Fractionated 1927nm Laser for Hyperpigmentation in Fitzpatrick Skin Phototypes V and VI: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Fractionated 1927nm Laser for Hyperpigmentation in Fitzpatrick Skin Phototypes V and VI (NCT05493280), a non-randomized na study. The primary outcome is Change in Spots - Front of Face (Part 1).

2. Clinical Question

The study asks whether treatment with a fractionated 1927nm non-ablative laser is associated with a change in measured facial spots among people with hyperpigmentation and Fitzpatrick Skin Phototypes V and VI. It also describes an exploratory interest in pre- and post-procedure skin-care regimens intended to limit unwanted pigmentation changes or scarring. The registry record does not report numerical results for the primary measure, so it does not establish the size or precision of any change.

3. Trial Design

This completed pilot study is registered as NCT05493280. The registry lists enrollment of 15 and identifies the study as non-randomized, unmasked, and crossover. Its phase is listed as NA. The study began on 2022-11-14, and primary completion is recorded as 2024-07-26.

The listed intervention is the MOXI device. The registry describes two Part 2 intervention group labels: “Part 2 Intervention (after Part 1)” and “Part 2 Intervention only.” It also describes Part 1 and Part 2 care arrangements using labels that include “Healthy Participants.” In the pre-treatment-only description, participants are pre-treated with tretinoin/hydroquinone before treatment and receive no post-treatment care. In the post-treatment-only description, participants wash out of topical medications, receive treatment, and use Temovate for 4 days afterward.

These descriptions indicate that topical care differs across the described intervention arrangements. However, the registry record does not report the detailed sequence of treatment periods, washout timing, or how participants were assigned to the arrangements. Those details should not be inferred from the crossover label alone. Because allocation is non-randomized, and masking is absent, the study does not provide a randomized, blinded comparison of treatment strategies.

The primary outcome is restricted to subjects who completed Part 1. The number of such subjects is not reported in the registry record. Enrollment is not the same as the number contributing to this outcome, and the record does not give enough information to establish how many participants contributed measurements at each follow-up time.

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: Out of 10 subjects who completed Part 1 (Pre-Treatment Group), only 6 continued to washout and Part 2 portion of this study and thus additional subjects were enrolled in part 2 (Post-Treatment Group) as represented in the data table below.

Part 1 Intervention (7 months)

Washout Period (1 month)

Part 2 intervention (7 months)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Subjects who completed Part 1 intervention are only analyzed and reported here.

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: 12 subjects started Part 1 (Pre-Treatment Group), and after washout, in Part 2 portion of this study, 3 additional subjects were enrolled as represented in the table below.

6. Primary Endpoint

The registry lists the primary outcome as Change in Spots - Front of Face (Part 1), measured over Baseline, 1 Month and 3 Months.

The primary endpoint is change in the count of spots on the front of the face. The registry describes the outcome as a quantitative assessment of overall spots using VISIA 3D analysis. A “count” refers to the number of individual features detected in the region of interest. Measurements are specified at baseline, 1 Month, and 3 Months, and the outcome is summarized as a mean with a standard deviation.

A count of detected facial spots gives a numerical way to describe the amount of a visible feature in a defined facial region over time. In general, an objective count can help make changes easier to compare across measurement occasions than an unstructured description alone. It is still a measure of detected features, not a complete description of pigmentation, skin appearance, patient experience, or scarring. The registry record does not report additional endpoint details such as the exact image-processing settings or reproducibility of the measurement.

The stated analysis population is subjects who completed the Part 1 intervention. The record does not provide the numerical mean counts, changes, or standard deviations at the specified time points. Therefore, the direction, magnitude, and precision of the endpoint change cannot be determined from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary outcome as a continuous measure summarized by a mean and standard deviation. For this endpoint, the underlying measure is a count of detected spots. A mean describes the average count in the analyzed observations, while a standard deviation describes how spread out individual observations are around that mean. These summaries answer different questions: the mean describes the central value, and the standard deviation describes variation among observations.

What does change over time mean?

The endpoint is assessed at baseline, 1 Month, and 3 Months. In general, a change score compares a follow-up measurement with a baseline measurement for the same outcome. Repeated measurements can describe whether the measured count differs over time, but interpretation depends on which participants contribute data at each occasion and how within-participant correlation is handled. The registry record does not report the numerical results or the analysis method used to handle repeated measurements.

A mean change can be informative when its definition and analyzed population are clear. For example, a change could be calculated from paired observations, or a model could estimate change while using information from multiple visits. Those approaches may rely on different assumptions. The registry record does not say which approach was used, whether the primary comparison was between visits or against a prespecified target, or whether any covariates were included. These methods cannot be reconstructed from the endpoint description.

Why does the design matter?

In a randomized comparison, assignment by chance can help balance measured and unmeasured characteristics between groups, on average. This study is listed as non-randomized, so that protection against systematic group differences is not established. An unmasked design means participants and study personnel were not blinded according to the registry’s masking entry. For an image-based count, the registry does not report whether image assessors were masked separately.

A crossover design generally means a participant may receive or experience more than one intervention condition in sequence. Comparisons in crossover studies can be affected by changes over time, order, or carryover from an earlier condition. The registry record does not report the sequence details, washout interval, or analysis methods used to address these issues. The group descriptions identify Part 2 after Part 1 and Part 2 only, but do not establish how the crossover comparisons were analyzed.

What does a confidence interval contribute?

In general, a confidence interval expresses uncertainty around an estimated effect. It helps distinguish a precise estimate from one compatible with a broad range of effects. A confidence interval does not correct a biased design, missing data, or a poorly specified outcome; it quantifies uncertainty under the assumptions of the calculation. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be judged.

A p-value, when reported, describes how compatible the observed data are with a specified null hypothesis under the statistical model. It does not measure the size or importance of an effect. The record gives no primary-outcome p-value or hypothesis test. The stated sample-size planning assumptions refer to a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. These are planning assumptions, not a report of the trial’s own design or evidence of observed power. No sample-size illustration values are stated in the registry record.

Why can over-dispersion matter for count outcomes?

As a general statistical point, count data may vary more than a simple probability model assumes. This is called over-dispersion. If it is present and not handled appropriately, standard errors and confidence intervals can be misleading. A count outcome can also have a skewed distribution or many observations clustered at similar values. The registry record does not report the distribution of spot counts or whether over-dispersion was assessed. It therefore does not support a claim about which count-data model, if any, would be appropriate.

Finally, the primary outcome population is described as Part 1 completers. Analyses restricted to completers can be affected if completion is related to outcome or treatment experience. In general, methods for missing measurements rely on assumptions about why data are missing. The registry record does not report missing-data methods or a comparison of participants with and without follow-up measurements. No statistical method or assumption should be attributed to the investigators beyond what the record states.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 18 outcome measures and 0 analyses. It identifies the front-of-face spot-count change as the primary outcome, but does not report a statistical analysis plan or explain how multiple outcomes or time points were handled. The registry record therefore does not establish whether a multiplicity adjustment was planned or applied.

In general, when several outcomes or comparisons are tested, the chance of obtaining at least one apparently notable result can increase. Methods that address multiplicity can help control that risk, but the appropriate approach depends on the study’s hypotheses and analysis plan. No adjustment should be assumed from the existence of a primary outcome label alone.

The record says that the primary endpoint is assessed at baseline, 1 Month, and 3 Months, and that only subjects who completed Part 1 are analyzed and reported for that endpoint. It does not report how many participants completed Part 1 or contributed data at each time point. Missing measurements, withdrawals, and reasons for missingness are not reported in the registry record. Nor does the record state whether the analysis used only complete cases, imputed missing values, or applied another approach.

These omissions matter because both the choice of analysis population and the handling of unavailable measurements can affect an estimated change. The registry description alone cannot establish whether the reported analysis, if any, followed a prespecified plan. The numeric results and methods needed to assess multiplicity and missing-data assumptions are not reported in the registry record.

11. 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.

The registry lists safety counts for three group labels. For Part 1 Intervention, 12 were at risk for serious adverse events and 0 were affected; 12 were at risk for other adverse events and 0 were affected, with 0 deaths. For Part 2 Intervention (after Part 1), the corresponding counts are 6 at risk and 0 affected for serious events, 6 at risk and 0 affected for other events, and 0 deaths. For Part 2 Intervention only, the counts are 3 at risk and 0 affected for serious events, 3 at risk and 0 affected for other events, and 0 deaths.

These figures mean that the registry reports no affected participants in the listed adverse-event categories within those group records. They should not be interpreted as proof that the intervention has no safety risks. Safety counts from a pilot study describe events recorded in the listed groups; they do not establish that an event is impossible or estimate risk precisely. The registry lists no top serious adverse-event terms. Additional definitions, event-collection procedures, and severity details are not reported in the registry record.

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

The record establishes that a pilot study was conducted to quantify changes in a VISIA 3D count of front-of-face spots after fractionated 1927nm non-ablative laser treatment. It also documents different pre- and post-treatment topical-care arrangements and gives safety counts for the listed intervention groups. The study is recorded as completed, with enrollment of 15.

However, the registry record does not report numerical results for the primary endpoint. It therefore does not show the direction or size of change in spot counts, nor does it provide a confidence interval or other measure of precision. The result cannot be characterized as statistically significant or not statistically significant from the information reported. The absence of a numerical result in the registry is not evidence of no effect.

The design is non-randomized and unmasked, and the registry does not define a like-for-like control comparison. Its crossover designation is not accompanied by the sequence, timing, or analysis details needed to evaluate period and carryover effects. Moreover, the primary endpoint is reported only for subjects who completed Part 1, while the number of completers and the handling of missing measurements are not stated. These features limit causal interpretation and leave uncertainty about how representative the analyzed participants are.

The safety record reports zero affected participants for serious and other adverse events and zero deaths in each listed group. Those counts describe the registry entries; they do not establish the absence of unrecorded events or rule out uncommon harms. Overall, the registry supports a description of the study question, design, endpoint, and recorded safety counts, but not a quantitative conclusion about the primary outcome or the effect of treatment.

13. Why This Trial Matters Statistically

This study raises a statistical question about how to measure change in a visible skin feature in people with Fitzpatrick Skin Phototypes V and VI. The primary outcome uses a count of individual features detected in a defined facial region, rather than a general impression of appearance. That makes the measurement definition central to interpretation: a change in detected spots is not automatically equivalent to a change in every aspect of hyperpigmentation or to a change that matters to participants.

The study also describes different topical-care arrangements around the laser intervention. This creates an analytic challenge: differences in observed change could reflect the laser, the accompanying care, timing, or other differences between non-randomized groups. A clear comparison and transparent analysis are needed to separate those possibilities. The registry record does not report enough detail to determine how that separation was approached.

Repeated measurements at baseline, 1 Month, and 3 Months provide a framework for describing change over time. In general, the value of such measurements depends on consistent assessment, clear handling of within-participant data, and transparent reporting of who contributed observations at each visit. Here, the record identifies the endpoint and time points but does not provide the numerical outcome results or analysis details.

The statistical importance of this pilot record is therefore primarily in the design and measurement question it documents. It illustrates why a defined endpoint, an explicit comparator, and complete reporting of estimates and uncertainty are important for interpreting a clinical study. The registry record does not provide the outcome evidence needed to quantify the observed change, so no treatment-effect conclusion can be drawn from it alone.

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.

Several limitations specific to this study affect interpretation. First, allocation is non-randomized and masking is listed as none. Differences between participants or assessments could therefore be associated with the intervention arrangements, and the registry does not report a separate masking procedure for image assessment.

Second, the study is labelled crossover, but the registry record does not describe treatment sequence, period length, washout timing, or methods for accounting for order and carryover. The arm descriptions identify Part 2 after Part 1 and Part 2 only, but do not fully explain how participants entered each arrangement or how comparisons were formed. The distinct topical-care descriptions also make it difficult to attribute any change to the laser alone.

Third, the primary outcome population is restricted to Part 1 completers. The number of completers and the number with observations at each time point are not reported. Missing-data reasons and methods are also not reported in the registry record. This limits assessment of possible selection from analyzing completers.

Finally, numerical primary-outcome results and analysis methods are not reported, despite the record listing 18 outcome measures and 0 analyses. The follow-up schedule ends at 3 Months, so the registry endpoint description does not address measurements beyond that time. The record also does not report details about image processing, measurement reproducibility, or the statistical model used. These gaps prevent assessment of precision, multiplicity, and the robustness of any estimated change.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Fractionated 1927nm Laser for Hyperpigmentation in Fitzpatrick Skin Phototypes V and VI — NCT05493280.
• Registry record last updated 2025-12-15; status last verified 2025-11.
• Results first posted 2025-11-14.
• 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.

18. Record Summary

NCT05493280 is a completed, non-randomized, unmasked crossover pilot study sponsored by University of Texas Southwestern Medical Center. It lists enrollment of 15 and evaluates MOXI, described as fractionated 1927nm non-ablative laser treatment for hyperpigmentation in Fitzpatrick Skin Phototypes V and VI. The study began on 2022-11-14, with primary completion on 2024-07-26.

The primary endpoint is the mean change in front-of-face spot count measured by VISIA 3D at baseline, 1 Month, and 3 Months. The endpoint population is described as subjects who completed Part 1. Numerical outcome results, analysis methods, and the number of Part 1 completers are not reported in the registry record. Safety entries list zero serious adverse events, zero other adverse events, and zero deaths in each of the three intervention group records.