Efficacy and Tolerability Evaluation of a Topical MD Based on SHBF in Management of Radiodermatitis.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy and Tolerability Evaluation of a Topical MD Based on SHBF in Management of Radiodermatitis. (NCT04483856), a randomized na study. The primary outcome is Number of Participants With Progression of Radio Therapy Induced Skin Reaction.

2. Clinical Question

3. Trial Design

The registry describes a randomized, controlled, prospective, single-center, post-marketing interventional study. Its design is parallel, with DermoRelizema cream compared directly with Dexeryl. The masking designation is single; the brief summary specifies that physician assessments and evaluations were performed in a blind fashion. It does not state that participants or other personnel were masked, so the extent of masking beyond the blinded physician assessment is not reported in the registry record.

The recorded enrollment is 70. The primary outcome data are reported for 35 participants assigned to DermoRelizema cream and 35 assigned to Dexeryl. The registry lists the study phase as NA. The study status is completed, with a start date of 2020-11-02 and primary completion recorded as 2023-02-16. These dates describe the registry record; they do not establish when any particular participant entered or completed follow-up.

The intervention descriptions set out a treatment period beginning around a week before radiotherapy and continuing to 14 days after its end. The primary outcome timeframe is two weeks after the last radiotherapy session, day 35-42. Secondary assessments include progression at the conclusion of radiotherapy and at study end, and adherence assessed up to 1 year. These are distinct assessment timeframes, and the participant counts differ across posted outcomes.

The registry record does not report the randomization procedure, allocation concealment, a protocol, or a statistical analysis plan. It also does not report a sample-size justification for the trial. The separate planning illustrations use the observed effects and stated assumptions; they should not be read as evidence that those effects or assumptions informed the original design.

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 Number of Participants With Progression of Radio Therapy Induced Skin Reaction, measured over two weeks after the last RT sessiont,day 35-42.

The primary endpoint is the number of participants with progression of radiotherapy-induced skin reaction. The registry identifies the measure as a participant count and places its assessment two weeks after the last radiotherapy session, day 35-42. The primary objective describes evaluating progression and toxicity using the Radiation Therapy Oncology Group / European Organization for Research and Treatment of Cancer (RTOG/EORTC) grading system.

A participant count gives a direct summary of how many people in each group met the recorded progression outcome at the assessment. Comparing counts in groups of the same reported size can describe the observed frequency of the outcome without relying only on a difference in average severity scores. It is still important to know how progression was defined, how borderline grades were handled, and whether the assessment was complete for all participants. Those operational details are not reported in the registry record.

The posted primary result records 35 participants with progression among 35 in the DermoRelizema cream group and 33 among 35 in the Dexeryl group. The reported risk difference for Dexeryl relative to DermoRelizema cream is -0.057. This contrast is an estimate of the difference between the groups, not a direct measure of an individual participant’s experience, and its precision depends on the number of observations and the variability that would arise across comparable samples.

The endpoint is clinically interpretable as a progression count, but it does not by itself describe the severity or duration of reactions, symptoms, patient opinion, or treatment adherence. The registry lists such domains among secondary outcomes. Their role is complementary: they can add context to a progression count, but they do not change what the primary endpoint measures.

7. Results Posted in the Registry

• Dexeryl: 94.3% (33/35) versus 100.0% (35/35) on control; risk difference -5.7 percentage points (95% CI -13.4 to 2.0), risk ratio 0.94 (0.87–1.02); unadjusted two-proportion z-test p = 0.151.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Progression of Radio Therapy-induced Skin Reactions Using the Grading System of the Radiation Therapy Oncology Group / European Organization for Research and Treatment of Cancer (RTOG/ EORTC)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Dexeryl: 83.9% (26/31) versus 90.0% (27/30) on control; risk difference -6.1 percentage points (95% CI -22.9 to 10.7), risk ratio 0.93 (0.77–1.13); unadjusted two-proportion z-test p = 0.478.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Dexeryl and the control. The interval gives the range of effects that remain compatible with the data.

Adherence to Treatment of Patients

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Dexeryl: mean 97.50 versus 96.50 on control; difference 1.00 (95% CI -3.31 to 5.31), standardized effect d = 0.12; z-test p = 0.649.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Dexeryl and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary outcomes covering progression and severity of radiotherapy-induced skin reactions, radiation symptoms, patient opinion, adherence, and adverse events. The posted numerical secondary results include a progression assessment at the conclusion of radiotherapy and at study end, and an adherence assessment. Numerical results for the other listed secondary outcomes are not reported in the registry record.

At the secondary progression assessment, the posted counts are 27 of 30 in the DermoRelizema cream group and 26 of 31 in the Dexeryl group. The reported risk difference is -0.061, with an interval from -0.230 to 0.107 and an unadjusted p-value of 0.478. For adherence, the group means are 96.5 and 97.5, with standard deviations of 7.98 and 8.82. The mean difference is 1.0, with an interval from -3.309 to 5.309 and an unadjusted p-value of 0.649. These results add context, but they are not substitutes for the primary endpoint.

In general, secondary outcomes can help describe whether observations are consistent across different aspects of a study. They may capture dimensions that a primary outcome does not, but differences in measurement, assessment time, and analyzed participants make direct comparison difficult. The secondary progression assessment has different reported denominators from the primary assessment. The registry record does not explain the reasons for those differences, so they should not be treated as a simple repeated measurement of the same analysis population.

Unadjusted secondary p-values carry less weight when several outcomes are examined because repeated testing increases the chance of finding an apparently unusual result by chance. In general, interpretation depends on whether outcomes and analyses were pre-specified and whether any adjustment or hierarchy was planned. That information is not reported in the registry record. The secondary results are therefore best treated as descriptive and exploratory alongside the primary result, rather than as independent confirmation.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Progression of Radio Therapy-induced Skin Reactions Using the Grading System of the Radiation Therapy Oncology Group / European Organization for Research and Treatment of Cancer (RTOG/ EORTC)
• Evaluation of the Radiation Symptoms (0 Best Result, 40 Worst Results)
• Severity of Radio Therapy-induced Skin Reactions Using the Grading System of the Radiation Therapy Oncology Group / European Organization for Research and Treatment of Cancer (RTOG/ EORTC)
• Severity of Radiation Dermatitis With Radiation Dermatitis Severity (RDS) Scoring Scale
• Number of Participants With Progression of Radio Therapy Induced Skin Reaction
• Patient Opinion on Cream With a Likert Scale
• Adherence to Treatment of Patients
• Occurrence of Adverse Events

9. Statistical Interpretation

10. Statistical Methods Explained

What does the risk difference represent?

A risk difference expresses the difference between the proportions of participants with an event in two groups. Here the event is progression of radiotherapy-induced skin reaction, and the reported contrast is Dexeryl relative to DermoRelizema cream. A negative estimate means the observed event proportion is lower in the group named first in that contrast than in the reference group, while the magnitude describes the estimated absolute separation. The posted estimate is -0.057. It should be interpreted alongside its confidence interval, not as a fixed or known difference that would necessarily recur in another study.

For a binary outcome, the participant count and the number assessed both matter. The count of events alone is not enough to compare groups if the numbers assessed differ. The primary outcome reports 35 of 35 for DermoRelizema cream and 33 of 35 for Dexeryl, with equal reported denominators. The record does not explain whether the denominators represent all randomized participants, all treated participants, or another analysis population.

How is the relative risk different?

The relative risk compares the event proportion in one group with the event proportion in another. A value of one represents equal proportions; values on either side of one represent different relative event frequencies in opposite directions. The reported relative risk is 0.943, with an interval from 0.869 to 1.023. The interval spans the value that represents no relative difference, so the estimate does not pin down a single direction for the underlying comparison.

Relative and absolute measures answer related but distinct questions. The risk difference describes separation on an absolute scale, while the relative risk describes the relationship between the proportions. Neither measure conveys the severity of a reaction, its duration, or its effect on symptoms. The registry does not report a clinical threshold for interpreting the size of either contrast.

What does a confidence interval add?

In general, a confidence interval describes the uncertainty around an estimate under the statistical method used. A narrower interval indicates greater precision, while a wider interval leaves a broader range of plausible values. It does not mean that every value in the interval is equally likely, and it is not a guarantee that the interval contains the true effect. The confidence intervals posted for the primary outcome extend across the relevant no-difference value for each reported measure, so the data do not tightly distinguish the possibility of little or no group difference from a difference in either direction.

The registry record does not specify the confidence level or the precise method used to construct these intervals. That information is not reported in the registry record, so the interval should be interpreted using the values as posted rather than assuming a particular method.

What does the unadjusted p-value tell the reader?

In general, a p-value describes how unusual data at least as inconsistent with a null model would be if that model and the test assumptions held. It is not the probability that the null hypothesis is true, and it does not quantify clinical importance. The primary unadjusted p-value is 0.151. The registry record does not report a multiplicity adjustment, a pre-specified decision threshold for the primary analysis, or the full testing procedure. The stated 0.05 significance level belongs to the planning illustration assumptions, and should not be taken as confirmation of the trial’s own testing plan.

For a binary outcome, standard methods can depend on assumptions about the sampling process and how participants are analyzed. The registry record provides no detailed method description, so the precise test underlying the posted p-value is not reported in the registry record. No adjusted or model-based primary analysis is listed.

How should the planning illustrations be read?

In general, a sample-size calculation estimates how many participants would be needed under specified assumptions to detect an effect with a chosen power and significance level. The posted planning illustrations use the observed effect, two-sided significance level 0.05, equal allocation, and a normal approximation. They show planning for 100%, 75%, and 50% of the observed effect, with participants per arm for 80% and 90% power.

These are planning illustrations, not observed power and not a reconstruction of the trial’s original design. They are conditional on the stated assumptions and on the observed effect being an appropriate basis for planning. The record does not report the original sample-size rationale or establish that the illustration assumptions were used when the trial was designed.

The same distinction applies to the adherence outcome, which is a mean measured in units on a scale and reported with a standard deviation. In general, standard deviations describe variability among observations, whereas a standard error describes uncertainty in an estimated mean. The posted adherence comparison gives a mean difference of 1.0, an interval from -3.309 to 5.309, and an unadjusted p-value of 0.649. The registry does not report an adjusted analysis for that outcome.

11. Confidence Intervals and Precision

The primary risk-difference estimate is -0.057, and its confidence interval extends from -0.134 to 0.020. This is a broad span relative to the point estimate and includes values on both sides of zero. The result therefore does not identify a precise direction or magnitude for the group contrast. The relative-risk estimate is 0.943, with an interval from 0.869 to 1.023; it likewise spans values on both sides of one, the relative-risk value corresponding to no difference.

In general, confidence intervals express the uncertainty associated with an estimate under a statistical method. When an interval includes the no-difference value, the data remain compatible with no group difference as well as with differences in either direction within the interval. That does not show that the groups are equivalent. Demonstrating equivalence or non-inferiority requires an appropriate pre-specified margin and analysis, neither of which is reported in the registry record.

The posted primary denominators are 35 in each group. Even with equal reported denominators, event estimates from a study of this size can be imprecise, particularly when event counts are close to the group totals. Precision is about the range of values supported by the data, not whether the point estimate appears close to a particular value. The interval should therefore carry more interpretive weight than treating -0.057 as an exact underlying difference.

The registry record does not state the confidence level or interval-construction method. This limits the amount that can be inferred about the procedure behind the bounds. The data also do not include a posted adjusted estimate, and missing-data handling is not reported in the registry record. Such omissions limit assessment of whether the interval fully represents all relevant uncertainty. The posted estimates are informative as descriptions of the recorded comparison, but their precision does not support a narrow conclusion about the underlying contrast.

12. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary outcome and multiple secondary outcomes. It does not report a testing hierarchy, a multiplicity adjustment, or a statistical analysis plan specifying how results across outcomes were to be interpreted. The posted p-values are explicitly unadjusted for the primary and reported secondary comparisons. In general, examining several outcomes can increase the chance of at least one apparently notable result even when there is no underlying effect. A pre-specified strategy can help manage that issue, but such a strategy is not reported in the registry record.

The record does not report whether any interim analyses were planned or conducted. The existence, timing, and consequences of interim looks at accumulating data are therefore not reported in the registry record. No assumptions about stopping rules or adaptations can be made from the posted information.

Missing-data handling is also not reported in the registry record. The record does not explain how participants without a measurement at an assessment were handled, whether any imputation was used, or whether the primary analysis included all randomized participants. The primary outcome denominators are 35 per group, whereas the secondary progression and adherence denominators are smaller and differ between groups. Those observed denominators do not establish why participants are not included in each secondary result.

Analysis populations are not reported in the registry record. It is therefore not possible to determine from the posted results whether the analysis was intention-to-treat, per-protocol, based on participants who received treatment, or defined in another way. These distinctions matter because different analysis populations can yield different estimates, especially if exclusions or missing assessments are related to outcome or treatment.

The registry lists no reported analyses beyond the posted summary comparisons. It does not provide enough detail to assess model assumptions, covariate adjustment, prespecified subgroup analyses, or sensitivity analyses. These omissions do not invalidate the posted descriptive counts or estimates, but they limit assessment of how robust the statistical conclusions are to analysis choices.

13. 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 zero serious adverse events in the DermoRelizema cream group and zero in the Dexeryl group. It also reports zero other adverse events in each group, and zero deaths in each group. The reported at-risk counts are 35 for each group for both serious and other adverse events.

These figures describe what was recorded in the registry during the study; they do not establish that no adverse events could occur, or that the groups have identical safety profiles. When no events are recorded, the data still have limited ability to rule out uncommon events, particularly in a study with the reported group sizes. The record does not provide event-specific descriptions because no serious adverse-event terms are listed.

The registry record does not report detailed safety definitions, the method for collecting events, the observation period for adverse events, or whether all participants completed safety follow-up. The zero counts should consequently be read as the posted event totals, not as a comprehensive estimate of risk outside the study conditions. They do not support medical advice or a broad conclusion about safety.

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

The posted primary results describe the observed counts and estimates for progression of radiotherapy-induced skin reactions at the specified assessment. They show 35 participants with progression among 35 in the DermoRelizema cream group and 33 among 35 in the Dexeryl group. The estimated risk difference is -0.057, with a confidence interval from -0.134 to 0.020. The relative-risk estimate is 0.943, with an interval from 0.869 to 1.023, and the unadjusted p-value is 0.151.

These statistics do not establish that one treatment is better or worse, and they do not show that the treatments are equivalent. The confidence intervals include the no-difference value for both reported effect measures, leaving uncertainty about the direction and size of the underlying group difference. Equivalence would require a defined margin and a suitable analysis; these are not reported in the registry record.

The result is specific to the study population, products, treatment schedule, endpoint definition, and assessment timeframe recorded in the registry. The record describes women with breast cancer receiving radiotherapy at a single center. It does not report detailed eligibility criteria or enough information about the study population to determine how broadly the findings apply. The posted endpoint concerns progression, not every aspect of skin reaction, symptoms, severity, or patient experience.

The registry reports a randomized design and physician assessments performed in a blind fashion, but it does not provide details of the allocation procedure or the full masking arrangements. Missing-data methods, analysis populations, and a statistical analysis plan are also not reported. Those omissions limit conclusions about the analysis and how well the results might generalize to other settings.

The safest statistical reading is that the registry records an uncertain comparison, not a definitive treatment claim. The posted counts and estimates describe the observed data, while the intervals show that a range of underlying effects remains compatible with them. They should be interpreted as trial results rather than personalized guidance or a guarantee about outcomes for any individual.

15. Why This Trial Matters Statistically

This trial is statistically informative because it illustrates how a direct randomized comparison can produce a clear set of observed counts but still leave uncertainty about the underlying difference. A point estimate is only one summary of the comparison. The primary risk-difference interval spans zero, and the relative-risk interval spans one; both convey that the posted data do not tightly identify the direction of a group contrast.

The endpoint is a participant count for progression, an outcome that can be expressed using both absolute and relative measures. Seeing both scales can prevent over-reliance on a single number. The absolute contrast describes a difference in event proportions, while the relative contrast describes their ratio. In this study the two forms of estimate tell a consistent story about uncertainty, rather than furnishing independent evidence.

The record also highlights why outcome timing and denominators matter. The primary result is assessed two weeks after the last radiotherapy session, while the secondary progression assessment uses other timepoints and has different reported denominators. A reader should not assume these are interchangeable assessments or that changes in counts reflect a treatment effect without knowing how follow-up and analysis populations were handled.

Finally, the posted secondary and safety information must be interpreted in context. Unadjusted comparisons across multiple outcomes are less conclusive than a pre-specified primary analysis, and zero reported adverse events do not demonstrate absence of risk. The registry record does not report the analysis plan, missing-data approach, or multiplicity strategy. Recognizing what the estimates can and cannot establish is central to sound interpretation of clinical trial statistics.

16. 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.

Several trial-specific limitations affect interpretation. The primary endpoint is progression assessed at a defined follow-up, but the registry record does not describe the detailed criteria used to classify progression, the handling of changes in RTOG/EORTC grades, or how disagreements between assessments were resolved. Although physician assessment is described as blind, details of assessor procedures and whether masking could be maintained are not reported.

The study is described as single-center and includes women with breast cancer receiving radiotherapy. The registry does not provide detailed eligibility criteria, baseline characteristics, radiotherapy details, or information about variation in clinical care. The extent to which participants and treatment conditions represent other settings is therefore not reported in the registry record.

The primary counts are reported for 35 participants per group, while posted secondary outcomes have smaller and differing denominators. The record does not explain the reasons for these differences or report the missing-data approach and analysis populations. This makes it difficult to assess whether observed secondary results reflect incomplete follow-up, outcome-specific availability, or another analysis decision.

The registry lists several secondary outcomes, but numerical results are not reported for every listed outcome. It also does not report a protocol, a statistical analysis plan, a sample-size justification, multiplicity procedures, interim analyses, or adjusted analyses. The planning illustrations do not fill those gaps: they are based on observed effects and stated assumptions, rather than a reported original design rationale.

Finally, safety results are limited to posted event counts, without detailed event definitions or collection methods. These gaps do not erase the descriptive results, but they constrain how confidently the findings can be generalized or interpreted beyond the specific posted outcomes and assessment periods.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Efficacy and Tolerability Evaluation of a Topical MD Based on SHBF in Management of Radiodermatitis. — NCT04483856.
• Registry record last updated 2025-05-15; status last verified 2025-04.
• Results first posted 2025-05-15.
• 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.

20. Record Summary

The registry record describes a completed, randomized, parallel, single-center, prospective, controlled, post-marketing study of DermoRelizema cream compared with Dexeryl for radiotherapy-induced skin reactions in women with breast cancer. It records enrollment of 70, a start date of 2020-11-02, and primary completion on 2023-02-16. Physician assessments are described as performed in a blind fashion.

The primary endpoint is the number of participants with progression of radiotherapy-induced skin reaction two weeks after the last radiotherapy session, day 35-42. The posted counts are 35 of 35 for DermoRelizema cream and 33 of 35 for Dexeryl. The risk difference is -0.057, with an interval from -0.134 to 0.020; the relative risk is 0.943, with an interval from 0.869 to 1.023. The unadjusted p-value is 0.151.

The registry lists additional outcomes, with numerical secondary results posted for progression and adherence. It reports zero serious adverse events, other adverse events, and deaths in both groups. The statistical analysis plan, missing-data handling, and analysis populations are not reported in the registry record.