A Single-Center Open-Label Study of 1064 nm for Nonablative Skin Rejuvenation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Single-Center Open-Label Study of 1064 nm for Nonablative Skin Rejuvenation (NCT03421691), a na na study. The primary outcome is Degree of Improvement Rating at 12 Weeks Post-final Treatment.

2. Clinical Question

3. Trial Design

The registry records a completed, single-center, open-label study with a single-group model. The study title identifies the intervention as 1064 nm for nonablative skin rejuvenation. The intervention arm is described as the excel V Laser Genesis procedure utilizing a 1064 nm laser. Enrollment was 17. The registry lists the phase as NA and allocation as NA; masking is listed as NONE. These design labels indicate that the record does not describe a randomized allocation or a masked treatment assignment.

The study started on 2016-03-15, and primary completion was recorded as 2018-02-07. The sponsor is Cutera Inc., and the status is COMPLETED. The registry lists skin pigment and photoaging as conditions. Further details about the clinical setting, eligibility criteria, participant flow, treatment schedule, and follow-up beyond the primary endpoint timeframe are not reported in the registry record.

A single-group design can describe changes observed within participants over time, but it does not provide a concurrent untreated or alternative-treatment group for comparison. The baseline reference in the primary endpoint is the starting point for judging photographic improvement; it is not a randomized control. Changes over time in a single group can reflect the intervention, but also other influences, and the design alone cannot separate these explanations.

The study is open-label, while the primary outcome description specifies assessment by independent blinded reviewers. These statements refer to different aspects of the study: open-label describes the overall study masking status, while the outcome description says that reviewers rating photographs were blinded. The registry does not report details of how reviewer blinding was maintained or whether other study personnel or participants were blinded. Protocol details, including any planned statistical analysis, are not reported in the registry record.

4. Participant Flow and Accounting

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

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Degree of Improvement Rating at 12 Weeks Post-final Treatment, measured over 12 weeks post-final treatment.

The primary endpoint is the degree of improvement from baseline, judged from post-treatment photographs at 12 weeks post-final treatment. Independent blinded reviewers used the Physician's Global Assessment of Improvement Scale. The recorded measure is a mean score on a scale, with standard deviation specified as the dispersion measure. Higher scores indicate better outcomes. The scale describes 4 as very significant improvement, 3 as significant improvement, 2 as moderate improvement, 1 as mild improvement, and 0 as no change.

A global improvement rating is used to condense a reviewer's overall judgment of visible change into an ordered score. Photographs give reviewers a common record to assess, and independent blinded review can reduce the influence of knowledge about treatment assignment on ratings. These are general features of such assessment approaches; the registry record does not report the rating procedures in greater detail.

The endpoint is framed as change from baseline, but the record does not report a mean score, standard deviation, participant-level scores, or an estimated change. It also does not report the number of photographs assessed or the handling of ratings from multiple reviewers. Thus, the endpoint definition is available, but the observed degree of improvement and its precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record describes a continuous primary outcome summarized as a mean with a standard deviation. A mean describes the average score across the participants included in an analysis. A standard deviation describes how dispersed individual scores are around that mean. They answer different questions: the mean locates the average rating, while the standard deviation describes variability among ratings. Neither is reported as an outcome result in the registry record.

What would a confidence interval communicate?

In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision, and a wider interval indicates less precision. It is not a range guaranteed to contain the true value, nor does it show the distribution of individual participant scores. The registry record does not report a confidence interval for the primary endpoint.

For this endpoint, a complete statistical account would make clear what quantity was estimated: for example, whether the reported mean was the endpoint score at follow-up or a mean change from baseline. It would also describe the analyzed participants, how baseline and follow-up assessments were paired, and how missing or unusable photographs were handled. Those details and an endpoint estimate are not reported in the registry record, so no numerical effect or precision can be interpreted.

Why does the single-group design matter?

In general, within-group assessment can describe how observations differ from baseline, but it cannot by itself distinguish a treatment-related change from changes that might have occurred over time for other reasons. A concurrent comparison group can help estimate the difference between treatment strategies under the study design. This record identifies a single group and no comparator arm. The baseline reference is part of the endpoint definition, not an alternative-treatment comparison.

The primary outcome is based on an ordered rating scale with categories from no change to very significant improvement. The registry treats the outcome as a continuous measure summarized by a mean and standard deviation. In general, mean-based summaries can be useful for describing average scores, but interpretation should also respect the meaning and ordering of the rating categories. The record does not report additional analyses of the score distribution or alternative summaries.

What does reviewer blinding contribute?

In general, blinding assessors to treatment information can reduce the chance that expectations influence an outcome rating. The endpoint description says that independent blinded reviewers assessed post-treatment photographs. The overall study masking status is listed as NONE, and the study is described as open-label. These labels can coexist because the reviewers' blinding is a specific feature of outcome assessment rather than evidence that the entire study was masked. How the reviewers were blinded, how many reviewers assessed each photograph, and how disagreements were resolved are not reported in the registry record.

The registry lists one outcome measure and 0 analyses. The outcome definition therefore identifies what was intended to be measured, but a measurement definition is not itself a statistical result. No p-value, confidence interval, estimated mean, standard deviation, or analysis population is reported. The statistical plan, including any adjustment, model choice, or handling of repeated reviewer assessments, is not reported in the registry record.

How should planning illustrations be understood?

In general, sample-size calculations describe planning under stated assumptions; they are not observed evidence and are not a substitute for the trial's outcome analysis. The planning illustration associated with the posted calculations uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers effects stated as fractions of the observed effect. The illustration is not the design of this single-group trial: it assumes two arms, whereas the registry records one group. Its sample-size values should therefore be read as planning illustrations, not as the number enrolled or as observed power.

The registry does not report the trial's own sample-size justification. It also does not report an observed primary effect in the outcome record summarized for this analysis, so no trial result can be inferred from a planning calculation. In general, observed power is not a useful replacement for an effect estimate and its confidence interval; the uncertainty around the estimate is more directly informative. The record does not contain the outcome results needed to assess that uncertainty.

Over-dispersion is a general concern when the observed variability is greater than assumed by a statistical model. If a model underestimates variability, its uncertainty estimates can be too small and its inferences too optimistic. This is a general statistical point, not a finding about this study: the registry record does not report a fitted model, an over-dispersion assessment, or data from which such a finding could be evaluated.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Excel V Laser")
n   <- c(10)
m   <- c(1.4)
sp  <- c(0.8)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Excel V Laser  10  1.400  0.800  0.828  1.972

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and does not report any analyses. The listed primary endpoint is the degree of photographic improvement at 12 weeks post-final treatment. A registered endpoint description does not establish which analysis was performed, whether there were additional exploratory outcomes, or how the analysis was selected and reported. The statistical analysis plan and any approach to multiplicity are not reported in the registry record.

In general, multiplicity arises when several outcomes, time points, groups, or analyses are examined. Testing many possibilities can increase the chance of a seemingly notable result occurring by chance. Prespecified analysis plans and transparent reporting help readers understand which comparisons were planned. No multiplicity adjustment or strategy is reported for this record, and the absence of such details should not be interpreted as proof that no additional analyses took place.

The record does not report missing-data methods, the number of participants with usable endpoint photographs, or an analysis population definition. It is not possible to determine whether every enrolled participant contributed to the primary endpoint, whether some assessments were unavailable, or how any missing observations were handled. The registry's enrollment count of 17 and the safety denominator of 16 do not establish the endpoint analysis denominator.

In general, missing data can affect interpretation when participants without observed outcomes differ from those with recorded outcomes. The direction and size of any impact depend on the missingness pattern and analysis assumptions. Those details cannot be assessed because participant flow, endpoint availability, and missing-data handling are not reported in the registry record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists serious adverse events for the Excel V Laser group as 0 affected among 16 at risk, and deaths as 0 among 16 at risk. It also lists other adverse events as affecting 16 among 16 at risk. These are event counts and denominators as recorded, not estimates of comparative risk: the study has a single group and no concurrent control arm.

The record does not list serious adverse event terms. It also does not provide descriptions of the other adverse events, their severity, duration, timing, or assessed relationship to the intervention in the information. The reported total for other adverse events therefore cannot be interpreted as a count of a particular symptom or as evidence about how events arose.

The safety denominator of 16 differs from the enrollment of 17. The reason for that difference is not reported in the registry record. Without participant-flow information and event-level detail, the counts cannot show whether all enrolled participants were followed for safety or how safety events were collected. A zero count for reported serious events does not establish that serious harm is impossible; it describes the registry's reported count in this group.

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

The registry record establishes that a completed, open-label, single-group study evaluated the excel V Laser Genesis procedure utilizing a 1064 nm laser for skin rejuvenation. It defines a primary outcome based on independent blinded reviewers' ratings of post-treatment photographs at 12 weeks post-final treatment. The outcome scale describes degrees of improvement, with higher scores indicating better outcomes.

The record does not report the primary outcome result or an analysis. It therefore does not establish the average rating, how variable ratings were, how precise an estimate might be, or how many enrolled participants contributed to the endpoint. The endpoint's stated purpose and scoring rules should not be mistaken for evidence about the observed outcome.

The design also limits what a within-group result could establish. Without a separate comparator group, the study cannot directly estimate how the outcome would differ under another treatment or no treatment. A change from baseline can be described, but other factors over time may also influence it. This is a general limitation of uncontrolled before-and-after comparisons, not a claim about what occurred in this study.

The safety listing reports 0 serious adverse events and 0 deaths among 16 at risk, alongside other adverse events affecting 16 among 16 at risk. These counts do not characterize event types or establish causal relationships. They also do not answer how safety compares with another option.

Overall, the record documents the study question, intervention, endpoint definition, and selected safety counts, but it does not provide outcome analyses needed to quantify results. It does not support a conclusion about the magnitude or precision of improvement, or a comparative assessment of benefits and harms. The statistical interpretation is constrained by the absence of posted endpoint results and by the single-group design.

14. Why This Trial Matters Statistically

This study illustrates an important distinction between registering an outcome and reporting its results. The registry gives a defined primary endpoint: a photographic improvement rating from baseline at 12 weeks post-final treatment, assessed by independent blinded reviewers. That definition helps clarify what the study intended to measure. But without the mean score, standard deviation, analysis population, or other results, readers cannot assess the observed magnitude or precision.

It also highlights how study design shapes interpretation. A single-group study can describe within-group observations, but it cannot directly compare the procedure with an alternative. The open-label status and absence of a separate comparator are relevant context, while the stated reviewer blinding is a distinct safeguard for the photographic ratings. Neither feature substitutes for reporting the actual endpoint analysis.

The safety record demonstrates why denominators and event detail matter. The serious adverse event denominator is 16, while total enrollment is 17, and the record does not explain the difference. The overall other adverse event count is listed, but event terms and details are not. Clear participant flow and event descriptions would help readers understand exactly what the safety counts cover.

Statistically, the record is a useful example of why an endpoint description, planning calculation, and trial result are different kinds of information. A planning illustration is not an observed finding, and a scale definition is not an estimate. Interpretation requires the analysis results, their uncertainty, and a transparent account of who contributed data. Those elements are not reported in the registry record summarized for this study.

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 most consequential limitation for statistical interpretation is that the registry record does not report the primary endpoint result or any analysis. The outcome is defined, but the mean rating, standard deviation, confidence interval, and analyzed participant count are not reported. As a result, the observed magnitude and precision cannot be evaluated.

The study is recorded as a single-group, open-label design with no comparator arm. Any within-group change would not provide a direct estimate of the difference between the procedure and another treatment. The primary endpoint specifies blinded photographic reviewers, but details about the blinding process, number of reviewers, and rating agreement are not reported in the registry record.

The enrollment total is 17, while the safety listings use a denominator of 16. The record does not explain this difference, and participant flow is not reported. The endpoint-specific denominator, completeness of photographs, and reasons for any missing observations are also not reported. These gaps prevent readers from evaluating whether the primary outcome analysis represents all enrolled participants.

Further limitations include the absence of reported eligibility and participant characteristics, procedural details, statistical analysis plan, and missing-data methods. The registry lists no serious adverse event terms and does not describe the other adverse events. The record also does not report the trial's sample-size justification. These omissions restrict assessment of generalizability, reproducibility, and the scope of safety and efficacy conclusions that can be drawn from the registry entry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Single-Center Open-Label Study of 1064 nm for Nonablative Skin Rejuvenation — NCT03421691.
• Registry record last updated 2023-09-06; status last verified 2023-08.
• Results first posted 2023-09-06.
• 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

NCT03421691 is a completed, single-center, open-label, single-group study sponsored by Cutera Inc. It records enrollment of 17 participants and evaluates the excel V Laser Genesis procedure utilizing a 1064 nm laser for skin rejuvenation. The recorded conditions are skin pigment and photoaging.

The primary endpoint is a mean improvement rating from baseline, based on post-treatment photographs at 12 weeks post-final treatment and assessed by independent blinded reviewers using the Physician's Global Assessment of Improvement Scale. The registry does not report the endpoint result or an analysis. Safety listings report 0 serious adverse events among 16 at risk, 0 deaths among 16 at risk, and other adverse events affecting 16 among 16 at risk. Further endpoint, analysis, participant-flow, and event details are not reported in the registry record.