Subject Reported Target-lesion Numeric Rating Scale Evaluation by Subjects With Plaque Psoriasis Treated With Clobex® (Clobetasol Propionate) Spray 0.05%: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Subject Reported Target-lesion Numeric Rating Scale Evaluation by Subjects With Plaque Psoriasis Treated With Clobex® (Clobetasol Propionate) Spray 0.05% (NCT01893567), a na phase 4 study. The primary outcome is Subject Reported Target Lesion Severity Score..

2. Clinical Question

3. Trial Design

This is a completed Phase 4 study with a single-group model. The registry lists Clobex spray as the intervention and plaque psoriasis as the condition. Enrollment is recorded as 28. The study start is listed as 2013-07 and primary completion as 2013-10. These are registry dates; they do not by themselves describe how long each participant was followed.

The stated aim was to investigate the utility of a technology-based rating scale for assessing improvement in plaque psoriasis with Clobex spray treatment. The primary outcome is a subject-reported target-lesion severity score at the end of the study, with a 2 weeks timeframe. An investigator-reported target lesion severity score is listed as a secondary outcome. The record names 2 outcome measures, but does not supply the secondary endpoint's numerical result or details of its measurement schedule.

Allocation is recorded as not applicable, masking as none, and the design as single-group. No control group or randomized allocation is described. This structure can describe scores recorded among participants receiving the intervention, but it cannot separate changes associated with treatment from changes that might occur over time for other reasons. A within-group endpoint score is not a controlled estimate of comparative effectiveness.

The registry marks the study completed, but the record does not report a primary endpoint analysis. The population field for the primary outcome is blank, and no analysis population is specified. The enrollment figure should therefore not be assumed to be the number contributing endpoint data. Details such as eligibility criteria, site structure, treatment adherence, and participant disposition are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

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 Subject Reported Target Lesion Severity Score., measured over 2 weeks.

The primary endpoint is the subject-reported mean score on the target-lesion numeric rating scale at the end of the study. The scale is described as ranging from 0, for no psoriasis, to 10, for very severe psoriasis. It asks subjects to rate the severity of a target lesion, making the endpoint a patient-reported measure rather than an investigator-assigned score. The registry gives a timeframe of 2 weeks.

A subject-reported score can capture the participant's own assessment of the lesion. That may be useful when the study is specifically asking whether a technology-based rating scale can be used to assess psoriasis severity. The record also lists an investigator-reported target lesion severity score as a secondary outcome, so the stated outcome set includes both subject and investigator assessments. The record does not explain how the technology was implemented or how the subject and investigator measures were intended to be compared.

The planned summary is a mean, with standard deviation identified as the dispersion measure. In general, a mean describes the average score in the measured group, while a standard deviation describes the spread of individual scores around that average. Neither endpoint value is reported in the registry record. The description identifies an end-of-study score, not a change-from-baseline endpoint; baseline scores and a baseline-to-endpoint change are not reported. Without the numerical result and its variability, the endpoint's observed level and precision cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry is limited. The primary endpoint is described as a mean on a continuous scale, with standard deviation as the dispersion measure. The registry lists 0 analyses and does not provide an endpoint estimate, standard deviation, confidence interval, or hypothesis-test result. General statistical concepts can clarify what those planned summaries would mean, but they cannot substitute for an unreported result.

What does a mean describe?

In general, the mean is the arithmetic average of observed scores in the analysis group. For this endpoint, it would summarize subject-reported target-lesion severity at the end of the study. The score's scale anchors give the average a clinical direction: lower scores indicate less reported severity on the scale, and higher scores indicate greater reported severity. The registry does not provide the actual average, so no observed severity level can be stated.

A mean can conceal variation among individuals. Two groups or samples could have the same average while having different distributions of scores. The standard deviation is a general measure of how dispersed individual scores are around the mean. A small standard deviation indicates that scores lie closer to the mean; a larger one indicates greater spread. The registry identifies standard deviation as the intended dispersion measure but does not report its value.

Why does the analysis population matter?

An endpoint summary depends on which observations are included. Enrollment is listed as 28, but the registry does not state the number with an endpoint score or define the primary analysis population. If some participants lack an end-of-study score, the mean among participants with observed scores may differ from the mean that would have been obtained had all enrolled participants been measured. How missing scores were handled is not reported. The enrollment figure alone cannot resolve this issue.

What would a confidence interval add?

In general, a confidence interval presents a range of values compatible with the data and the statistical procedure used. It helps readers assess the precision of an estimate: a narrower interval indicates greater precision under the method's assumptions, while a wider interval indicates more uncertainty. A confidence interval for a mean would require information about the estimate, variability, and analysis sample. No interval is reported, so the precision of the primary endpoint cannot be evaluated from the registry record.

How should the single-group design be understood?

Because this is a single-group study with allocation recorded as not applicable and masking recorded as none, the primary score is not a between-group treatment contrast. A single-group mean can describe the participants who were measured, but it does not provide a randomized comparison. If change from baseline were calculated, that change would still be a within-group observation rather than a controlled estimate of what would have happened without treatment. The registry does not report a baseline score or a change analysis.

General statistical interpretation also depends on the measurement and study conduct. A rating scale's usefulness may involve more than calculating a mean: consistency, completeness, and the meaning of score changes can matter. The registry does not report validation results, reliability analyses, or criteria for interpreting a meaningful change. No conclusion about these properties can be drawn from the stated endpoint definition alone.

What do the planning illustrations represent?

The planning assumptions describe illustrations based on fractions of an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. These are planning calculations, not observed power, and they do not turn the study into a two-arm comparison. The actual study is recorded as single-group. The registry record does not report an effect estimate on which to base an independent interpretation of those illustrations. Planning sample sizes describe hypothetical future designs under their assumptions; they are not evidence about the precision or success of this completed study.

For a continuous outcome, general planning methods use an assumed effect and variability to estimate the number of participants needed for a chosen design and target power. Such calculations are sensitive to those assumptions. They do not show that a study with a particular enrollment has achieved a given power after data collection. The record does not report a prospective sample-size justification or the assumptions used by the study team. The planning approach described in the registry should therefore be kept separate from the trial's observed design and from its unreported endpoint analysis.

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("Clobex Spray")
n   <- c(28)
m   <- c(4)
sp  <- c(2.5)
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  Clobex Spray  28  4.000  2.500  3.031  4.969

11. Multiplicity, Missing Data and Analysis Populations

The registry names a primary subject-reported target lesion severity score and an investigator-reported target lesion severity score as a secondary outcome. It also lists 2 outcome measures. However, it does not report the results for either measure or describe a statistical analysis plan. The number of outcomes alone does not show whether multiple hypotheses were tested, which outcomes were analyzed together, or whether any adjustment for multiple testing was planned.

In general, testing several outcomes can increase the chance of obtaining an apparently notable result by chance if each is assessed separately. Statistical plans may address this issue by defining a primary endpoint, specifying an order of testing, or adjusting inference. None of those details is reported in the registry record. Since no analyses are listed, there are no reported p-values to interpret in light of multiplicity.

Missing-data methods are also not reported. The record does not give the number of participants with an end-of-study score, explain how missing scores were handled, or describe sensitivity analyses. These details matter because the analyzed mean may depend on which participants had usable observations and on the assumptions used for missing values.

The primary outcome population field is blank, and no analysis population is defined. The record does not state whether the analysis included all enrolled participants or a subset. Enrollment of 28 should not be treated as the endpoint denominator without an analysis count. The registry also does not describe exclusions or participant flow. Consequently, the completeness and representativeness of the endpoint data cannot be assessed.

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.

Most frequent non-serious adverse event terms

The safety record lists 0 participants affected by serious adverse events among 28 at risk, and 0 deaths. It lists 4 participants affected by other adverse events among 28 at risk. These are counts as recorded in the registry; the record does not provide event descriptions for the other adverse events or identify their severity, timing, or relationship to treatment. No serious adverse event terms are listed.

These figures should be read as safety counts for the reported groups, not as a complete account of all possible harms. The record does not describe how adverse events were collected, the observation period for safety, or whether any participants discontinued because of an event. It also does not provide additional clinical detail that would help interpret the reported events. A zero count in this record means no affected participants are listed for that category; it does not establish that an event is impossible or that risk is absent.

The safety counts do not provide a comparison with an untreated or alternative-treatment group, because the study is single-group. They therefore cannot establish whether the reported events occurred more or less often than they would have under another condition. The registry information supports only a limited description of the reported counts.

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

This study is relevant to a focused measurement question: it was intended to investigate use of a technology-based, subject-reported rating scale for a target psoriasis lesion during Clobex spray treatment. The registry identifies the scale anchors, the planned mean summary, the end-of-study timing, and an investigator-reported severity score as a secondary outcome. Those details clarify what the study set out to measure.

The record does not report the primary mean or its standard deviation, nor does it provide a baseline value, change estimate, confidence interval, or analysis. As a result, it does not show the observed score at the end of the study, the amount of any change, or the precision of an estimate. The stated goal of assessing improvement cannot be treated as evidence that improvement was observed.

The single-group design also limits causal interpretation. There is no comparator group in the record, and no randomized or masked comparison is described. A score measured after treatment, even if reported, would not alone distinguish treatment-related change from other explanations such as natural fluctuation, changes in reporting, or other events over time. These are general considerations for uncontrolled studies; the registry does not establish that any particular alternative explanation occurred.

The record likewise does not establish the reliability, validity, or clinical interpretability of the rating scale. Those questions would require reported measurement analyses or other supporting evidence, which is not included. The presence of a subject-reported endpoint and a secondary investigator-reported endpoint does not itself show that the measures agree or that either is sensitive to change.

Accordingly, the record defines a study question and reports limited design and safety information, but it does not supply the outcome evidence needed to answer that question. It should not be read as a demonstration that Clobex spray does or does not improve psoriasis, or that the rating scale is or is not useful. Those conclusions are not supported by the posted results.

14. Why This Trial Matters Statistically

This trial matters statistically because it places a patient-reported measurement tool at the center of a clinical study question. A rating scale is not only a way to produce a number: its usefulness depends on whether the score can be collected consistently and whether it captures a meaningful aspect of the condition. The registry's focus on a target-lesion numeric rating scale makes measurement itself an important part of the study's stated purpose.

The record also distinguishes a subject-reported measure from an investigator-reported severity score. In general, these perspectives can provide different information, and comparing them can be informative when the measurement plan and analyses are reported. Here, the investigator score is listed as a secondary outcome, but no results or comparison analyses are reported. The study record therefore identifies a potentially relevant measurement question without resolving it.

The single-group design is important to the interpretation. It may describe scores within a treated group, but it does not provide a concurrent control for separating treatment effects from other changes over time. That distinction is especially important when the stated aim concerns improvement. A within-group score and a controlled treatment contrast answer different questions.

Finally, the absence of a reported endpoint analysis limits what readers can learn from the completed record. Without the mean, variability, analysis population, and handling of missing scores, neither the result nor its precision can be judged. This is a useful reminder that a clearly defined endpoint and a completed study status do not by themselves provide the numerical evidence needed for statistical interpretation.

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.

Several trial-specific limitations follow directly from the registry record. The study is single-group, has no listed comparator, and is unmasked. These features mean the record cannot provide a randomized, controlled estimate of treatment effect. Allocation is recorded as not applicable, so there is no basis for interpreting the study as a comparative allocation design.

The primary endpoint is an end-of-study score, but the registry does not report a baseline score or a change-from-baseline result. The endpoint's mean and standard deviation are also absent. This leaves the primary result and its precision unavailable. Although enrollment is listed as 28, the record does not state how many participants contributed endpoint data, define the analysis population, or describe missing data.

The stated aim refers to a technology-based rating scale, but the record does not explain the technology, the scale's administration, or any evaluation of measurement performance. It does not report validity, reliability, responsiveness, or criteria for interpreting a change. The secondary investigator-reported outcome is named, but its results and relationship to the subject-reported score are not reported.

The registry provides limited information about participant characteristics, eligibility, treatment administration, adherence, and disposition. These omissions make it difficult to assess the enrolled population or understand how the study was conducted. No protocol-based sample-size justification, interim-analysis information, or detailed statistical plan is reported in the registry record. The safety record gives counts, but not event descriptions or collection details. Together, these gaps constrain both the clinical interpretation and the statistical appraisal of this trial.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Subject Reported Target-lesion Numeric Rating Scale Evaluation by Subjects With Plaque Psoriasis Treated With Clobex® (Clobetasol Propionate) Spray 0.05% — NCT01893567.
• Registry record last updated 2022-09-27; status last verified 2018-08.
• Results first posted 2014-07-11.
• 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

The registry describes a completed Phase 4, single-group study of Clobex spray in plaque psoriasis. Enrollment is listed as 28, with study start in 2013-07 and primary completion in 2013-10. The stated aim was to investigate a technology-based rating scale for assessing improvement during treatment.

The primary endpoint is the subject-reported mean target-lesion severity score at 2 weeks on a 0 to 10 scale. An investigator-reported target lesion severity score is listed as a secondary outcome. The registry record does not report endpoint values, variability, an analysis population, or an analysis. It lists 0 serious adverse events and 0 deaths, and reports 4 participants affected by other adverse events. With no comparator and no reported primary result, the record defines the question and design but does not provide an estimate of treatment effect or scale performance.