Trial to Test if Antibiotic Ointments & Cream Will Sting After Application on a Minor Wound After Tape Stripping Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Trial to Test if Antibiotic Ointments & Cream Will Sting After Application on a Minor Wound After Tape Stripping Injury (NCT02320695), a randomized na study. The primary outcome is Mean Change From Post-Tape Stripping in Subject Assessment of Stinging Sensation Immediately After Investigational Product Application.

2. Clinical Question

3. Trial Design

This was a randomized, single-masked crossover study with 60 enrolled subjects. In a crossover design, participants receive or experience more than one condition, so each participant may contribute observations under multiple conditions. This can make within-person comparisons informative because characteristics that remain stable within a participant do not vary between that participant’s conditions. The registry record does not report the sequence of applications, washout procedures, timing between applications, or details of how the crossover was incorporated into the sponsor’s analysis.

The study created minor wounds on the inner arms using tape stripping and assessed stinging after application. The listed conditions were saline, isopropyl alcohol, pain-relieving cream, antibiotic/pain-relieving ointment, original ointment, and pain-relief ointment. The product descriptions specify an amount of 0.3 cc. The record identifies randomization and single masking, but does not identify who was masked or describe the randomization procedure.

The primary outcome analysis was based on subjects who initiated tape stripping and perceived stinging immediately after alcohol application. Although 60 subjects were enrolled, the arm-level primary outcome counts range from 33 to 34. Those counts should not be confused with the enrollment total: they reflect the reported analysis counts for the primary outcome conditions. The registry record does not explain the difference between enrollment and these outcome counts in further detail.

The study is marked completed. Its start and primary completion are both recorded as 2015-03. The registry record does not report the original statistical design assumptions, the planned sample size justification, or detailed procedures for handling repeated measurements and missing observations.

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: Analysis was based on all randomized subjects who initiated the tape-stripping procedures and perceived sting sensation immediately after the application of alcohol.

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 Mean Change From Post-Tape Stripping in Subject Assessment of Stinging Sensation Immediately After Investigational Product Application, measured over Post-tape stripping to immediately after investigational product application.

The primary endpoint is the mean change in subject assessment of stinging from after tape stripping to immediately after product application. Subjects rated stinging on an ordered scale: 0 meant no stinging, 1 mild, 2 moderate, and 3 severe. Change was defined as the rating immediately after application minus the rating after tape stripping. Thus, a negative change indicates a lower rating after application than at the post-tape-stripping assessment; a positive change indicates a higher rating.

This change score is useful because it expresses the immediate response relative to the subject’s rating after the injury procedure, rather than describing only the post-application rating. It is still a summary of subjective ratings, not an objective measure of tissue response. A mean can compactly describe the average change in a group, while the standard deviation describes the spread of individual changes around that mean. Neither statistic alone shows how many subjects reported each scale category.

The registry identifies the analysis population as randomized subjects who initiated tape stripping and perceived sting sensation immediately after alcohol application. The endpoint therefore does not represent every enrolled subject unless they met those conditions. The registry record does not report a separate clinical threshold for an important change on this scale or further details about the scale’s validation.

7. Results Posted in the Registry

• Isopropyl Alcohol: mean 0.82 versus -0.29 on control; difference 1.11 (95% CI 0.69 to 1.53), standardized effect d = 1.25; z-test p = <0.001.
• Pain Relieving Cream: mean -0.55 versus -0.29 on control; difference -0.26 (95% CI -0.62 to 0.10), standardized effect d = -0.34; z-test p = 0.161.
• Antibiotic/Pain Relieving Ointment: mean -0.65 versus -0.29 on control; difference -0.36 (95% CI -0.73 to 0.01), standardized effect d = -0.46; z-test p = 0.059.
• Original Ointment: mean -0.47 versus -0.29 on control; difference -0.18 (95% CI -0.53 to 0.17), standardized effect d = -0.25; z-test p = 0.312.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Mean Clinician Rating of Overall Wound Condition on Day 1

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Isopropyl Alcohol: mean 2.10 versus 2.42 on control; difference -0.32 (95% CI -0.71 to 0.07), standardized effect d = -0.29; z-test p = 0.112.
  • Pain Relieving Cream: mean 2.22 versus 2.42 on control; difference -0.20 (95% CI -0.59 to 0.19), standardized effect d = -0.18; z-test p = 0.318.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Isopropyl Alcohol and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pain Relieving Cream and the control. The interval gives the range of effects that remain compatible with the data.

Mean Clinician Rating of Overall Wound Condition on Day 8

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Isopropyl Alcohol: mean 1.35 versus 1.43 on control; difference -0.08 (95% CI -0.36 to 0.20), standardized effect d = -0.10; z-test p = 0.569.
  • Pain Relieving Cream: mean 1.37 versus 1.43 on control; difference -0.06 (95% CI -0.36 to 0.24), standardized effect d = -0.07; z-test p = 0.697.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Isopropyl Alcohol and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pain Relieving Cream and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes are clinician ratings of overall wound condition on Day 1 and Day 8. Across the listed conditions, the group means are relatively close within each assessment day, while the reported standard deviations indicate variation among subjects. This broad pattern is descriptive: the registry does not post sponsor analyses for these secondary outcomes, and the simple recalculations are limited to comparisons involving isopropyl alcohol and pain-relieving cream.

These clinician assessments concern overall wound condition at follow-up, whereas the primary outcome concerns the subject’s immediate stinging sensation after application. They address different observations, reporters, and time points. A pattern in wound-condition ratings therefore cannot be taken as confirmation or contradiction of an immediate sting comparison. The registry record does not provide a definition of the clinician rating scale or a threshold for meaningful differences.

The secondary results are best treated as supporting context rather than as a second primary test. Multiple outcomes and comparisons create more opportunities for chance findings when each is examined separately. Unless the analysis plan accounts for that multiplicity, an isolated unadjusted result carries less evidential weight than a prespecified primary analysis considered within its planned testing framework. The registry record does not report a multiplicity procedure for the secondary outcomes, and it does not report sponsor inferential analyses for them.

The Day 1 and Day 8 summaries also do not establish a change over time: the posted means are separate day-specific summaries, and no longitudinal comparison is reported. Nor do these secondary outcomes provide a substitute for missing details about the primary crossover analysis. They add information about clinician-rated wound condition, but their interpretation remains limited by the absence of scale details, adjustment information, and reported sponsor comparisons.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Mean Clinician Rating of Overall Wound Condition on Day 1
• Mean Clinician Rating of Overall Wound Condition on Day 8

9. Statistical Interpretation

10. Statistical Methods Explained

What does a mean change describe?

A mean is the arithmetic average of the observations in a group. For this endpoint, each observation is a subject’s post-application rating minus that subject’s post-tape-stripping rating. The reported mean change condenses those individual changes into one group-level value. It does not show the distribution of ratings, whether responses were similar across subjects, or how many subjects experienced no change.

The scale is bounded from 0 to 3 and has ordered categories. Treating its change as a continuous measure and reporting a mean is the approach reflected in the registry’s posted results. General statistical caution applies: an average on an ordered, bounded scale may not convey every feature of the response pattern. The standard deviation gives a measure of variation in the observed changes, but it does not resolve that limitation.

What does the standard deviation add?

The standard deviation describes how dispersed observations are around their mean. A larger standard deviation indicates more variability in the observed subject-level changes; it is not the uncertainty in the mean itself. The standard error, by contrast, describes the estimated sampling variability of a mean under a statistical model. General statistical explanation: uncertainty in a mean depends both on variability among observations and on the number of observations.

The posted arm-level standard deviations range from 0.58 to 0.94 for the primary outcome conditions. Their presence helps put the group means in context, but does not reveal the within-subject association between conditions. That association can matter in a crossover analysis.

What is a mean difference?

A mean difference compares two group means by subtracting one from the other. The simple recalculations compare each product’s mean change with the saline mean change. A negative estimate means the product’s mean change is lower than saline’s on the defined scale; a positive estimate means it is higher. This direction is mathematical and should not by itself be read as a judgment about clinical importance.

These simple recalculations use posted summary statistics and are unadjusted. In a crossover study, outcomes from the same subject across conditions are related. A calculation that does not use the paired subject-level data cannot directly account for that within-person relationship. The registry record does not provide the individual observations or enough information to reconstruct the dependence structure.

Why does the sponsor analysis matter?

The registry reports ANCOVA results for four comparisons against saline. ANCOVA is a regression-based method that estimates a comparison while accounting for covariates included in the model. Which covariates were used, how the crossover structure was handled, and the model’s other details are not reported in the registry record. The sponsor’s estimates differ from the simple summary-statistic recalculations, and the record gives no explanation. Because the sponsor’s results are the reported analysis, they take precedence over the simple recalculations for interpretation.

How should p-values be read?

A p-value measures how incompatible the observed data are with a particular null model, assuming the model and its assumptions apply. A smaller p-value indicates greater incompatibility with that model; it does not quantify the probability that the null model is true or the chance that a result is due to chance. Nor does it measure the size or importance of a difference. The reported recalculated p-values are unadjusted for the multiple comparisons made in the simple recalculations, and the registry does not report a multiplicity adjustment for the sponsor analyses.

What does a confidence interval show?

A confidence interval gives a range of estimates compatible with the data and the method’s assumptions. General statistical explanation: repeated use of a method with the stated confidence level would produce intervals that cover the fixed target value at that frequency in the long run. A single interval is not a probability statement about the true value. Its width conveys precision: narrower intervals represent more precise estimates, while wider intervals leave more uncertainty about plausible values.

For a mean difference, an interval that includes zero is compatible with no difference as well as with differences in either direction. An interval that excludes zero is evidence against a zero difference under the interval’s assumptions, but does not by itself establish clinical importance. The sponsor’s reported intervals are 95% confidence intervals. The recalculated comparisons also have intervals, but the sponsor’s analysis remains the primary reported analysis where the two approaches disagree.

Why can crossover structure affect precision?

General statistical explanation: if two measurements from the same subject tend to move together, a paired comparison can use that relationship and may estimate a within-subject contrast more precisely than an analysis treating the observations as independent. If the association is not accounted for, the estimated uncertainty may differ from that of an analysis using the paired data. The registry record does not report the crossover-specific model details needed to assess this directly. That missing information is especially relevant when comparing a summary-statistic recalculation with the sponsor’s ANCOVA results.

11. Confidence Intervals and Precision

Precision concerns how tightly the data locate an estimated comparison, not whether the estimate is important. The recalculated mean differences have confidence intervals that reflect uncertainty under the calculation’s assumptions. For pain-relieving cream, antibiotic/pain-relieving ointment, and original ointment, the intervals include zero, so the recalculated results are compatible with no difference as well as with values in either direction. For pain-relief ointment, the interval lies below zero; for isopropyl alcohol, it lies above zero. These statements describe the unadjusted recalculations and do not override the sponsor’s reported results.

The sponsor’s ANCOVA estimates also have 95% confidence intervals. For pain-relieving cream and antibiotic/pain-relieving ointment, those intervals extend across zero. For original ointment and pain-relief ointment, the reported intervals are below zero. This pattern differs from some of the recalculated comparisons, underscoring that the analysis method affects the result. The registry record does not provide the ANCOVA model details or an explanation for the discrepancy.

Confidence intervals are more informative than a yes-or-no label based on a p-value because they indicate the range of effect sizes compatible with the data under the method. A wide interval signals less precision and leaves greater uncertainty about the magnitude. A narrow interval can still include effects too small to matter, because statistical precision and clinical importance are separate questions. The registry record does not state a threshold for a clinically meaningful change in stinging, so the clinical importance of any estimated difference cannot be determined from these results alone.

Each analysis count is modest relative to the total enrollment, and some counts differ across conditions. Those details help explain why estimates may remain uncertain, but they do not identify the cause of missing observations or their potential effect. The record does not report a missing-data analysis. In addition, these summary results do not provide the paired data needed to assess how within-subject correlation affects precision in the crossover design.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are illustrations based on an observed effect, not the trial’s original design assumptions. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is the stated fraction of the observed effect. The original trial’s sample-size justification and design assumptions are not reported in the registry record.

The 80% power column gives the estimated number of participants per arm under those assumptions for an 80% chance of detecting the specified effect if that effect were the true one. The 90% power column gives the corresponding planning number for a 90% chance. Power is a design calculation conditional on assumptions; it is not a measure of how likely the observed result is to be true.

Rows planning for 100%, 75%, and 50% of the observed effect illustrate how the required sample size changes when the target effect is smaller. A smaller effect is harder to distinguish from random variation, so the planning figures increase as the target effect shrinks. The values are not predictions of what a future trial would observe and do not account for design features or analysis choices beyond the listed assumptions.

This is not observed power. The illustrations are calculated from the observed effect and should not be used to retrospectively claim that the completed study was adequately or inadequately powered. In particular, the original trial’s crossover design and sponsor analysis may require planning assumptions different from the simplified two-arm illustration.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 1.110; pooled standard deviation σ = 0.891.
2. n = 2 × (1.96 + 0.842)² × 0.891² / 1.110² = 10.1, rounded up to 11 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 1.11                      # observed difference in means
sigma <- 0.891403387922662                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2320695)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 11 (80% power), 14 (90% power)
 75% of observed effect: n per arm = 18 (80% power), 25 (90% power)
 50% of observed effect: n per arm = 41 (80% power), 55 (90% power)
power.t.test: 11.2 
Simulated power at n = 11 per arm: 0.793 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry reports the sponsor’s ANCOVA comparisons of saline with pain-relieving cream, antibiotic/pain-relieving ointment, original ointment, and pain-relief ointment. No sponsor comparison against isopropyl alcohol is listed. The sponsor estimates are -0.12, -0.20, -0.28, and -0.31, respectively, with reported p-values of 0.187, 0.101, 0.002, and <0.001.

The simple recalculations from posted means and standard deviations produce different estimates and, for some comparisons, a different inferential pattern. They are unadjusted summary-statistic calculations and do not reproduce the sponsor’s ANCOVA. The registry record does not report the model covariates, the detailed treatment of the crossover structure, or another explanation for the difference. It is therefore not possible to reconcile the analyses from the registry information alone.

Where a discrepancy exists, the sponsor’s own analysis takes precedence as the reported trial analysis. The recalculations can serve as a transparent comparison based on the posted group summaries, but should not be presented as a correction to the sponsor’s result. The distinct estimates are a reason to interpret the findings with attention to analysis method rather than selecting the result that appears more conclusive.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome, several treatment conditions, and two secondary outcomes, with multiple analyses reported. Each additional comparison creates another opportunity for an apparently unusual result to occur by chance if many tests are considered. General statistical explanation: multiplicity procedures can control the chance of false-positive conclusions across a family of tests, but they may also affect precision and the interpretation of individual p-values. The registry record does not report whether the sponsor prespecified a family of comparisons or used an adjustment for multiplicity. The simple recalculated p-values are unadjusted.

The registry identifies the primary analysis population as randomized subjects who initiated tape stripping and perceived sting immediately after application of alcohol. This is a defined subset of the randomized group, rather than an explicitly stated analysis of every randomized subject. The record does not describe whether other analysis populations were prespecified or how subjects who did not meet the primary population definition were handled.

There are fewer primary outcome observations per condition than the 60 enrolled subjects, and the counts vary across conditions. The record does not explain the reasons for these differences, report missingness by reason, or describe an imputation or sensitivity analysis. General statistical explanation: missing outcomes can affect both precision and the estimated comparison, especially if the chance of having an observed outcome is related to the outcome itself. Without information about why observations are absent, the direction or size of any resulting bias cannot be established.

The crossover design also makes the analysis population and handling of incomplete condition sequences relevant. The registry record does not report whether all subjects completed all conditions, how incomplete sequences were treated, or how within-subject correlation was modeled in the ANCOVA. It does not report interim analyses, a detailed statistical analysis plan, or an original sample-size justification. These omissions limit independent assessment of prespecification and of the sponsor analysis’s assumptions; they do not establish that a particular procedure was or was not used.

16. 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 5% reporting threshold.

For the overall group, the registry reports 60 subjects at risk for serious adverse events and 0 affected. For other adverse events, it likewise reports 60 at risk and 0 affected. The number of deaths is not reported in the registry record. No top serious adverse-event terms are listed.

These figures describe the registry’s adverse-event summary for the recorded group. They do not mean that every possible symptom or event was assessed in the same way, nor do they establish the absence of events outside the reporting definitions and observation period. The registry record does not provide further detail about adverse-event collection, severity grading, attribution, or duration of safety follow-up.

A zero count in a group of 60 should be read as no affected subjects recorded in this summary, not as proof that an event cannot occur. Safety interpretation depends on what was monitored, how events were defined, and how long subjects were followed. The available safety figures are limited to the counts reported in the registry record and do not support broader conclusions.

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

The results describe immediate subject-rated stinging after products were applied to tape-stripping injuries. The reported means show different average changes across conditions, and the sponsor’s ANCOVA analyses report comparisons of four products with saline. These findings apply to the study’s specific injury procedure, application conditions, analysis population, and rating scale. They do not directly answer how the products feel when used on other kinds of wounds or in other settings.

An estimate describes the direction and size of a comparison under its analysis method; a confidence interval describes uncertainty around that estimate. Neither is a stand-alone measure of clinical value. The registry record does not state how large a change on the 0-to-3 rating scale would be important to subjects. Consequently, statistical results cannot by themselves establish whether a difference would be noticeable or meaningful in practice.

The sponsor analysis and simple recalculations do not fully agree. The sponsor’s own analysis takes precedence, but its model details and the explanation for the discrepancy are not reported in the registry record. This limits the ability to independently assess why the estimates differ. The crossover design may be relevant to precision, but the registry information does not allow the within-subject analysis to be reconstructed.

The secondary clinician ratings concern wound condition at later assessments and are not substitutes for the primary sting outcome. They provide a different type of information, and their results are not accompanied by sponsor inferential analyses in the registry. Similarly, the adverse-event summary is limited to its recorded counts and does not establish broader safety conclusions.

Overall, the registry supports a description of the observed immediate sting ratings and the reported comparisons, with uncertainty arising from the modest outcome counts, incomplete analysis details, and discrepancy between the sponsor analysis and summary-statistic recalculations. It does not establish effects beyond the measured outcomes, nor does it support medical advice.

18. Why This Trial Matters Statistically

This study illustrates why an endpoint’s definition matters. The primary outcome is not simply a post-application rating: it is a change from the post-tape-stripping rating. The subtraction determines the direction of the reported mean difference, so interpretation depends on understanding the reference measurement and the scale. A change score can answer a focused question about immediate response while still leaving the distribution of individual responses hidden by a group mean.

It also illustrates a central issue in crossover trials. Measurements from the same subject across conditions are generally not interchangeable with measurements from separate subjects. The within-person relationship can affect estimated uncertainty. Because the registry reports summary means and standard deviations but does not report the crossover model details, simple recalculations may not reproduce the sponsor’s analysis. The difference between those results makes transparent reporting of methods especially important.

Confidence intervals and estimates add context that a p-value alone cannot provide. They show the range of values compatible with a method and help distinguish precision from importance. Here, the absence of a stated threshold for a meaningful scale change means that even a comparatively precise estimate cannot be translated into a clinical importance judgment from the registry record alone.

Finally, this record illustrates the limits of interpreting multiple endpoints and comparisons without a reported multiplicity plan. Secondary ratings can broaden the descriptive picture, but unadjusted findings across many comparisons warrant caution. Reporting who was analyzed, why observations are missing, how repeated measures were handled, and how comparisons were prespecified would help readers evaluate the results more fully.

19. 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 analysis population is restricted to randomized subjects who began tape stripping and perceived sting after alcohol application. This criterion limits direct interpretation to that analysis group. The registry record does not report how many subjects were excluded for each reason, or whether the population definition was prespecified.

The primary outcome counts are 33 or 34 per condition, compared with 60 enrolled. Counts also differ for one condition. The record does not explain the missing observations, describe whether subjects completed every crossover condition, or report sensitivity analyses for missing data. These omissions prevent assessment of whether incomplete observations could affect the estimates.

The study uses a crossover design, but the application sequence, washout, period effects, carryover considerations, and detailed statistical handling of repeated observations are not reported. These design details can matter when comparing conditions experienced by the same subject. The simple recalculations use posted summary statistics and are not a substitute for a crossover-specific analysis of subject-level data.

The registry reports sponsor ANCOVA results for four comparisons, but does not report the model’s covariates or explain why the results differ from the simple recalculations. No sponsor comparison with isopropyl alcohol is listed. The registry also does not report a multiplicity adjustment, a statistical analysis plan, or the original sample-size justification.

The rating scale is subjective and bounded, and the record does not report a threshold for a meaningful change. The secondary clinician scale is not described in detail, and sponsor analyses for those outcomes are not reported. Generalizability is also limited by the specific tape-stripping injury procedure and the immediate assessment timeframe; participant characteristics and further setting details are not reported in the registry record.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Trial to Test if Antibiotic Ointments & Cream Will Sting After Application on a Minor Wound After Tape Stripping Injury — NCT02320695.
• Registry record last updated 2016-01-05; status last verified 2015-12.
• Results first posted 2015-11-18.
• 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.

23. Record Summary

NCT02320695 is a completed randomized, single-masked crossover study of stinging after products were applied to tape-stripping injuries on the inner arms. It enrolled 60 subjects. The primary outcome was the mean change in subject-rated stinging from after tape stripping to immediately after application, using a scale from 0 for no stinging to 3 for severe stinging.

The registry reports outcome means and standard deviations, sponsor ANCOVA comparisons of saline with four products, two secondary clinician-rated wound-condition outcomes, and an overall adverse-event summary. The sponsor estimates differ from simple unadjusted recalculations based on the posted summary statistics; the sponsor’s own analysis takes precedence. The registry record does not explain the discrepancy or report several details needed to assess the crossover analysis, missing data, multiplicity, or original sample-size design.