An Efficiency of a Moisturizer Containing Licochalcone A, L-carnitine and 1,2-decanediol With Adapalene Gel in Acne: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Efficiency of a Moisturizer Containing Licochalcone A, L-carnitine and 1,2-decanediol With Adapalene Gel in Acne (NCT02173054), a randomized phase 3 study. The primary outcome is Reduction of Undesirable Effects.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group, phase 3 trial with triple masking. It lists a planned enrollment of 120 and the status as completed. The listed start was 2014-07, and the primary completion was 2015-02. The sponsor was Mahidol University.

Three regimens are listed: adapalene gel alone, adapalene gel with placebo moisturizer, and adapalene gel with Eucerin. The regimen descriptions specify adapalene application in the evening in all groups. The moisturizer and placebo-moisturizer groups also applied their assigned cream in the morning and after adapalene in the evening. The registry title describes the study as evaluator-blind and vehicle-controlled. It does not specify which people or roles were masked under the triple-masking designation, so the masking arrangements beyond those descriptions are not reported in the registry record.

The comparisons address different questions. Adapalene with Eucerin versus adapalene alone contrasts moisturizer use with no listed moisturizer, while adapalene with Eucerin versus adapalene with placebo moisturizer compares the active moisturizer against the placebo-moisturizer regimen. Adapalene with placebo moisturizer versus adapalene alone also contrasts moisturizer application with no listed moisturizer. The record does not report a prespecified hierarchy for these comparisons or identify which pairwise contrast was intended to carry the main inference.

The study included 40 participants at risk in each group in the adverse-event record. The primary outcome description identifies assessments at the 2nd week, 4th week, and 8th week. The record does not report the randomization method, allocation concealment, the planned sample-size justification, or the statistical analysis plan. Those details should not be inferred from the design labels or enrollment count.

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:

Analysis population for the primary outcome, as defined in the registry: The reasons for drop out were lack of compliance (n=1, group A: adapalene gel alone) and consent withdrawal at patient's request (n=1, group C: adapalene with Eucerin)

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 Reduction of Undesirable Effects, measured over 2nd week, 4th week, and 8th week.

The primary outcome is titled reduction of undesirable effects and is expressed as a number of participants. It concerns local tolerance during use of adapalene gel, rather than acne severity. Skin signs—erythema, dryness and scaling—were assessed by a dermatologist. Participants were interviewed about stinging or burning and pruritis. Each was rated using the categories none, mild, moderate, and severe.

Assessments were scheduled for the 2nd week, 4th week, and 8th week. The registry description says that the worst score for each parameter was defined as the worst local tolerance score and compared among the three groups. It does not explain how a participant-level reduction was defined, whether change from baseline was required, or how the different signs and symptoms were combined, if at all. The exact scoring and derivation rules are therefore not reported in the registry record.

Local-tolerance outcomes are relevant to a trial that investigates moisturizer use alongside a topical treatment that may be associated with irritation. They capture observable skin signs and participant-reported sensations, which are distinct types of information. A count of participants can be easy to interpret, but the meaning depends on the event definition and the threshold used to classify a participant as having a reduction. Those details, along with group counts and comparisons, are not reported in the registry record. The outcome title alone cannot establish how many participants improved or whether the groups differed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the outcome scale describe?

The registry describes ratings with four ordered categories: none, mild, moderate, and severe. These categories have an order, but the distance between adjacent categories is not necessarily equal. For example, treating the move from none to mild as numerically equivalent to the move from moderate to severe would require an assumption that the record does not state. The description does not report whether the categories were analyzed as ordered scores, converted into a binary classification, or summarized through another method.

The primary outcome is framed as a number of participants, while the underlying tolerance assessments include skin signs and reported sensations. A participant count requires a rule for deciding who qualifies as having a reduction. That rule could depend on a change from an earlier score, a threshold at a visit, or another definition; the exact rule is not reported in the registry record. Without it, the endpoint cannot be reconstructed from its title alone.

Why distinguish counts from ratings?

A count of participants with an event or outcome can be interpreted as the number meeting a defined criterion. The criterion is essential: different thresholds can produce different counts from the same underlying ratings. Here, the description says the worst score of each parameter was used, but does not fully specify how that information became the participant count. No primary-outcome counts are reported, so neither the count nor the comparison can be interpreted quantitatively.

Ratings from a dermatologist and symptoms from participants also represent different perspectives. A visible sign and a reported sensation need not occur together. Combining them can provide a broader view of local tolerance, but the combining rule should be stated to make the result reproducible. No such rule beyond the stated worst-score description is reported in the registry record.

What would a group comparison need to show?

A statistical comparison would ordinarily identify the groups being contrasted, the outcome definition, and an effect estimate, together with an indication of uncertainty. A confidence interval is a range that expresses the precision of an estimate under the assumptions of the analysis; wider intervals generally indicate less precision. A p-value, when reported, addresses compatibility of the data with a specified null model and is not a measure of effect size or clinical importance. These are general statistical principles. The registry record does not report an estimate, confidence interval, or p-value for the primary outcome.

There are three possible pairwise contrasts among the listed regimens. Their interpretations differ because the regimens differ in whether a moisturizer is used and whether it is Eucerin or placebo moisturizer. If multiple contrasts or multiple outcome features are tested, the chance of at least one nominally unusual result can increase. A prespecified analysis plan can define which comparisons are primary and how multiplicity is handled. The plan and any multiplicity adjustment are not reported in the registry record.

How should the assessment schedule be understood?

Assessments at the 2nd week, 4th week, and 8th week create repeated observations over time. Repeated measurements from the same participant are related, so an analysis that uses all visits may need to account for within-participant dependence. Alternatively, an analysis might define a single summary such as a worst score, but the exact role of the visits in the primary comparison is not fully explained. The record does not report a model or a rule for missing visit data.

Using a worst score can focus attention on the most severe recorded experience, but it may differ from an analysis of average experience or change over time. The exact interval over which the worst value was selected is not stated. The definition, visit handling, and analysis method are therefore necessary to understand what a resulting participant count would represent.

What can planning calculations tell readers?

Sample-size calculations are planning tools that describe the number of participants that might be needed under stated assumptions. They are not observed results and should not be interpreted as observed power. General illustrations may use a target significance level, allocation assumptions, and a chosen effect to detect. The registry record does not report the trial's own sample-size justification, so the enrollment count alone cannot establish whether the study was planned to detect a particular difference.

When a planning illustration is based on an observed effect, it describes the sample size associated with that effect under its stated assumptions. It does not validate the effect or show that the original trial had that level of power. A recalculation from summary statistics, if available, is also distinct from the sponsor's analysis and may not reproduce an adjusted or prespecified analysis. No primary outcome summary statistics or sponsor analysis are reported in the registry record, so such a comparison cannot be interpreted for this trial.

For count outcomes, the statistical model should reflect how the outcome is defined and how participants are allocated. For repeated outcomes, the analysis should account for repeated observations when it uses them. These are general considerations, not claims about the method used in this trial. The statistical plan, model, handling of uncertainty, and adjustment strategy are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists five outcome measures and 26 analyses. The primary outcome spans several categories or time points, and no single comparison is reduced to one reported result in the posted record. This makes it especially important to know which outcome definition, visit, and group contrast were designated as primary for inference. That hierarchy is not reported in the registry record.

Multiplicity is the general issue that arises when several hypotheses or comparisons are examined. If many comparisons are considered, interpreting each result as if it were the only test can overstate the evidence from an isolated finding. Common approaches include identifying a primary comparison in advance or adjusting inference across a defined family of tests. The registry record does not report whether such a strategy was prespecified or used. No p-values or effect estimates are available to assess how multiplicity might affect interpretation.

The primary outcome description identifies repeated assessments at the 2nd week, 4th week, and 8th week. It does not report the analysis population, whether all randomized participants were included in the primary analysis, or how missing observations were handled. The record notes lack of compliance for one participant in group A, adapalene gel alone, and consent withdrawal at the patient's request for one participant in group C, adapalene with Eucerin. It does not provide a complete accounting of attendance or missing outcome measurements by visit.

There is no reported imputation method, sensitivity analysis for missing data, or definition of an intention-to-treat or per-protocol population. These details matter because results can depend on who is included and what assumptions are made about unavailable measurements. No conclusion about the robustness of the primary comparison to missing data can be drawn from the registry record.

11. Safety Results

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

Other (non-serious) adverse events

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

The adverse-event record lists 40 participants at risk in each of the three groups. It records zero serious adverse events and zero other adverse events for adapalene gel alone, adapalene gel with placebo moisturizer, and adapalene gel with Eucerin. These are the event figures in the registry record; they do not provide a detailed event listing or explain how adverse events were collected.

The death field is not reported in the registry record. A missing value should not be interpreted as a reported zero. The entry of zero events also does not establish that no participant experienced the local signs or symptoms assessed for the primary endpoint. Those assessments covered erythema, dryness, scaling, stinging or burning, and pruritis, whereas the adverse-event fields are a separate record.

These figures describe the recorded counts, not a definitive comparison of safety between regimens. The record does not report uncertainty estimates or a statistical comparison for these event counts. It also does not give enough detail to assess event ascertainment, event duration, or the severity of non-serious events. The appropriate reading is limited to what is entered: no serious or other adverse events are recorded in the listed groups, and deaths are not reported in the registry record.

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

The trial asks whether local tolerance during adapalene use differs when Eucerin moisturizer is added, with adapalene alone and adapalene plus placebo moisturizer as comparison regimens. Its design and outcome description make that question identifiable. However, the registry record does not report the primary outcome counts, group comparison, or uncertainty. The posted information therefore cannot establish whether one regimen had more or fewer participants with reduced undesirable effects, or how precise any difference might be.

The title of the outcome should not be mistaken for a result. “Reduction of undesirable effects” names the intended endpoint, but does not say how many participants met its definition. The assessment categories and visit schedule describe data collection, not the observed pattern. Similarly, the listed secondary outcomes on acne severity do not establish improvement or worsening in acne severity because their results are not reported in the registry record.

The adverse-event entries contain zero serious and zero other adverse events in all three groups. This is a narrow report of recorded adverse-event counts and is not a substitute for the local-tolerance outcome. The record does not report deaths, nor does it provide a full account of adverse-event ascertainment or the distribution of the tolerance ratings.

Several elements needed for a statistical interpretation are absent: the exact participant-level definition of reduction, the primary analysis population, the missing-data approach, the prespecified comparison, and the inferential results. Without those details and results, it is not possible to judge effect magnitude, precision, or the influence of alternative analytic choices. The record supports a description of what the investigators intended to evaluate, but not a claim about the direction or strength of the findings.

These limits do not mean the trial found no difference. They mean that the posted registry information does not report enough outcome data to determine what was observed. Distinguishing an unreported result from a null result is essential: absence of a result in the registry record is not evidence that the groups were equivalent.

13. Why This Trial Matters Statistically

This trial is statistically instructive because a clear clinical question does not by itself provide an interpretable result. The listed groups allow readers to distinguish moisturizer use from no listed moisturizer and the active moisturizer from a placebo moisturizer. Yet a valid comparison also needs a clear endpoint definition, participant counts, an analysis plan, and estimates of uncertainty. Those result details are not reported in the registry record.

The primary outcome combines a participant-level count with underlying ratings from more than one source. Dermatologist-assessed signs and participant-reported symptoms may represent different aspects of tolerance. A worst-score approach can emphasize the most severe recorded rating, but the rule for turning these ratings into a reduction count needs to be explicit. This illustrates why operational definitions matter as much as outcome labels.

Repeated assessments at the 2nd week, 4th week, and 8th week also raise a general design and analysis issue: a result can depend on whether the analysis compares visits separately, models the repeated observations, or uses a summary such as a worst score. The record names the schedule and mentions the worst local tolerance score, but does not report enough detail to identify the full analytic approach.

Finally, the record lists multiple outcomes and analyses without reporting a multiplicity strategy or the main inferential results. When many outcomes or comparisons are considered, a prespecified plan helps readers understand which evidence was intended to answer the primary question. The trial therefore illustrates the distinction between a registered design and a statistically assessable result: readers need outcome data and analysis details to evaluate magnitude, precision, and robustness, not only the study's purpose and group structure.

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 of the registry record for interpretation is that it does not report the primary outcome results. It gives no counts for reduction of undesirable effects by group and no effect estimate, confidence interval, or test result. The outcome description also does not fully define how the ordinal ratings and repeated assessments were converted into a participant-level reduction.

The record does not report baseline local-tolerance scores, so change from baseline cannot be assessed. It does not give the distribution of ratings for individual signs or symptoms, or separate results at the 2nd week, 4th week, and 8th week. The timing and rule for selecting the worst score are not fully specified. This limits understanding of the endpoint even apart from the missing group results.

Information about missing measurements is limited. The record notes lack of compliance for one participant in the adapalene-gel-alone group and consent withdrawal at the patient's request for one participant in the adapalene-with-Eucerin group. It does not report visit-level completion, the primary analysis population, or the handling of missing data. The randomization method, allocation concealment, full masking roles, sample-size justification, and statistical analysis plan are also not reported in the registry record.

The adverse-event entries list no serious or other adverse events in the groups, but do not include detailed event descriptions or a reported death count. They cannot be used to reconstruct the primary tolerance ratings. The record also lists secondary acne-severity outcomes without results. These gaps mean that neither efficacy-related outcomes nor the precision and robustness of the primary comparison can be evaluated from the registry information alone.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: An Efficiency of a Moisturizer Containing Licochalcone A, L-carnitine and 1,2-decanediol With Adapalene Gel in Acne — NCT02173054.
• Registry record last updated 2017-01-23; status last verified 2016-11.
• Results first posted 2016-02-26.
• 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

NCT02173054 is a completed, randomized, parallel-group, triple-masked phase 3 trial sponsored by Mahidol University. It enrolled 120 participants with acne and compared adapalene gel alone, adapalene gel with placebo moisturizer, and adapalene gel with Eucerin. The listed study start was 2014-07, and primary completion was 2015-02.

The primary outcome was reduction of undesirable effects, assessed through local-tolerance signs and symptoms at the 2nd week, 4th week, and 8th week. Secondary outcomes concerned acne severity and the Acne Severity Index. The registry record does not report outcome values or statistical comparisons. It records zero serious and zero other adverse events in each group, with 40 participants at risk per group; deaths are not reported in the registry record.