This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Value of Patch Testing in Direct Diet Therapy for Eosinophilic Esophagitis (NCT02227836), a na na study. The primary outcome is Sensitivity of Patch Testing.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02227836 |
| Phase | NA |
| Condition | Eosinophilic Esophagitis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with eosinophilic esophagitis. The registry record lists an enrollment of 8, but does not report further eligibility details or a fuller description of the analyzed population.
Intervention
Participants underwent allergy patch testing (APT). The record describes the study purpose as assessing whether APT can help predict effective dietary therapy. The intervention is listed as a device, and the available protocol description is incomplete.
Comparator
No separate comparator group is listed. The study is classified as single-group, with allocation recorded as NA and masking recorded as none. It therefore does not provide a like-for-like comparison between APT and another testing or treatment strategy.
Primary question
The primary outcome is titled Sensitivity of Patch Testing. The registry defines it as the number of subjects with total positive APT reactions correlated to histologic findings, assessed up to 120 hours after application of the patch test. The record does not report the observed count or an analysis of the relationship with histology.
3. Trial Design
This was a completed pilot study of allergy patch testing in eosinophilic esophagitis, sponsored by Mayo Clinic. The registry lists enrollment of 8, a single-group model, allocation as NA, and masking as none. The study began in 2014-08 and reached primary completion in 2017-09. Its phase is listed as NA.
The intervention is named Allergy Patch Testing and classified as a device. The arm description says participants would undergo APT and begins to describe placing dry food mixtures in saline and applying them to the participant’s back in aluminum cups. The remaining protocol description is truncated in the registry record, so the complete set of tested foods and procedural details are not reported in the registry record.
The stated study purpose was to assess whether APT could help predict effective dietary therapy. The primary outcome was sensitivity of the patch test, described in relation to positive APT reactions and histologic findings. No separate comparison arm is listed, so the design cannot estimate a treatment contrast between APT and another approach. The registry record lists one outcome measure and no posted analyses. It does not report a protocol-level sample-size justification, a statistical analysis plan, or an explanation of how histologic findings were used to classify patch-test results.
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
| Stage | Allergy Patch Testing APT |
|---|---|
| STARTED | 8 |
| COMPLETED | 8 |
| NOT COMPLETED | 0 |
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.
| Characteristic | Unit | Allergy Patch Testing APT |
|---|---|---|
| Participants analysed | 8 | |
| Age, Continuous | years | 43 (SD 11) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 4 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: United States | participants | 8 |
| Allergic history | Participants | 7 |
6. Primary Endpoint
The registry lists the primary outcome as Sensitivity of Patch Testing, measured over up to 120 hours after application of patch test.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is titled Sensitivity of Patch Testing, has participants as its unit, and is assessed up to 120 hours after patch-test application. The registry definition is the number of subjects with total positive APT reactions correlated to histologic findings. This frames the outcome as a count of participants, rather than reporting a sensitivity estimate as a proportion or percentage.
In general, sensitivity describes how often a test is positive among people classified as having the target condition according to a reference standard. Histologic findings appear in the registry definition as the basis for correlation, but the record does not specify the histologic classification rule, the threshold for a positive APT result, or the exact way the correlation was to be summarized. It also does not report the number of participants with relevant histologic findings, the number with positive patch tests, or a cross-classification of the two.
A test-performance endpoint can be useful for examining whether test results correspond to a reference assessment. However, without the underlying counts and a stated calculation method, the endpoint’s value and precision cannot be evaluated from the registry record. No observed endpoint result is reported.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study question and design, but it does not provide a numerical result for the primary outcome. Although the endpoint is described as a participant count relating positive APT reactions to histologic findings, no count, sensitivity estimate, confidence interval, or test-versus-histology breakdown is reported. The record therefore does not permit an assessment of how closely patch-test findings corresponded to histologic findings in the enrolled participants.
The study enrolled 8 participants and used a single-group design. Those details describe the scale and structure of the study, not the direction or size of an endpoint result. With no separate comparator group, the design also does not supply a direct randomized or controlled estimate of what would have happened under another testing strategy. The stated purpose concerns whether patch testing can help predict effective dietary therapy, but a result demonstrating such prediction is not reported in the registry record.
In general, an estimate should be read together with its uncertainty. A confidence interval describes a range of values compatible with the observed data under the statistical method used; a wider interval indicates less precision. No interval is reported for the primary endpoint, and the available record does not give enough outcome counts to reconstruct one. No p-value or inferential analysis is reported either. This absence should not be interpreted as evidence of no association or as evidence of a particular level of accuracy.
The safety record lists 8 participants at risk for serious adverse events, 0 affected, and 0 deaths. It also lists 8 at risk and 0 affected in the other adverse-event category. These are descriptive registry counts for this group. They do not establish that the risk of an event is absent, and the record does not state a safety observation period or list serious adverse-event terms.
Overall, the posted information supports a description of a small, completed pilot study and its intended endpoint, but not a conclusion about the observed sensitivity of APT or its predictive performance. The absence of posted analyses leaves both the magnitude and precision of the primary outcome unknown.
9. Statistical Methods Explained
The registry record identifies a binary outcome type and describes the primary endpoint as a count of participants. For a binary outcome, each participant is classified into an outcome category, such as meeting or not meeting a specified definition. A count can describe how many participants meet that definition, but it is not by itself a complete test-performance estimate. Interpreting sensitivity generally requires knowing which participants are positive according to the reference assessment as well as which test results are positive.
What does sensitivity mean?
In general, sensitivity is the proportion of participants with the target condition, as defined by a reference standard, who have a positive test result. Its interpretation depends on explicit rules for both the reference classification and the test threshold. The registry says the outcome concerns total positive APT reactions correlated to histologic findings, but does not report those operational rules or the underlying participant-level categories. It describes a count, and no numerical count or sensitivity estimate is posted.
What can a single-group design estimate?
A single-group study can describe outcomes observed among participants who received the intervention. Without a separate comparator, it cannot directly estimate a between-group difference. This distinction matters because a descriptive count in the enrolled group does not show what the result would have been under a different testing approach. The registry lists no allocation to comparison groups and no masking. The record does not report whether any other design features were used to limit measurement or interpretation bias.
How should uncertainty be assessed?
In general, statistical estimates are more informative when accompanied by measures of uncertainty, such as a confidence interval. A confidence interval reflects the variability expected under a statistical model and shows how precisely the available data estimate the quantity of interest. For a binary endpoint, the amount of information depends on the relevant outcome counts and the denominator used for the estimate. The record gives enrollment of 8 but does not report the primary outcome counts or a confidence interval. As a result, the precision of the endpoint cannot be assessed from the posted results.
When event counts are small, estimates can be unstable and uncertainty can be substantial. This is a general statistical consideration, not a claim about the unreported endpoint value in this study. A missing estimate should not be replaced with an assumed value, and no recalculated result can be derived from the information in the registry record.
What do the planning assumptions mean?
In general, sample-size illustrations estimate how many participants might be needed under specified design and effect assumptions. Such planning figures are not observed outcomes and are not the same as observed power. The listed assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Those assumptions describe a hypothetical two-arm planning framework, whereas this study is listed as single-group. The record does not report the trial’s own sample-size justification, and the observed effect needed to anchor an illustration is not reported with the primary outcome. Any such planning illustration should therefore be read as hypothetical rather than as a description of the study’s design or result.
What analyses are posted?
The registry record lists one outcome measure and zero analyses. It does not report a statistical analysis plan, a method for handling missing outcome data, or an analysis population. It also does not report adjusted or unadjusted estimates, p-values, confidence intervals, or a participant-level outcome breakdown. Since these are absent, the statistical method used to turn the stated endpoint into a result is not reported in the registry record. The central methodological limitation is therefore not a choice between competing reported analyses, but the lack of a posted numerical analysis to interpret.
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.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Allergy Patch Testing APT | 8 | 1 | 12.5% | 0.3% to 52.7% | 2.2% to 47.1% | 2.8% to 48.2% |
R code and output
arm <- c("Allergy Patch Testing APT")
n <- c(8)
events <- c(1)
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 Allergy Patch Testing APT 8 1 12.5 0.3 52.7 2.2 47.1 2.8 48.211. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure, titled Sensitivity of Patch Testing, and zero analyses. It does not report whether additional outcomes were prespecified outside the listed registry outcome, whether any interim analyses were planned or conducted, or whether any adjustment for multiple testing was intended. These details are not reported in the registry record, so it is not possible to assess how multiplicity was handled.
In general, multiplicity arises when several outcomes, comparisons, time points, or subgroup analyses are examined. Considering many results can increase the chance of finding an apparently notable result by chance. A statistical plan can specify which result is primary and how other tests will be interpreted. The available record identifies a primary outcome but does not describe a broader analysis plan.
Missing-data methods and analysis populations are also not reported in the registry record. The record does not state whether every enrolled participant contributed endpoint data, how unavailable histologic findings or incomplete patch-test readings would be handled, or whether an intention-to-treat or other analysis population was defined. Enrollment of 8 is reported, but it does not establish how many participants had evaluable data for the primary endpoint.
Without these details and without posted outcome analyses, the impact of missing observations, exclusions, or multiple testing cannot be assessed. These are reporting gaps, not evidence that missingness or multiplicity affected the result.
12. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Allergy Patch Testing APT | 0 | 8 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Allergy Patch Testing APT | 0 of 8 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Allergy Patch Testing APT | 0 of 8 |
The adverse-event record lists 8 participants at risk for serious adverse events and 0 affected. It reports 0 deaths. For the other adverse-event category, it also lists 8 at risk and 0 affected. No serious adverse-event terms are listed.
These figures are counts recorded for the study group. They indicate that no affected participants or deaths were recorded in the listed categories; they do not establish that the underlying event risk is zero. With only 8 participants enrolled, the safety counts describe a limited group and should not be treated as a precise estimate of event frequency in a wider population. This is a general limitation of interpreting event counts from a small study.
The registry record does not report the safety observation period, detailed event definitions, or additional context about how adverse events were collected. The absence of listed serious-event terms does not supply that missing context. These figures are descriptive registry data and do not determine the safety of patch testing in other settings.
13. What the Result Does, and Does Not, Mean
The record documents a completed pilot study of allergy patch testing in eosinophilic esophagitis, with enrollment of 8 and a single-group design. It identifies a primary endpoint intended to relate positive APT reactions to histologic findings, with assessment up to 120 hours after patch-test application. These details explain what the study set out to examine.
The registry record does not report the endpoint count, a sensitivity estimate, a comparison with another testing strategy, or a statistical analysis. It therefore does not show whether APT results corresponded to histologic findings in the enrolled participants, how large any correspondence was, or how precisely it was estimated. The stated aim of assessing prediction of effective dietary therapy is not itself evidence that predictive performance was demonstrated.
In general, a pilot study can provide descriptive information and help frame questions for further research, but its interpretation depends on the actual outcomes and methods reported. Here, the absence of numerical primary-outcome results prevents even a descriptive account of the observed endpoint. The single-group structure also limits conclusions that require comparison with an alternative strategy.
The safety counts report 0 participants affected by serious adverse events among 8 at risk and 0 deaths. These counts describe what is recorded for this study group; they do not establish a zero risk or determine safety beyond the study. Overall, the record supports conclusions about the study’s registered design and intended outcome, but not a conclusion about APT accuracy, dietary-treatment prediction, comparative performance, or the precision of any effect.
14. Why This Trial Matters Statistically
This study raises a statistical measurement question: how should a patch-test result be compared with a reference assessment, and what quantity should represent that correspondence? The registry names sensitivity and refers to histologic findings, but describes the endpoint as a participant count. Clear definitions of a positive test, a positive reference assessment, and the calculation method are essential for interpreting a test-performance result.
The study also illustrates why design structure matters. A single-group study can describe observations in participants who underwent APT, but it does not provide a direct comparison with another strategy. The intended question about predicting effective dietary therapy is broader than the endpoint description alone, and the registry does not report an analysis linking test results to dietary outcomes.
Reporting the denominator, outcome counts, and uncertainty would allow readers to assess the scale and precision of an estimate. The record lists enrollment of 8 but does not report the primary outcome result or its uncertainty. This limits statistical interpretation regardless of the study’s stated purpose.
Finally, planning calculations should be kept separate from observed findings. The described planning assumptions involve equal allocation between two arms, while the registered study is single-group. Any planning illustration based on an observed effect would not turn that effect into a trial result, nor would it establish the precision of an unreported endpoint. This distinction is especially important when reading small pilot studies and registry records with no posted analyses.
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 supports only a limited account of the trial. Enrollment was 8, and the design is listed as single-group with no masking and no allocation to a comparison arm. This structure limits direct comparative interpretation. The record does not provide the primary endpoint result, so the observed sensitivity or its precision cannot be evaluated.
The endpoint definition leaves important measurement details unspecified. It refers to total positive APT reactions correlated with histologic findings but does not report the threshold for a positive result, how histology was categorized, or how the relationship was calculated. The full intervention protocol is also not available in the arm description, which ends partway through a description of the food mixtures and application procedure.
The record does not report participant eligibility details beyond the condition, the number with evaluable endpoint data, missing-data handling, analysis populations, a statistical analysis plan, or a protocol-level sample-size justification. It also does not report an analysis connecting APT findings with dietary-therapy outcomes, despite describing prediction of effective dietary therapy as the study purpose.
Safety information is limited to the reported counts; the observation period and additional collection details are not reported in the registry record. These reporting limitations do not establish that procedures were absent or that data were not collected. They mean that the posted record does not provide the information needed to evaluate those aspects of the study.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Value of Patch Testing in Direct Diet Therapy for Eosinophilic Esophagitis — NCT02227836.
- Registry record last updated 2019-04-17; status last verified 2019-03.
- Results first posted 2019-04-17.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT02227836 is a completed Mayo Clinic pilot study titled Value of Patch Testing in Direct Diet Therapy for Eosinophilic Esophagitis. The official title is Efficacy of Allergy Patch Testing in Directed Dietary Therapy of Eosinophilic Esophagitis: A Pilot Study. It lists enrollment of 8, a single-group design, no masking, and allergy patch testing as the intervention.
The primary outcome is titled Sensitivity of Patch Testing and is described as a count of participants with total positive APT reactions correlated to histologic findings, assessed up to 120 hours after application. The record lists one outcome measure and zero analyses, with no primary outcome result reported. It records 0 participants affected by serious adverse events among 8 at risk and 0 deaths. The record does not provide a statistical analysis plan or a numerical estimate of patch-test sensitivity.