This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study of a Novel Multi-Wavelength Laser for Tattoo Removal (NCT02910505), a na na study. The primary outcome is Tattoo Clearing as Rated by Investigator.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02910505 |
| Phase | NA |
| Condition | Tattoo Removal |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Cutera Inc. |
| Results posted | Yes |
2. Clinical Question
Population
People with tattoos enrolled in a single-center study. The registry reports enrollment of 8; further eligibility details and participant characteristics are not reported in the registry record.
Intervention
Treatment with the investigational Cutera enlighten laser, a device described as offering multiple wavelengths for tattoo removal.
Comparator
There is no separate comparison group in this single-group study. The registry lists allocation as NA, and the study is not a randomized comparison.
Primary question
What degree of tattoo clearing did the investigator rate 6 weeks post-final treatment, using the Physician's Global Assessment of Improvement?
This is a question about an investigator-rated outcome after treatment, rather than a comparison of the laser with another treatment or with no treatment. The registry identifies the primary measure as a score on a scale, with higher scores indicating better outcomes. Its categories range from 0, meaning no clearing, to 4, meaning very significant or complete clearing.
The record does not report the observed score, its standard deviation, or an analysis of the primary outcome. It therefore does not establish what clearing score participants received, how varied their scores were, or how precisely the average score was estimated. It also does not report participant-level factors that would help describe to whom the findings might apply.
3. Trial Design
This was a completed, single-group device study with enrollment of 8. The registry describes it as a single-center study evaluating the safety and efficacy of an investigational version of the Cutera enlighten laser for tattoo removal. The listed intervention is the enLighten Laser, and the treatment arm is described as treatment with the investigational Cutera enlighten laser.
The record lists allocation as NA, masking as NONE, and the model as SINGLE GROUP. There is no randomized assignment or like-for-like control group. Consequently, the study is not structured to estimate a comparative treatment effect. Its primary outcome is an investigator rating following treatment, not a difference between assigned groups.
The study start is recorded as 2016-10, and primary completion as 2017-06-28. Its status is COMPLETED. Completion describes the registry status; it does not itself show that outcome results were entered or analyzed. The record lists one outcome measure and zero analyses. It gives no primary outcome estimate, standard deviation, confidence interval, or p-value.
The registry does not report the treatment schedule, number of treatment sessions, laser settings, tattoo characteristics, or details of the assessment process beyond the stated rating and timeframe. It also does not report a protocol rationale for enrollment of 8, or the methods used to select and enroll participants. Those omissions limit assessment of how the study was conducted and how broadly its results could apply.
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
| Stage | Treatment |
|---|---|
| STARTED | 8 |
| COMPLETED | 1 |
| NOT COMPLETED | 7 |
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.
| Characteristic | Unit | Treatment |
|---|---|---|
| Participants analysed | 8 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 |
| Race (NIH/OMB): White | Participants | 7 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Tattoo Clearing as Rated by Investigator, measured over 6 weeks post-final treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is tattoo clearing as rated by the investigator, measured as a score on a scale 6 weeks post-final treatment. The registry describes the assessment as the Physician's Global Assessment of Improvement. Scores are ordered from 0, no clearing, through 1, mild clearing, 2, moderate clearing, and 3, significant clearing, to 4, very significant or complete clearing. Higher scores indicate better outcomes.
An investigator rating gives a structured way to characterize the observed degree of clearing at a stated time after treatment. It can summarize a clinical assessment on a common scale, but it is not a direct measure of tattoo pigment or a patient-reported outcome. The registry does not describe assessor training, whether ratings were independently checked, or whether the rating procedure was standardized across participants.
The endpoint is specified as a mean, with standard deviation as the measure of dispersion. A mean can summarize the center of numeric scores, while the standard deviation describes how spread out the scores are around that center. General statistical caution applies because the listed response categories are ordered ratings with a bounded range. Treating category steps as equally spaced is an assumption; the registry does not explain whether that assumption was evaluated.
No observed mean or standard deviation is reported in the registry record. Thus the endpoint definition is available, but its result and the variation in ratings are not.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a clinically interpretable primary outcome and a defined assessment time: investigator-rated tattoo clearing 6 weeks post-final treatment. It also states the direction of the scale, from no clearing at 0 to very significant or complete clearing at 4. These details clarify what the study intended to measure. They do not supply the observed outcome.
No primary outcome result is reported in the registry record. There is no mean score, standard deviation, confidence interval, or p-value, and the registry lists zero analyses. Consequently, there is no posted numerical estimate of the average clearing rating and no reported measure of uncertainty around such an estimate. The available record cannot show whether observed scores clustered near one category or varied across the scale.
Because this is a single-group study, even a reported average score would describe outcomes in the treated group, rather than a difference between treatment and control. Without a comparison group, changes attributable to treatment cannot be separated from other possible explanations, such as natural changes over time, participant selection, or the way the assessment was made. These are general limitations of interpreting an uncontrolled study, not claims that any particular alternative explanation occurred in this study.
The enrollment of 8 is relevant to the scale of the study, but enrollment alone does not reveal how many participants contributed to the primary endpoint. The analysis population and the number with an outcome assessment are not reported in the registry record. It is therefore not possible to determine whether outcome data were available for all enrolled participants or whether any missing observations affected the summary.
The record does report safety counts. For the treatment group, 0 of 8 participants at risk are listed as having a serious adverse event, and 0 deaths are reported among 8 at risk. The registry also lists 8 of 8 at risk as affected by other adverse events. These are separate categories; the other-adverse-event count should not be read as a serious-adverse-event count. The record does not provide additional detail about the non-serious events in the registry record.
Sample-size planning illustrations, where reported, should be understood as planning calculations rather than evidence about the precision of this study's result. The stated assumptions use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a fraction of the observed effect. They are not observed power. Since the registry record does not report the primary outcome result, no conclusion about the observed magnitude or precision can be drawn from those planning assumptions alone.
9. Statistical Methods Explained
The primary endpoint is described using a mean and standard deviation. In general, a mean is a measure of the center of a set of numeric observations. A standard deviation describes their spread around that center. Together, they can convey both an average rating and how much individual ratings differ. They do not, by themselves, show the full distribution, such as whether ratings concentrate in particular categories or whether the data are asymmetric.
There is an important measurement consideration for this endpoint. The categories from 0 to 4 have a clear order, but the registry does not establish that the distance between adjacent categories is equivalent. Calculating a mean treats the scale as numeric in a way that makes the category steps comparable. As a general matter, that can be a useful summary, but readers should recognize the underlying assumption. A mean can also fall between response categories even though no participant selected that exact value. No distributional summary or alternative analysis is reported in the registry record.
A confidence interval, in general, describes a range of values compatible with the data and the statistical procedure used, while reflecting sampling uncertainty. It is not a guarantee that the true value lies within the interval. For a mean score, an interval would help communicate how precisely the average was estimated. The registry record does not report a confidence interval for the primary outcome, because it does not report an outcome analysis or a mean estimate.
A p-value, in general, quantifies how unusual data at least as extreme as those observed would be under a specified null model and assumptions. It does not measure the size or clinical importance of an effect, and it is not the probability that a hypothesis is true. A p-value also requires a defined inferential question and analysis. No primary outcome p-value or statistical test is reported in the registry record. It would therefore be inappropriate to infer statistical significance or to reconstruct a test from the endpoint description alone.
Dispersion matters because participants' ratings may not all be alike. In general, over-dispersion means that variability is greater than a statistical model expects. If a method assumes less variation than is present, uncertainty can be understated and inferential conclusions can be too confident. The registry specifies standard deviation as the dispersion measure for the primary endpoint, but does not report its value or describe a model for the outcome. Whether over-dispersion was assessed is not reported in the registry record.
For continuous outcomes, general choices can include methods based on a mean and methods that make fewer assumptions about the distribution. The suitability of a method depends on the measurement scale, the distribution of observations, the research question, and the analysis plan. The record does not report which inferential method, if any, was planned for this endpoint. The outcome being labeled as a mean does not establish a particular test or model.
In a single-group study, an outcome mean is descriptive of participants with measured outcomes. It is not a treatment-versus-control contrast. General causal interpretation is more limited without a comparison group, since there is no concurrent estimate of what would have happened under an alternative condition. The registry's design fields identify a single group and no random allocation, so the primary question should be read as a post-treatment description, not a randomized efficacy comparison.
The registry states that planning illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These are planning assumptions, not a report of this study's analysis. In general, sample-size calculations estimate the number of participants needed for a chosen design and target effect under stated assumptions. A calculation based on an observed effect can be sensitive to that estimate, and it does not establish that the original study had adequate power. Such planning figures are not observed power and do not replace an outcome estimate with its uncertainty.
There are no recalculated primary outcome statistics to compare with a sponsor analysis in the registry entries. The record lists zero analyses and does not report the primary result. It also does not report an analysis plan, a prespecified test, an adjustment model, or a decision rule. The statistical method used for the primary endpoint is therefore not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and zero analyses. The primary outcome is identified as investigator-rated tattoo clearing 6 weeks post-final treatment. These entries do not establish whether the protocol included other outcomes, exploratory analyses, or multiple time points beyond what the registry record lists. A full multiplicity plan is not reported in the registry record.
Multiplicity arises in general when several hypotheses or outcomes are tested, because repeated testing can increase the chance of at least one apparently notable finding by chance. Statistical plans may address this through prespecified priorities or adjustments, but the appropriate approach depends on the study aims and analysis. The record does not report whether any multiplicity adjustment or hierarchy of outcomes was planned. Since no primary analysis is reported, there is no posted p-value set from which to assess how multiplicity was handled.
Missing-data handling is also not reported in the registry record. Enrollment of 8 does not establish that all participants completed treatment or had a rating at the specified assessment time. The safety risk set is 8 for the reported treatment group, but that safety count does not establish the number included in the primary outcome analysis. The number with endpoint data, reasons for missingness, and any method for handling missing observations are not reported.
The analysis population is not reported in the registry record. It is therefore not possible to tell whether the endpoint was intended to be analyzed among all enrolled participants, those who received treatment, or participants with available assessments. No assumptions about missing outcomes or exclusions should be made from the record alone.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Treatment | 0 | 8 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment | 0 of 8 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment | 8 of 8 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Treatment |
|---|---|---|
| Erythema | Skin and subcutaneous tissue disorders | 8 of 8 |
| Edema | Skin and subcutaneous tissue disorders | 7 of 8 |
| Purpura | Skin and subcutaneous tissue disorders | 1 of 8 |
The registry lists serious adverse event counts for the Treatment group. There were 0 participants affected among 8 at risk, and deaths were 0 among 8 at risk. These figures describe the recorded serious-event and death counts in the registry; they do not establish that all possible safety outcomes were assessed or reported.
The same record lists 8 participants affected by other adverse events among 8 at risk. This is a separate category from serious adverse events. The event terms, severity breakdown, timing, and participant-level details for those other adverse events are not reported in the registry record details. No serious-event terms are listed.
These counts should be read as descriptive safety information for a small single-group study, not as a comparative risk estimate. There is no control group for comparison, and the record does not report an analysis of safety rates. A count of zero serious events in the registry does not prove that serious events cannot occur, while the other-adverse-event count alone does not identify the type or clinical significance of those events. Further details are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed, single-group study evaluated an investigational multi-wavelength laser for tattoo removal and specified investigator-rated tattoo clearing 6 weeks post-final treatment as its primary outcome. It describes the score categories, their direction, the summary measure, and the planned timeframe. It also reports enrollment of 8 and basic safety counts for the treatment group.
However, the registry record does not report the observed primary outcome result. No mean score, standard deviation, confidence interval, or primary outcome analysis is listed. The endpoint's description is not evidence that any particular amount of clearing was observed. The record cannot support a conclusion about the average rating, participant-to-participant variability, or precision of an outcome estimate.
The design also limits what can be inferred. With one group and no randomized comparator, the study does not estimate a difference between the laser and another treatment or a control condition. In general, an outcome observed after treatment cannot alone establish that treatment caused the outcome. Any comparative or causal interpretation would require evidence not reported in this registry record.
The safety entries are descriptive: no serious adverse events and no deaths are listed among the 8 at risk, while other adverse events are listed for 8 of 8. The record does not provide event terms or a comparison group. These entries should not be extended beyond the categories and counts recorded.
Overall, the registry gives information about study design, endpoint definition, timing, and recorded safety counts, but not the primary numerical result. The statistical interpretation is consequently limited to what was planned and recorded, rather than a judgment about the magnitude, precision, or comparative effect of the laser.
13. Why This Trial Matters Statistically
Small single-group device studies can be statistically informative when their outcomes and assessment procedures are clearly defined. This record names a primary rating, explains the score direction and categories, and specifies the timing relative to the final treatment. Those details make the intended measurement more interpretable than an outcome label without a scale or timeframe.
The record also illustrates why a well-defined endpoint is not a substitute for a reported result. A mean and standard deviation are specified, but neither the mean nor the standard deviation appears in the registry record. Without those values, readers cannot describe the observed level or spread of ratings, and without an uncertainty estimate they cannot assess precision. The record lists zero analyses, leaving the primary outcome statistically unevaluated in the posted results.
The single-group design is important when framing the question. A post-treatment score can describe the treated participants, but the absence of a comparator means the design does not provide a randomized estimate of a treatment contrast. This distinction is central to statistical interpretation: the question the design can address is narrower than whether the intervention outperforms an alternative.
The safety counts also show why categories must be kept distinct. The record reports no serious adverse events but reports other adverse events for all 8 participants at risk. Without event descriptions or comparative data, those counts are informative as registry entries but do not characterize the events in detail or estimate relative safety.
For clinical researchers and biostatisticians, the record highlights the value of transparent reporting of outcome summaries, uncertainty, analysis populations, missing data, and methods. Those details would be needed to interpret the primary measure beyond its definition.
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 main limitation for statistical interpretation is that the primary outcome result is not reported in the registry record. Although the endpoint, scale, summary parameter, dispersion measure, and assessment timeframe are specified, there is no mean, standard deviation, confidence interval, or p-value. The registry lists zero analyses.
The single-group design has no randomized comparator, so it cannot estimate a between-group treatment effect. The absence of masking, recorded as NONE, may also be relevant to an investigator-rated endpoint: in general, awareness of treatment can influence subjective assessment. The record does not report whether any safeguards were used to standardize or verify ratings.
Enrollment was 8, and the primary outcome analysis population is not reported. The number of participants with an assessment, any exclusions, and reasons for missing outcome data are also not reported. The record does not describe eligibility criteria or participant characteristics in the registry record, limiting assessment of representativeness.
Further study details are not reported in the registry record, including the treatment schedule, number of sessions, device settings, tattoo characteristics, and rating procedures beyond the named scale and timeframe. The statistical analysis plan, sample-size justification, missing-data methods, and multiplicity approach are not reported. The planning assumptions described in the record do not fill those gaps or provide observed evidence about outcome precision.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of a Novel Multi-Wavelength Laser for Tattoo Removal — NCT02910505.
- Registry record last updated 2023-09-21; status last verified 2023-09.
- Results first posted 2023-09-21.
- 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.
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18. Record Summary
NCT02910505 is a completed, single-center, single-group study of an investigational version of the Cutera enlighten laser for tattoo removal. The registry reports enrollment of 8, allocation as NA, and masking as NONE. The study start is recorded as 2016-10, and primary completion as 2017-06-28.
The primary outcome is investigator-rated tattoo clearing 6 weeks post-final treatment, summarized as a mean score with standard deviation. Scores range from 0 for no clearing to 4 for very significant or complete clearing, with higher scores indicating better outcomes. The observed result is not reported in the registry record, which lists one outcome measure and zero analyses.
For the treatment group, the registry reports 0 serious adverse events among 8 at risk, 0 deaths among 8 at risk, and other adverse events affecting 8 of 8 at risk. Details of those other events are not reported in the registry record details.