Effects of Whole Sprouts on Airway Allergic Inflammation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Whole Sprouts on Airway Allergic Inflammation (NCT01522703), a randomized na study. The primary outcome is Exhaled Nitric Oxide Concentrations.

2. Clinical Question

The study asks whether a short dietary intervention with broccoli sprouts is associated with changes in airway inflammatory measures, oxidative stress, and symptoms in adults with asthma and aeroallergen sensitization. The registry record identifies exhaled nitric oxide concentration as the primary outcome, with results reported at 3 days. It posts group summaries, but does not post an analysis comparing the groups.

The question therefore has two parts. First, what are the reported endpoint values in each group? Second, how much evidence do those values provide about a difference between the interventions? The posted medians are 19.0 ppb for broccoli sprouts and 22.0 ppb for the alfalfa-sprout placebo control. The inter-quartile ranges are 15.0 to 43.0 ppb and 12.0 to 32.0 ppb, respectively. These summaries describe each group separately; they do not, by themselves, quantify uncertainty in a between-group effect or establish whether a difference is distinguishable from chance variation.

The registry describes the study as a pilot. Its summary refers to 40 adults, while the enrollment field lists 51. The record does not explain that difference. Outcome rows list 20 participants in each group, but the analysis population and reasons why those outcome counts differ from the enrollment figure are not reported in the registry record.

3. Trial Design

The registry describes a randomized, double-blind, parallel-group, placebo-controlled trial. Participants were assigned to broccoli sprouts or alfalfa sprouts, the latter identified as the placebo control. The brief summary characterizes the study as a pilot and describes adults with asthma and aeroallergen sensitization as the population of interest. It also gives an age range of 18-50 years. Further eligibility criteria are not reported in the registry record.

The intervention descriptions specify that participants ate the assigned sprouts in a sandwich or wrap daily for 3 consecutive days. The primary outcome was exhaled nitric oxide concentration at 3 days. The record lists an outcome summary for 20 participants in the broccoli-sprout group and 20 in the alfalfa-sprout group.

The enrollment field lists 51 participants, whereas the brief summary says the study would randomize 40 adults. These are different figures in the record, and it does not explain the reason. The outcome rows each list 20 participants; the relationship between those rows, enrollment, and the number randomized is not reported in the registry record.

The study status is completed. The record identifies Johns Hopkins University as sponsor. It lists the start as 2012-03 and primary completion as 2015-03. These administrative details do not fill in the missing analysis information: no statistical analysis is posted, and the record does not describe allocation concealment, the exact masking procedures, adherence assessment, or handling of participants who did not complete the intervention.

The randomized design is intended to make groups comparable on average, while masking may reduce some influences on behavior or measurement. Those design features do not replace a reported analysis. In this record, the posted endpoint information consists of group-level medians and inter-quartile ranges, without a stated comparative estimate, confidence interval, or test result.

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 Exhaled Nitric Oxide Concentrations, measured over at 3 days.

The primary endpoint is exhaled nitric oxide concentration, reported in ppb at 3 days. Exhaled nitric oxide is a measurement used to characterize airway inflammation. It is a biological marker rather than a direct report of symptoms or daily functioning, and a value from this endpoint alone cannot describe every aspect of asthma or allergic inflammation.

The registry reports the endpoint as a median with an inter-quartile range. A median describes the central value after observations are ordered. The inter-quartile range describes the spread of the middle portion of the observations. These summaries can be useful when values are skewed or when a mean and standard deviation would not describe the distribution well. The reason this reporting format was selected is not reported in the registry record.

At 3 days, the posted median is 19.0 ppb for broccoli sprouts, with an inter-quartile range of 15.0 to 43.0 ppb. For the alfalfa-sprout placebo control, the median is 22.0 ppb, with an inter-quartile range of 12.0 to 32.0 ppb. These are group summaries, not individual participant values. The record does not post a baseline value, a change-from-baseline summary, or a comparative estimate for this endpoint. It also does not explain whether the measurement was analyzed as a change or as an endpoint value beyond the stated outcome description.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What do the posted summaries describe?

The outcome is summarized separately in each arm using a median and inter-quartile range. The median is a measure of location: it identifies the middle of an ordered set of observations. The inter-quartile range is a measure of spread around that location. In general, medians and inter-quartile ranges are useful descriptions when a distribution is asymmetric or includes unusually high or low values. The registry record does not state why this summary format was chosen or show the underlying values.

The posted values are not a direct estimate of the contrast between broccoli sprouts and placebo. A comparative estimate would summarize how the groups differ under a specified analysis, and a confidence interval would show the range of effects reasonably compatible with the data and method. Neither is reported. The posted medians and ranges should therefore be read as descriptive group summaries, not as a treatment-effect estimate.

Why is a comparison needed?

In a randomized trial, the primary statistical question is generally about the difference between assigned groups, rather than whether a result within either group appears large or small on its own. Separate summaries do not account for the uncertainty in a between-group contrast. A test or interval also depends on choices such as the analysis population, outcome scale, and statistical method. Those choices are not reported in the registry record.

A confidence interval, in general, communicates both the direction and precision of an estimated effect. A narrow interval indicates greater precision under the analysis assumptions; a wide interval indicates more uncertainty. A p-value, in general, measures how compatible the observed data are with a specified null hypothesis under a statistical model. Neither a p-value nor a confidence interval is posted for this outcome. Their absence means that the registry record does not allow readers to assess the precision or statistical evidence for a comparative effect.

What does the endpoint summary not show?

An inter-quartile range describes variation among participant measurements. It is not a confidence interval around the median, and it is not an interval around the difference between arms. Overlap between the two inter-quartile ranges cannot be used as a substitute for a formal test. Likewise, the fact that the reported medians differ numerically does not establish that the interventions differ. Such a conclusion requires a comparative analysis and its uncertainty.

Over-dispersion is a general issue in count data: variation greater than a model expects can make standard errors too small if the model is not appropriate. That concept is not directly enough to characterize this endpoint, which is reported as a continuous concentration summarized by medians and inter-quartile ranges. The registry record does not report a distributional model, a variance assessment, or a method for handling unusual values. It would be inappropriate to infer that any particular model or correction was used.

How should planning illustrations be read?

The sample-size section contains planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The illustrations describe participants per arm for 80% power and for other stated planning assumptions, not the number actually analyzed. They are not evidence that the trial was designed around those assumptions, and they are not observed power. The registry record does not report the trial's own sample-size justification or the assumptions used to plan enrollment.

Planning calculations are conditional: they show what sample size might be required under specified assumptions about an effect and variability. They do not demonstrate that the assumed effect is real, and they do not repair the absence of a reported trial comparison. Because the record does not post a comparative analysis for this outcome, planning illustrations should not be mistaken for evidence about whether the intervention had an effect.

What analysis information is absent?

No analysis is posted for the listed endpoint. The analysis population, handling of missing endpoint values, method of comparing groups, adjustment for baseline, and treatment of any deviations from assignment are not reported in the registry record. The record also does not state whether there were interim analyses or describe a statistical analysis plan. Those details matter because they define how the observed data are turned into an estimate and how uncertainty is assessed.

The record lists one outcome measure and no posted secondary outcomes. It does not provide a multiplicity strategy, and the absence of such a report should not be interpreted as evidence that no additional outcomes were measured. The limited information supports a descriptive reading of the posted endpoint values, but not an independent reconstruction of the intended analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure: exhaled nitric oxide concentration at 3 days. It lists no posted secondary outcomes and no analyses. The study objective mentions inflammatory measures, oxidative stress, and symptoms, but the record does not provide posted results for those additional domains. It is not reported in the registry record whether they were prespecified outcomes, collected but not posted, or outside the registry's results entry.

Multiplicity refers, in general, to the problem of interpreting results when several outcomes, time points, subgroups, or statistical tests are examined. If many comparisons are made, the chance of finding an apparently notable result can rise unless the analysis accounts for those comparisons. The registry record does not report a multiplicity plan, so readers cannot determine whether or how any such adjustment was intended. This absence does not establish that multiple analyses occurred.

Missing-data handling is also not reported. The outcome rows show 20 participants in each group, but the record does not say whether these counts represent everyone randomized, everyone with a measured endpoint, or another analysis population. It does not report missing endpoint counts, reasons for missingness, imputation, or sensitivity analyses. The enrollment field lists 51, while the brief summary describes 40 adults; the record does not explain the difference or how it relates to the outcome rows.

The statistical analysis plan, interim analyses, and analysis populations are not reported in the registry record. Without those details, readers cannot assess whether the posted endpoint values follow an intention-to-treat analysis, a per-protocol analysis, or another approach. Nor can they judge whether the analysis accounted for baseline values or other prespecified factors. These gaps do not invalidate the descriptive summaries, but they limit what can be concluded from them.

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 adverse-event section lists 20 participants at risk in each group. It reports 0 participants with serious adverse events and 0 with other adverse events in the broccoli-sprout group, and the same counts in the alfalfa-sprout placebo-control group. These entries describe the registry's posted event counts for the groups and the population at risk listed there.

Zero recorded events in these rows should be read narrowly. It means that the registry reports no affected participants for these event categories in the listed groups; it does not establish that no events occurred outside the recorded categories or observation period. The registry record does not explain how events were defined, how they were collected, or the duration and completeness of safety follow-up. It also does not provide a list of non-serious event terms.

Deaths are not reported in the adverse-event rows. The record's blank death entries should not be interpreted as a posted count of zero deaths. These summaries are not a complete safety assessment, and they do not allow a comparison of event risk beyond the counts shown. The safety figures should be considered alongside the record's limited information about follow-up and event ascertainment.

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

The result means that the registry record posts a median exhaled nitric oxide concentration of 19.0 ppb for the broccoli-sprout group and 22.0 ppb for the alfalfa-sprout placebo-control group at 3 days. It also reports the inter-quartile ranges and lists 20 participants in each outcome row. These figures describe the observed endpoint summaries as entered in the record.

The result does not mean that broccoli sprouts caused a change in exhaled nitric oxide relative to placebo. The record does not post a comparative estimate, a confidence interval, or a statistical test. The apparent difference between the medians cannot be interpreted on its own as evidence of an intervention effect. The inter-quartile ranges describe participant-level spread and do not show the precision of the group contrast.

Nor does this endpoint alone answer the broader study objective. The summary refers to airway inflammatory measures, oxidative stress, and symptoms, but only exhaled nitric oxide is listed as a posted outcome measure. Results for the other objectives are not reported in the registry record. The short observation period described for the primary outcome also cannot establish what happened at other times.

The trial is identified as a pilot, and the record contains an inconsistency between the enrollment field, which lists 51, and the summary, which describes 40 adults. Each group has an outcome count of 20. The record does not explain the relationship among these figures. This makes it important not to treat the displayed outcome rows as a complete accounting of recruitment or follow-up.

In general, a randomized comparison can help estimate differences between assigned interventions, but the design alone is not a result. A clear interpretation requires the analysis population, a prespecified or described method, and an estimate with uncertainty. Those elements are not reported. The appropriate reading is therefore descriptive: the page presents the endpoint values recorded for each group, while the comparative effect and its precision remain unreported.

13. Why This Trial Matters Statistically

This trial illustrates the difference between having numerical outcome summaries and having an interpretable comparative result. The record gives a median and inter-quartile range for each assigned group, which lets readers see where the recorded values lie and how they vary. But without an analysis comparing groups, those summaries do not answer the central randomized-trial question about the contrast between interventions.

The distinction is important in biostatistics because descriptive summaries and inferential results serve different purposes. A median describes the observed group; a confidence interval or other uncertainty measure would describe how precisely a comparative effect has been estimated. Treating the inter-quartile ranges as if they expressed uncertainty in that effect would confuse participant-level variation with precision about a group contrast.

The record also demonstrates why registration details should be read together rather than in isolation. It describes a pilot involving 40 adults, lists enrollment as 51, and posts outcome counts of 20 in each group. These figures may refer to different stages or definitions, but the record does not explain their relationship. A reader should report the inconsistency, not resolve it by speculation.

Finally, the study objective is broader than its posted endpoint results. The objective includes inflammatory measures, oxidative stress, and symptoms, while the results entry lists only exhaled nitric oxide. The gap between research aims and posted results is a useful reminder that one endpoint cannot stand in for all outcomes of interest. The registry record supplies descriptive information, but its missing analysis details prevent a precise statement about the comparative result.

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 main limitation for interpreting this trial from the registry record is the absence of a posted comparative analysis. The record gives group medians and inter-quartile ranges for the primary endpoint, but no treatment-effect estimate, confidence interval, or p-value. It therefore does not show the precision of the difference between groups or provide a formal basis for judging the evidence for a difference.

The record does not reconcile the enrollment figure of 51 with the summary's description of 40 adults. The endpoint rows each list 20 participants, but the relationship of these counts to recruitment, randomization, and analysis is not reported. The record does not identify the analysis population or explain whether outcome data were missing.

Only one outcome measure is posted, although the objective also mentions oxidative stress and symptoms. Results for those areas are not reported in the registry record. No baseline endpoint values, individual participant data, or change-from-baseline summaries are posted. The rationale for summarizing the endpoint with a median and inter-quartile range is also not reported.

Further details that could inform interpretation are absent, including the statistical analysis plan, the method used to compare groups, multiplicity handling, missing-data procedures, and whether interim analyses occurred. The registry record does not describe adherence, exact masking procedures, or safety-event ascertainment and follow-up. These omissions do not change the values that are posted, but they limit independent assessment of how complete and representative those values are.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effects of Whole Sprouts on Airway Allergic Inflammation — NCT01522703.
• Registry record last updated 2017-01-19; status last verified 2016-10.
• Results first posted 2017-01-19.
• 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

This completed randomized, double-blind, parallel-group pilot compared broccoli sprouts with alfalfa-sprout placebo in adults with asthma and aeroallergen sensitization. The intervention descriptions specify daily consumption for 3 consecutive days. The primary endpoint was exhaled nitric oxide concentration at 3 days, reported as a median and inter-quartile range.

The posted endpoint summaries are 19.0 ppb, with an inter-quartile range of 15.0 to 43.0 ppb, for broccoli sprouts, and 22.0 ppb, with an inter-quartile range of 12.0 to 32.0 ppb, for alfalfa-sprout placebo control. Each outcome row lists 20 participants. No analysis or comparative estimate is posted.

The enrollment field lists 51, while the brief summary describes 40 adults; the record does not explain the difference. No secondary outcomes are posted. The safety section lists 0 serious and 0 other affected participants in each group; deaths are not reported in its rows. The record does not report the analysis plan, missing-data methods, or multiplicity approach.