High Dose Omega-3 Fatty Acids in the Treatment of Sport Related Concussions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for High Dose Omega-3 Fatty Acids in the Treatment of Sport Related Concussions (NCT01814527), a randomized na study. The primary outcome is Number of Days to Return to Full Unrestricted Athletic Participation.

2. Clinical Question

The clinical question is framed around return to sport rather than a laboratory marker or a symptom score alone. The posted primary outcome is a continuous measure: the number of days until unrestricted participation. Results are given as a mean and 95% confidence interval for each arm. These arm-specific summaries describe the observed groups; they do not by themselves establish the size or precision of a treatment-versus-placebo difference. A direct comparative estimate and its uncertainty are not reported in the registry record.

3. Trial Design

The registry describes a randomized, double-blind, parallel-group study comparing docosahexaenoic acid with placebo. Enrollment is listed as 62. The study status is completed, with a start date of 2013-07 and primary completion date of 2017-07. East Carolina University is the sponsor. The phase is listed as NA.

After an athlete was identified as having sustained a concussion by East Carolina University Sports Medicine staff and qualified for the study, the brief description says the athlete would be randomly assigned to one of the two groups. The experimental intervention was a standardized omega-3 fatty acid dose containing 2200mg of DHA for 30 days after concussion onset, or longer for participants with continued symptomatology. The placebo group received an equal amount of capsules. Both groups were described as receiving standard and usual care for concussed athletes at East Carolina University.

Double masking indicates that the registry classifies the study as double-blind, but which people were masked and how masking was maintained are not reported in the registry record. The allocation method, concealment procedures, eligibility criteria in full, and details of adherence assessment are also not reported in the registry record.

The primary outcome was the number of days from concussion onset to return to unrestricted full participation in the athlete’s sport, with a 30-day timeframe listed. The registry reports an outcome count of 23 in the docosahexaenoic acid arm and 32 in the placebo arm. The reason these outcome counts do not match the overall enrollment count is not reported in the registry record. Participant flow, including the number randomized to each group and any exclusions from the posted outcome, is not reported in the registry record.

The brief description mentions time to symptom resolution, normalization of computerized neurocognitive testing, and computerized postural stability testing as study interests. No secondary outcome results are posted. The registry does not report the intended sample-size justification, allocation ratio details, analysis population, or full statistical analysis plan.

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

Reasons for not completing this period:

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 Number of Days to Return to Full Unrestricted Athletic Participation, measured over 30 days.

The primary endpoint is the number of days from concussion onset until the athlete returns to unrestricted full participation in their respective sport. It is a continuous outcome reported as a mean in days, with a 95% confidence interval for each arm. The registry lists a 30-day timeframe.

This endpoint captures a practical event in the recovery process: resumption of full athletic participation without restriction. Recording elapsed days gives the result a direct time scale and allows the two randomized groups to be described using the same measure. It is distinct from symptom resolution or performance on neurocognitive and postural stability assessments, which are mentioned in the brief description but do not have posted results as secondary outcomes.

The registry reports a mean of 11.0 days for docosahexaenoic acid, with a 95% confidence interval from 9.1 to 13.0, and a mean of 11.9 days for placebo, with a 95% confidence interval from 10.0 to 13.8. The endpoint summaries are arm-specific. A treatment effect would ordinarily be expressed as a between-group contrast, with its own uncertainty; that comparative estimate is not reported in the registry record.

The posted description does not explain how return to unrestricted participation was assessed, who made that determination, or how athletes whose return extended beyond the listed timeframe were handled. Those details are important for understanding the operational measurement of the endpoint and are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: each athlete’s time to return to unrestricted athletic participation is measured in days, and the registry reports a mean for each arm. The accompanying 95% confidence intervals give information about uncertainty in those arm-specific means. No method for calculating the intervals is reported in the registry record.

What does a mean describe?

In general, a mean is an average that combines the values observed across participants. It can be a concise summary when the distribution is reasonably represented by its center, but it does not describe the spread or shape of individual return times on its own. A few unusually long or short times can influence a mean. The registry does not report a standard deviation, median, range, or distributional plot for this outcome, so the variation among participants cannot be assessed from the posted summaries.

How should a confidence interval be read?

In general, a confidence interval describes the uncertainty of an estimate under a specified statistical procedure and its assumptions. A narrower interval indicates more precision for that estimate than a wider interval, all else being equal. The 95% confidence intervals in this record apply to the reported mean in each arm. They are not individual prediction intervals and do not state where most participants’ outcomes lie. The record does not name the method or assumptions used to construct them.

Why is an arm comparison needed?

For a randomized trial, the main comparative question concerns the difference between outcomes under the two assigned groups. A formal analysis would ordinarily report a contrast, such as a difference in mean days, with an uncertainty interval and possibly a test result. Those quantities are not reported in the registry record. The two separate arm means and their confidence intervals cannot replace a direct estimate of the contrast, because the uncertainty of a comparison depends on both groups and on the method used for the analysis. No comparison statistic or p-value should be inferred from the arm summaries.

What do the outcome counts contribute?

The registry attaches counts of 23 and 32 to the two arm summaries. These counts tell readers how many observations accompany the reported results, but the record does not clarify the exact analysis population or explain the relation of these counts to the enrollment of 62. It does not report how many participants were randomized to each arm, whether all randomized participants had outcome data, or what happened when a return time was not observed. Counts alone cannot identify the reason for incomplete information.

Why can missingness affect interpretation?

In general, missing outcome data can affect a group mean if participants without observed results differ from participants whose outcomes are included. The direction and extent of any effect depend on why information is missing and on the analysis method. The record does not describe missing-data frequency, reasons, assumptions, or methods. It also does not state whether results follow an intention-to-treat approach or another analysis population. Consequently, the impact of missing data cannot be evaluated from the registry record.

What is over-dispersion, and is it relevant?

In general, over-dispersion means that observed variability is greater than a statistical model expects. It matters when a model’s uncertainty estimates depend on a variance assumption that does not fit the data. This registry result is presented as a mean with a confidence interval, and the analysis model and participant-level distribution are not reported. There is therefore no basis in the record to assess over-dispersion or to say whether a model-based adjustment was needed.

What does a planning calculation mean?

In general, a sample-size calculation describes how many participants a proposed study might need under stated assumptions about the effect to detect, variability, significance level, allocation, and analysis. It is a design illustration, not a measure of what the completed study achieved. A calculation based on an observed effect is especially dependent on that estimate and should not be described as observed power. Any planning figures associated with this result are illustrations, not evidence that the study had a particular probability of detecting an effect. The registry record does not report the trial’s own sample-size justification or planned effect assumptions.

More broadly, the available statistical reporting is limited to arm-level means and confidence intervals for the primary outcome, along with the reported outcome counts. The registry does not provide the comparative estimate, analysis method, assumptions, or full participant flow needed to reproduce or fully evaluate the primary analysis. General statistical explanations do not fill in those trial-specific omissions.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure: number of days to return to full unrestricted athletic participation. It also mentions symptom resolution, neurocognitive testing, and postural stability in the brief description, but no secondary outcome results are posted. The record does not report whether additional outcomes were prespecified, how they were defined, or whether analyses were conducted but not posted.

In general, multiplicity arises when several outcomes or statistical tests are considered. Testing many questions can increase the chance of at least one apparently notable result by chance, so a statistical plan may specify which outcomes are primary and whether any adjustment is used. The registry record does not report a multiplicity strategy, and no comparative test results are posted. It is therefore not possible to assess whether multiplicity was addressed in the trial’s analyses.

Missing-data information is also limited. The enrollment is 62, while the primary outcome summaries have counts of 23 for docosahexaenoic acid and 32 for placebo. The registry does not explain the difference, give participant flow, describe reasons for absent outcomes, or report how incomplete follow-up was handled. The analysis population is not reported in the registry record; it is not stated whether the result is based on all randomized participants, participants with available outcome data, or another defined group.

In general, missingness can influence a treatment comparison when the chance of having an observed outcome is related to the outcome itself or to group assignment. Statistical methods can make assumptions about unobserved values, but the record does not report any such assumptions or procedures. The posted summaries should therefore be interpreted without presuming a particular missing-data method or multiplicity adjustment.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry reports serious adverse events in 0 of 23 participants at risk in the docosahexaenoic acid group and 0 of 32 at risk in the placebo group. Other adverse events are also reported in 0 of 23 and 0 of 32, respectively. Deaths are reported as 0 in each group.

These figures are counts recorded for the groups and denominators listed in the registry. They indicate that no serious adverse events, other adverse events, or deaths were recorded in those reported groups. They do not show that the risk of an event is impossible, and they should not be treated as evidence that the two groups have identical safety profiles. With no events reported, the record does not provide an event-based comparison of risk between arms.

The safety entry does not provide event definitions, the observation period for adverse events, methods of ascertainment, or detail about how events were judged related to the intervention. The registry lists no serious adverse-event terms. Safety interpretation is therefore limited to the reported zero counts and at-risk group sizes; additional monitoring details are not reported in the registry record.

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

The result describes mean days to return to unrestricted participation among the participants represented in the posted arm summaries. The docosahexaenoic acid group had a mean of 11.0 days, with a 95% confidence interval from 9.1 to 13.0. The placebo group had a mean of 11.9 days, with a 95% confidence interval from 10.0 to 13.8. These figures describe each group separately.

They do not, by themselves, establish the size of a treatment effect. A direct between-group estimate and its confidence interval are not reported in the registry record, nor is a p-value. The arm summaries therefore cannot support a statement that the intervention caused a change in return time or that a difference was statistically significant. They also do not establish equivalence or absence of an effect.

The registry describes a randomized, double-blind, placebo-controlled design, but important details for judging the analysis are unavailable. The relation between enrollment of 62 and outcome counts of 23 and 32 is not explained. Missing-data handling, analysis population, and statistical methods are not reported. These omissions limit how confidently the arm summaries can be interpreted as a complete randomized comparison.

The result concerns return to unrestricted athletic participation, not every aspect of concussion recovery. The study description mentions symptom resolution, neurocognitive testing, and postural stability, but no secondary outcome results are posted. The record also does not provide enough information to evaluate whether the outcome assessment was applied consistently or whether follow-up was complete.

Accordingly, the posted values are best understood as descriptive estimates with stated uncertainty for the observed groups. They do not resolve the comparative clinical question, and they do not establish that either intervention is effective or ineffective. A fuller interpretation would require a reported between-group analysis, participant flow, outcome assessment details, and the prespecified analysis methods.

13. Why This Trial Matters Statistically

This trial is statistically instructive because it shows the difference between reporting results within each randomized arm and reporting the comparison that answers the main trial question. The means and confidence intervals describe the arm-specific return times, but a treatment effect requires a direct contrast between the groups. That contrast and its uncertainty are not reported in the registry record.

The distinction matters because readers can otherwise be tempted to compare arm summaries informally. Separate confidence intervals address uncertainty around separate means; they are not a formal test of the difference. A well-interpreted randomized trial result should connect the outcome definition, analysis population, estimated group contrast, and uncertainty around that contrast.

The record also highlights the importance of participant accounting. Enrollment is listed as 62, while the primary outcome summaries are accompanied by counts of 23 and 32. Without a flow of participants from enrollment through outcome assessment and analysis, the reason for these counts and the possible role of missing results remain unclear. Reporting those details supports assessment of both precision and potential bias.

Finally, this study description names several outcomes of interest, while results are posted only for the primary return-to-participation measure. A clear distinction between primary and secondary questions, together with a transparent analysis plan, helps readers understand how multiplicity and selective reporting are addressed. The registry does not report those analysis details, so the posted statistics permit a descriptive reading but not a complete evaluation of the planned comparative analysis.

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 limitation for interpreting the result is that no direct comparison of docosahexaenoic acid with placebo is reported. Arm-level means and confidence intervals are available, but the registry provides no comparative estimate, uncertainty interval for a contrast, or p-value. The record also reports zero analyses, so the statistical evidence for the primary question cannot be reconstructed from the posted outcome summaries.

The outcome counts of 23 and 32 are not reconciled with the enrollment of 62. The registry record does not report participant flow, the number randomized to each arm, reasons for missing outcomes, or how incomplete data were handled. The analysis population and intention-to-treat status are not reported. These omissions make it difficult to assess whether the posted summaries represent all randomized participants or a selected subset.

The registry does not explain the method used to calculate the confidence intervals, the distribution of individual return times, or the assessment process for unrestricted participation. A mean alone cannot show how much individual outcomes varied. Details of adherence, the masking procedure, allocation concealment, and eligibility criteria beyond the brief description are also not reported in the registry record.

The study description refers to symptom resolution, neurocognitive functioning, and postural stability, but secondary results are not posted. The analysis plan, multiplicity handling, and sample-size justification are not reported. These gaps constrain interpretation of both the primary comparison and the broader set of questions described for the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: High Dose Omega-3 Fatty Acids in the Treatment of Sport Related Concussions — NCT01814527.
• Registry record last updated 2024-04-24; status last verified 2024-04.
• Results first posted 2024-04-24.
• 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, double-blind, parallel-group study sponsored by East Carolina University, comparing docosahexaenoic acid with placebo in athletes with concussion. Enrollment is listed as 62, and the study start and primary completion dates are 2013-07 and 2017-07.

The primary outcome is days from concussion onset to unrestricted full athletic participation, with a 30-day timeframe. The reported means are 11.0 days for docosahexaenoic acid and 11.9 days for placebo, with 95% confidence intervals of 9.1 to 13.0 and 10.0 to 13.8. The accompanying outcome counts are 23 and 32. No comparative analysis or secondary outcome results are posted.

The record reports zero serious adverse events, other adverse events, and deaths in both groups. Participant flow, missing-data handling, analysis population, statistical methods, and the trial’s sample-size justification are not reported in the registry record.