ProvodineTM Decreases Hand Contamination: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for ProvodineTM Decreases Hand Contamination (NCT04023682), a na phase 4 study. The primary outcome is Control Period-Count the Number of Baseline Colony Forming Units Cultured From Anesthesiologist's Hands.

2. Clinical Question

The study was intended to assess whether adding Provodine to usual practice was associated with hand contamination measurements across the day. Cultures were described at the beginning of the day and after cases, with the control and intervention periods using different hygiene procedures. The broader study aim was to examine whether the product could provide lasting protection on providers’ hands; that aim is not itself a result.

The primary outcome as registered is specifically a control-period baseline measure, obtained before the first case. It does not, by itself, quantify a difference between the control and intervention periods. The registry lists other outcomes for cultures after the first and second cases in both periods and for providers acquiring a pathogen or commensal during the day. Those outcomes could inform questions about changes over time or across periods, but their results are not reported in the registry record.

Accordingly, the record describes a clinical question and a measurement plan, not an answer about the size or direction of any change in contamination. It also does not report whether any observed culture differences were considered statistically reliable.

3. Trial Design

This is registered as a Phase 4, single-group study with no masking. Allocation is listed as not applicable. The arm description says each provider serves as their own control: a control phase uses standard hygiene practices, and an intervention phase adds Provodine hand sanitizer. This is a within-provider comparison, not a randomized comparison between separate treatment groups.

The registry records enrollment of 31. The brief description also says “Fifteen anesthesia providers” and then gives counts of 15 main operating room and 5 ambulatory surgery center providers. Those statements are internally inconsistent, and the record does not clarify the discrepancy. Enrollment is not necessarily the same as the number included in an outcome analysis; analyzed participant counts are not reported in the registry record.

The planned control-period measurements include cultures before the first case and after the first and second cases. In the intervention period, the description includes a beginning-of-day culture, a culture after a hand scrub, and cultures after the first and second cases. The record describes the intervention as Provodine hand sanitizer alongside usual hand hygiene practice. The primary outcome is the control-period baseline colony-forming-unit count, with an average of one day as its timeframe.

The recorded study start is 2013-12, the primary completion is 2014-11, and the status is completed. These dates describe the registry record’s study timeline; they do not establish when individual participants were assessed or how long each contributed measurements. The protocol’s full sequence, recruitment process, and conduct details are not reported in the registry record.

Because the same providers were intended to contribute measurements in both periods, measurements from one person should not automatically be treated as independent observations. The registry record does not state how that dependence was handled in analysis. It also does not report a statistical analysis plan or results for the proposed within-provider comparisons.

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

Reasons for not completing this period:

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 Control Period-Count the Number of Baseline Colony Forming Units Cultured From Anesthesiologist's Hands, measured over Average of 1 day.

The registered primary endpoint is the number of baseline colony forming units cultured from an anesthesiologist’s hands during the control period. The measurement is taken before the provider’s first case of the day, after usual hand hygiene practice, and is described as an average of one day. Colony forming units are the recorded unit for the culture count.

This endpoint is a continuous measure summarized in the registry as a mean with a standard deviation. In general, a mean describes the average observed measurement, while a standard deviation describes how spread out the measurements are around that average. The count gives a quantitative measure of culturable contamination at a defined point in the day. It is not a direct measure of infections in patients, and the endpoint description does not claim that it captures every type of contamination.

The endpoint is useful for characterizing the control-period baseline, but it is not a direct intervention effect. The study description says a comparison between control and intervention phases was intended; a contrast between those phases would require outcome measurements from both periods and a stated method for comparing them. The primary endpoint title and description do not give such a contrast or report its estimate.

No mean, standard deviation, participant-level count, confidence interval, or test result for this endpoint is reported in the registry record. Thus, the endpoint definition can be described, but its observed level and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as a mean of a continuous outcome, with standard deviation as its measure of dispersion. In general, a mean is calculated by averaging the measurements in an analysis set. A standard deviation describes how much those individual measurements vary around that average. Neither summary is reported for the registered primary endpoint, so no numerical description of the baseline culture counts is available from the registry record.

What does a confidence interval add?

In general, a confidence interval expresses uncertainty around an estimated quantity under a specified statistical model and sampling process. A narrow interval indicates greater precision than a wide interval, while an interval that includes values corresponding to little or no difference may leave the size and direction of an effect uncertain. Interpreting an interval requires knowing what was estimated, how it was calculated, and which observations were included. The registry record does not report a confidence interval for the primary outcome or a control-versus-intervention comparison.

Why does the within-provider structure matter?

The arm description says providers serve as their own controls. In general, paired or repeated-measure designs use observations from the same person to make comparisons, rather than treating each measurement as if it came from an unrelated person. The measurements within a provider are likely to be statistically dependent by virtue of being repeated observations on that provider. Analyses that account for pairing or repeated observations can represent that structure; methods that assume independence may not. This is a general methodological point, not a claim about the analysis used in this study. The registry record reports zero analyses and does not specify a method for handling repeated measures.

The planned observations also occur at different points in the day and in different study periods. A comparison across those times could be affected by the timing and order of observations. In general, when periods occur in sequence rather than being randomized, changes over time can be difficult to separate from an intervention-period difference. The registry record does not describe random ordering of periods, a washout, or methods for addressing period effects, so none should be assumed.

How should culture counts be analyzed?

In general, count outcomes can have features that differ from measurements that are approximately symmetric around a mean. For example, counts may be concentrated near lower values or show variability that changes with their average. Over-dispersion means that the observed variability exceeds what a chosen count model expects; if present and ignored, uncertainty estimates can be misleading. These are general considerations for count data, not reported characteristics of the culture results in this study. The registry lists a mean and standard deviation for the primary measure but does not state whether counts were transformed, modeled with a count distribution, or checked for over-dispersion.

Different analysis choices answer different questions. An analysis of mean counts addresses average levels, while an analysis based on a count model can make assumptions about the distribution and relationship between the average and variability. A paired analysis can focus on within-provider changes. The registry record does not identify which, if any, of these approaches was used. It is therefore not possible to infer an analysis method from the outcome summary format alone.

What do the planning assumptions establish?

The registry’s planning description specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the detectable effect is a stated fraction of the observed effect. It further says time-to-event planning uses total events, while other planning results are expressed as participants per arm. These are descriptions of planning illustrations, not the registered study design: the study itself is listed as single-group, with allocation not applicable and providers serving as their own controls. The actual planning figures are not reported in the registry record.

In general, sample-size planning depends on a defined outcome, target effect, variability, design, significance level, and desired power. A planning result illustrates the sample size associated with chosen assumptions; it does not show the chance that this completed study detected an effect. The record does not report the trial’s own sample-size justification or a prespecified power calculation. No observed power conclusion can be drawn.

A p value, if reported, would summarize compatibility of data with a null hypothesis under a particular model; it would not measure the size or importance of a difference. An estimate and confidence interval would be needed to assess magnitude and precision. Since the registry record reports neither an analysis nor outcome estimates, there is no inferential result to interpret.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Anesthesia Provider Hands")
n   <- c(31)
m   <- c(589.3)
sp  <- c(823.7)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Anesthesia Provider Hands  31  589.300  823.700  287.164  891.436

11. Multiplicity, Missing Data and Analysis Populations

The registry lists seven outcome measures: the control-period baseline measure and outcomes concerning cultures after the first and second cases in both the control and intervention periods, along with acquisition of a pathogen or commensal during the day. It reports zero analyses. No hierarchy of outcomes, multiplicity adjustment, or strategy for interpreting multiple statistical tests is reported in the registry record.

In general, testing multiple outcomes or comparisons can increase the chance of at least one apparently unusual result under a null model. Prespecifying a primary question and using an appropriate multiplicity strategy can help frame interpretation. The record identifies a primary endpoint but does not report whether any formal adjustment was planned or used. With no posted analyses, the effect of any multiplicity strategy cannot be assessed.

Missing-data handling is not reported in the registry record. The record does not say whether any participants lacked cultures, whether any scheduled measurements were missed, or how incomplete records would be handled. It also does not report the number of participants included in each outcome analysis or define analysis populations, such as all enrolled participants or only those with complete measurements.

These omissions matter because the number and pattern of available measurements can affect both estimates and their uncertainty. A completed study status does not establish that all enrolled participants contributed every planned culture. The registry enrollment is 31, but the analysis denominator for any outcome is not reported in the registry record. No assumptions about missingness or exclusions can therefore be attributed to the analysis.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists an adverse-event group titled “Anesthesia Provider Hands.” In that group, 31 are recorded as at risk for serious adverse events and 0 as affected; 31 are recorded as at risk for other adverse events and 0 as affected. Deaths are recorded as 0. No serious adverse-event terms are listed.

These figures mean that the registry record reports no serious events, other events, or deaths in the listed group. They do not establish that no events occurred outside the scope or definitions used for this reporting, and they do not demonstrate that an intervention is free of risk. The record does not give event definitions, surveillance procedures, reporting windows, or further detail about how adverse events were collected.

The safety counts are not a comparison between randomized groups: the study is registered as single-group, allocation is not applicable, and the group listed concerns anesthesia provider hands. The figures should be read as the registry’s reported counts, not as a comparative safety estimate or proof of a causal relationship.

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

The registry record documents a study intended to measure hand cultures among anesthesia providers during control and intervention periods. It specifies a baseline control-period primary endpoint and describes additional culture measurements after cases and during the intervention period. The record does not report numerical findings for those outcomes, so it does not establish the observed size or direction of any difference in culture counts.

The distinction between a study aim and a study result is important. The stated aim concerns whether Provodine provides lasting protection on providers’ hands. The registered endpoint is a culture count at a particular point under control-period practice, and the additional outcomes concern measurements at other points. Without the observed measurements and an analysis comparing periods, the stated aim cannot be answered from the registry record.

Even if a difference between periods were reported, general interpretation would depend on its size, precision, analysis method, and the conditions under which observations were collected. A statistical result would address the measured outcome and model assumptions; it would not automatically establish effects on patient infections or other outcomes that are not reported as measured results in the registry record.

The single-group, within-provider design can support comparisons of repeated measurements in the same providers, but it is not a randomized comparison between separate groups. General concerns include dependence among repeated observations and possible differences over time or across cases. The registry record does not report how these issues were addressed. Its zero reported analyses and absent outcome estimates mean that no statistical conclusion about the intervention’s effect can be drawn.

The safety record lists zero affected for serious and other adverse events and zero deaths in the listed group. Those counts describe what was entered in the registry; they should not be treated as proof of an absence of risk. Overall, the record establishes the planned question and certain design details, but not the empirical result.

14. Why This Trial Matters Statistically

This study is statistically notable for its within-provider structure. When the same provider is observed under control and intervention conditions, a comparison can focus on changes within people rather than differences between unrelated groups. In general, this can reduce the influence of stable person-level differences. It also creates repeated observations that require suitable analysis; treating them as independent can misstate uncertainty.

The timing of the cultures makes the structure more involved than a single measurement per provider. The registry describes cultures before the first case and after cases, with measurements in both control and intervention periods. These observations represent different time points and potentially different conditions. A meaningful analysis needs to define which measurements are being contrasted and how within-provider dependence and timing are handled. The analysis approach is not reported in the registry record.

The record also illustrates why endpoint definitions and reported results must be distinguished. The primary outcome is a control-period baseline count, while the study aim concerns whether adding Provodine changes hand contamination across the day. A baseline endpoint can characterize the control period but cannot on its own quantify an intervention contrast. The registry lists other relevant outcomes, yet reports zero analyses and no outcome estimates.

For statistical readers, the record therefore raises questions that cannot be resolved by the registration details alone: how repeated cultures were summarized, how missing observations were treated, whether the analysis accounted for counts’ distribution, and how multiple outcomes were interpreted. The registry record does not report those methods. Recognizing the gaps is important to avoid treating a completed study or a stated study aim as evidence of a measured effect.

15. 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 central limitation for interpreting this study is that outcome results and analyses are not reported in the registry record. The primary endpoint is defined, but no mean, standard deviation, comparative estimate, confidence interval, or test result is reported. Consequently, the size, direction, and precision of any observed difference cannot be evaluated.

The registered design is single-group, with providers serving as their own controls, and no masking. This design description does not support an interpretation as a randomized comparison between separate groups. In general, sequential period comparisons can be influenced by time-related changes as well as by an intervention; the record does not describe a strategy for separating those influences.

The participant description is internally inconsistent: it states “Fifteen anesthesia providers” and also lists 15 main operating room and 5 ambulatory surgery center providers. Enrollment is recorded as 31, but the registry does not explain the discrepancy or report the number analyzed for each outcome. The analysis population and missing-data procedures are not reported.

The registry identifies seven outcome measures but reports zero analyses. It does not report how repeated measurements within providers were handled, whether count-data assumptions were assessed, or whether a multiplicity strategy was used. The study’s own sample-size justification is also not reported; the listed planning description concerns an illustration based on the observed effect and does not establish the study’s design or precision.

Finally, the adverse-event counts are sparse registry summaries without event definitions or collection details. They describe the reported counts but cannot establish that no events occurred beyond what was recorded. These limitations restrict both efficacy interpretation and safety interpretation to the registry’s stated design and reported information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: ProvodineTM Decreases Hand Contamination — NCT04023682.
• Registry record last updated 2021-08-02; status last verified 2021-07.
• Results first posted 2021-08-02.
• 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.

19. Record Summary

NCT04023682 is registered as a completed Phase 4, single-group study of Provodine hand sanitizer and hand contamination among anesthesia providers. Allocation is listed as not applicable, masking as none, and enrollment as 31. The recorded study start is 2013-12, with primary completion in 2014-11.

The primary endpoint is the control-period baseline colony-forming-unit count before the first case of the day, summarized as a mean with standard deviation and a timeframe of an average of one day. The study description says providers serve as their own controls and lists additional culture and acquisition outcomes.

The registry record reports zero analyses and no numerical primary outcome findings or period-comparison results. It lists zero serious adverse events, zero other adverse events, and zero deaths in the anesthesia-provider-hands group. The brief participant description is internally inconsistent, and analysis populations, missing-data handling, and the statistical analysis plan are not reported.