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 Comparison of Efficacy, Safety and Tolerability of Two Different 810 nm Diode Lasers for Hair Reduction (NCT01212172), a randomized phase 3 study. The primary outcome is Change in Hair Growth.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01212172 |
| Phase | Phase 3 |
| Condition | Hypertrichosis |
| Allocation | Randomized |
| Design model | Single Group |
| Masking | Double |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of California, Irvine |
| Results posted | Yes |
2. Clinical Question
Population
The registry record concerns participants with hypertrichosis undergoing laser hair removal. It lists 20 enrolled participants and describes treatment of the lower legs or axilla. Further eligibility criteria, participant characteristics, and the analysis population for the hair-growth outcome are not reported in the registry record.
Intervention
One device was the Alma Soprano/SHR 810 nm diode laser, described as using low fluence and a high repetition rate in the official title. The brief summary identifies this system as Soprano XL in SHR mode. Device settings and treatment procedures beyond these descriptions are not reported in the registry record.
Comparator
The comparator was the LightSheer Duet 810 nm diode laser, described in the official title as using low fluence with vacuum assistance. The registry describes the study as a side-by-side, split-extremity comparison, but does not give further procedural details about how treatment sites were selected, assigned, or assessed.
Primary question
The primary question was how hair growth changed from baseline after treatment with each laser system. The endpoint was percentage reduction from baseline hair count at 1 month, 6 months, and 12 months following the last, fifth laser treatment. The registry record does not report the numerical hair-reduction results or a direct comparison between devices. It also lists a Pain Rating Scale as a secondary outcome, but does not report its results.
This is a device-to-device comparison, not a comparison of laser treatment with no treatment or with a different type of hair removal. That distinction matters when interpreting any result: a between-device contrast would address relative outcomes under the study conditions, not the effect of laser treatment versus an untreated condition. Since numerical primary outcome results are not reported in the registry record, the relative hair-reduction outcomes cannot be described from the record.
The question is clinically framed around hair reduction as well as subjects’ perspectives on tolerability and effectiveness. The registry lists the Pain Rating Scale as a secondary outcome and describes tolerability and perceived effectiveness in the brief summary. It does not report how those perspectives were measured beyond the named pain scale, or provide numerical findings for them.
3. Trial Design
The record identifies this as a Phase 3, randomized, double-masked study sponsored by the University of California, Irvine. It lists 20 participants as enrolled and gives the status as completed. The recorded start is 2010-09, and primary completion is recorded as 2013-09. These are registry entries; the record does not provide a fuller account of recruitment, treatment delivery, or follow-up conduct.
The official title describes a side-by-side comparison on an extremity, while the brief summary says the study aimed to compare the two 810 nm diode laser systems on the lower legs or axilla. The intervention descriptions identify Soprano/SHR and LightSheer. The record’s design descriptors include randomized allocation and double masking, and it also labels the model as single group. It does not explain how those descriptors were implemented together, how body sites were assigned, or who was masked. Those details should not be inferred from the title alone.
A split-extremity comparison can, as a general design concept, allow two treatments to be assessed within the same participant. Such designs may reduce the influence of participant-level differences when the treated sites are appropriately matched and the analysis accounts for the pairing. The registry record does not report the specific site-allocation process, whether all participants received both devices, or whether the analysis treated observations as paired. The side-by-side wording therefore supplies context, but is not enough to establish the exact analysis structure.
The primary outcome is change in hair growth, expressed as percentage reduction from baseline hair count. It is assessed at 1 month, 6 months, and 12 months following the last (5th laser) treatment. The record lists two outcome measures and one analysis, but does not identify a single primary time point or explain how outcomes across the listed time points were handled. Numerical primary outcome values, variability estimates, and a between-device estimate are not reported in the registry record.
The registry also lists Pain Rating Scale as a secondary outcome. It reports serious and other adverse-event counts by device group, but these counts do not substitute for the primary hair-growth outcome or the secondary pain assessment. The participant flow, exclusions, missing follow-up data, and analysis populations 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
| Stage | Soprano Duet 810 nm Diode Laser | LightSheer Duet 810 nm Diode Laser |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 9 | 9 |
| NOT COMPLETED | 1 | 1 |
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 | Side-by Side Comparsion of Soprano/SHR to Light Sheer |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 20 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 20 |
| Sex: Female, Male: Male | Participants | 0 |
| Region of Enrollment: United States | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Hair Growth, measured over 1 month, 6 month, 12 month.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | % hair reduction |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in hair growth, measured as percentage reduction from baseline hair count. In general, an endpoint based on change from baseline describes how a measured outcome differs from its starting value. Here, the specified measurement is hair count, and the percentage-reduction scale expresses the change relative to baseline rather than as a raw count difference.
The registry specifies assessment at 1 month, 6 months, and 12 months after the last, fifth laser treatment. These follow-up points address outcomes at different intervals after treatment; they should not be treated as interchangeable measurements. The record does not designate one of these time points as the sole primary comparison, nor does it explain whether the analysis considered each visit separately or used another approach.
Hair count is used because the stated research question concerns reduction in the amount of hair. A count-based measure offers an objective way to quantify that target, while a percentage change expresses the result relative to the participant’s baseline count. In general, interpretation also depends on how hair was counted, how sites were chosen, who performed assessments, and how counts were kept consistent across visits. Those measurement procedures are not reported in the registry record.
The endpoint is not a direct measure of every aspect of the treatment experience. The brief summary also refers to subjects’ perspectives on tolerability and effectiveness, and the registry names Pain Rating Scale as a secondary outcome. Those are distinct from hair-count reduction. Since numerical results for the primary endpoint are not reported in the registry record, the magnitude and precision of hair reduction at any listed follow-up point, and any difference between devices, cannot be assessed from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The main interpretive constraint is that the registry record describes the primary outcome but does not report its numerical results. It identifies percentage reduction from baseline hair count at 1 month, 6 months, and 12 months after the last treatment. However, no means, standard deviations, confidence intervals, p-values, or device-to-device effect estimates for hair reduction are reported in the registry record. It is therefore not possible to state which device had a larger observed reduction or how precisely any difference was estimated.
The record lists one analysis and two outcome measures, and it explicitly indicates that the primary outcome has several time points and was not reduced to one comparison. That distinction matters: several assessments over time can support different questions, such as whether outcomes differ at a particular visit or how patterns evolve across visits. Without the results and analysis details, neither the direction nor the strength of a time-specific or overall comparison can be described.
Twenty participants were enrolled. That enrollment count alone does not establish how many contributed data at each visit, whether all participants received both devices, or how many observations entered the primary analysis. The number of participants included in the primary outcome analysis and the handling of incomplete follow-up are not reported in the registry record. In particular, an enrollment count should not be read as the denominator for every endpoint.
The safety entries list no serious adverse events affecting participants in either device group: 0 of 20 at risk for Soprano/SHR and 0 of 20 at risk for Light Sheer. The record also lists other adverse events affecting 6 of 20 in the Soprano/SHR group and 5 of 20 in the Light Sheer group. These are event-category counts, not measures of hair reduction or pain, and do not establish the comparative safety profile on their own. The death entries are null rather than numerical counts, so deaths are not reported in the registry record.
There is no basis in the registry record for a claim about statistical significance or clinical importance of the primary outcome. A p-value would address compatibility with a specified statistical null under an analysis model; it would not, by itself, describe the size or practical importance of a difference. An effect estimate and an interval would be needed to assess magnitude and precision. Neither is reported for hair reduction.
The registry’s planning assumptions describe an illustration based on an observed effect, with two-sided significance level 0.05, equal allocation, and a normal approximation. Those planning illustrations are not trial outcomes or observed power. The numerical planning outputs are not reported in the registry record. More importantly, because the observed primary effect itself is not reported, no conclusion about the trial’s ability to detect a particular effect should be drawn from enrollment alone.
9. Statistical Methods Explained
Statistical interpretation begins with the outcome’s scale and the structure of the comparison. The primary measure is percentage reduction from baseline hair count, summarized using a mean and standard deviation according to the registry description. A mean gives the average outcome within the observations being analyzed. A standard deviation describes how spread out individual observations are around that mean. Neither quantity is reported numerically for the primary outcome in the registry record.
What does a mean describe?
For a continuous measure, the mean is a compact description of the central value in a group or at a visit. In this trial, it would describe average percentage hair reduction for a device at a specified follow-up point, if those results were reported. The mean alone does not show whether participants had similar outcomes or whether outcomes varied substantially. The standard deviation provides information about that variability, but it is not a confidence interval and does not directly express uncertainty in the estimated mean.
When the purpose is to compare devices, the contrast between their outcomes is usually more informative than either group’s mean in isolation. A direct contrast estimates the difference between device outcomes under the specified analysis. The interpretation of such a contrast depends on its direction, size, and uncertainty. The registry record does not report a numerical contrast, confidence interval, or p-value for the primary endpoint, so these features cannot be evaluated.
Why does the split-extremity description matter?
As a general statistical concept, a within-participant or paired comparison uses the fact that two observations may come from the same person. If the two treated sites are appropriately paired, the analysis can focus on the within-person difference rather than treating all site observations as independent. This may account for stable characteristics shared by the participant. The statistical method must reflect the actual assignment and measurement structure. Although the official title describes a side-by-side, split-extremity study, the registry record does not report whether the primary analysis used paired differences or another method.
Randomized allocation is listed, but the precise unit of randomization and the assignment procedure are not reported in the registry record. The record also labels the model as single group while naming two device interventions. It does not explain the relationship between those design descriptors. The analysis method, including any adjustment for pairing or other covariates, is not reported in the registry record. It would be inappropriate to assume a particular model or test solely from the title or the design labels.
What does a confidence interval contribute?
In general, a confidence interval gives a range of values compatible with the data and the assumptions of a specified statistical method. It conveys uncertainty around an estimate and helps readers judge whether the data are consistent with a narrow range of effects or a wider range. Its interpretation depends on the model, the observations included, and the way the interval was calculated. No confidence interval for the primary hair-reduction comparison is reported in the registry record.
A p-value, in general, summarizes how unusual data at least as incompatible with a specified null hypothesis would be if that null and the analysis assumptions held. It does not measure the probability that the null is true, and it does not tell readers whether a difference is important. A p-value for the primary outcome is not reported in the registry record. Without an estimate and its uncertainty, a significance label alone would not be enough to judge the size or precision of a treatment contrast in any event.
How should repeated follow-up be considered?
The primary endpoint is assessed at 1 month, 6 months, and 12 months after the last treatment. Repeated measurements from the same participant are generally related rather than independent. General methods for repeated outcomes account for that relationship and distinguish time-specific comparisons from an overall pattern. The registry record does not report whether a repeated-measures method was used, whether each time point was analyzed separately, or how the several time points were handled in the single listed analysis.
Multiple assessments can also raise multiplicity concerns. In general, testing or interpreting several outcomes or time points can increase the chance that at least one result appears noteworthy by chance if no adjustment or prespecified hierarchy is used. Whether multiplicity was addressed, and how, are not reported in the registry record. The existence of several time points does not establish that a particular correction was required or used; that depends on the planned inferential questions and analysis strategy, which are not reported.
What do planning calculations mean?
The registry describes planning illustrations based on an observed effect. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are planning assumptions, not a report of the trial’s design justification. The sample-size justification and numerical planning outputs are not reported in the registry record. Because the observed primary effect is also not reported, the planning framework cannot be independently interpreted from the registry information alone.
General sample-size calculations estimate how many observations might be needed to detect an effect under specified assumptions. A planning illustration based on an observed effect does not establish the probability that the completed study detected that effect, and it is not observed power. Such calculations depend on the effect size, variability, allocation, outcome structure, and analysis assumptions. The registry does not report enough primary outcome information to assess those inputs for this comparison.
Overall, the endpoint definition and some design labels are available, but the inferential results and the statistical analysis details needed to interpret them are not. General statistical principles help explain what those missing items would contribute; they cannot substitute for the unreported estimates and methods.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome has three stated follow-up points: 1 month, 6 months, and 12 months after the last treatment. The registry notes that the outcome has several time points and was not reduced to one comparison. It lists one analysis, but does not explain whether that analysis refers to one time point, a combined approach, or another summary. The prespecified primary time point, if any, is not reported in the registry record.
In general, multiplicity arises when several statistical comparisons are considered together. Repeated time points, more than one outcome, or multiple treatment contrasts can create several opportunities to observe an apparently unusual result. Methods for addressing multiplicity may include defining a primary comparison in advance, using a testing hierarchy, or adjusting inference. Which approach is suitable depends on the study’s questions and statistical plan. Whether any such approach was prespecified or used is not reported in the registry record.
The registry names Pain Rating Scale as a secondary outcome and identifies two outcome measures overall. Its numerical results and analysis details are not reported in the registry record. The record does not specify whether the secondary outcome was inferential, descriptive, or part of a multiplicity strategy.
Missing-data handling and the analysis populations are also not reported in the registry record. The enrollment count is 20, but that does not disclose the number with hair-count observations at each follow-up, the number completing all follow-up, or the number included in the analysis. The record does not describe exclusions, withdrawals, imputation, or a rule for analyzing incomplete observations. It also does not state whether analyses followed an intention-to-treat principle or another population definition. As a result, the completeness and representativeness of the primary analysis cannot be assessed from the registry record.
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 |
|---|---|---|---|
| Soprano/SHR 810 nm Diode Laser | 0 | 20 | 0.0% |
| Light Sheer 810 nm Diode Laser | 0 | 20 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Soprano/SHR 810 nm Diode Laser | 6 of 20 |
| Light Sheer 810 nm Diode Laser | 5 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Soprano/SHR 810 nm Diode Laser | Light Sheer 810 nm Diode Laser |
|---|---|---|---|
| Burn | General disorders | 6 of 20 | 5 of 20 |
The registry reports serious adverse events by device group. For Soprano/SHR 810 nm Diode Laser, 0 of 20 participants at risk were listed as affected by a serious adverse event. For Light Sheer 810 nm Diode Laser, the corresponding count was also 0 of 20. These entries describe the recorded serious-event counts for the groups and period represented in the registry results.
The record also lists other adverse events: 6 of 20 participants at risk in the Soprano/SHR group and 5 of 20 in the Light Sheer group were affected. The registry does not provide event terms for these other events in the information, nor does it explain their severity, timing, duration, or relationship to treatment. They should not be assumed to have been pain ratings or primary hair-growth outcomes.
A zero serious-event count does not show that the risk is absent; it means that no serious events were recorded among the participants at risk in these entries. With 20 listed at risk in each group, the counts summarize a limited group and do not characterize every possible adverse event or longer-term safety experience. The death entries are null, not numerical zeroes, so deaths are not reported in the registry record. The safety counts alone do not establish that one device is safer than the other.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed study was registered as a randomized, double-masked comparison of two 810 nm diode laser systems. It describes a primary hair-growth outcome, its measurement scale, and three follow-up points after the last treatment. It also records enrollment and adverse-event counts. These are useful features for understanding what the study was intended to examine.
The record does not establish the magnitude of hair reduction with either device, the difference between devices, or the precision of that difference. Numerical primary outcome means and standard deviations, effect estimates, confidence intervals, and p-values are not reported in the registry record. Therefore, the registry information does not support a conclusion that one device produced more or less hair reduction, or that their outcomes were similar.
Absence of a reported difference is not evidence that the devices were equivalent. Equivalence or non-inferiority requires a defined margin and an analysis designed to assess that question; such a margin and analysis are not reported in the registry record. Similarly, a claim of statistical significance or lack of significance cannot be made without the relevant results and analysis details.
The brief summary refers to subjects’ perspectives on tolerability and effectiveness, and the registry lists Pain Rating Scale as a secondary outcome. The corresponding numerical results are not reported in the registry record. The adverse-event entries provide limited descriptive safety information, but they do not answer the efficacy question and do not fully describe tolerability.
Finally, enrollment of 20 does not by itself show whether the study was adequately powered, whether all participants completed follow-up, or whether the results would generalize beyond the study participants and settings. The sample-size justification, analysis populations, and participant characteristics are not reported in the registry record. The most defensible reading is therefore descriptive: the record identifies the planned comparison and some safety counts, while leaving the primary efficacy results and key analysis details unavailable.
13. Why This Trial Matters Statistically
This study illustrates why a registry entry should be read in layers. The design labels, outcome definition, time points, and safety counts each answer different questions. A completed status and a stated primary endpoint do not by themselves provide the evidence needed to compare outcomes; numerical estimates and their uncertainty are also necessary. Here, the primary outcome is clearly described, but its results are not reported in the registry record.
The side-by-side, split-extremity framing also highlights a central statistical issue: observations from the same participant may be related. If treatment sites are paired within participants, an analysis that recognizes that pairing can differ from one that treats observations as unrelated. The registry does not report the assignment details or analysis method, so readers cannot determine how that feature was handled. This makes the study a useful example of why a design title is not a substitute for an analysis description.
Several follow-up points create another interpretive issue. Hair reduction was assessed at 1 month, 6 months, and 12 months after the last treatment, but the registry does not identify a single primary time point or explain how the time points were analyzed. That leaves unresolved whether the intended emphasis was a particular visit, a trend over time, or another summary. Without that information, a reader cannot evaluate the inferential target or multiplicity handling.
The safety entries further show why denominator and event categories matter. The record distinguishes serious from other adverse events and gives participants at risk for each group. Those counts should be read as descriptive entries, not as a complete characterization of safety or a substitute for comparative outcome estimates. Overall, the record offers useful design context while demonstrating the limits of drawing conclusions when the principal outcome analysis is absent.
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 interpretation is the absence of numerical primary outcome results. Although the registry specifies percentage reduction from baseline hair count and three assessment times, it does not report the observed values, variability, or direct comparison between devices. The primary efficacy question therefore cannot be answered from the registry record.
The record does not report the statistical analysis method, the primary time point, or how the several follow-up assessments were handled. The design description combines randomized and double-masked labels with a single-group model and a side-by-side split-extremity title, but does not explain the operational details. The randomization unit, site assignment, masking procedures, and use of paired analysis are not reported in the registry record.
Participant flow and endpoint denominators are also unavailable. The record lists 20 enrolled, but does not state how many contributed hair-count data at each follow-up or whether any participants withdrew or were excluded. Missing-data handling and the analysis population are not reported. Without these details, it is not possible to assess the completeness of follow-up or the potential effect of missing observations.
The record provides limited detail about the outcome measurement process. Procedures for selecting and counting hair, maintaining consistency across assessment visits, and handling differences between body sites are not reported in the registry record. Participant characteristics and eligibility criteria beyond the stated condition are also not reported, limiting assessment of how representative the enrolled group may have been.
Finally, the safety information gives counts but not the terms and circumstances of the other adverse events. The death entries are null, and no numerical results are given for the Pain Rating Scale. These limitations do not show that the study was conducted poorly; they describe what cannot be evaluated from the registry information available.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparison of Efficacy, Safety and Tolerability of Two Different 810 nm Diode Lasers for Hair Reduction — NCT01212172.
- Registry record last updated 2016-02-05; status last verified 2015-10.
- Results first posted 2016-02-05.
- 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
NCT01212172 is a completed Phase 3 study sponsored by the University of California, Irvine. The registry lists randomized allocation, double masking, a single-group model, and 20 enrolled participants. The study compared the Soprano/SHR 810 nm diode laser with the LightSheer Duet 810 nm diode laser for hair reduction.
The primary outcome was percentage reduction from baseline hair count at 1 month, 6 months, and 12 months following the last, fifth laser treatment. Pain Rating Scale was listed as a secondary outcome. The registry record does not report numerical primary outcome or pain-scale results, the analysis method, or the analysis populations.
Serious adverse events affected 0 of 20 participants at risk in each device group. Other adverse events affected 6 of 20 in the Soprano/SHR group and 5 of 20 in the Light Sheer group. Deaths are not reported in the registry record. These entries do not provide a numerical comparison of hair reduction or establish a difference between the devices.