions From Baseline for Investigational Product and Reference Standard at 30 Seconds and 6 Hours Post-product Application, measured over 30 seconds and 6 hours post-product application.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Log10 CFU/cm^2 |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is described as antimicrobial log10 reductions from baseline for the investigational product and reference standard. Measurements are specified for 30 seconds and 6 hours after application, at abdominal and groin sites. The unit is Log10 CFU/cm^2, and the summarized quantity is a mean with a 95% confidence interval. The outcome description refers to bacterial reductions after application; the registry record does not report the endpoint estimates or confidence intervals.
In general, CFU/cm^2 expresses microbial colony-forming units per unit of skin area, while a log10 scale represents changes in orders of magnitude rather than equal additive changes in raw counts. A reduction from baseline describes the change in the measured count relative to the baseline measurement. As a general interpretation, a larger positive reduction corresponds to a greater decline in the measured count; this does not establish a clinical benefit.
The record says this outcome includes requirements outlined by Health Canada for demonstrating immediate and persistent antimicrobial activity against a reference standard, identified as 60% v/v 1-Propanol. That describes the purpose assigned to the endpoint in the registry record. It does not, by itself, show that any particular result met a requirement. Negative and active control comparators are explicitly excluded from this primary outcome description.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a multi-part primary outcome: mean log10 reductions from baseline at two post-application times and at abdominal and groin sites, for the investigational product and reference standard. It also lists five outcome measures and six analyses. The primary outcome is not reduced to one comparison because it includes several categories or time points. Consequently, a single overall estimate cannot be inferred from the outcome description alone.
The endpoint means and their 95% confidence intervals are not reported in the registry record. Nor are comparative estimates, p-values, or the number of participants contributing data to each endpoint analysis. The record therefore does not establish the size or precision of any observed difference between the investigational product and reference standard. The stated outcome definition is not itself a result.
In general, a confidence interval describes uncertainty around an estimate under the assumptions of the analysis used to construct it. A narrower interval indicates greater statistical precision than a wider interval, but an interval cannot be interpreted without its estimate, scale, and analysis context. Here, the endpoint is defined as a mean and a 95% confidence interval, but the interval bounds and means are not reported in the registry record.
The timing matters to interpretation. A measurement at 30 seconds addresses an early post-application time point, whereas a measurement at 6 hours addresses a later one. These measurements do not automatically represent the same effect or answer interchangeable questions. Likewise, abdominal and groin sites are separate measurement settings in the outcome description. The registry record does not report site-specific estimates, a combined estimate, or how any site and time-point results should be prioritized.
Because the reference standard is identified as 60% v/v 1-Propanol, the primary outcome is framed as a comparison against that standard rather than against the active or negative controls. Those controls are listed as interventions but excluded from the primary outcome description. No results for those controls are reported in the registry record in the registry record for this analysis.
The record's enrollment figure is not a substitute for outcome-specific sample sizes. Enrollment does not reveal how many participants had complete measurements at each site and time point, whether every enrolled participant was analyzed, or whether the analysis accounted for the study's multiple products and measurement settings. Those details are not reported in the registry record. The data described support identifying the question and its measurement structure, but not quantifying an efficacy contrast or its uncertainty.
9. Statistical Methods Explained
The endpoint is a continuous measurement summarized as a mean, with a 95% confidence interval. The study outcome is expressed in log10 CFU/cm^2 and framed as a reduction from baseline. The registry record does not report the statistical model, the precise calculation of each reduction, or the method used to construct confidence intervals.
What does a log10 reduction represent?
In general, a logarithmic scale expresses values in terms of powers of a base. A change on a log10 scale is not interpreted in the same way as an equal numerical change in raw colony counts. Reporting log10 CFU/cm^2 can make wide-ranging microbial counts more manageable to summarize and compare. A baseline reduction compares a post-application measurement with the baseline measurement, but the exact formula and handling of observations below a measurement limit are not reported in the registry record.
Because the reported endpoint is a mean, it represents a summary across observations included in an analysis. In general, a mean can conceal variation among participants or sites: similar means can arise from different distributions of individual measurements. The registry record does not report the distribution of the endpoint values, a measure of between-participant variability other than the stated confidence interval, or results for individual participants.
How should the confidence interval be read?
In general, a confidence interval gives a range of values compatible with an estimate under the statistical method and assumptions used. Its width conveys precision: an estimate with a wider interval is less precise than one with a narrower interval. A confidence interval does not describe the range of individual participant measurements, and it does not by itself establish clinical importance. The registry record specifies 95% confidence intervals for the mean endpoint, but their bounds and the method used to calculate them are not reported in the registry record.
For a comparison between products, the interpretation depends on what contrast was estimated and on its confidence interval. The primary outcome description names the investigational product and reference standard, but does not state a single contrast or provide a numerical comparison. It includes more than one site and more than one post-application time. The registry record does not state whether estimates were calculated separately for each setting, combined across settings, or adjusted for other factors.
Why do sites and times matter?
In general, measurements taken from the same person, or from related sites or time points, may be statistically dependent rather than independent. Ignoring dependence can affect uncertainty estimates. The brief summary says each subject would receive two planned study products on abdominal and/or groin sites, while the design entry identifies a parallel model. The record does not explain the participant-level and site-level structure in sufficient detail to identify which observations were paired or how any dependence was handled. No particular statistical model should be inferred from those descriptions.
Over-dispersion is a general possibility in count-related data: observed variability can exceed what a simple model assumes. When it occurs, a model that accounts for the extra variation may give more appropriate uncertainty estimates. This is a general statistical consideration, not a claim that over-dispersion was present in this study. The registry record does not describe a count-data model, a distributional assumption, a diagnostic check, or an adjustment for over-dispersion. The endpoint is reported on a log10 scale, but that alone does not identify the model used.
What do the planning illustrations mean?
The sample-size assumptions described with the record are planning illustrations computed from an observed effect, not the trial's own design. They use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. Such illustrations are conditional on those assumptions and are not evidence of the trial's original planning rationale. They are not observed power. The trial's own sample-size justification is not reported in the registry record.
In general, a planning calculation estimates how many participants may be needed under specified assumptions to detect a target effect with a chosen probability, or power. Changing the target effect or assumptions can change that estimate. A calculation based on an observed effect is especially dependent on that estimated effect and should not be read as proof that the study was adequately planned or that a result is reliable. No numerical sample-size illustration is stated in the registry record details used for this analysis.
The registry record lists five outcome measures and six analyses, but those counts do not reveal the analytical choices. The statistical methods, covariate adjustments, handling of repeated measurements, outlier rules, and assumptions used for the outcome analyses are not reported in the registry record. This distinction matters: endpoint definitions identify what was intended to be measured, while an analysis plan explains how the observed measurements were converted into estimates and uncertainty.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome spans multiple measurement settings: the investigational product and reference standard, abdominal and groin sites, and measurements at 30 seconds and 6 hours. The registry record lists five outcome measures and six analyses, and states that the primary outcome has several categories or time points rather than one reduced comparison. When multiple estimates are examined, general statistical practice considers whether the chance of false-positive findings across the family of comparisons should be controlled or otherwise addressed. The registry record does not report a multiplicity adjustment, a hierarchy of comparisons, or a designated primary contrast.
The analysis populations are not reported in the registry record. It is therefore not stated whether analyses included all randomized participants, only participants with observed measurements, or another defined group. The record does not report how deviations from assigned products or protocol procedures were handled, nor whether any per-protocol or other sensitivity populations were used.
Missing-data methods are also not reported in the registry record. The available description does not say how absent baseline or post-application measurements were handled, whether reasons for missing measurements were recorded, or whether an analysis assessed the effect of missing data on results. No assumptions about missingness or imputation should be inferred.
Interim analyses and stopping rules are not reported in the registry record. The record does not describe an analysis plan in enough detail to determine how outcome selection, missing observations, or the multiple sites and times were addressed. Without those details, the number of registered measures and analyses alone cannot establish whether multiplicity or missing data affected any result.
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 |
|---|---|---|---|
| Investigational Product | 0 | 609 | 0.0% |
| Reference Standard | 0 | 419 | 0.0% |
| Active Control | 0 | 609 | 0.0% |
| Negative Control | 0 | 605 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Investigational Product | 0 of 609 |
| Reference Standard | 0 of 419 |
| Active Control | 0 of 609 |
| Negative Control | 0 of 605 |
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 |
|---|---|
| Investigational Product | 0 of 609 |
| Reference Standard | 0 of 419 |
| Active Control | 0 of 609 |
| Negative Control | 0 of 605 |
The registry record lists adverse-event groups for the investigational product, reference standard, active control, and negative control. For each group, it reports serious events affecting 0 participants, other events affecting 0 participants, and deaths of 0. The listed numbers at risk are 609 for the investigational product, 419 for the reference standard, 609 for the active control, and 605 for the negative control.
These are group-level registry entries. The brief summary says each subject would receive two planned products, so the group counts should not be added to infer a number of unique participants. The record does not explain the relationship between group membership and individual participants in detail. No serious adverse-event terms are listed.
In general, a recorded zero means that the registry entry reports no events of that category for the stated group; it does not by itself explain how events were collected, monitored, or classified. The registry record does not provide additional detail on adverse-event definitions, collection periods, severity, relatedness, or missing safety data. These figures should therefore be read as the reported counts, not as a complete account of safety monitoring or as proof that no unrecorded events occurred.
12. What the Result Does, and Does Not, Mean
The registry record defines a study of antimicrobial activity on skin in healthy volunteers. Its primary outcome concerns mean changes in log10 CFU/cm^2 from baseline, measured at two application sites and two post-application times, for the investigational product and reference standard. This design description clarifies what the study intended to assess, but the endpoint means and confidence intervals are not reported in the registry record.
Without those estimates, the magnitude and precision of the observed endpoint results cannot be assessed. The record does not report a single summarized comparison, and it does not provide numerical results for the multiple sites and times in the registry record used for this analysis. No conclusion about the direction, size, or statistical uncertainty of an investigational-product contrast can be drawn from the endpoint definition alone.
The stated purpose is to evaluate immediate and persistent antimicrobial activity in relation to a reference standard. A result on a laboratory microbial-count endpoint would describe that measured outcome in the study setting. In general, it would not by itself establish effects on clinical infection, patient outcomes, or other settings or populations. The registry record identifies healthy volunteers and skin sites; it does not establish that findings apply beyond those conditions.
The adverse-event entries report zero serious events, zero other events, and zero deaths for each listed group. Those entries are not a substitute for detailed safety information, which is not reported in the registry record. Likewise, the enrollment count does not establish the number of observations included in every endpoint analysis.
The results should therefore be interpreted within the limits of the registered information: the study question, intervention categories, measurement scale, sites, times, and reported group-level safety counts are described, while the numerical efficacy estimates and key analysis details are not reported in the registry record. This distinction separates what the design intended to measure from what can be concluded about the observed data.
13. Why This Trial Matters Statistically
This trial raises a useful statistical challenge: its primary outcome is not a single measurement at one time. It encompasses different products, application sites, and post-application times. A reader must distinguish the endpoint definition from the comparisons actually estimated and avoid collapsing distinct settings into one conclusion without a stated analysis plan.
The outcome is also expressed as a reduction on a log10 microbial-count scale. In general, scale choice affects how an estimate should be interpreted and summarized. Understanding whether a reported value is a raw count, a change from baseline, or a contrast between products is essential. Here, the record identifies a mean reduction and its unit but does not report the numerical estimates or the precise calculation method.
The study description also illustrates why design labels need context. The record identifies randomized allocation, single masking, and a parallel model, while the brief summary says each subject would receive two planned products at abdominal and/or groin sites. Those statements do not explain the full assignment and measurement structure. That structure matters for deciding whether observations are independent, paired, or otherwise related, and for choosing appropriate uncertainty estimates.
Finally, registry entries can identify an endpoint and list adverse-event counts without providing enough information to evaluate the analysis in depth. The number of outcome measures and analyses does not reveal how comparisons were prioritized, how missing data were handled, or whether multiplicity was addressed. This record is a reminder that statistical interpretation depends both on what was measured and on transparent reporting of how the data were analyzed.
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 the primary outcome is that its numerical estimates and 95% confidence intervals are not reported in the registry record. The registry entries available describe the endpoint but do not give the observed results, comparative estimates, or p-values. The magnitude and precision of the reported antimicrobial reductions therefore cannot be assessed from this information.
The outcome covers several sites and time points, but the registry record does not report the results for each combination or identify a single prioritized comparison. It does not describe whether estimates were combined across sites, how multiple measurements per participant were handled, or what statistical model was used. The brief summary's two-products-per-subject description and the parallel-model designation are not reconciled in the registry record.
Although enrollment is reported as 1935 and the brief summary describes a planned minimum of 516, the record does not state outcome-specific analysis sample sizes or how many participants contributed complete measurements at each site and time. The relationship between these enrollment entries is not explained. Analysis populations, missing-data methods, and sensitivity analyses are not reported in the registry record.
The record lists five outcome measures and six analyses but does not describe multiplicity procedures or a hierarchy of outcomes. It also does not report the statistical model, assumptions, covariate adjustments, or the trial's sample-size justification. The stated sample-size assumptions concern planning illustrations based on an observed effect, not the original study design.
For safety, the record lists zero serious events, zero other events, and zero deaths in each group, but does not provide detailed definitions, collection periods, or monitoring procedures. These limitations restrict interpretation to the study's registered descriptions and reported counts; they do not establish the quality or completeness of unreported analyses.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of the Antimicrobial Effectiveness of CHG/IPA — NCT04035161.
- Registry record last updated 2021-08-17; status last verified 2021-07.
- Results first posted 2021-08-17.
- 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
NCT04035161, titled Evaluation of the Antimicrobial Effectiveness of CHG/IPA, is listed as completed. The registry record identifies a randomized, controlled study in healthy volunteers at a single site, with single masking and a parallel model. The brief summary describes a partially blinded design and a planned minimum of 516 volunteers; enrollment is listed as 1935.
The primary outcome is mean log10 reduction from baseline in bacterial counts at abdominal and groin sites, at 30 seconds and 6 hours after application, comparing the investigational product with the reference standard. The reference standard is identified as 60% v/v 1-Propanol. The registry record does not report the endpoint estimates or confidence intervals.
The record lists four intervention categories and safety groups. Each group has zero reported serious events, zero other events, and zero deaths. Detailed analysis methods, missing-data handling, analysis populations, and multiplicity procedures are not reported in the registry record.