Pulsed Dye Laser Treatment and Oxymetazoline Hydrochloride (HCL) 1% Cream for Erythematotelangiectatic Rosacea: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pulsed Dye Laser Treatment and Oxymetazoline Hydrochloride (HCL) 1% Cream for Erythematotelangiectatic Rosacea (NCT04153188), a randomized phase 4 study. The primary outcome is Clinical Erythema Assessment (CEA) Score At 6-Month Post-Baseline.

2. Clinical Question

The study’s central statistical question concerns the difference in average investigator-rated erythema between the two assigned regimens at the specified follow-up. The posted mean was 1.6 for pulsed dye laser plus cream and 2.4 for cream alone. An unadjusted comparison calculated from those arm summaries estimates the cream-only mean to be 0.8 points higher. That contrast describes the observed group averages; it does not by itself establish why they differed or how well the result would generalize beyond the participants studied.

The registry describes this as a pilot study. It was randomized, parallel-group, and unmasked. The primary outcome is a continuous score, while other listed measures include patient assessments, global aesthetic improvement, vessel size, satisfaction, and pain associated with laser treatment. Numerical results for most listed secondary outcomes are not reported in the registry record.

3. Trial Design

This was a Phase 4, randomized, parallel-group study listed as completed. It enrolled 34 participants with erythematotelangiectatic rosacea. The registry describes the study as comparing pulsed dye laser used as an adjunct to oxymetazoline HCL 1% cream with the cream alone, for participants with moderate or severe disease. Masking is listed as none, so the study was open-label.

The combined-treatment arm used once-daily cream for 4 weeks before the first of 3 monthly Vbeam Prima pulsed dye laser treatments. The arm description says that once-daily cream continued during the 6-month post-baseline study period. Its text also begins to describe a 3-day cream washout, but the remaining wording is truncated in the registry record; the precise timing and application of that washout are therefore not reported in the registry record. The comparator arm used once-daily cream during the 6-month study.

The primary endpoint was the mean Clinical Erythema Assessment score at 6 months post-baseline. This investigator-rated outcome used a 5-point scale from 0, clear, to 4, severe. The primary summaries use 14 participants in the combined arm and 11 in the cream-only arm. The registry’s outcome description also reports that two participants in the combined arm and one in the cream-only arm dropped before the 2-month visit, and that one participant in each arm dropped before the 6-month visit.

The randomization method, allocation ratio, recruitment setting, detailed eligibility criteria, and original sample-size justification are not reported in the registry record. The number enrolled does not by itself establish how many participants were initially assigned to each arm or explain the differing denominators used for the primary outcome and safety summaries. Formal statistical analyses are not listed in the 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.

Before assignment: Four subjects dropped prior to 1 month post baseline visit (three subjects from Arm 2 and one subject from Arm 1). Therefore, thirty subjects are included in the analysis (17 subjects from Arm 1 and 13 subjects from Arm 2)

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Arm 1- Two subjects dropped before 2-month post-baseline visit and one subject dropped before the 6-month post baseline visit. Arm 2- One subject dropped before 2-month post-baseline visit and one subject dropped before the 6-month post baseline 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 Clinical Erythema Assessment (CEA) Score At 6-Month Post-Baseline, measured over 6-month post-baseline.

The primary endpoint is the mean Clinical Erythema Assessment score at the 6-month post-baseline visit. Investigators graded erythema on a 5-point scale, with 0 meaning clear and 4 meaning severe. Higher scores indicate worse outcome. The endpoint therefore represents an ordered clinical rating recorded numerically and summarized as an average for each study arm.

A mean provides a concise description of the group’s central score and allows the average scores in the two randomized arms to be compared. It does not show the full distribution of participant scores: the same mean could arise from different mixtures of low and high ratings. The posted standard deviation gives additional information about variation among scores within each arm, though it also does not reveal every individual value.

Using the 6-month assessment makes the endpoint a comparison at a specified follow-up rather than a summary across all visits. The registry also lists Clinical Erythema Assessment at earlier follow-up visits as a secondary outcome, but the primary result is specifically the 6-month mean. The primary outcome description says the reported means were calculated for each arm at that visit. The record’s notes on participants who dropped before follow-up are relevant when interpreting the available outcome denominators; the method used to handle missing scores is not reported in the registry record.

As a general statistical point, a clinical score can be useful for comparing average severity while remaining dependent on how consistently assessors apply the scale. The record identifies investigator grading but does not report assessor training, reliability checks, or other measurement procedures.

7. Results Posted in the Registry

• Oxymetazoline HCL 1% Cream: mean 2.40 versus 1.60 on control; difference 0.80 (95% CI 0.01 to 1.59), standardized effect d = 0.80; z-test p = 0.047.

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.

Measurement of The Percentage of Subjects Reporting Satisfaction At the 6-Month Post-Baseline Visit

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Oxymetazoline HCL 1% Cream: 63.6% (7/11) versus 85.7% (12/14) on control; risk difference -22.1 percentage points (95% CI -55.9 to 11.7), risk ratio 0.74 (0.45–1.22); unadjusted two-proportion z-test p = 0.199.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Oxymetazoline HCL 1% Cream and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary assessments covering investigator-rated erythema at earlier visits, participant self-assessment, investigator and participant global aesthetic improvement, vessel size, satisfaction, and pain associated with pulsed dye laser treatment. These measures span clinician ratings, participant reports, and a treatment-experience outcome. Together they could add context to the primary score by describing related aspects of appearance and experience, but they are not interchangeable measures of the same construct.

The primary result is an investigator-rated mean score at 6 months. Secondary outcomes could help assess whether patterns in other measures align with that result, but the registry does not provide enough numerical secondary results to determine whether there was a consistent pattern across endpoints and visits. The one posted numerical secondary comparison concerns satisfaction; other secondary numerical results are not reported in the registry record. Formal analyses are not listed.

Secondary findings generally warrant less weight than a prespecified primary result when their analysis plan is unclear. Multiple outcomes, assessment times, and possible comparisons create more opportunities for chance findings. Without a reported multiplicity strategy, a nominal result from one secondary measure should be treated as exploratory rather than as independent confirmation of the primary result. Likewise, unavailable numerical results cannot be interpreted as evidence of no difference or as support for the primary finding.

Useful context would include the planned hierarchy of outcomes, the treatment of repeated measurements, the number of participants contributing to each assessment, and the handling of missing values. These details are not reported in the registry record. The secondary endpoint list shows the range of outcomes considered, but does not establish which were analyzed, how they were modeled, or whether results were selected for posting.

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

• Clinical Erythema Assessment (CEA) At the 1- ,2- and 3-Month Post-Baseline Visits
• Subject Self-Assessment (SSA) At the 1- ,2-, 3- and 6-Month Post-Baseline Visits
• Mean Investigator Assessment of Global Aesthetic Improvement (GAI) Grades At the 1-, 2-, 3- and 6-Month Post-Baseline
• Mean Subject Assessment of Global Aesthetic Improvement (GAI) Grades At the 1-, 2-, 3- and 6-Month Post-Baseline
• Measurement of Improvement in Vessel Size At the 1-, 2-, 3- and 6-Month Post-Baseline Visits
• Measurement of The Percentage of Subjects Reporting Satisfaction At the 6-Month Post-Baseline Visit
• Measurement of Pain Associated With PDL Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

The primary measure is a continuous numerical score summarized by its mean and standard deviation in each arm. The registry describes the underlying Clinical Erythema Assessment as a 5-point rating from 0, clear, to 4, severe. Although the scale has ordered categories, the posted primary summary treats the scores numerically and reports arm means. The mean answers a group-level question about average score; it does not imply that every participant experienced a change equal to that average.

What does the mean difference describe?

The posted arm means are 1.6 for pulsed dye laser plus oxymetazoline cream and 2.4 for oxymetazoline cream alone. The unadjusted contrast is oriented as the cream-only mean minus the combined-treatment mean, giving 0.8. With higher scores indicating worse outcome, a positive value under that orientation means the observed average score was higher in the cream-only group. The contrast is calculated from the posted summaries and is not an adjusted estimate for baseline score, covariates, or other factors.

A difference in means is expressed in the same units as the underlying score. Its interpretation depends on the scale and the clinical context. The registry does not report a threshold for a clinically important difference, so the numerical contrast cannot be classified from the record as small, moderate, or important in clinical terms. It is also not a percentage change, and it should not be converted into one without additional information and an explicitly chosen method.

What does the standard deviation add?

The standard deviation describes how dispersed individual scores are around the group mean. Both arms have a posted standard deviation of 1.0. In general, a larger standard deviation indicates more variation among participant scores, while a smaller one indicates scores more clustered around the mean. A standard deviation is not the same as the standard error: the former describes participant-level variability, whereas the latter describes uncertainty in an estimated mean. The registry does not present individual participant scores, so the distribution, possible floor or ceiling effects, and shape of score variation cannot be assessed from the means and standard deviations alone.

How should the p-value be read?

The unadjusted p-value for the mean comparison is 0.047. In general, a p-value measures how unusual data at least as different as those observed would be under a specified statistical model when the null hypothesis is assumed. Its interpretation depends on that model and on the analysis being selected in advance. It is not the chance that the observed difference arose randomly, and it does not quantify the probability that one regimen is better. The registry does not report a formal statistical analysis plan, so whether this comparison was prespecified in the same form as calculated cannot be established from the record.

Unadjusted means that the comparison is not described as corrected for other variables or for multiple comparisons. The record lists several secondary measures and assessment visits. When many hypotheses are examined, the chance of observing at least one nominally small p-value can increase. General methods for addressing multiplicity include defining a primary hypothesis in advance, adjusting significance thresholds, or treating secondary results as exploratory. Which approach, if any, was planned for this study is not reported in the registry record.

What does the confidence interval communicate?

A confidence interval expresses uncertainty around an estimated contrast. In general, it gives a range of values compatible with the observed data under the method’s assumptions; it is not a range containing a fixed proportion of individual participant outcomes. The interval for the primary mean difference extends from just above zero to 1.59. Its position indicates that the interval is on the positive side under the stated contrast orientation, while its width indicates that the magnitude is not pinpointed precisely. The registry does not state the interval’s confidence level in the outcome description, so that level should not be inferred from the displayed bounds alone.

General statistical reasoning also distinguishes statistical uncertainty from clinical importance. A narrow interval can still be centered on an unimportant difference, and a wide interval can include both modest and larger effects. Here, the registry does not report a clinical-importance threshold for the score, so interpretation should focus on the observed scale, estimate, and uncertainty without attaching an unsupported clinical label.

Why can small groups make estimates uncertain?

With fewer observations, each participant’s score can have greater influence on the group summary, and estimates can vary more from sample to sample. Standard errors and confidence intervals reflect some of this sampling uncertainty, but they do not correct bias due to missing data, unmasking, measurement differences, or selective reporting. The primary summaries are based on 14 and 11 participants. The registry notes participants dropping before visits, but does not describe a missing-data method, analysis population, or sensitivity analysis. Thus, the available summaries do not reveal whether conclusions would be similar under other defensible approaches to missing outcomes.

Randomization is a design feature intended to make treatment groups comparable on average, including for factors not measured by investigators. It does not guarantee that small groups will be balanced on every characteristic, and the record does not provide baseline characteristics or details of the randomization process. No masking was used, which means participants and investigators were not listed as blinded. In general, awareness of assigned treatment may affect subjective ratings or participant reports. The registry does not report safeguards or assessor masking that would clarify this concern.

Overall, the posted comparison is an unadjusted summary-based estimate with a nominal p-value and an interval. It conveys the direction and approximate magnitude of the observed mean-score contrast, while leaving important questions about the planned analysis, missing-data handling, measurement procedures, and multiplicity unanswered.

11. Confidence Intervals and Precision

The primary mean difference is 0.8 points, using cream alone minus pulsed dye laser plus cream. The reported interval extends from just above zero to 1.59. Because the lower bound is close to zero, the data allow a small contrast; the upper bound allows a more substantial contrast in the same direction. The interval is not especially informative about a single precise magnitude, even though it lies above zero.

Confidence intervals are useful because they show a range of estimates compatible with the data under the statistical method. They are not a measure of the spread of individual participants’ scores; the arm standard deviations, both 1.0, describe that participant-level variability. Nor does an interval directly state whether a difference matters clinically. The registry does not report a threshold for a meaningful change on the assessment scale.

The group summaries are based on 14 participants in the combined arm and 11 in the cream-only arm. These are small outcome groups, so the estimate may be sensitive to individual ratings. The registry notes dropouts before follow-up, but does not report how missing scores were handled. The displayed interval cannot account for uncertainty from unreported analysis choices or possible bias from missingness, unmasking, or measurement practices.

For satisfaction, the posted risk-difference interval spans zero, so it is compatible with differences in either direction. Its breadth signals substantial uncertainty in that secondary comparison. The registry does not report formal analyses for the secondary outcomes. Across these results, precision should be considered separately from the direction of an estimate and from any judgment about clinical relevance.

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 participants and not total events. They are illustrations based on the observed effect, rather than a record of the original study’s design calculation. The assumptions listed for these illustrations are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The original sample-size assumptions for the trial are not reported in the registry record.

The 80% power column describes the number of participants per arm that the stated planning calculation estimates would be needed to have an 80% chance of detecting the chosen effect under its assumptions. The 90% power column uses a higher target chance of detecting that effect, so it generally requires more participants. These are planning targets, not a guarantee that a future study will detect an effect, and they do not describe the probability that the current study’s result is correct.

For planning at 100% of the observed mean difference, the illustration gives 25 participants per arm for 80% power and 33 per arm for 90% power. Planning for 75% of the observed effect gives 44 and 59 participants per arm, respectively. Planning for 50% of the observed effect gives 99 and 132 participants per arm. The pattern is expected: a smaller effect is harder to distinguish from random variation, so more participants are needed to achieve the same target power.

These calculations use the effect observed in a small study as their starting point, and that estimate itself is uncertain. They are not observed power: observed power is not a useful substitute for interpreting the estimate and its interval. The figures are best read as conditional planning illustrations under the stated assumptions, not as proof that the completed trial was adequately or inadequately sized.

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 = 0.800; pooled standard deviation σ = 1.000.
2. n = 2 × (1.96 + 0.842)² × 1.000² / 0.800² = 24.5, rounded up to 25 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 <- 0.8                      # observed difference in means
sigma <- 1                     # 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(4153188)
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 = 25 (80% power), 33 (90% power)
 75% of observed effect: n per arm = 44 (80% power), 59 (90% power)
 50% of observed effect: n per arm = 99 (80% power), 132 (90% power)
power.t.test: 25.5 
Simulated power at n = 25 per arm: 0.791 (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. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary endpoint and lists multiple secondary measures assessed at several follow-up visits. Repeated assessment and multiple outcomes raise a multiplicity question: if many statistical comparisons are made, some may appear unusual by chance even when there is no underlying effect. General approaches include prioritizing a primary endpoint, adjusting for the number or structure of comparisons, or explicitly labeling secondary analyses exploratory. The multiplicity strategy for this study is not reported in the registry record.

The comparison available for the primary outcome is unadjusted, and the registry lists no formal reported analyses. It does not state whether the primary analysis was prespecified in a statistical analysis plan, whether interim analyses were conducted, or whether any adjustment was planned for baseline characteristics. Interim analyses and the full statistical plan are not reported in the registry record. Consequently, the posted p-value should be read as a nominal unadjusted result rather than as evidence that multiplicity was addressed.

Missing outcome data also affect interpretation. The primary outcome description notes participants who dropped before the 2-month visit and before the 6-month visit in each arm. The posted primary summaries use 14 and 11 participants, while the study enrollment was 34. The registry does not explain the complete flow from enrollment and assignment to each analysis denominator. The reasons for dropping, whether participants were excluded from particular analyses, and whether missing values were imputed are not reported in the registry record.

In general, complete-case analysis can be biased if the chance of an outcome being observed is related to the outcome itself or to treatment experience. Other approaches may use assumptions about the missing outcomes, but no method can be attributed to this study from the available record. The analysis population—such as all randomized participants or only those with observed endpoint data—is not reported in the registry record. Sensitivity analyses evaluating alternative missing-data assumptions are also not reported.

These reporting gaps do not prove that the analysis was improperly conducted. They mean that the robustness of the posted comparison cannot be evaluated fully from the registry record. Clear prespecification, participant flow, analysis-population definitions, and missing-data sensitivity analyses would help readers assess how much confidence to place in the estimate.

15. 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 registry reports 0 serious adverse events among 17 participants at risk in the pulsed dye laser plus oxymetazoline cream group, and 0 among 13 participants at risk in the cream-only group. Deaths are listed as 0 in both groups. These counts describe what was recorded for the stated safety groups; they do not establish that no serious event could occur or that the two regimens have equivalent safety.

The group sizes are limited, and the observation period and detailed adverse-event collection procedures are not described in the available safety summary. A zero count in a study of this size leaves uncertainty about uncommon events. The registry lists no top serious adverse-event terms. It also reports other adverse events affecting 3 participants in the combined arm and 2 in the cream-only arm; those counts are distinct from the serious adverse-event counts.

Safety counts should be interpreted alongside the number at risk and the study’s follow-up and reporting procedures. The registry record does not provide event descriptions or enough detail to assess severity and timing for the other events. These figures are descriptive and should not be treated as a comprehensive comparison of safety.

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

The posted primary data show a lower mean investigator-rated erythema score at 6 months in the arm receiving pulsed dye laser plus oxymetazoline cream than in the arm receiving cream alone. The means were 1.6 and 2.4, respectively, and the unadjusted contrast was 0.8 points in the direction of a higher score for cream alone. The interval extends from just above zero to 1.59, indicating uncertainty about the exact size of the difference. The unadjusted p-value is 0.047.

These statistics describe the observed participants and the particular endpoint. They do not establish that the difference was caused by the added laser treatment, quantify a benefit for every participant, or show that the difference is clinically important. No threshold for a clinically important CEA difference is reported in the registry record. The p-value is not a probability that the result is true, and the interval does not describe the range of individual responses.

The study was randomized, which is an important design feature for comparative questions, but it was unmasked and the outcome was investigator-rated. The record does not report the randomization procedure, assessor masking, baseline score distribution, or a formal analysis plan. Those omissions limit assessment of possible measurement and analysis influences. The number of participants contributing primary outcome data was also limited, and the record notes dropouts before follow-up without describing how missing data were handled.

The registry lists secondary outcomes, but most numerical secondary results and formal analyses are not reported. Therefore, the primary result cannot be considered confirmed by a broad, consistently reported pattern across other outcomes. The safety summary records no serious adverse events in either group, but the groups are small and the event counts do not rule out uncommon harms.

The result is best treated as a pilot comparison that describes a difference in observed group averages and leaves meaningful uncertainty. It does not establish outcomes beyond the measured follow-up or in populations and schedules not represented in the record. No treatment recommendation follows from these statistics alone.

17. Why This Trial Matters Statistically

This study illustrates how a randomized comparison can be described with an interpretable endpoint while still leaving substantial uncertainty. The primary result is a mean difference on an investigator-rated scale, so readers can see both the direction and scale of the observed contrast. The standard deviations and interval add information beyond the means, but the small outcome groups limit precision and make individual observations potentially influential.

It also shows why a nominal p-value is only one part of interpretation. The unadjusted p-value is 0.047, but the registry lists multiple secondary outcomes and assessment visits without reporting a multiplicity strategy or formal analysis plan. A statistically unusual-looking result should be considered with its interval, design, missing data, and the wider set of outcomes rather than treated as a standalone verdict.

Missing-data reporting is especially relevant in a study with follow-up assessments. The record notes dropouts and gives outcome denominators, but does not explain the analysis population or how missing scores were treated. That prevents readers from judging whether alternative reasonable approaches might change the estimate. Similarly, the open-label design and investigator rating make measurement procedures relevant, yet details about assessor masking and reliability are not reported.

Finally, the sample-size illustrations clarify the distinction between observed results and future planning. They show how required enrollment increases when planning to detect a smaller effect, under stated assumptions. They are not a retrospective measure of whether the completed study had enough power. Together, these points make the record useful for understanding effect estimation, precision, multiplicity, and transparent reporting in a small clinical trial.

18. 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 features specific to this trial constrain interpretation. It is described as a pilot study and enrolled 34 participants, while the primary summaries include 14 in the combined arm and 11 in the cream-only arm. Small groups limit precision and may not capture the range of outcomes that could occur in a larger study. The registry does not provide baseline characteristics, so the balance of the groups on initial erythema or other features cannot be assessed from the record.

The study was open-label and used an investigator-rated primary outcome. Awareness of treatment assignment can influence subjective assessment, and the record does not report whether outcome assessors were masked or whether rating consistency was evaluated. The outcome scale is described, but no clinically important difference threshold is reported.

The primary outcome description notes dropouts before follow-up, but reasons for withdrawal, participant flow by analysis, and missing-data handling are not reported in the registry record. Formal analysis methods, the randomization procedure, the allocation ratio, and the original sample-size justification are also not reported. The sample-size illustration is based on the observed effect and should not be mistaken for the trial’s own design rationale.

Secondary outcomes cover several domains and visits, but most numerical results and any multiplicity approach are not reported. The available unadjusted primary comparison therefore cannot be placed within a fully documented prespecified analysis framework. The registry’s arm description for the combined regimen is truncated where it refers to a cream washout, leaving the detailed timing of that element unclear. These limitations do not invalidate the posted summaries, but they restrict independent assessment of how robustly they represent the trial’s intended comparison.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Pulsed Dye Laser Treatment and Oxymetazoline Hydrochloride (HCL) 1% Cream for Erythematotelangiectatic Rosacea — NCT04153188.
• Registry record last updated 2022-03-31; status last verified 2022-03.
• Results first posted 2022-03-18.
• 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.

22. Record Summary

NCT04153188 is a completed Phase 4 randomized, open-label, parallel-group pilot study sponsored by Candela Corporation. It enrolled 34 participants with erythematotelangiectatic rosacea and compared pulsed dye laser plus oxymetazoline HCL 1% cream with the cream alone.

The primary endpoint was mean Clinical Erythema Assessment score at 6 months post-baseline, on a scale from 0, clear, to 4, severe. The posted means were 1.6 for the combined regimen and 2.4 for cream alone. The unadjusted mean difference was 0.8, with an interval extending from just above zero to 1.59 and an unadjusted p-value of 0.047.

The registry notes dropouts before follow-up and lists multiple secondary outcomes, but formal analyses and most numerical secondary results are not reported in the registry record. The posted results are descriptive of this small study and should be read with the uncertainty and reporting limitations in mind.