Treatment of Bronchial Asthma With Borage and Echium Seed Oils: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment of Bronchial Asthma With Borage and Echium Seed Oils (NCT00806442), a randomized phase 1, phase 2 study. The primary outcome is Forced Expiratory Volume in 1 Second (FEV1).

2. Clinical Question

The stated aim was to determine the efficacy of the combination of borage seed oil and echium seed oil as a potential treatment for bronchial asthma. Secondary outcomes named in the registry record include peak flow rate, rescue use of short-acting beta-2 agonists, daytime symptoms, night-time awakenings, and urinary leukotriene levels. It also lists positive FEV1 percent-predicted change among C allele carriers and A homozygotes. These outcomes describe additional questions, but posted numerical results for them are not included in the record.

3. Trial Design

The registry describes a randomized, triple-masked, crossover trial in Phase 1 and Phase 2. It lists enrollment as 43 and status as completed. The study start is recorded as 2008-12 and primary completion as 2012-04. The sponsor is Brigham and Women's Hospital.

In a crossover design, participants receive more than one study condition over time, so comparisons can use measurements from the same participant under different conditions. That general feature differs from a parallel-group design, where each participant remains in one assigned group. The registry identifies the model as crossover, but does not report the sequence allocation details, the duration of each treatment period, or the procedures used to account for period or carryover effects. Although washout categories appear in the safety results, the washout schedule and its planned role in the efficacy analysis are not reported in the registry record.

The interventions are borage and echium seed oils and corn oil. The plant-seed-oil regimen is described as 2 g/day of borage seed oil and 7 g/day of echium seed oil, providing 1.6 g/day of GLA and 0.9 g/day of SDA. The placebo comparator is described as 9 g/day of corn oil. Masking is recorded as triple, but the identities of the masked parties and the masking procedures are not reported in the registry record.

The primary outcome is FEV1 in liters, with a timeframe of 6 weeks. The registry states that the primary outcome population includes participants who completed the study. Arm-level results are posted for Plant Seed Oil and Placebo, each with n of 28. Those arm counts should be read as the registry reports them; they do not disclose the sequence-level or period-level details needed to reconstruct a crossover analysis.

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: 43 subjects were enrolled and signed consent; however, only 39 were randomized into a treatment group. 3 subjects screen failed and 1 subject was lost to follow up prior to randomization.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Includes participants that completed the 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 Forced Expiratory Volume in 1 Second (FEV1), measured over 6 weeks.

Forced expiratory volume in 1 second (FEV1) is the volume of air a person can forcefully exhale during the first second of an effort. In general clinical measurement, it is used as an objective indicator of airflow and lung function. In asthma research, a change in FEV1 can therefore describe a change in measured respiratory function, although it does not by itself describe every aspect of symptoms or day-to-day disease experience.

The registry specifies FEV1 in liters, reports the mean, and gives a 95% confidence interval for each condition. The listed timeframe is 6 weeks, and the outcome description identifies plant seed oil versus placebo. A mean gives a group-level summary; it does not show the range of individual responses. A confidence interval conveys uncertainty around the estimated mean, rather than showing the spread of individual measurements.

The posted results include separate means and intervals for Plant Seed Oil and Placebo. A direct estimate of the within-participant treatment contrast, with its uncertainty, is not reported in the registry record. That distinction matters for a crossover trial because the treatment comparison should account for the fact that measurements can be linked within participants. FEV1 is the primary endpoint named in the record; the listed secondary outcomes address other lung-function, symptom, medication-use, and laboratory questions.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean describe?

For a continuous outcome such as FEV1, the mean is the average measurement within the reported condition. It is a concise summary of the group’s observed values. It does not show how widely individual values vary, whether values cluster around the mean, or whether some participants experienced changes in a different direction from the group average. The registry reports the mean for each condition but does not report a dispersion measure for those results.

How should a confidence interval be read?

A confidence interval expresses the statistical uncertainty around an estimated quantity. In general, a 95% confidence interval is produced by a procedure intended to cover the underlying quantity at that rate across repeated applications under its assumptions. It is not a display of individual participant values, and it is not a statement that a particular range contains the true value with a 95% probability. The registry gives a 95% confidence interval around each arm-level mean. Those intervals describe uncertainty in the means; they do not directly quantify uncertainty in the treatment contrast.

Why does the crossover structure matter?

In general, crossover analyses account for the fact that measurements made on the same participant are related. A paired comparison can focus on each participant’s outcome under one condition relative to that participant’s outcome under the other condition. This can differ from comparing two unrelated sets of observations. The posted arm-level means do not include the participant-level pairing or the distribution of within-participant differences, so those summaries cannot reproduce a paired estimate or its standard error.

Period and carryover effects are also general considerations in crossover studies. A period effect means that outcomes can change over time apart from the assigned condition; carryover refers to an effect of an earlier condition persisting into a later period. The registry record does not report whether or how the efficacy analysis addressed these considerations. The record identifies washout safety categories, but does not report enough design detail to infer the efficacy model or the adequacy of any washout procedure.

What analysis is reported?

The primary outcome is a continuous measure summarized as a mean with a 95% confidence interval. The registry record does not report a comparative effect estimate, a test statistic, a p-value, or an analysis model for the primary comparison. It also does not report standard deviations or the within-participant covariance needed to reconstruct the paired treatment estimate from the arm summaries. The registry lists zero analyses in the record, and the continuous endpoint is explicitly marked as lacking values that are missing or not estimable for a two-arm comparison.

These absences do not mean that no analysis was carried out; they mean that a comparative analysis is not reported in this registry record. The record does not describe a prespecified statistical plan, assumptions used in a model, or adjustments for any design features. Such details should not be inferred from the crossover label alone.

What do planning illustrations mean?

General sample-size calculations ask how much information a future study might need to detect a chosen effect under stated assumptions. The planning illustration described in the registry is based on the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; the target effect is expressed as a fraction of the observed effect. These are planning assumptions, not a report of the trial’s original design justification. The illustrations are not observed power and do not establish the probability that this completed trial detected an effect. No sample-size justification for the original study is reported in the registry record.

More generally, power is a property of a planned test under specified assumptions, not a measure of whether a particular result is reliable. A calculation based on an observed effect can be especially sensitive to that estimate. Planning illustrations can help frame future design questions, but they do not substitute for a reported treatment-effect estimate and confidence interval from the trial itself.

What does the posted precision cover?

The arm-level intervals convey precision for the reported condition means. Precision of a treatment comparison depends on the variation in the contrast being estimated. In a crossover trial, that includes the relationship between measurements from the same participant. Without the paired contrast and its uncertainty, the posted intervals do not answer how precisely the conditions differ. This is why descriptive values and comparative inference should be kept separate when reading the registry results.

10. Multiplicity, Missing Data and Analysis Populations

The registry names the primary FEV1 outcome and six secondary outcomes. The additional outcomes include peak flow rate, rescue use of short-acting beta-2 agonists, daytime symptoms, night-time awakenings, urinary leukotriene levels, and a genotype-related FEV1 percent-predicted outcome. When several outcomes are examined, the chance of at least one apparently notable result can increase. In general, a statistical plan may specify how to interpret or adjust for multiple comparisons. Such a plan, including any multiplicity adjustment, is not reported in the registry record.

The record lists zero analyses, and numerical results for the secondary outcomes are not included in the posted information. The number of outcome measures is listed as seven. The available primary outcome results are arm-level means and confidence intervals; a comparative analysis is not reported for this continuous endpoint. Readers therefore cannot assess the results across the full set of outcomes or determine whether any multiplicity procedure was applied.

The primary outcome population is described as including participants who completed the study. The registry does not report the missing-data procedure, reasons for non-completion, or how missing measurements were handled. It also does not report an intention-to-treat analysis population or another detailed analysis-population definition. These omissions limit assessment of whether the posted results represent all randomized participants or only those with available completed-study measurements.

Although enrollment is listed as 43 and the posted outcome groups each have n of 28, the registry does not explain the relationship between those figures in the efficacy analysis. In a crossover study, group labels can refer to treatment conditions rather than independent sets of people. The record does not give enough detail to infer participant flow, completeness by sequence, or the treatment of incomplete crossover data.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: wheeze (7.1%).

The serious adverse event figures are reported separately for Plant Seed Oil, Placebo, Washout After Plant Seed Oil, and Washout After Placebo. The registry lists zero serious adverse events among the 28 at risk in each of the Plant Seed Oil and Placebo categories. For washout after Plant Seed Oil, it lists one serious adverse event among 14 at risk; for washout after Placebo, it lists zero among 14 at risk. These are category-specific registry counts, not a comparative safety analysis.

The record lists wheeze at 7.1% among the top serious terms. It does not provide enough context in the reported information to assign that term to a particular condition or to reconcile it with the category counts, so it should be read as a separately posted registry item. Deaths are not reported in the registry record.

The counts for other adverse events are also listed by category: 13 among 28 for Plant Seed Oil, 14 among 28 for Placebo, 6 among 14 for Washout After Plant Seed Oil, and 5 among 14 for Washout After Placebo. These categories should not be added together to estimate unique affected participants; the crossover design means a participant may contribute to more than one condition or period. In general, an adverse event reported during a trial is not, by itself, evidence that the study intervention caused it. The registry does not report a causal safety analysis in the information.

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

The posted results establish that the registry contains mean FEV1 values and 95% confidence intervals for Plant Seed Oil and Placebo at the stated 6-week timeframe. The means are 2.31 liters and 2.25 liters, respectively. These are descriptive condition-level results for the outcome population identified as study completers. They do not, by themselves, provide a treatment-effect estimate or its precision.

The record does not report the direct crossover comparison, its confidence interval, or a p-value. The arm-level confidence intervals cannot be used as a replacement for the paired comparison that would account for within-participant measurements. Thus the posted results do not establish the statistical strength or precision of a difference between conditions. They also do not support a conclusion about whether the intervention did or did not have an effect.

The registry’s stated aim and endpoint focus on FEV1, while its secondary outcomes cover symptoms, rescue medication use, peak flow, and urinary leukotriene levels. FEV1 is an objective lung-function measure, but it is not a complete measure of asthma experience or every possible outcome relevant to the trial. Numerical results for the secondary outcomes are not reported in the information available in the registry record.

The reported safety counts provide descriptive event information across treatment and washout categories. They do not establish that an event was caused by a condition, and the registry does not report a comparative safety analysis. The absent efficacy comparison and the limited outcome reporting mean that the posted record supports a careful description of the observed summaries, rather than a broad conclusion about benefits or harms.

Finally, the stated planning illustrations are not observed power and are not evidence about the trial’s ability to detect an effect. They use assumptions based on an observed effect and describe planning scenarios. They do not replace transparent reporting of the actual analysis, missing-data handling, and treatment contrast.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it is identified as a randomized, triple-masked crossover study, while the primary outcome results are posted as separate condition-level means and confidence intervals. That makes the difference between descriptive summaries and a design-appropriate comparative analysis especially important. In a crossover study, the relationship between measurements from the same participant can be central to estimating the treatment contrast. The registry’s arm summaries do not expose that pairing.

The record also illustrates why confidence intervals must be interpreted in relation to the quantity they describe. The posted intervals express uncertainty around each condition mean. They do not directly give uncertainty around the within-participant treatment contrast. A reader who relies on the separate intervals alone could mistake condition-level precision for comparative precision.

Another statistical issue is the scope of the outcome set. FEV1 is identified as primary, alongside six secondary outcomes. Multiple outcomes can create interpretive challenges, particularly if analyses or adjustments are not reported. The registry record does not describe a multiplicity plan or provide numerical secondary results in the reported information.

Finally, the record marks the trial as completed but does not report the comparative primary analysis or details of missing-data handling and analysis populations beyond the completer description. This limits independent assessment of the treatment contrast and of how broadly the posted results apply to enrolled participants. The example underscores the value of reporting a design-appropriate effect estimate, its uncertainty, and clear analysis-population and missing-data methods alongside descriptive arm summaries.

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 principal trial-specific limitation in the registry record is the absence of a reported comparative analysis for the continuous primary outcome. The record provides condition means and confidence intervals but says that values are missing or not estimable for a two-arm comparison. It does not provide a paired treatment estimate, its uncertainty, or a p-value. The reader therefore cannot evaluate the size or precision of the primary contrast from the posted results.

The crossover design also makes the missing analysis details consequential. The record does not report the treatment sequence allocation, treatment-period structure, participant-level paired data, or the model used for the primary outcome. It does not say whether period or carryover effects were assessed. Although washout categories appear in safety reporting, the registry does not describe the washout schedule for interpreting efficacy results.

The primary outcome population is described as participants who completed the study, but no detailed participant-flow account or missing-data method is reported. The registry does not explain how the enrollment figure relates to the posted outcome group counts or how incomplete crossover observations were handled. This restricts assessment of selection and missing-data effects.

Further limitations are the lack of a reported statistical plan, including a multiplicity approach for the primary and secondary outcomes, and the absence of numerical results for the named secondary outcomes in the information reported. The record also does not provide context for the serious adverse event term listed at 7.1%, and deaths are not reported. These are limitations of the reported record and do not establish what analyses or procedures may have been conducted outside it.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Treatment of Bronchial Asthma With Borage and Echium Seed Oils — NCT00806442.
• Registry record last updated 2017-07-03; status last verified 2017-06.
• Results first posted 2017-07-03.
• 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

The registry describes a completed randomized, triple-masked crossover trial in Phase 1 and Phase 2, sponsored by Brigham and Women's Hospital. It lists enrollment as 43 and studies borage and echium seed oils against corn oil in bronchial asthma. The primary endpoint is mean FEV1 in liters at 6 weeks among participants who completed the study.

The posted means are 2.31 for Plant Seed Oil and 2.25 for Placebo, each with a 95% confidence interval; each arm reports n of 28. A direct two-arm analysis for this continuous endpoint is not reported. Six secondary outcomes are named, but numerical secondary results are not included in the reported record. Safety counts are presented across treatment and washout categories, without a reported comparative safety analysis.

The record does not describe the primary statistical model, missing-data handling, or multiplicity procedure. Its arm-level summaries support descriptive interpretation, but do not provide the paired treatment-effect estimate and uncertainty needed to assess the primary crossover comparison.