Study to Evaluate Product Duration of Use Experience With Alclometasone Dipropionate Cream: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate Product Duration of Use Experience With Alclometasone Dipropionate Cream (NCT02075632), a na phase 2 study. The primary outcome is Number of Participants With Incorrect Duration of Use of the Medication.

2. Clinical Question

3. Trial Design

NCT02075632 is a completed Phase 2 study sponsored by GlaxoSmithKline. The registry lists a start date of 2006-09 and primary completion in 2006-11. Its title describes an evaluation of product duration-of-use experience with alclometasone dipropionate cream. The official title describes a multicenter, open-label study; the design fields specify a single group, no masking, and allocation as not applicable.

Participants applied alclometasone dipropionate cream 0.05% to affected areas, following label instructions for 14 days. The study’s stated purpose was to evaluate whether participants followed short-term-use instructions in a population with itchy skin conditions. The population was divided into a chronic-condition cohort and an occasional-itch cohort. The registry enrollment is 310, but the record does not establish that this is the number evaluable for the primary outcome. Evaluable status required medication use at least once and use information at least 8 days after enrollment.

The listed primary outcome was the number of participants with incorrect duration of use, assessed during Day1-Day 14. The record defines incorrect use as use for more than 7 consecutive days and/or more than three times in a day. Two secondary outcomes are named: number of times per day participants used the product, and number of days of use.

This design can describe use behavior in the enrolled study population, subject to the reported outcome and analysis information. It does not include a randomized control group. The two cohorts are not described as randomized treatment arms, and the registry explicitly cautions that they are not a like-for-like control comparison. The record does not report a detailed statistical plan, sample-size justification, or analysis results.

4. Participant Flow and Accounting

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

Before assignment: Participants with itchy skin conditions, who would use OTC treatments for relief

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: A participant was evaluable for analysis of the rate of incorrect use if he or she used the study medication at least once and provided use information at least 8 days after the enrollment visit.

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 Number of Participants With Incorrect Duration of Use of the Medication, measured over Day1-Day 14.

The primary endpoint counts participants classified as having incorrect duration of use during Day1-Day 14. Its operational definition includes use for more than 7 consecutive days and/or use more than three times in a day. The “and/or” matters: a participant could meet the endpoint through either behavior or through both. Although the endpoint title emphasizes duration, its definition also includes a frequency-of-use criterion.

This kind of endpoint is used to describe whether use behavior aligns with the stated instructions. It is not a measure of symptom improvement, disease control, or comparative treatment efficacy. The registry also says participants were asked why they used the medication in this way and could select multiple reasons, if applicable. Those reasons may help characterize reported behavior, but the record does not report their results.

The outcome applies to an evaluable population: a participant had to use the study medication at least once and provide use information at least 8 days after enrollment. That requirement defines who could contribute to the primary analysis, but the registry does not report how many participants met it or how missing use information was handled. It also does not report the primary endpoint count, rate, uncertainty interval, or statistical test. Consequently, the endpoint’s definition is available, but its observed result cannot be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the question a study was designed to address. This study asked whether participants followed short-term-use instructions, and its primary endpoint classified use behavior using duration and daily frequency criteria. The endpoint is a participant count, not a continuous measurement. For a count endpoint of this kind, an analysis commonly reports the number meeting the definition and a denominator; a rate may also be accompanied by an uncertainty interval. These are general statistical conventions, not methods reported for this study. The registry record does not provide the primary result or its analysis.

What does an uncertainty interval tell a reader?

In general, a confidence interval describes the precision of an estimate under a specified statistical procedure. A narrow interval indicates greater precision than a wide interval, while either interval can still be affected by study design, measurement, and missingness. The registry record does not report a confidence interval for the primary outcome, so its precision cannot be evaluated.

Why does the design affect interpretation?

General statistical principle: randomized assignment supports a treatment comparison by creating groups whose assignment is not chosen according to participant characteristics, on average. This study is listed as single-group, with allocation not applicable and no masking. It therefore does not provide a randomized comparator for estimating a treatment effect. The chronic-condition and occasional-itch cohorts are population categories, not randomized arms. Differences between such cohorts can reflect differences in who is included or their circumstances as well as other factors, so they should not be interpreted as causal treatment contrasts.

Open-label means masking was none in the registry fields. In general, awareness of the product and study instructions can affect reported or recorded behavior. That is a potential consideration for self-reported use measures, not evidence that reporting was biased in this study. The registry does not describe the collection instrument, verification procedures, or any assessment of measurement reliability.

How should the endpoint rule be read?

The primary endpoint combines two criteria: use for more than 7 consecutive days and/or more than three times in a day. A combined rule can classify a participant as meeting the endpoint through either component. These components may reflect different behavior patterns, and the registry does not report separate results for them. The record says participants were asked for reasons for incorrect use and could choose multiple reasons, so reason categories would not necessarily be mutually exclusive.

The primary analysis population was defined by use of the medication at least once and provision of use information at least 8 days after enrollment. In general, an evaluable-population definition can differ from an all-enrolled population. Interpretation requires knowing how many participants qualified, how many did not, and why information was unavailable. Those counts and explanations are not reported in the registry record. The enrollment value alone cannot establish the analysis denominator.

What do the listed planning assumptions mean?

The registry includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. These are described as planning illustrations computed from the observed effect, not as the trial’s own design. The record does not report the illustration values or the observed primary effect needed to interpret them. Such calculations are hypothetical sample-size planning, not observed power. The two-arm equal-allocation assumption also does not describe this single-group study. No sample-size justification for the trial is reported in the registry record.

General statistical principle: over-dispersion occurs when count variability exceeds what a simple model assumes. If present, it can make standard errors and uncertainty estimates from an overly restrictive model unreliable. There is no count-model result or evidence of over-dispersion reported for this study, and the primary endpoint is a participant classification rather than a reported repeated-event count. This general issue should not be mistaken for a method used in the registry analysis.

The registry names secondary measures of number of times per day and number of days of use, but gives no results or analytic details for them. It does not report the statistical test, model, covariate adjustment, handling of repeated measurements, interim analyses, or other elements of a statistical analysis plan. These methods cannot be inferred from the endpoint title or study design.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Chronic Condition", "Occasional Itch")
n      <- c(161, 143)
events <- c(97, 89)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Chronic Condition  161  97  60.2  52.2  67.9  52.5  67.5  52.5  67.5
ARM  Occasional Itch  143  89  62.2  53.8  70.2  54.1  69.8  54.1  69.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and two secondary outcomes: number of times per day participants used the product and number of days of use. It does not report results for these measures, statistical tests, or a plan for controlling multiplicity. In general, when several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase unless the analysis plan accounts for the set of tests. That general concern cannot be quantified for this study from the registry record. The record does not describe interim analyses or other planned comparisons.

The primary analysis population is defined by medication use at least once and use information at least 8 days after enrollment. The registry does not report the number meeting that definition, the amount or pattern of missing use information, or how missing observations were handled. It also does not report whether analyses used any other population definition, such as all enrolled participants. No imputation or sensitivity analysis is described.

The registry says participants could select multiple reasons for incorrect use. If those reason categories were reported, a participant could contribute to more than one category; the record does not give the reason results or explain their analysis. Overall, multiplicity handling, missing-data methods, and analysis populations beyond the stated evaluability rule are not reported in the registry record.

12. 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 1% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: malignant neoplasm (0.6%).

The registry reports safety counts separately for Chronic Condition and Occasional Itch. In Chronic Condition, 162 participants were listed as at risk for serious adverse events and 1 was affected; 162 were listed as at risk for other adverse events and 4 were affected. In Occasional Itch, 144 participants were listed as at risk for serious adverse events and 0 were affected; 144 were listed as at risk for other adverse events and 3 were affected. The top serious term is listed as Malignant Neoplasm, 0.6%.

These are descriptive counts. They should not be treated as a randomized comparison between cohorts or as an estimate of a treatment effect. The record does not give further details about event timing, duration, severity beyond the serious/other categories, or statistical uncertainty for these counts. The death counts are not reported in the registry record. A zero affected count in a cohort is a recorded count for that category, not proof that the underlying risk is absent.

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

The study addresses a practical measurement question: whether participants followed short-term-use instructions for alclometasone dipropionate cream. The registry specifies the use rule and the population definition for evaluating the primary endpoint. It also describes two participant cohorts and lists secondary measures related to frequency and days of use. Those elements clarify what the study intended to measure.

However, the registry record does not report the primary endpoint count or rate, its denominator, or its statistical uncertainty. It therefore does not show how often participants met the incorrect-use definition or how precisely that frequency was estimated. Without those results, the record cannot support a conclusion about the observed level of adherence to the instructions.

The design also limits what the study can answer. A single-group, open-label study without a randomized comparator can describe reported use in its study population, but it cannot establish a comparative treatment effect. The two cohorts are not like-for-like control groups. The primary endpoint is a use-behavior measure, not a clinical outcome; it does not report symptom response or disease improvement.

The safety counts provide descriptive information by cohort, but they do not fill the gap in the primary outcome reporting and should not be interpreted as a comparative safety estimate. The registry does not report the statistical plan, missing-data handling, or the number evaluable for the primary analysis. Accordingly, the most defensible interpretation is limited to the study purpose, design, endpoint definition, and recorded safety counts; the primary outcome result itself is not reported in the registry record.

14. Why This Trial Matters Statistically

Duration-of-use behavior is a distinct question from whether a product changes symptoms or disease outcomes. Measuring use against stated instructions can help characterize how participants use a product in a study setting. This trial’s endpoint makes that question explicit by defining incorrect use through consecutive days of use and daily frequency. The registry also describes asking participants why they used the medication in that way, with multiple reasons allowed.

Statistically, the definition needs to be read alongside the analysis population. Participants needed to use the medication at least once and provide use information at least 8 days after enrollment to be evaluable for the primary endpoint. The enrolled population and the evaluable population are not necessarily interchangeable; the record does not report the evaluable count. This distinction matters because a behavior estimate depends on who contributed information and how missing reports were handled.

The design is also important. The study is single-group, open-label, and not randomized. It can address descriptive use experience in its participants, but it does not create a randomized comparison. Chronic Condition and Occasional Itch identify different cohorts rather than control arms. Treating them as a comparison would overstate what the design supports.

The record’s limits are particularly consequential because it does not report the primary outcome result or its precision. The endpoint definition is available, but a reader cannot assess its observed frequency from the registry record. The study is therefore statistically informative about how a use-behavior question was framed, while the missing result prevents assessment of the primary finding.

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 primary limitation for interpreting the study is that the registry record does not report the primary endpoint result. It gives neither the number classified as having incorrect use nor the corresponding analysis denominator, uncertainty interval, or test result. The enrollment value of 310 should not be read as the primary analysis population because evaluability had additional requirements and the qualifying count is not reported.

The design is single-group, open-label, and has no randomized comparator. The cohorts differ by the type of itchy condition described and are explicitly not a like-for-like control comparison. Consequently, the record does not support causal comparisons between cohorts or estimates of comparative treatment effects. Masking was none, and the registry does not describe how use information was collected or verified.

The endpoint combines duration and frequency criteria. Separate results for those components are not reported. Participants could select multiple reasons for incorrect use, but no reason results or analysis details are listed. Although secondary measures are named, their results are not reported.

The registry does not report the statistical analysis plan, missing-data methods, number evaluable, interim analyses, or sample-size justification. The listed planning assumptions are illustrations, not the trial’s own design, and their numerical outputs are not reported. Safety information is limited to descriptive counts by cohort; death counts and further event details are not reported in the registry record. These limitations restrict interpretation to the design and definitions that are recorded, rather than conclusions about the primary outcome.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study to Evaluate Product Duration of Use Experience With Alclometasone Dipropionate Cream — NCT02075632.
• Registry record last updated 2014-09-05; status last verified 2014-08.
• Results first posted 2014-07-14.
• 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

NCT02075632 is a completed Phase 2, multicenter, open-label, single-group study sponsored by GlaxoSmithKline. The registry lists enrollment of 310, a start date of 2006-09, and primary completion in 2006-11. Participants applied alclometasone dipropionate cream 0.05% for 14 days according to label instructions.

The primary endpoint was the number of evaluable participants with incorrect duration of use during Day1-Day 14, defined as use for more than 7 consecutive days and/or more than three times in a day. The registry names two secondary use measures. It does not report the primary outcome result or analysis results. Safety counts are listed for the Chronic Condition and Occasional Itch cohorts, but they do not constitute a randomized comparison.