A Survey of Adults and Children With Allergic Rhinoconjunctivitis (MK-7243-021): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Survey of Adults and Children With Allergic Rhinoconjunctivitis (MK-7243-021) (NCT01535118), a registered phase not stated study. The primary outcome is Percentage of Participants Who Experienced Daily Symptoms Due to Allergic Rhinoconjunctivitis (ARC).

2. Clinical Question

The clinical question is descriptive rather than comparative. It concerns how frequently participants reported symptoms under a specified condition—when allergies were at their worst—and whether those symptoms occurred daily. The registry record says participants were asked about symptom frequency and severity. The primary outcome is the percentage reporting daily experience of different symptoms; it is not a measure of change after treatment or a comparison between therapies.

The record also names a secondary question about the percentage of participants who received allergy shots and had a co-morbid condition of asthma. That question describes treatment history and a co-existing condition, rather than an assigned treatment contrast. The registry record does not provide results for either question, nor does it report the count of respondents answering each item. As a result, the stated research question can be described, but the percentages observed in the survey cannot be determined from the registry record.

3. Trial Design

This study is described as a survey of adults and children with allergic rhinoconjunctivitis. Its official title is “National Allergies, Immunotherapy and RhinoConjunctivitis Survey in America,” and the registry title is “A Survey of Adults and Children With Allergic Rhinoconjunctivitis (MK-7243-021).” The sponsor is ALK-Abelló A/S. The listed enrollment is 2765, and the record gives the study status as completed.

The registry record describes a single group: adults and children with ARC who complete the survey. It does not describe treatment assignment, a control group, or a randomized comparison. The record identifies the allocation as not stated and notes that the arms are not a like-for-like control comparison. The group description should therefore be understood as a description of survey participants, not as evidence of separate intervention groups.

The study start is listed as 2012-01 and primary completion as 2012-05. Participants were asked about symptom frequency and severity when their allergies were at their worst. The primary outcome's timeframe is within 12 months prior to the survey. The record does not provide further details about recruitment, survey administration, eligibility criteria, question wording beyond the outcome description, or how responses were collected.

The primary outcome is a percentage of participants reporting daily experience of different ARC symptoms. A secondary outcome concerns participants who received allergy shots and had asthma as a co-morbid condition. The registry record reports six outcome measures overall, but only names that secondary measure in the available outcome description. It does not report outcome estimates or a statistical comparison. This design supports a description of reported survey responses; it does not, on the information recorded, establish a treatment effect or a causal relationship.

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

Analysis population for the primary outcome, as defined in the registry: The analysis population consisted of all participants who responded to the survey.

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 Percentage of Participants Who Experienced Daily Symptoms Due to Allergic Rhinoconjunctivitis (ARC), measured over Within 12 months prior to survey.

The primary endpoint is the percentage of participants who experienced daily symptoms due to allergic rhinoconjunctivitis. Participants were asked about the frequency and severity of ARC symptoms when allergies were at their worst. The timeframe is within 12 months prior to the survey, and the analysis population is described as all participants who responded to the survey.

This endpoint expresses symptom reporting as a proportion of survey respondents. It is suited to a descriptive question: how common was daily experience of each symptom in the responding group under the specified condition? Reporting a percentage can make the frequency of a response easier to interpret than a raw count when the number of people answering a question is known. However, a percentage depends on its denominator. The record does not state the number of respondents for each symptom item, and it does not report the resulting percentages.

In general, a symptom-frequency endpoint can describe what participants report, but it does not by itself establish why symptoms occurred or whether a treatment changed them. Here, the question refers to symptoms when allergies were at their worst, so the endpoint is not an estimate of average symptom frequency across all circumstances. The registry record does not report a severity score, a combined symptom score, or a comparison over time. The endpoint is therefore best understood as a set of descriptive percentages about daily symptom experience, with the numeric results not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary response summarized as a percentage: whether a participant experienced a particular ARC symptom daily under the question's stated circumstances. The registry record says participants were asked about frequency and severity when allergies were at their worst, and that percentages for different daily symptoms were calculated. It does not give the individual symptom categories, their counts, or the resulting percentages.

What does a percentage estimate?

In general, a percentage is a descriptive summary formed from the number of people meeting a specified response divided by the number of people whose responses are included for that item. Its interpretation depends on both the event definition and the denominator. In this study, the event is daily experience of a symptom, and the stated analysis population is all participants who responded to the survey. The record does not report whether each item used all survey respondents as its denominator or only those who answered that item, so the exact denominator for each percentage is not reported in the registry record.

When percentages are calculated separately for different symptoms, each one answers a distinct descriptive question. They should not automatically be treated as a single overall symptom measure. The registry record describes different symptoms but does not report a combined score, weighting scheme, or summary across symptoms. It also does not state how responses other than daily experience were grouped or coded.

How should uncertainty be assessed?

In general, a confidence interval communicates uncertainty around an estimate by giving a range of values consistent with the data and the method's assumptions. Its width depends on features such as the number of observations contributing to the estimate and the observed response pattern. An interval does not remove uncertainty, and its interpretation depends on how the data were collected and analyzed. The registry record does not report confidence intervals or other measures of uncertainty for the primary outcome. It also does not report the symptom-specific response counts needed to assess precision from the posted results.

A hypothesis test would address a different question, such as whether an observed difference between groups is inconsistent with a specified null model. No comparison group or like-for-like treatment contrast is described for the primary outcome, and the registry record reports zero analyses. No p-values or inferential tests are reported. There is therefore no basis in the record for interpreting a statistical test of the primary symptom percentages.

What does the survey design allow?

In general, survey results describe the people who responded, subject to how participants were selected, how questions were worded, and how complete the responses were. A survey may be affected by nonresponse if people who do not respond differ from those who do. Recall can also influence answers when people are asked to report experiences over a prior period. These are general considerations, not evidence that a particular bias occurred in this study. The registry record does not describe the sampling procedure, response rate, survey validation, or methods for handling incomplete answers, so their influence cannot be assessed.

The primary outcome asks about symptoms at their worst, with a recall timeframe within 12 months prior to the survey. This is not the same estimand as symptom frequency at a randomly selected time or average experience over the full recall period. In general, a question framed around a particularly severe period may elicit a different description than a question about typical experience. That framing is part of what the endpoint measures and should be retained when interpreting any percentage.

How should the other outcomes be read?

The registry record names a secondary outcome concerning the percentage of participants who received allergy shots and had a co-morbid condition of asthma. In general, a percentage describing two characteristics together is a descriptive joint measure; it does not by itself determine whether one characteristic caused the other. The record does not report its estimate, denominator, or analysis method. Six outcome measures are reported overall, but the record does not provide full details for each measure in the outcome information available.

The record's planning assumptions describe sample-size illustrations based on an observed effect, with equal allocation between two arms and a normal approximation. Those assumptions do not describe the survey's primary analysis, and a like-for-like two-arm comparison is not documented. No usable observed effect or analysis results are reported in the registry record. Any planning illustration should not be read as observed power or as evidence that the survey had a particular precision. The record does not report a sample-size justification for this survey.

10. Multiplicity, Missing Data and Analysis Populations

The registry record reports six outcome measures, while the primary outcome concerns daily ARC symptoms and one secondary outcome is named: the percentage of participants who received allergy shots and had co-morbid asthma. The record reports zero analyses and does not provide the outcome estimates. It does not describe a testing hierarchy, a multiplicity adjustment, or a plan for choosing among outcomes. These details are not reported in the registry record.

Multiplicity is a general concern when several outcomes or several symptom-specific estimates are examined. In general, the more statistical tests conducted, the greater the chance that at least one result appears noteworthy by chance if each is interpreted independently. Methods for controlling that issue depend on the study's aims and analysis plan. Because no analyses or inferential tests are reported, the registry record does not show whether multiplicity was addressed or whether it affected interpretation.

The outcome population is described as all participants who responded to the survey, but the record does not provide response counts for each question. It does not state how missing or incomplete answers were handled, whether participants could skip particular items, or whether any imputation was used. The number enrolled is not a substitute for an item-specific denominator. Consequently, completeness and the possible effect of missing responses on the reported percentages cannot be assessed from the registry record.

In general, missing survey responses can limit interpretation if people who answer differ systematically from those who do not. That is a methodological possibility, not a finding about this study. The record does not report a response rate or a comparison of respondents with nonrespondents. It also does not provide subgroup analysis populations or exclusions beyond the statement that the primary analysis population consisted of survey respondents.

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

The documented objective is to describe daily symptoms of allergic rhinoconjunctivitis among adults and children who responded to a survey, with questions framed around the time when allergies were at their worst. The primary outcome is a percentage for different symptoms, and the recall period is within 12 months before the survey. The record also identifies a secondary measure concerning allergy shots and co-morbid asthma.

The posted results do not report the symptom percentages, respondent counts, confidence intervals, or statistical tests. Therefore, the frequency of daily symptoms and the precision of any estimate cannot be quantified from the registry record. The listed enrollment of 2765 does not establish the denominator for each outcome item. The record says the analysis population consisted of survey respondents, but does not say how many answered each question.

In general, descriptive survey findings characterize the responses collected; they do not by themselves show that one exposure caused an outcome, or that a treatment changed symptoms. No like-for-like comparison group is described. The secondary outcome about allergy shots and asthma is also descriptive as stated, and the registry record does not report an estimate or analysis that would support an association claim.

The record does not provide enough information to judge how representative respondents were of adults and children with ARC more broadly. Recruitment, response rate, survey completion, and handling of unanswered items are not reported in the registry record. These omissions limit assessment of generalizability and of possible nonresponse or recall effects. They do not establish that such biases occurred, but they leave their potential influence unresolved.

Accordingly, what can be taken from the registry record is the study's subject, survey format, outcome definitions, and reported enrollment. What cannot be taken from it is a numeric estimate of symptom burden, an estimate of uncertainty, or evidence of a treatment effect. The absence of reported results should not be interpreted as evidence for either a high or a low frequency of symptoms.

12. Why This Trial Matters Statistically

This study is statistically notable as a descriptive survey rather than a treatment comparison. Its primary question concerns the percentage of participants reporting daily symptoms when their allergies were at their worst. That framing defines the target description: it is about reported experience in a particular context, not a change from baseline or a contrast between assigned therapies.

For descriptive outcomes, the denominator is central. The registry record lists enrollment of 2765 and defines the analysis population as survey respondents, but it does not report item-level response counts. A reader cannot determine from enrollment alone how many people contributed to each symptom percentage. This illustrates why participant totals and outcome denominators are not interchangeable.

The record also reports six outcome measures but zero analyses. It names the main symptom question and a secondary question involving allergy shots and asthma, yet no numerical estimates are reported. This distinction matters for statistical interpretation: an outcome definition tells readers what the study intended to measure, while an analysis result is needed to evaluate the observed value and its precision.

In general, survey estimates are interpreted in light of who was invited, who responded, how questions were framed, and how missing answers were handled. The registry record does not report those details. The recall period and “at their worst” framing are documented, so the context of the question is clear, but the extent to which the responses represent broader experience is not assessable from the record.

The study therefore illustrates the difference between a clearly stated descriptive aim and an interpretable statistical result. Without outcome values, denominators, and uncertainty estimates, readers can identify what was intended to be measured but cannot quantify the findings or judge their precision. That boundary is important when reading registry information for a completed survey.

13. 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 the primary symptom percentages or the counts underlying them. It also does not report confidence intervals or other measures of uncertainty. These omissions prevent assessment of the observed frequency and precision of the primary outcome.

Although enrollment is listed as 2765, the record does not state how many participants answered each survey item. The primary analysis population is described as all participants who responded to the survey, but item-level denominators, response rates, and missing-response handling are not reported. The extent of incomplete data and its possible effect on the percentages therefore cannot be evaluated.

The record gives limited detail about survey conduct. Recruitment procedures, participant eligibility criteria, question wording beyond the outcome description, survey mode, and validation are not reported in the registry record. The primary outcome refers to symptoms when allergies were at their worst during the 12 months before the survey. In general, a retrospective report may depend on recall, but the record does not provide evidence about whether recall affected these responses.

No comparison group or treatment assignment is described, and the record notes that the arms are not a like-for-like control comparison. The survey results, if reported, would therefore be descriptive and would not establish a treatment effect. The record reports six outcome measures but names only one secondary outcome in the outcome information available; it does not describe an analysis plan, multiplicity approach, or statistical tests.

Finally, the registry record does not report whether respondents represent the wider population of adults and children with ARC. Generalization beyond survey respondents cannot be assessed without information about recruitment and nonresponse. These limitations concern what can be evaluated from the registry record; they do not show that a particular bias or error occurred.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: A Survey of Adults and Children With Allergic Rhinoconjunctivitis (MK-7243-021) — NCT01535118.
• Registry record last updated 2017-03-03; status last verified 2017-01.
• Results first posted 2014-01-27.
• 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.

17. Record Summary

The registry record describes NCT01535118, a completed survey sponsored by ALK-Abelló A/S. Its title concerns adults and children with allergic rhinoconjunctivitis, and its official title is “National Allergies, Immunotherapy and RhinoConjunctivitis Survey in America.” Enrollment is listed as 2765; the study start is 2012-01 and primary completion is 2012-05.

Participants with ARC completed a survey. The primary outcome is the percentage who experienced different ARC symptoms daily when allergies were at their worst, within 12 months prior to the survey. The analysis population is described as survey respondents. A secondary outcome concerns allergy shots and co-morbid asthma. Six outcome measures are listed overall, and the record reports zero analyses.

The registry record does not report numeric outcome results, item-specific respondent counts, or uncertainty estimates. It describes no like-for-like control comparison. The posted information establishes the survey's scope and outcome definitions but does not allow the symptom percentages or their precision to be evaluated.