An Open-Label Study Investigating the Effects of Early Skin Barrier Protection on the Development of Atopic Dermatitis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Open-Label Study Investigating the Effects of Early Skin Barrier Protection on the Development of Atopic Dermatitis (NCT00806221), a na phase 2 study. The primary outcome is Incidence of Skin Irritation.

2. Clinical Question

These details define the question that can be addressed from the registry entry: what outcomes were intended to be observed among newborns receiving early emollient use. Without a recorded comparator and outcome results, the entry does not establish whether the intervention changed irritation or eczema outcomes. Nor does it show whether any observed skin irritation corresponded to atopic dermatitis. The registry record does not describe the operational definitions of irritation or eczema, how outcomes were assessed, or the criteria used to decide whether an event had occurred.

The research question has both a prevention aspect and a timing aspect. Delaying onset and preventing development are not identical outcomes: a study would need to define how onset was measured and over what follow-up period to distinguish them. The registry lists development of eczema as a secondary outcome, but its result and assessment details are not reported in the registry record. Accordingly, the recorded primary endpoint should not be treated as a direct result for the broader question of atopic dermatitis prevention.

3. Trial Design

The registry describes a phase 2, open-label study with a single-group model. Allocation is listed as NA, masking as none, and enrollment as 22. The study is marked completed. Its recorded start is 2006-11 and its primary completion is 2008-11. These registry entries describe the design and administrative status, but do not provide an outcome analysis.

Participants in the Emollient group received skin barrier protection from birth, using emollient identified as Cetaphil cream. Because the record describes a single group and no comparator, the design does not make a direct comparison between emollient use and a separate control condition. An open-label design means masking was not used, as the registry explicitly records. Further details about who knew treatment assignment, how treatment was applied, adherence, follow-up procedures, or co-interventions are not reported in the registry record.

The primary outcome is incidence of skin irritation at the 1 and 2 year time points, expressed as a count of participants. Development of eczema is listed as a secondary outcome. The registry lists four outcome measures overall, but the record does not report results for them. Nor does it describe the planned analysis population, how participants were handled if they did not complete follow-up, or whether measurements were made at additional visits.

For interpretation, the absence of a concurrent comparator is central. A single-group observation can describe events recorded among participants who received the intervention, but it cannot by itself separate intervention-associated changes from other explanations. The record does not report a protocol or statistical plan that would clarify how the investigators intended to address these design constraints. The completed status does not, on its own, indicate that outcome data or analysis results were posted.

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 Incidence of Skin Irritation, measured over 1 and 2 year time points.

The primary endpoint is titled Incidence of Skin Irritation. The registry defines its unit as participants and its parameter as a count of participants, with assessment at the 1 and 2 year time points. Thus, the endpoint is intended to represent how many participants experienced skin irritation at those specified times. The registry record does not provide the observed counts, a detailed definition of skin irritation, or information about how it was assessed.

In general, a participant count is useful because it expresses how many people had an event, rather than describing the event only as a laboratory or instrument measurement. Counts can help readers understand the observed burden of an outcome when the number assessed and the event definition are also clear. A count alone does not describe the duration, intensity, recurrence, or clinical importance of an event; those features would require additional outcome definitions or results.

The endpoint is not the same as the study’s stated purpose of examining whether early emollient use delays or prevents atopic dermatitis. The registry lists development of eczema as a secondary outcome, but does not report its result or clarify whether eczema and skin irritation were defined as overlapping outcomes. Therefore, the primary endpoint title should not be interpreted as a recorded atopic dermatitis result. The endpoint’s intended assessment times are stated, but the registry does not report whether measurements were completed at either time point or how missing observations were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

In general, statistical interpretation starts by identifying the outcome, the group being described, the time point, and the comparison of interest. For this study, the registry names incidence of skin irritation as the primary outcome, defines it as a count of participants, and identifies the 1 and 2 year time points. It records a single intervention group and no comparator. The endpoint results themselves are not reported in the registry record, so no numerical effect estimate or inferential result can be explained.

What does a participant count represent?

A count records how many participants meet an event definition. It is different from a continuous measurement, such as a score that can take a range of values, and different from a time-to-event measure, which records when an event occurs. The registry categorizes the primary outcome as binary and describes its meaning as participants with an event, expressed as counts. In general, binary outcomes classify each participant according to whether the defined event occurred. A count of affected participants is most interpretable alongside the number assessed and a clear account of the event definition. Those details and the observed endpoint counts are not reported in the registry record.

The title “incidence” can refer to new events over a period, but the registry’s stated parameter is a count of participants at specified time points. The record does not clarify whether the count refers to new cases since an earlier assessment, all participants with irritation by that time, or another operational definition. That distinction should not be assumed. It would be necessary to consult a fuller outcome definition or analysis report, neither of which is reported in the registry record.

How should uncertainty be understood?

In general, a confidence interval describes a range of values compatible with the observed data and the method used to construct the interval. It communicates precision as well as the estimate’s direction and scale. A narrow interval indicates greater precision than a wide interval, under the chosen model and assumptions. A confidence interval does not remove design limitations, make a non-comparative study comparative, or establish that an observed association is causal. No confidence interval for the clinical outcomes is reported in the registry record.

In general, a p-value describes how surprising data at least as extreme as those observed would be under a specified null hypothesis and statistical model. It is not the probability that the null hypothesis is true, nor a measure of clinical importance. Interpretation depends on the analysis plan, the outcome, and the design. No outcome p-value or analysis result is reported in the registry record, so there is no basis for describing statistical significance.

What does the design imply for estimation?

The registry records a single group receiving emollient and no comparator. In general, a within-group count can describe what was observed in participants who received an intervention. It cannot directly estimate a difference from a separate control group that was not included. A change over time, if measured, would also require careful interpretation: temporal change alone does not identify the intervention as its cause. The registry does not report a comparative analysis or results for the primary and secondary outcomes.

The open-label designation and absence of masking are design features stated in the record. In general, knowledge of treatment or study participation can matter for outcomes that involve assessment or reporting, depending on how the outcome is defined and measured. The registry does not describe outcome-assessment procedures or any safeguards against assessment differences, so their role cannot be determined from this entry.

How do planning assumptions differ from study results?

In general, sample-size planning considers a target effect, a significance level, allocation, and statistical assumptions to illustrate how many participants might be needed for a specified power target. The registry’s planning description says its illustration is computed from the observed effect, uses a two-sided significance level of 0.05, assumes equal allocation between two arms, and uses a normal approximation. It also distinguishes participant counts per arm from total event counts for time-to-event methods. These are planning assumptions, not a description of the enrolled study’s design: the registry lists a single group and allocation as NA.

The planning description refers to fractions of an observed effect, but the observed effect and numerical planning estimates are not reported in the registry record. Any planning illustration should therefore be understood as hypothetical and not as a result observed in this study. Sample-size illustrations are not observed power. They cannot demonstrate that the study had a particular probability of detecting an effect after the fact, and they cannot supply a missing efficacy analysis.

Why do outcome definitions and time points matter?

In general, a result is interpretable only in relation to what was measured and when. A count at a stated time point may differ in meaning from a count of all events over follow-up. Repeated assessments can also raise questions about whether the analysis treats each time point separately or accounts for within-participant dependence. The registry identifies two time points for the primary outcome but does not report the analysis approach, assessment completion, or handling of repeat observations. No analysis method should be inferred from the outcome title alone.

The study’s broader prevention aim and its primary endpoint are not identical descriptions. Skin irritation is the named primary endpoint; development of eczema is listed as a secondary outcome. In general, a result for one outcome does not automatically answer a question about another, even when outcomes are related. The registry does not define the relationship between these outcomes, and reports no results with which to assess either one.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Emollient")
n      <- c(22)
events <- c(0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Emollient  22  0  0.0  0.0  15.4  -0.0  14.9  0.1  14.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, identifies incidence of skin irritation as the primary outcome, and lists development of eczema as a secondary outcome. The primary endpoint also has the 1 and 2 year time points. In general, assessing several outcomes or time points can create multiplicity: the more statistical questions considered, the greater the chance that a result appears notable by chance if each is treated as a separate test. Statistical plans may address this through a prespecified hierarchy, adjustment, or another approach. The registry record does not report whether multiplicity was considered or how it was handled.

The registry lists no analyses. It does not report whether the outcomes were analyzed at each time point, combined, or assessed using another strategy. A planned statistical analysis, including any handling of repeated measures or choice of a primary time point, is not reported in the registry record. No adjustment or testing procedure should be inferred from the outcome listing alone.

Missing-data handling and analysis populations are also not reported in the registry record. The entry does not state how many participants contributed endpoint data at each assessment, whether all enrolled participants were included in an analysis, or how incomplete follow-up was treated. In general, missing observations can affect both the precision and interpretation of an estimate, particularly if the likelihood of missingness is related to outcome status. Without the number assessed and the analysis approach, the possible impact cannot be evaluated.

The completed status and the listed enrollment do not resolve these gaps. Outcome definitions, analysis populations, multiplicity procedures, and missing-data methods are necessary context for evaluating reported estimates, but they are not described in the registry record.

12. 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 registry safety listing is for the Emollient group. It records 0 serious adverse events among 22 participants at risk and 0 other adverse events among 22 participants at risk. These are counts of affected participants, not comparative estimates. The registry record does not list serious adverse event terms, and deaths are not reported in the registry record.

In general, a zero count means no events in that category were recorded in the listed group under the registry’s reporting framework. It does not prove that the intervention has no risk, and it does not establish how likely an event might be in a broader population. The interpretation depends on how events were collected, what counted as an event, and how long participants were observed. Those safety-collection details are not reported in the registry record.

There is no comparator group in this single-group record, so these figures cannot be used to compare safety with another treatment or with no treatment. The figures also do not describe the primary efficacy endpoint of skin irritation: the registry lists that as a separate outcome, with no result reported. The safety counts should therefore be read narrowly as the recorded adverse-event counts for the Emollient group, not as evidence of comparative safety or as a substitute for efficacy results.

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

The record establishes that the study investigated early skin barrier protection with an emollient in newborns and was completed as an open-label, single-group phase 2 study. It identifies skin irritation as the primary outcome and development of eczema as a secondary outcome. It also records enrollment of 22 participants and a limited set of adverse-event counts. These registry entries describe the study’s scope, not whether its intervention changed clinical outcomes.

The registry record does not report the primary outcome count, the secondary outcome result, or any statistical analysis. It therefore does not show how many participants experienced skin irritation at the stated time points or whether eczema developed. No estimate of intervention effect, uncertainty interval, or test result for these outcomes is reported. A conclusion that the intervention delayed or prevented atopic dermatitis cannot be drawn from the registry entry.

Even if outcome counts were available, the single-group design would constrain interpretation. A group’s observed outcomes are not a direct comparison with outcomes under an alternative condition. In general, comparative evidence requires an appropriate basis for estimating what would have occurred without the intervention or under another intervention. The registry does not describe such a comparator.

The listed safety counts should also be interpreted narrowly. The record reports no serious or other adverse events among the participants at risk in the Emollient group, while deaths are not reported in the registry record. Those counts do not establish an absence of risk, and they do not resolve the unreported efficacy outcomes.

Thus, the registry entry is informative about the research question, design, and outcome definitions at a high level. It is not sufficient to determine whether the intended prevention question was answered, the magnitude or precision of any outcome effect, or how the findings might apply beyond the participants enrolled. Those conclusions require outcome results, analysis details, and comparator information that are not reported in the registry record.

14. Why This Trial Matters Statistically

This trial matters statistically because its stated prevention question and primary endpoint are not the same outcome. The stated purpose concerns whether early emollient use might delay onset or prevent atopic dermatitis, while the primary endpoint is incidence of skin irritation. Development of eczema appears as a secondary outcome. Keeping these distinctions clear prevents a measure that may be related to the research topic from being mistaken for direct evidence about the broader prevention question.

The single-group design is another important feature. Statistical estimates do not become comparative merely because a study has a clinical intervention and a measured outcome. Without a comparator, a count can describe the intervention group but cannot directly quantify a difference against another condition. This distinction is fundamental when interpreting results from studies that are not randomized comparisons.

The registry also illustrates why design details and results need to be read separately. A completed status and a recorded enrollment do not supply endpoint counts, uncertainty estimates, or analysis methods. The record lists no analyses and reports no efficacy results. As a result, the statistical interpretation is mainly about what the design could describe and what the registry entry does not establish.

Finally, the planning description uses assumptions for an equal-allocation, two-arm illustration even though the recorded study has a single group. Recognizing that planning calculations are hypothetical, rather than observed study properties, helps avoid confusing a sample-size illustration with evidence about the trial’s actual power or results. In general, statistical conclusions should follow the design and analyses actually reported.

15. 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 results for the primary endpoint of skin irritation or for the secondary outcome of development of eczema. It also lists no analyses. This prevents assessment of the observed outcomes, their precision, or any statistical evidence of differences over time. The endpoint’s operational definition and assessment procedures are not reported, so the meaning of any possible event classification cannot be examined in detail.

The study is recorded as single group, open label, and without a comparator. This limits the ability to make a direct comparative inference from the design. The registry does not report how treatment adherence was measured, how follow-up was conducted, whether outcome assessors were involved, or whether other care could have influenced outcomes. No assumptions about those procedures are warranted.

The record identifies the primary outcome’s time points but does not report the number assessed at each time point or how missing observations were handled. Analysis populations and statistical methods are not reported. The registry lists four outcome measures but does not state whether multiplicity was addressed. These omissions limit interpretation even apart from the absence of outcome estimates.

The registry records 22 participants enrolled, but does not report enough detail about their eligibility, characteristics, or representativeness to assess how closely they reflect a wider population. It does not provide a trial-specific sample-size justification. Its planning description concerns an illustration based on an observed effect and two-arm assumptions, not the recorded single-group design; the observed effect and numerical planning estimates are not reported in the registry record.

These limitations are specific to the information recorded for this study. They do not demonstrate that procedures or analyses were absent in practice; they mean those details are not reported in the registry record and cannot be evaluated from it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: An Open-Label Study Investigating the Effects of Early Skin Barrier Protection on the Development of Atopic Dermatitis — NCT00806221.
• Registry record last updated 2017-07-11; status last verified 2017-06.
• Results first posted 2017-07-11.
• 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.

19. Record Summary

The registry identifies NCT00806221 as a completed phase 2, open-label, single-group study sponsored by Oregon Health and Science University. It records enrollment of 22 participants, allocation as NA, and masking as none. The recorded study start is 2006-11 and primary completion is 2008-11.

The intervention was Cetaphil cream for skin barrier protection from birth. The stated aim concerned delaying onset or preventing development of atopic dermatitis. The primary outcome was incidence of skin irritation, measured as a participant count at the 1 and 2 year time points; development of eczema was listed as a secondary outcome.

The registry record does not report efficacy outcome results or statistical analyses. Safety figures list 0 serious events and 0 other events among 22 participants at risk in the Emollient group; deaths are not reported in the registry record. The single-group design has no recorded comparator, so the entry does not provide a direct comparative estimate.