Neo-Synalar Modified 48 Hour Patch Test: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Neo-Synalar Modified 48 Hour Patch Test (NCT02168478), a na phase 4 study. The primary outcome is Evidence of Pre-Existing Sensitization by Use of the Erythemal Scoring Scale (ESS).

2. Clinical Question

The study is framed as a test for an allergic reaction that may indicate a pre-existing sensitivity, rather than as a treatment comparison. The protocol description focuses on skin responses after application and their persistence or worsening across assessments. It does not describe an assessment of symptom relief, disease control, or comparative treatment benefit.

The controls serve different interpretive roles. A response to the positive control can help establish that a skin reaction was detectable, while the negative control gives context for responses when saline is applied. The registry does not report results for either control or explain how control responses were incorporated into the primary endpoint analysis. Therefore, the clinical question can be described from the stated objective, but the result cannot be determined from the registry information available.

3. Trial Design

This was a completed Phase 4, single-group study with 206 participants enrolled. The registry identifies the sponsor as Noah Rosenberg, MD and records the study start and primary completion as 2014-06. Participants were healthy volunteers, and the protocol description says all subjects received each of the three patch materials: Neo-Synalar Cream, sodium lauryl sulfate, and saline.

The materials were applied to absorbent pads and kept in direct skin contact for 48 hours. The primary endpoint description specifies skin assessments at 48, 96 and 168 hours after application. The design is therefore a within-participant patch assessment, not a randomized comparison in which one group receives Neo-Synalar and another group receives a control. Allocation is listed as NA, masking as none, and the model as single group. The registry does not report a randomization process or blinding procedures.

The controls are included alongside the test cream, but their presence does not make the study a controlled treatment trial. No separate control arms, like-for-like group comparison, or randomized allocation are described. Responses to the different materials may be informative within the patch-test setting, but the registry does not report an analysis comparing those responses.

The registry record does not report the protocol’s sample-size justification, an enrollment target distinct from the reported enrollment, interim analyses, or a statistical analysis plan. The endpoint is described with its scoring rule and assessment times, but no primary outcome estimate or analysis is posted. Thus, the design details establish what was applied and when the response was assessed, while leaving the planned statistical procedures and outcome results unclear.

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: There was no wash-out or run-in period

Overall Study

Reasons for not completing this period:

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 Evidence of Pre-Existing Sensitization by Use of the Erythemal Scoring Scale (ESS), measured over 48, 96 and 168 Hours.

The primary endpoint is described as evidence of pre-existing sensitization measured using the Erythemal Scoring Scale (ESS). The scale records visible redness at the application site: 0 means no visible erythema, 0.5 means slight, barely perceptible erythema, 1 means mild erythema, 2 means moderate erythema, 3 means marked erythema, and 4 means severe erythema. Assessments are specified at 48, 96 and 168 hours after application.

The endpoint is not simply the presence of redness at one assessment. The registry defines pre-existing sensitization as an ESS score of 1 or greater that persists or worsens from one visit to the next. This rule makes both the score level and the pattern over time relevant. In general, requiring persistence or worsening can distinguish a continuing or increasing reaction from a transient finding, though the registry does not report how this rule was applied to individual observations.

The stated unit is the percentage of patients with an allergic reaction, and the outcome parameter is a number. However, the registry record does not report the resulting count or percentage for Neo-Synalar or either control. It also does not report how incomplete assessments, ambiguous readings, or differences between assessors were handled. Consequently, the endpoint definition is available, but the observed endpoint result and its precision cannot be evaluated from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods concern how observations are converted into estimates and how uncertainty is represented. In this study, the registry describes a score-based endpoint and a rule for classifying a reaction, but does not report the statistical analysis used to summarize the endpoint. The endpoint description should therefore be separated from an analysis result: a scoring rule says what would count as an event, while an analysis would say how many participants met the rule and how that estimate was calculated.

What does the ESS rule capture?

The ESS is an ordered scale: higher values indicate more pronounced erythema. The stated scale ranges from 0 to 4 and includes a 0.5 score for slight, barely perceptible erythema. The endpoint uses a threshold of 1 or greater, but also requires that the score persist or worsen between assessments. This combines a minimum level of redness with a temporal condition. In general, such a definition is more specific than counting any redness at a single visit, because it requires a continuing or increasing pattern.

That rule also makes the timing and completeness of observations important. Assessments are planned at 48, 96 and 168 hours after application. To determine whether a score persisted or worsened, readings across visits must be available and comparable. The registry does not report how evaluators were trained, whether readings were independently assessed, or how missing visits were treated. It also does not state whether the threshold was applied separately for each material or how results from multiple materials were combined.

What would an outcome estimate mean?

For a binary endpoint such as meeting or not meeting the stated sensitization definition, a count would indicate the number of participants classified as having the endpoint. A percentage would express that count relative to a specified analysis denominator. In general, the denominator matters: participants enrolled, participants assessed, and participants with complete follow-up are not necessarily the same set. Here, the registry gives enrollment of 206 but does not report the primary endpoint denominator or the endpoint count or percentage.

Statistical uncertainty is commonly conveyed with a confidence interval. In general, an interval describes a range of estimates compatible with the observed data under a specified method and assumptions. Its width depends on the information available and the method used. No confidence interval, standard error, or other uncertainty measure for the primary endpoint is reported in the registry record. It is therefore not possible to judge how precisely the endpoint frequency was estimated.

Why do the study design and analysis need to match?

This is a single-group patch-test study. All subjects are described as receiving Neo-Synalar Cream, sodium lauryl sulfate, and saline. The registry does not describe a randomized allocation to separate arms. A two-arm treatment comparison would answer a different question from a within-participant patch assessment. In general, a valid analysis must respect the design and the way observations are linked. If the same person contributes readings for multiple materials or times, those observations may be related; treating them as independent without justification can give misleading uncertainty.

The record does not state whether any paired or repeated-measures method was used. It does not report a statistical test, model, adjustment, or prespecified contrast. Nor does it report an analysis comparing the test material with either control. The stated positive- and negative-control roles are part of the clinical testing context, but they do not establish that a particular statistical comparison was planned or performed.

What do the planning assumptions describe?

The registry’s planning description refers to a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of an observed effect. These are assumptions for planning illustrations, not a report of the study’s actual analysis. The study itself is identified as single group, and the registry does not report the trial’s own sample-size justification. Sample-size illustrations are prospective planning aids: they describe how a hypothetical design might be sized under assumptions. They are not observed power and do not establish whether an effect was present.

More generally, power is a design property under specified assumptions about the effect, variability, significance threshold, and analysis. It is not a measure of whether a completed study has demonstrated a result. An observed estimate and its uncertainty are needed to interpret what the data show. Here, the primary endpoint result is not reported, so a planning illustration cannot substitute for it.

What remains unavailable?

The registry lists 1 outcome measure and 0 analyses. It gives a detailed endpoint description but no posted primary result. It does not report the analysis population, handling of missing data, multiplicity procedures, or a method for deriving uncertainty. General statistical principles can explain why these details matter, but they cannot determine how the study was actually analyzed. Accordingly, interpretation should remain descriptive: the protocol specifies a patch procedure and an ESS-based classification rule, while the endpoint findings and statistical analysis are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The endpoint is assessed at 48, 96 and 168 hours and involves three patch materials. These multiple times and materials create several possible summaries or comparisons. In general, if many statistical tests are performed, the chance of at least one apparently unusual result can increase unless the analysis plan addresses multiplicity. The registry does not report whether multiple comparisons were planned, whether one time point or material had priority, or whether any adjustment was used. The endpoint description does specify a persistence-or-worsening rule, but that is not a complete multiplicity plan.

The registry lists 1 outcome measure and 0 analyses. No primary endpoint estimate, inferential test, confidence interval, or prespecified analysis population is reported. The record also does not report how missing ESS readings were handled, whether participants with incomplete assessments were excluded, or whether any sensitivity analysis was conducted. Enrollment of 206 does not by itself establish how many participants contributed usable endpoint data.

These omissions affect interpretation because the denominator and missing-data method determine what population the estimate describes. In general, excluding participants with incomplete assessments can yield a result that differs from one based on all enrolled participants, particularly if missingness is related to the response. The registry does not provide enough information to assess that possibility. It also does not report whether subgroup analyses were planned or performed. The appropriate conclusion is that multiplicity and missing-data procedures are not reported in the registry record, rather than assuming that no such procedures existed.

11. Safety Results

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

Other (non-serious) adverse events

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

The safety summary lists a Patch Test Group with 202 participants at risk. It records 0 participants affected by serious adverse events and 0 affected by other adverse events. The deaths field is not reported in the registry record. These figures are descriptive counts in the registry’s safety summary and should be read separately from the ESS-based primary endpoint.

A zero count in a posted summary means that no affected participants are recorded for that category in the reported group. It does not establish that all participants completed every assessment, that no skin reactions occurred, or that no events outside the registry’s reporting definitions were observed. The primary endpoint specifically evaluates erythema over scheduled assessments, while the adverse-event summary uses serious and other adverse-event categories. The record does not explain how those categories were defined or how they relate to ESS findings.

The safety denominator is 202, while total enrollment is 206. The registry does not explain this difference or state whether the safety population and endpoint population were defined in the same way. No adverse-event terms are listed among the most frequent serious events. These summaries do not provide a comparative safety estimate because the study has no separate randomized comparison group, and they should not be used to infer outcomes beyond the recorded categories.

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

The record establishes that a patch test was conducted in healthy volunteers using Neo-Synalar Cream, sodium lauryl sulfate as a positive control, and saline as a negative control. It describes a 48-hour period of skin contact and scheduled ESS assessments at 48, 96 and 168 hours. It also defines pre-existing sensitization as a score of 1 or greater that persists or worsens from one assessment to the next. These details explain the intended measurement.

The record does not report how many participants met that definition, what percentage they represented, or how precisely the frequency was estimated. It therefore does not support a conclusion about the observed frequency of pre-existing sensitization in this study. The control results are also not reported, so their observed response patterns cannot be used to contextualize the test-cream result.

The safety summary records 0 serious and 0 other adverse events among 202 participants at risk, but those entries do not replace the missing primary endpoint result. A defined erythema response is not necessarily identical to an adverse-event category. The registry does not explain how the two were reconciled.

This single-group, unmasked design is not a randomized comparison of treatments and does not answer whether Neo-Synalar is more or less effective than another treatment. The registry also does not report the statistical analysis, endpoint denominator, or missing-data handling. The defensible interpretation is limited to the study’s stated procedure and outcome definition, together with the safety counts recorded. Conclusions about the endpoint’s observed frequency or its precision are not possible from the registry record.

13. Why This Trial Matters Statistically

This study illustrates a distinction that is central to clinical statistics: a clearly defined endpoint is not the same as a reported result. The registry explains how erythema is scored and how persistence or worsening determines the sensitization classification. But without the number of participants meeting that rule, readers cannot estimate how often the endpoint occurred. A detailed protocol definition can improve clarity while still leaving the principal empirical finding unavailable.

It also highlights the importance of matching statistical interpretation to design. Participants received all three patch materials, so the study is not a randomized, parallel-group comparison. Treating the positive and negative controls as separate randomized arms would misrepresent the described design. If outcomes are assessed repeatedly within the same participant, the dependence among those readings may matter for statistical analysis. The registry does not state how this was handled.

Denominators and missing observations are equally important. Enrollment is 206, while the safety summary lists 202 at risk. Without a stated endpoint analysis population, enrollment cannot be assumed to be the denominator for the primary result. This is a useful reminder that participant flow, evaluable observations, and the definition of an analysis population are part of interpreting an estimate, not administrative details.

Finally, planning calculations should not be confused with evidence from a completed study. The registry describes planning assumptions for hypothetical two-arm illustrations, whereas the study is single group. Such assumptions cannot answer the clinical question or replace a reported endpoint estimate. The record therefore demonstrates how design, endpoint definition, analysis, and reporting each contribute to a statistically interpretable trial.

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 primary limitation for interpretation is that the registry record does not report the primary endpoint result. There is no count or percentage meeting the prespecified ESS-based definition, no endpoint denominator, and no measure of precision. Although the endpoint is described at multiple assessment times, the record does not provide the individual or summarized readings needed to understand the response pattern.

The registry also does not report results for sodium lauryl sulfate or saline. Their roles as positive and negative controls are stated, but their observed responses are unavailable. This limits interpretation of the test-cream readings and prevents assessment of whether the controls behaved as expected in this study.

The design is single group and unmasked, with all subjects receiving all three materials. It does not provide a randomized comparison between separate groups. The record does not report whether skin assessments were standardized across evaluators or whether any procedure was used to reduce observer variability. It also does not specify how the analysis accounted for repeated assessments within participants.

Enrollment was 206, while 202 participants are listed as at risk in the safety summary. The registry does not explain the difference or report participant flow, endpoint completeness, or missing-data handling. It does not report a sample-size justification, analysis plan, interim analyses, multiplicity procedures, or inferential methods. These omissions do not establish that such procedures were absent; they mean they are not reported in the registry record. Finally, the study concerns healthy volunteers in a patch-test setting, and the registry does not establish how its findings would apply to other populations or clinical contexts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Neo-Synalar Modified 48 Hour Patch Test — NCT02168478.
• Registry record last updated 2015-12-11; status last verified 2015-11.
• Results first posted 2015-12-11.
• 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

NCT02168478 is a completed Phase 4, single-group, unmasked patch-test study with 206 participants enrolled. Healthy volunteers received Neo-Synalar Cream, sodium lauryl sulfate aqueous solution at 0.40% as a positive control, and saline as a negative control. Materials remained in skin contact for 48 hours.

The primary outcome is described as pre-existing sensitization assessed using the ESS at 48, 96 and 168 hours. The criterion is an ESS score of 1 or greater that persists or worsens across visits. The registry record does not report the primary outcome result or its statistical analysis. Safety reporting lists 0 serious and 0 other adverse events among 202 participants at risk; deaths are not reported in the registry record. The analysis population, missing-data procedures, and multiplicity methods are also not reported.