Finacea 15% and Brimonidine 0.33% Gel in the Treatment of Rosacea - A Pilot Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Finacea 15% and Brimonidine 0.33% Gel in the Treatment of Rosacea - A Pilot Study (NCT02147691), a randomized phase 4 study. The primary outcome is Investigator Global Assessment (IGA) at Baseline.

2. Clinical Question

These details distinguish the study’s clinical aim from the primary outcome actually posted. The study included other outcome topics, including lesion counts, clinician and subject erythema assessments, and dermatology-related quality of life. But the registry record does not provide a treatment-period estimate for those outcomes in the results represented by the primary endpoint. The central statistical question that can be addressed from the reported primary data is limited: what baseline Investigator Global Assessment values were recorded in each arm among the analyzed participants? Those values do not answer whether the arms changed differently during treatment.

3. Trial Design

This was a completed, randomized, single-masked, parallel-group phase 4 pilot study sponsored by Derm Research, PLLC. The registry record lists 22 enrolled participants and acne rosacea as the condition. The study began in 2014-05, reached primary completion in 2015-01, and is marked completed. These are registry milestones; they do not establish the length of treatment or follow-up for an individual participant.

The two arm descriptions distinguish combination treatment from brimonidine monotherapy. In the combination arm, the described regimen was azelaic acid 15% on the face each morning, brimonidine 0.33% 30 minutes later, and azelaic acid 15% each evening. The comparator arm is described as brimonidine 0.33% gel. The record does not give further details about treatment duration, adherence, randomization sequence generation, allocation concealment, or the identity of the masked group.

The primary endpoint is Investigator Global Assessment at baseline, measured in units on a scale described from 0 to 4: 0 is clear, 1 almost clear, 2 mild, 3 moderate, and 4 severe. The combination arm has a reported mean of 3.0 with standard deviation 0.0 among 6 participants. The brimonidine arm has a mean of 3.1 with standard deviation 0.3 among 11 participants. These are baseline summaries, not change scores or follow-up outcomes.

The record lists 20 outcome measures, including secondary outcomes concerning lesion counts, erythema, and Dermatology Life Quality Index. It lists 16 secondary outcomes as posted, while the analysis count is 0. The record does not report a treatment-period primary comparison in the available results. The small pilot enrollment and absence of posted comparative estimates mean the study record supports description of the design and baseline values, but not an estimate of treatment effect.

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: Subjects could be excluded if less than 18 years of age, who does not have moderate to severe rosacea as determined by the Investigator Global Assessment (IGA), who has not completed the specified washout for medications as outlined in the protocol or who has been in another investigational study within 30 days of the Baseline visit.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Only participants who were not lost to follow up or did not withdraw consent were included in the final analysis.

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.

Population: subjects between 18 years and 85 years of age with moderate to severe rosacea

6. Primary Endpoint

The registry lists the primary outcome as Investigator Global Assessment (IGA) at Baseline, measured over Baseline.

Investigator Global Assessment (IGA) is a clinician-rated summary of rosacea severity. In this record, it is described on a scale from 0 to 4, with 0 meaning clear, 1 almost clear, 2 mild, 3 moderate, and 4 severe. The endpoint is reported in units on a scale, with the mean and standard deviation used to describe the arm-level values.

General: A global assessment can condense a clinical impression into an ordered scale, making severity easier to summarize across participants. It is a different kind of outcome from a lesion count or a patient-reported assessment. The scale’s interpretation depends on the stated category definitions and on consistent assessment. The registry record does not give further details about assessor training, scoring procedures, or how the score was used in an analysis.

The primary outcome reported in the record is explicitly IGA at baseline. Its role is therefore descriptive of participants’ starting status, rather than evidence about improvement or worsening after treatment. The combination arm’s mean was 3.0, with standard deviation 0.0 among 6 participants; the brimonidine arm’s mean was 3.1, with standard deviation 0.3 among 11 participants. A baseline score cannot by itself show whether treatment changed IGA, whether changes differed between arms, or whether either regimen affected papules, pustules, or erythema.

For a treatment-effect question, a post-baseline endpoint or a comparison of change from baseline would be needed, with an analysis appropriate to the study design. Such a primary treatment-period estimate is not reported in the registry record. The baseline measure remains useful for describing the analyzed groups, but its statistical meaning should not be extended beyond that purpose.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized, single-masked, parallel-group study. Its primary outcome is continuous in the sense that it is summarized as a mean and standard deviation, although the underlying IGA scale is defined by ordered severity categories. The distinction between a design description and an analysis result matters: randomization describes assignment to groups, while an estimate of a treatment effect requires an outcome measured in a way that supports a between-group comparison. The available primary result is a baseline description.

What do the mean and standard deviation describe?

The mean is an average of the recorded scores in an analysis group. The standard deviation describes how dispersed the recorded scores are around that average. Together, they offer a compact description of the group, but they do not show every individual score or the shape of the distribution. A small standard deviation can occur when scores are alike; it does not itself demonstrate measurement quality or clinical importance.

Here, the reported mean and standard deviation belong to IGA at baseline. They do not describe the amount of change after treatment. They also do not show whether the combination and monotherapy groups had different trajectories. The reported means are 3.0 and 3.1, with standard deviations 0.0 and 0.3, respectively, for the combination and brimonidine arms. The associated participant counts are 6 and 11. The registry record does not give individual-level observations or a treatment-period estimate.

Why is a baseline comparison not a treatment-effect analysis?

A treatment-effect analysis compares outcomes after assignment, or compares changes from baseline, using a defined method. A baseline score is measured before treatment effects could be reflected in the endpoint. Baseline values can describe the groups and may help assess their starting profile, but they do not show what happened during treatment. Even when a trial is randomized, a baseline contrast is not an estimate of the effect of receiving one intervention rather than another.

General: In a randomized trial, assignment is intended to create groups that can be compared without systematic allocation according to participant characteristics. Randomization does not remove uncertainty, ensure identical groups in a small study, or compensate for missing outcome data. The registry says the study was randomized but does not report sequence generation or allocation concealment, so those procedural details cannot be assessed from this record.

What does an uncertainty interval contribute?

General: A confidence interval pairs an estimate with a range reflecting sampling uncertainty under the model and assumptions used. Wider intervals usually indicate less precision, while narrower intervals indicate greater precision. An interval for a between-arm effect would concern a specified contrast, such as a difference in a follow-up outcome or change. No such interval is reported for the primary result. The standard deviations are not confidence intervals and should not be read as showing the uncertainty in the difference between arms.

General: A hypothesis test can assess whether observed data are compatible with a specified null hypothesis, conditional on the analysis assumptions. A p-value does not measure the size or clinical relevance of a difference, and it is not the probability that the null hypothesis is true. There is no posted p-value for the primary two-arm comparison. The registry’s result status says values are missing or not estimable for a two-arm comparison of this continuous endpoint, so a treatment-comparison test cannot be reconstructed from the posted primary summary.

What does the design information establish?

The parallel-group model means the record describes separate groups assigned to different regimens, rather than a crossover in which each participant receives both. The single-masked label indicates masking was used at one level, but the record does not identify who was masked. The listed interventions are azelaic acid 15% and brimonidine 0.33%. The combination arm’s schedule is described in the registry, while the brimonidine arm is described as brimonidine 0.33% gel. These design labels do not provide an analysis plan.

General: Over-dispersion is a concern when observed variability is greater than a statistical model expects. It can make standard errors too small if the model fails to account for the extra variability. It is especially relevant to some count or clustered outcomes, where a simple model may underestimate spread. The record lists lesion-count outcomes but does not report the distributions, model, or dispersion assessment. No claim about over-dispersion can therefore be made for these outcomes.

How should planning illustrations be distinguished from observed findings?

General: A sample-size calculation is a planning exercise that asks how many participants might be needed under stated assumptions about an effect, variability, significance level, allocation, and model. It is not an outcome of the trial and does not show that a study had a particular probability of detecting its observed result. The planning description associated with the record specifies a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects set as stated fractions of an observed effect. It also says that non-time-to-event planning values are participants per arm.

That planning description is not evidence of the original design justification. The registry record does not report the trial’s own sample-size justification or the assumptions originally used by investigators. No observed treatment-effect estimate is available for the primary comparison in the posted results, and no resulting planning target is stated in the information for this result. Planning illustrations, when available, must not be mistaken for observed sample sizes, outcomes, or observed power.

Finally, a continuous endpoint’s mean and standard deviation alone are not enough to recover every relevant analysis detail. A treatment comparison may depend on the timing of measurements, missingness, prespecified covariates, distributional assumptions, and the chosen model. Those details are not reported for a primary treatment-period analysis. Statistical interpretation should therefore stay with the descriptive baseline values and the limits explicitly recorded.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 20 outcome measures and 16 secondary outcomes as posted. The secondary outcome topics include lesion counts, clinician’s erythema assessment, subject erythema visual analog scale assessment, Dermatology Life Quality Index, and erythema. Some labels appear more than once in the listed outcome topics. The record reports no analysis records, and the available results do not give comparative estimates for these secondary measures.

When a study evaluates many outcomes or makes multiple comparisons, the chance of obtaining at least one apparently notable result can increase. General: Multiplicity methods can address this issue by adjusting the interpretation or testing procedure across a defined family of comparisons. The registry record does not report a multiplicity strategy, a hierarchy of outcomes, or a prespecified family of comparisons. It is therefore not possible to determine how any multiplicity would have been handled.

The primary endpoint description says that only participants who were not lost to follow-up or did not withdraw consent were included in the final analysis. The arm-level primary outcome counts are 6 and 11, while enrollment is reported as 22. The record does not report the number or reasons for missing observations, the number lost to follow-up, the number who withdrew consent, or how missing data were handled beyond the stated exclusion.

The analysis population is not described as an intention-to-treat population, and the registry record does not report whether participants were analyzed according to randomized assignment regardless of treatment received. It also does not report imputation, sensitivity analyses, or a comparison of included and excluded participants. These omissions limit assessment of potential bias due to missing data and make it unclear how well the analyzed groups represent all enrolled participants.

Because the primary outcome is a baseline measure, missingness and exclusion still matter for the description of the analyzed groups. They are especially important for interpreting whether those groups represent the randomized population. The available information does not establish the direction or magnitude of any missing-data effect.

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 5% reporting threshold.

Most frequent non-serious adverse event terms

The safety summary reports serious adverse events affecting 0 participants in the combination arm, among 10 at risk, and 0 participants in the brimonidine 0.33% arm, among 12 at risk. These are counts for the safety groups, not the primary outcome analysis groups. The registry record does not report death counts; those entries are not populated. No serious adverse-event terms are listed.

The summary also reports adverse events other than serious adverse events affecting 3 participants among 10 at risk in the combination arm and 4 among 12 at risk in the brimonidine arm. These counts should be read separately from the serious-event counts. The record does not provide event descriptions, severity details, timing, or a breakdown of participants with multiple events in the information available for this result.

General: A count of zero reported serious events means none were recorded in the listed safety group during the reported study period; it does not prove that an event is impossible or that risks are identical between groups. Safety findings are more informative when their definitions, observation period, event details, and group denominators are clear. The registry record does not report enough detail to make a precise comparative safety assessment.

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

The primary result documents baseline Investigator Global Assessment values in the analyzed groups. The combination arm had a mean of 3.0 and standard deviation of 0.0 among 6 participants. The brimonidine 0.33% arm had a mean of 3.1 and standard deviation of 0.3 among 11 participants. These summaries describe starting severity as measured by the stated IGA scale; they are not evidence of change after treatment.

The study summary describes an aim of investigating whether azelaic acid 15% combined with brimonidine 0.33% could be more effective than brimonidine alone for papules or pustules and erythema. The posted primary outcome does not directly answer that treatment question because it is recorded at baseline. The registry record does not report a primary treatment-period comparison, a change-from-baseline estimate, or a confidence interval for an effect.

Therefore, the available numbers cannot establish that the combination was better, worse, or equivalent to brimonidine alone. They also cannot establish that the treatments produced no difference. A missing or non-estimable comparison is not evidence of equivalence; it means the registry record does not provide the estimate needed to assess the contrast. Likewise, the absence of posted analysis records for secondary outcomes means their outcome labels should not be interpreted as evidence of benefit or harm.

General: Statistical uncertainty and clinical importance are separate considerations. An estimate can be uncertain even when its point value appears notable, and a precise estimate can still be too small to matter clinically. Interpreting either requires an appropriate treatment contrast, its uncertainty, and context for what magnitude matters. Those elements are not reported for the primary treatment effect in this record.

The study remains informative about its registered design, intervention descriptions, outcome topics, and the baseline values posted for the analyzed participants. It does not support a conclusion about treatment efficacy from the primary result. Safety counts are also limited descriptions: the record reports no serious events in the listed groups, but lacks event details and does not provide a full comparative safety analysis.

13. Why This Trial Matters Statistically

This trial is statistically instructive because the stated clinical objective and the posted primary endpoint do not align in time. The objective concerns whether combination treatment might be more effective than brimonidine alone for rosacea features. The primary endpoint is IGA at baseline. A baseline measure describes participants before the treatment effect could be assessed; it cannot substitute for a comparison of outcomes during or after treatment.

The distinction is important when reading registry results. A trial may be randomized and still have no posted estimate that answers its central comparative question. Here, the record identifies a parallel-group randomized design and two regimens, but the analysis count is 0 and the primary comparison is identified as missing or not estimable. The correct interpretation is a limitation in the available comparative evidence, not a finding that the treatments are the same or that a difference is absent.

The record also illustrates why denominators must be tied to the outcome being described. The primary IGA summaries use arm counts of 6 and 11, while the safety summaries list 10 and 12 participants at risk. Those figures serve different purposes and should not be interchanged. The record does not explain the full flow from the enrollment of 22 participants to each analysis group, so interpretation should remain specific to the reported denominator.

Finally, multiple outcome topics and missingness raise questions that need transparent reporting. The record lists 20 outcome measures, 16 secondary outcomes as posted, and no analysis records. It does not report a multiplicity plan or detailed missing-data methods. For clinical researchers, this emphasizes the value of prespecified analyses, clear analysis populations, and results that report effect estimates with uncertainty. Without those details, descriptive data can still be read accurately, but they cannot carry the weight of a treatment-effect conclusion.

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 most consequential limitation is that the primary endpoint is IGA at baseline, while the study’s stated aim concerns comparative treatment effectiveness. The posted baseline means do not measure response to either regimen. The record does not report a follow-up primary estimate, change from baseline, confidence interval, or p-value for a between-arm comparison. It therefore does not provide the main statistical quantity needed to evaluate the stated comparative question.

The primary outcome analysis includes 6 participants in the combination arm and 11 in the brimonidine arm. The record reports total enrollment of 22, but does not provide a participant flow accounting for the outcome counts. It states that participants lost to follow-up or withdrawing consent were excluded from the final analysis, yet gives no counts, timing, or reasons for those exclusions. Missing-data handling beyond this exclusion is not reported.

The record does not report the randomization procedure, concealment method, masking identity, treatment duration, analysis model, covariate adjustment, or assumptions used for a treatment-period analysis. It also does not report a multiplicity approach despite listing multiple outcome measures. These are limitations of what can be assessed from the registry record, not evidence that a particular procedure was or was not used.

The IGA summaries are group-level mean and standard deviation values. The record does not provide participant-level scores, distributional information, assessor details, or additional measurement-quality information. A standard deviation of 0.0 in one group at the reported precision limits assessment of variability from the summary alone; it does not explain why the scores have no reported spread.

The safety results provide event counts and at-risk denominators but not event descriptions or detail about observation time. Death counts are not reported in the registry record. Taken together, the limitations mean the posted information supports a narrow descriptive account of baseline IGA and safety counts, not a complete assessment of comparative effectiveness or safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Finacea 15% and Brimonidine 0.33% Gel in the Treatment of Rosacea - A Pilot Study — NCT02147691.
• Registry record last updated 2015-09-30; status last verified 2015-08.
• Results first posted 2015-09-30.
• 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

NCT02147691 is a completed randomized, single-masked, parallel-group phase 4 pilot study of azelaic acid 15% plus brimonidine 0.33% versus brimonidine 0.33% gel for acne rosacea. The registry record reports enrollment of 22 and lists Derm Research, PLLC as sponsor. The study began in 2014-05 and reached primary completion in 2015-01.

The primary endpoint is Investigator Global Assessment at baseline, on a scale from 0 to 4. The combination arm mean was 3.0, with standard deviation 0.0 among 6 participants; the brimonidine arm mean was 3.1, with standard deviation 0.3 among 11 participants. These are baseline descriptions, not treatment-effect estimates. The record lists 20 outcome measures, 16 secondary outcomes as posted, and 0 analysis records. A two-arm comparison for the continuous primary endpoint is reported as missing or not estimable.

Safety summaries list 0 serious adverse events in each group. Other adverse events affected 3 participants among 10 at risk in the combination group and 4 among 12 at risk in the brimonidine group. Death counts are not reported in the registry record. The available results do not provide a comparative treatment-effect estimate.