Comparative Study Between CellFX and Electrodessication in Sebaceous Hyperplasia (SH) Lesions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparative Study Between CellFX and Electrodessication in Sebaceous Hyperplasia (SH) Lesions (NCT04539886), a randomized na study. The primary outcome is Percentage of Lesions With Improvement as Assessed With the Global Aesthetic Improvement Scale (GAIS).

2. Clinical Question

This question concerns an investigator-rated lesion outcome, not a participant-level measure of overall health or satisfaction. It is also distinct from a question about safety: adverse events are recorded separately. The results should therefore be read as a comparison of the posted lesion-improvement percentages at the specified assessment, with the uncertainty indicated by their confidence intervals. They do not by themselves establish that the treatments are equivalent, or that one is better than the other.

3. Trial Design

The registry describes a multicenter, prospective, randomized, single-blinded, parallel-group study comparing the CellFX System with electrodessication for sebaceous hyperplasia lesions. The study status is completed. Enrollment is listed as 60. The recorded start date is 2020-09-28, and the primary completion date is 2021-02-02. The study phase is listed as NA.

The two intervention groups are described as participants treated with the CellFX System and participants treated with intralesional electrodessication. The CellFX intervention uses an electrical pulse console, a handpiece, and a sterile single-patient-use tip; the registry lists several tip sizes. The comparator uses a Hyfrecator electrosurgical unit and a non-insulated epilation needle electrode to apply current within a lesion. Further details of how treatment was delivered, including the full description of the CellFX energy setting, are not reported in the registry record.

The primary effectiveness assessment was made by a blinded investigator during a live assessment. The registry calls the study single-blinded, but the identity of the party or parties who were masked is not reported in the registry record. Details of the randomization sequence, allocation concealment, and any procedures used to maintain masking are also not reported in the registry record.

The reported arm results give n=59 for each group, while the registry enrollment is 60. The record does not explain the relationship between enrollment and the arm-level result counts. Because the primary endpoint is expressed as a percentage of lesions, and the arm results are labeled as participants treated, the exact lesion and participant denominators for the endpoint are not clear from the registry record. This distinction matters: a participant count is not necessarily the number of lesions assessed.

The primary assessment was scheduled for 60 days post last treatment, up to a maximum of 3 months. The registry does not report a detailed schedule of visits, treatment frequency, or how lesions were selected for assessment beyond the description of 2.5mm lesions.

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: Not applicable, since randomization occurred at the time of enrollment, defined as the time when intervention of the device occurred.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 2.5mm SH lesions were assessed at 60-days post-last treatment of the lesion with either CellFX or Electrodessication by blinded Investigator during live assessments using Global Aesthetic Improvement Scale (GAIS). The Global Aesthetic Improvement Scale ranges from 1=Very Much Improved or Excellent Corrective Result to 5=Worsened Appearance Compared with Original Condition.

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: The Study Design was a split-face design, so all 60 participants are presented in the baseline analysis population.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Lesions With Improvement as Assessed With the Global Aesthetic Improvement Scale (GAIS), measured over 60 days post last CellFX or Electrodessication treatment, up to a maximum of 3 months..

The primary endpoint is the percentage of sebaceous hyperplasia lesions judged to have improved on the Global Aesthetic Improvement Scale (GAIS). A blinded investigator made the assessment live at 60 days after the last CellFX or electrodessication treatment, up to a maximum of 3 months. The primary endpoint description specifically refers to 2.5mm lesions.

The registry describes GAIS as a five-point scale ranging from 1, “Very Much Improved or Excellent Corrective Result,” to 5, “Worsened Appearance Compared with Original Condition.” The outcome turns that rating into a percentage of lesions with improvement. However, the precise rating or ratings counted as “improvement” are not stated in the registry record. That missing definition makes it harder to reproduce the endpoint from individual ratings or to assess exactly how borderline ratings were classified.

General explanation: a percentage provides an interpretable summary of how often an event or classification occurred in the assessed units. Here the unit named in the endpoint is a lesion, not necessarily a participant. The result can therefore describe lesion appearance while not capturing how many participants experienced improvement across all of their lesions. Those are different questions.

A confidence interval accompanies each percentage. General explanation: a confidence interval communicates the statistical uncertainty around an estimate under the assumptions of the method used to calculate it. Its width is relevant to precision; it does not show that a treatment effect is certain, and it is not a guarantee that the true value lies within the interval. The method used to calculate these intervals is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the study as randomized, single-blinded, and parallel-group. General explanation: random allocation is intended to make treatment groups comparable, on average, with respect to both measured and unmeasured characteristics. A parallel-group design assigns participants to one treatment group for the comparison rather than comparing sequential treatment periods within the same participant. The registry record does not describe the randomization sequence or allocation concealment, so the implementation cannot be assessed from the posted information.

What does the reported percentage represent?

The endpoint is a percentage of lesions assessed as improved on GAIS. The registry describes a scale from 1, very much improved or excellent corrective result, to 5, worsened appearance compared with original condition. The scale anchors alone do not specify the rule used to convert ratings into the binary category “improvement.” The rating threshold, handling of missing assessments, and any adjudication procedure are not reported in the registry record.

General explanation: when a continuous or ordinal rating is converted into an improved/not-improved classification, the threshold affects the resulting percentage. A clearly stated threshold makes the endpoint reproducible and helps readers understand what counts as success. In this record, the endpoint label is available, but the exact classification rule is not.

Why does the unit of analysis matter?

The endpoint names lesions as its unit, while the arm results identify participants treated and give n=59 per group. A participant may have one or more lesions, but the number of lesions assessed per participant is not reported in the registry record. Nor does the record describe whether the analysis accounted for possible correlation among lesions from the same participant.

General explanation: outcomes from lesions belonging to one participant may be more alike than outcomes from lesions in different participants. Treating every lesion as independent when observations are clustered can make statistical uncertainty appear smaller than it is. Appropriate methods can account for clustering, but the method used for this endpoint is not reported in the registry record. The record also does not clarify whether the reported n refers to the participants contributing to the endpoint, another analysis set, or an arm-level count distinct from the lesion denominator.

How should the confidence intervals be read?

The CellFX estimate is 76.2%, with a 95% confidence interval of 67.0% to 85.5%. The electrodessication estimate is 75.5%, with a 95% confidence interval of 66.6% to 84.4%. General explanation: a confidence interval presents a range of values compatible with an estimate under the calculation method and its assumptions. It conveys uncertainty about each group’s percentage. The registry record does not state the interval calculation method, and separate group intervals are not a substitute for a confidence interval around the between-group contrast.

General explanation: greater precision is generally reflected by a narrower interval, while a wider interval indicates more uncertainty. The interval does not express the probability that a specific treatment is beneficial, and it does not by itself establish a meaningful difference. The registry reports no formal analysis of the contrast, so the strength of evidence for a between-group difference cannot be determined from the endpoint summaries alone.

What analyses are reported?

The registry lists zero analyses. It does not report the statistical model, any adjustment variables, the handling of clustering, or a method for comparing the groups. It also does not report a planned hypothesis, a significance threshold for the primary comparison, or an analysis population definition. These details should not be inferred from the fact that the study was randomized or from the presence of confidence intervals.

General explanation: a prespecified analysis plan can distinguish primary confirmatory questions from exploratory ones and can define how incomplete data, multiple outcomes, or departures from the planned analysis are handled. The plan and any deviations are not reported in the registry record. The confidence intervals appear with the primary outcome, but the record does not explain whether they were part of the prespecified analysis or how they were calculated.

What does over-dispersion mean in general?

General explanation: for count outcomes, over-dispersion occurs when observations vary more than a simple count model assumes. It can arise from heterogeneity across participants or clustering of repeated observations. In such settings, a model that allows extra variation may give more realistic uncertainty than a model that assumes all observations vary according to a simpler distribution. The primary outcome is reported as a percentage of lesions, and the registry does not report a count model or another model that would permit a specific assessment of over-dispersion. This concept is relevant as a general statistical consideration, not as a claim about the model used in this trial.

The registry includes sample-size assumptions for planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. The numerical planning estimates and the fractions are not reported in the registry record. These illustrations are not the trial’s own design justification and should not be interpreted as observed power. The trial’s sample-size justification and the statistical plan are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 3 outcome measures, but no secondary outcome results are posted. It lists zero analyses. The available result concerns the primary lesion-improvement endpoint. The other outcome measures, their result status, and any planned hierarchy among outcomes are not reported in the registry record.

Multiplicity arises when several outcomes, time points, subgroups, or comparisons are tested. General explanation: as the number of statistical tests grows, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that issue. The registry record does not report a multiplicity adjustment, a testing hierarchy, or an explanation of whether multiplicity was considered. Because no formal analysis is listed, the record does not support a conclusion about how multiple comparisons were handled.

Missing-data handling is also not reported in the registry record. The posted arm results give n=59 per group, but the record does not explain whether these counts represent all randomized participants, participants with an available primary assessment, or another set. It does not report how missing lesion ratings were treated, whether participants or lesions were excluded, or whether sensitivity analyses were conducted. The difference between the enrollment listing and the arm-level n is not explained in the registry record and should not be interpreted as evidence of a particular reason for missing data or exclusion.

The analysis population is not reported in the registry record. There is no stated intention-to-treat, per-protocol, or other population definition. In addition, the relationship between participant counts and lesion-level denominators is unclear. These gaps limit assessment of whether the reported percentages include all randomized participants and eligible lesions, and how incomplete assessments might affect the estimates.

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.

Most frequent non-serious adverse event terms

The registry reports zero serious adverse events among the 59 participants listed at risk in the CellFX group and zero among the 59 listed at risk in the intralesional electrodessication group. It reports 3 other adverse events in the CellFX group and zero in the comparator group. Deaths are reported as zero in both groups. No serious adverse-event terms are listed.

These are event counts in the registry record, not a complete description of the safety experience. The record does not report the nature, severity, timing, duration, or relatedness of the 3 other events. It also does not describe how adverse events were collected or define the observation period for safety reporting. Without those details, the counts cannot explain what happened to participants or how events were judged.

General explanation: zero recorded events in a study does not establish that an event is impossible or that a treatment has no risk. It means that no events of that category were reported in the recorded group over the study’s reporting and observation conditions. The at-risk counts indicate the group denominators used for these safety summaries; they should not be assumed to be the same as the lesion denominators for the primary endpoint.

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

The posted primary endpoint estimates describe the percentage of assessed lesions judged improved by a blinded investigator at the specified follow-up. The registry reports 76.2% for CellFX and 75.5% for intralesional electrodessication, with the corresponding 95% confidence intervals of 67.0% to 85.5% and 66.6% to 84.4%. The intervals indicate uncertainty around each estimate, while the registry does not report a formal estimate or test of the between-group contrast.

These results do not establish that the treatments are equivalent. Equivalence requires a prespecified acceptable difference and a suitable analysis; neither is reported in the registry record. They also do not establish noninferiority or superiority. Similar-looking group percentages and overlapping confidence intervals cannot substitute for a direct comparison designed and analyzed for a specific claim.

The endpoint is an investigator rating of lesions, not a direct measure of every aspect of participant experience. The record does not report the exact rule for classifying a GAIS score as improved, the lesion denominator, or how multiple lesions from one participant were handled. The findings therefore cannot be translated into a participant-level chance of improvement from the registry record alone.

The result pertains to the stated assessment after the last treatment, at 60 days and up to a maximum of 3 months. It does not establish longer-term effects, recurrence, or durability, which are not reported in the registry record. Nor do the effectiveness percentages establish the balance of benefits and harms. Safety reporting is limited to the posted event counts and does not describe the other adverse events.

General explanation: a trial result is most informative when the outcome is clearly defined, the analysis matches the design, uncertainty is reported for the comparison of interest, and missing observations are accounted for transparently. Several of those details are not reported in the registry record. The results can be read as descriptive registry estimates from a randomized comparison, but the available record does not support broader claims about comparative clinical performance.

13. Why This Trial Matters Statistically

This trial is statistically notable because its primary outcome is expressed as a percentage of lesions, while the arm results are labeled in terms of participants. That distinction raises a basic analysis question: what was counted in the numerator and denominator, and how were multiple lesions from the same participant handled? The registry record does not provide those details. This is not a minor technical issue; the unit of analysis determines how an estimate should be interpreted and how its uncertainty should be calculated.

The study also illustrates the difference between separate group summaries and a comparative effect estimate. The posted percentages and confidence intervals allow readers to see the reported outcome levels and the uncertainty around each group estimate. They do not provide a direct confidence interval or formal test for the contrast. A randomized comparison is most directly interpreted through an estimate of the between-group difference, with its uncertainty and the prespecified criterion for decision-making.

The blinded investigator assessment is relevant because the endpoint involves judging appearance. The registry states that the investigator was blinded for live assessments, but does not describe who else was masked or how masking was maintained. The definition of “improvement” on the five-point scale is also not reported. Clear outcome rules and masking details help readers assess the possibility of measurement bias.

Finally, the record leaves important analysis details unresolved: it lists no analyses, gives no analysis-population definition, and does not describe missing-data handling or multiplicity procedures. These omissions show why a result should not be interpreted from the point estimates alone. Precision, outcome definition, analysis unit, and transparent methods all shape what can be concluded from a clinical trial record.

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 registry record does not report the exact GAIS threshold used to classify a lesion as improved. Although the scale anchors are described, the rule that converts ratings into the primary percentage is not stated. This limits reproducibility and leaves uncertainty about the clinical interpretation of the reported percentages.

The endpoint is defined at the lesion level, but arm results are labeled as participants and report n=59 per group. The record does not give the lesion denominators or clarify how multiple lesions from one participant were handled. It also does not explain the relationship between the enrollment listing of 60 and the arm-level counts. These gaps prevent a clear assessment of the endpoint’s analysis unit and completeness.

The registry describes a randomized, single-blinded design but does not report sequence generation, allocation concealment, or the identity of the masked parties beyond the blinded investigator in the endpoint description. It does not report a statistical analysis plan, an analysis population, missing-data methods, or a formal comparison for the primary endpoint. The method used to calculate the confidence intervals is not stated.

The listed outcome measures include no posted secondary results, and no analyses are listed. The record does not describe longer-term follow-up results, the handling of multiplicity, or a sample-size justification. Safety information is limited to event counts; the types and circumstances of the other adverse events are not reported. These are limitations of what can be assessed from the registry record, not proof that the underlying study did not collect additional information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Comparative Study Between CellFX and Electrodessication in Sebaceous Hyperplasia (SH) Lesions — NCT04539886.
• Registry record last updated 2024-04-25; status last verified 2024-04.
• Results first posted 2024-04-25.
• 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

The registry describes a completed, multicenter, prospective, randomized, single-blinded, parallel-group comparison of the CellFX System and intralesional electrodessication for sebaceous hyperplasia lesions. Enrollment is listed as 60. The primary outcome is the percentage of lesions assessed as improved on GAIS at 60 days after the last treatment, up to a maximum of 3 months.

The reported primary percentages are 76.2% for CellFX and 75.5% for intralesional electrodessication, with 95% confidence intervals of 67.0% to 85.5% and 66.6% to 84.4%, respectively. The registry lists zero serious adverse events in each group, 3 other adverse events in the CellFX group, zero in the comparator group, and zero deaths in both groups.

The record does not report a formal primary between-group analysis, the precise improvement threshold, the lesion denominators, or key analysis and missing-data methods. The posted estimates therefore describe the registry results but do not establish equivalence, noninferiority, or superiority.