Hidradenitis Suppurativa Wound Care: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Hidradenitis Suppurativa Wound Care (NCT04354012), a na phase 2 study. The primary outcome is Percent Change in Wound Size.

2. Clinical Question

3. Trial Design

The registry describes a prospective case series of wound care for hidradenitis suppurativa, classified as phase 2 and as a single-group study. Enrollment was 5. The study status is completed; the recorded start date is 2021-02-04 and the primary completion date is 2024-08-28. These dates describe the registry record and do not establish how long any individual participant was followed.

All participants were assigned to the treatment group, which received methylene blue, gentian violet, and ovine forestomach wound dressings for HS lesions. Allocation is listed as not applicable, and masking is listed as none. There is no separate control group or randomized allocation described. The design therefore supports descriptive reporting of outcomes within this group, rather than a like-for-like comparison between treatment strategies.

The primary outcome was percent change in wound size, measured from baseline to week 8. The registry describes assessment of healing over 8 weeks of follow-up using Endoform and Hydrofera Blue products. It also lists change in pain assessment scores among secondary outcomes. The record contains nine outcome measures, but does not provide the outcome values or a statistical analysis for them. Repeated entries for pain scores do not, on their own, establish the assessment schedule or indicate how those entries were analyzed.

The registry record does not report a sample-size justification, detailed analysis plan, eligibility criteria, or the number of participants with endpoint measurements. The enrollment count should not be read as confirmation that every participant contributed data at every planned assessment. Without a comparator and with a small enrolled group, the design is primarily descriptive; it cannot determine what would have happened to similar participants under another care approach.

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 Percent Change in Wound Size, measured over Measure from Baseline to week 8.

The primary endpoint is percent change in wound size from baseline to week 8. It is intended to express how wound size changed during the specified follow-up period, using baseline wound size as the reference. A percentage-change measure can make changes relative to the starting size easier to describe than a raw change alone, although interpretation still depends on how wound size was measured and how the percentage was calculated. Those measurement and calculation details are not reported in the registry record.

The endpoint is relevant to the stated objective of monitoring wound healing. The registry specifies a mean as the summary measure and a full range as the dispersion measure. In general, a mean summarizes the average across observed measurements, while a full range describes the span from the smallest to the largest observation. The mean can conceal differences between individual participants; the range can be strongly influenced by extreme observations. These considerations matter particularly in a small case series.

The registry record gives the endpoint definition and timeframe, but not the observed mean, range, individual values, or an estimate of uncertainty. Thus, the endpoint's planned role can be described, but the magnitude and variability of observed wound-size change cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a prospective, single-group case series. In general, a prospective design follows participants forward from an identified starting point and records outcomes over time. A case series can provide a structured description of observations in a group receiving a specified approach, but it does not by itself estimate how those observations compare with what would have happened under an alternative approach. This distinction is important because there is no separate control group in this study.

Allocation is listed as not applicable, and masking is listed as none. Random allocation, in general, helps make treatment groups comparable with respect to both measured and unmeasured characteristics, especially when enough participants are included. It does not apply to a single-group case series with no parallel group. Masking, in general, can reduce the influence of knowledge of treatment assignment on assessment or reporting. The absence of masking does not prove that measurements were biased, but it means the record does not describe that design safeguard. Further details about measurement procedures and assessors are not reported in the registry record.

The primary endpoint is percent change in wound size from baseline to week 8. This is a repeated-time assessment in the broad sense that a baseline measure is compared with a later measure. The registry does not state the exact wound-measurement method, the formula for percent change, whether one or multiple lesions were assessed per participant, or how multiple wounds would be combined. Those details affect what the endpoint represents and how it can be reproduced, and are not reported in the registry record.

The primary outcome is specified as a mean with a full range. In general, the arithmetic mean combines all recorded values into one measure of central tendency. A range reports the lowest and highest observed values and gives a simple indication of spread. With a small dataset, the mean may shift noticeably when one observation is unusually large or small, while the range is determined entirely by its two endpoints. A range does not show the distribution of the remaining observations. The registry does not post the mean, range, or the individual observations, so these summaries cannot be interpreted for this case series.

Precision is a separate issue from the size of an estimate. In general, a confidence interval communicates uncertainty around an estimate under stated statistical assumptions. Larger samples often permit greater precision, but the actual precision depends on variability and the analysis as well as the sample size. No confidence interval or other uncertainty estimate for the primary endpoint is reported in the registry record. It would not be appropriate to infer one from the enrollment count alone.

Over-dispersion is a general statistical concept that arises when observed variability exceeds what a chosen model assumes. If that mismatch is ignored, standard errors and inferential conclusions can be unreliable. The registry record does not describe a fitted statistical model, a dispersion assessment, or an analysis requiring such a check. Thus, over-dispersion is a general methodological consideration, not a reported feature of this case series.

The record lists nine outcome measures and no analyses. It does not specify whether outcomes were analyzed individually, jointly, or with an adjustment for multiple testing. In general, when many outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase if each is assessed independently at a conventional threshold. Methods for addressing multiplicity depend on the aims and analysis plan. No adjustment method or prespecified hierarchy is reported in the registry record.

Planning calculations are not outcome analyses. The stated sample-size illustration assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes planning for fractions of an observed effect. These assumptions are not a description of the actual single-group design and do not establish the study's original enrollment rationale. The registry record does not report a sample-size justification for this case series. Planning illustrations are also not observed power: they do not show the probability that this completed study detected an effect, and cannot replace an outcome estimate or its uncertainty.

For a time-to-event calculation, general methods may count events rather than participants, while other planning methods may express sample size per arm. The stated illustration convention distinguishes those quantities. It does not indicate that a time-to-event endpoint was analyzed in this study; the primary endpoint in the registry is percent change in wound size.

Finally, a completed registry status indicates that the study is recorded as completed, not that every planned measurement is available or that the analysis is complete in the public record. The registry records zero analyses and does not report an analysis population, missing-data method, or primary endpoint estimate. These omissions limit reproducibility and prevent statistical evaluation of the planned wound-size outcome.

10. Multiplicity, Missing Data and Analysis Populations

The record lists nine outcome measures, including repeated entries for change in pain assessment scores. It does not explain whether those entries represent different timepoints, scales, or other distinctions. Their repetition should not be interpreted as evidence of a particular measurement schedule. The registry record does not report a prespecified hierarchy among outcomes, a family of primary tests, or a multiplicity adjustment.

In general, multiplicity concerns arise when several outcomes, timepoints, or comparisons are assessed. If each is tested separately without adjustment, the chance of at least one result appearing noteworthy by chance can increase. Adjustment methods can control aspects of this risk, but the appropriate method depends on the research question and analysis plan. Since no analyses or outcome results are reported, there is no multiplicity-adjusted or unadjusted finding to interpret.

The record does not report how missing wound-size or pain assessments were handled, whether participants with incomplete follow-up were included in analyses, or how the analysis population was defined. It also does not state how many participants had measurements at baseline and week 8. Enrollment of 5 is not enough to determine the number contributing to any specific endpoint. General statistical practice distinguishes the participants enrolled from those with usable data for a particular analysis; the registry record does not provide that accounting.

There is no reported imputation method, sensitivity analysis, or explanation of missingness. These omissions matter because analyses of incomplete data can depend on assumptions about why observations are missing. The record also does not report a detailed statistical analysis plan, so it is not possible to assess whether endpoint choices and analysis procedures were specified before results were known.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry reports 0 serious adverse events among 5 participants at risk, 0 other adverse events among 5 participants at risk, and 0 deaths. No serious adverse event terms are listed. These are the posted safety counts for the treatment group; they are not estimates of the probability of an event beyond this small group.

In general, observing no events in a small study does not establish that an intervention has no risk. It means only that no events in the recorded categories were reported among the participants counted as at risk in the registry. The precision of any broader safety conclusion would depend on the amount of observation and completeness of event collection, details that are not reported in the registry record.

The record does not describe definitions for the adverse-event categories, the surveillance procedures, the time window used for safety collection, or whether all enrolled participants completed safety follow-up. The at-risk counts are listed as 5 for both serious and other events, but the record does not give participant-level safety information. The zero counts should therefore be read as registry-reported counts, not as proof that no symptoms or other events occurred.

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

The record establishes that a completed prospective case series enrolled 5 participants with hidradenitis suppurativa and assessed a combination of methylene blue, gentian violet, and ovine forestomach wound dressings. Its primary question concerned percent change in wound size from baseline to week 8. The registry record does not report the numerical result for that endpoint, so the amount and variability of observed change cannot be stated.

The study's single-group design means that it does not offer a randomized comparison with another treatment or a control condition. General interpretation: a before-and-after observation can describe change during follow-up, but cannot by itself show that the intervention caused the change. Nor can it establish how the same participants would have fared under a different approach. The absence of masking and the unreported measurement details add uncertainty about how assessments were conducted.

The posted safety counts are 0 serious adverse events, 0 other adverse events, and 0 deaths, with 5 participants at risk in each event category. These counts are descriptive and limited to the recorded group and safety reporting. They do not establish that risk is absent, particularly when the sample is small and event ascertainment details are not reported.

The registry's completed status should not be confused with a complete statistical report. It lists nine outcome measures and no analyses, and does not give the primary result, confidence interval, p-value, or an explanation of missing data. The available information therefore supports a description of the study's objective, design, enrollment, and recorded safety counts, but not a quantitative judgment about wound-size change, its precision, or its cause.

Any sample-size illustration is a planning exercise based on stated assumptions, not evidence that the study had a particular probability of detecting a treatment effect. It is not observed power and does not compensate for an absent comparator or missing outcome results. The result does not establish comparative effectiveness, causation, or generalizability to people beyond those represented in this small case series.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of the difference between a registered clinical question and a reported result. The registry specifies a primary wound-size endpoint and its assessment period, but does not report the numerical endpoint result. A clear endpoint definition is useful for understanding what investigators intended to measure; without outcome values and an analysis, it is not possible to assess what the study observed.

The design also illustrates what a single-group case series can and cannot address. Such a design can document how outcomes were observed in a treated group. It does not provide a randomized counterfactual comparison, so observed change cannot be attributed to the wound-care regimen alone. Recognizing this distinction helps prevent descriptive follow-up from being interpreted as a comparative treatment effect.

The enrollment of 5 highlights why sample size and precision need to be considered separately from whether a study is marked completed. In general, small datasets can produce unstable summaries, and a mean or range may not fully convey individual variation. The registry does not provide the outcome data or uncertainty estimates needed to assess those properties for this study.

The record also shows why outcome accounting matters. Nine outcome measures are listed, including repeated pain-assessment entries, but the analyses, handling of missing data, and multiplicity approach are not reported. Clear reporting of outcome definitions, analysis populations, missing observations, and statistical methods helps readers understand how reported findings were obtained and how much confidence to place in them.

Finally, safety counts of zero are meaningful as recorded counts but require context about the size of the group and the process used to collect events. This record offers a concise reminder that safety observations, statistical precision, and evidence of comparative effects are distinct questions, each requiring its own information.

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 most direct limitation is the absence of posted primary outcome results. Although the endpoint, summary measure, and timeframe are identified, the registry record does not provide the mean or full range for percent change in wound size. It therefore cannot support a quantitative description of wound-size change or its variability. The record also lists no analyses, so no inferential results are available.

Enrollment was 5, and there was no comparator group. The small group limits how broadly descriptive observations can represent other people with HS, while the single-group design prevents a direct estimate of how outcomes compare with another care approach. The record does not report participant characteristics that would help readers assess how closely the group resembles other populations.

Details needed to interpret the endpoint are also absent: the wound-measurement procedure, the calculation of percent change, and the handling of multiple lesions are not reported in the registry record. The record does not state the number with baseline and week 8 measurements or explain how incomplete observations were handled. The study is marked completed, but that status does not resolve these reporting gaps.

Masking is listed as none. The record does not describe who assessed wound size or whether assessors used standardized or independent measurement procedures. It also does not report the timing and handling of co-interventions. These omissions limit assessment of measurement consistency and of factors that could accompany changes over time.

For safety, the record reports zero serious and other adverse events among 5 participants at risk and zero deaths, but does not describe event definitions, surveillance, or the safety observation window. Finally, the presence of nine outcome measures without reported analyses or a stated multiplicity approach makes it difficult to understand how outcomes were intended to be interpreted. These limitations concern what can be learned from the registry record; they do not establish that unreported procedures or data were absent from the conduct of the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Hidradenitis Suppurativa Wound Care — NCT04354012.
• Registry record last updated 2025-10-22; status last verified 2025-08.
• Results first posted 2025-10-07.
• 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

NCT04354012 is a completed, prospective, single-group case series listed as phase 2. The registry reports enrollment of 5 participants and evaluates methylene blue, gentian violet, and ovine forestomach wound dressings for hidradenitis suppurativa lesions. The primary endpoint is percent change in wound size from baseline to week 8, summarized by a mean and full range.

The record lists nine outcome measures and no analyses. It does not report a numerical primary endpoint result, uncertainty estimate, missing-data approach, or analysis population. Safety counts are 0 serious adverse events among 5 at risk, 0 other adverse events among 5 at risk, and 0 deaths. With no comparator and no posted endpoint estimate, the registry supports description of the study design and recorded counts, but not a quantitative conclusion about wound-size change or a comparative treatment effect.