Effects of Avocado When Added to a Meat Patty on Inflammation in Healthy Men: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Avocado When Added to a Meat Patty on Inflammation in Healthy Men (NCT01397071), a randomized na study. The primary outcome is Change of Endothelial Function by Measurement of Flow-mediated Vasodilation Using the Reactive Hyperemia Index (RHI).

2. Clinical Question

3. Trial Design

This was a randomized, unmasked crossover trial sponsored by the University of California, Los Angeles. The registry record lists enrollment of 11 and status as completed. The study began in 2011-08, with primary completion in 2012-02. The phase is listed as NA.

In a crossover design, a participant receives more than one study condition, with outcomes compared across those conditions within the same participant. This can reduce the influence of stable differences between participants, because each participant can serve as their own comparator. That is a general feature of crossover studies, not evidence that the analysis in this trial used a particular paired statistical method. The registry record does not report the sequence in which meals were given, whether meal order was randomized, or whether a washout interval was used.

Randomized allocation is recorded, while masking is recorded as none. The record does not describe the allocation procedure or explain which people, if any, were aware of meal assignment. The arm descriptions distinguish a ground beef patty with fresh avocado added just prior to consumption from a test burger without avocado.

The primary outcome is described as change from baseline in RHI at 2 hours post-ingestion. The record also lists a secondary outcome concerning change in the inflammation marker IkB-alpha. Although it lists 2 outcome measures and 2 analyses, details of the analysis methods, analysis populations, and handling of repeated observations are not reported in the registry record. Enrollment is not necessarily the same as the number of participants with complete endpoint data; that number is not reported.

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: 17 healthy male volunteers were recruited and screened; 6 failed screen; 11 participants completed crossover study.

Consumption of Beef Patty Alone

Consumption of Beef Patty With Avocado

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 Change of Endothelial Function by Measurement of Flow-mediated Vasodilation Using the Reactive Hyperemia Index (RHI), measured over Baseline and 2 hours post-ingestion.

The primary endpoint is change from baseline in reactive hyperemia index (RHI), measured at 2 hours post-ingestion after consumption of the beef patty with or without avocado. RHI is derived from peripheral arterial tonometry (PAT), a noninvasive measurement. As described in the registry record, it compares the post-to-pre occlusion PAT amplitude in the tested arm with the corresponding ratio in the control arm.

The registry describes RHI as a measure of endothelial dysfunction and states that increasing scores indicate improvement in coronary endothelial function. The possible score range is 1 to 3. The record identifies RHI less than 1.67 as a sign of endothelial dysfunction and RHI equal to or greater than 1.67 as normal function. These are the registry’s endpoint descriptions; they do not establish what an observed change in this trial was.

Using a change from baseline aims to represent how the measurement shifts after a meal relative to the participant’s starting value. Measuring the endpoint after ingestion links it to the meal exposure under study. As a general statistical matter, the interpretation depends on the observed values, their variability, and the comparison method. Numerical group or condition results, estimates of the change, and uncertainty intervals are not reported in the registry record, so the size and precision of any change cannot be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The trial is recorded as randomized and crossover, with no masking. In general, randomization is intended to make the assignment process less dependent on participant characteristics or investigators’ expectations. The record does not explain the randomization procedure, how the order of meal conditions was assigned, or whether allocation was concealed. Those details are not reported in the registry record.

A crossover design compares conditions within participants, who receive each condition rather than remaining in a single parallel group. In general, this can account for stable participant-level differences when the analysis appropriately uses the paired structure. It also makes the sequence of conditions, changes over time, and possible carryover relevant design considerations. The registry record does not report the sequence, washout arrangements, or an analysis method that would show how within-participant dependence was handled. It would therefore be inappropriate to assume a particular paired test or model.

The primary measure is continuous: change in RHI from baseline to 2 hours post-ingestion. For continuous data, a mean describes the average measurement or change, while a standard deviation describes how dispersed individual observations are around that mean. The endpoint record identifies the mean as its parameter and standard deviation as its dispersion measure. It does not report the actual condition means, standard deviations, or a between-condition estimate. A numerical comparison cannot be reconstructed from the endpoint description alone.

A confidence interval, in general, expresses the uncertainty around an estimated quantity under the assumptions of the analysis. It helps readers assess which effect sizes are compatible with the data and how precisely the effect is estimated. A p-value, in general, describes how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and the analysis assumptions. Neither measure gives the probability that a treatment works. No confidence interval or p-value for the primary comparison is reported in the registry record, so neither statistical precision nor evidence against a null comparison can be evaluated.

Variation in a crossover study can arise from differences between participants and from changes within a participant across conditions. In general, a paired analysis can use the within-participant comparison and may be more informative than treating observations as independent, but the exact analysis must match the design and available data. The reported enrollment does not reveal how many participants had complete paired measurements. Missing-data counts, exclusions, and the analysis population are not reported in the registry record.

Randomization and lack of masking describe aspects of design, not the strength or direction of an observed effect. Unmasked assignment can matter when expectations could influence behavior, measurement, or reporting; whether this affected the study cannot be determined from the record. The primary endpoint uses a noninvasive PAT measurement, but the record does not state whether assessors were masked or how measurement quality was monitored.

The registry lists a secondary inflammation-marker outcome and 2 outcome measures and 2 analyses. A statistical analysis plan, prespecified model, handling of multiple outcomes, and any approach to multiplicity are not reported in the registry record. Multiplicity matters in general when several outcomes or comparisons are examined, because the chance of a false-positive finding can increase if results are selected or interpreted without accounting for the number of tests. The registry entries do not show whether an adjustment was planned or used.

The record does not report a sample-size justification, target detectable effect, or statistical plan. Any sample-size illustration based on an observed effect is a planning illustration, not observed power and not evidence that the study was adequately or inadequately powered. No such calculation should be treated as a substitute for the unreported endpoint estimate and its uncertainty. The sponsor’s own analysis would take precedence over a simple unadjusted recalculation if a discrepancy were identified; the registry entries do not provide such a recalculation or a discrepancy status to interpret.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures and 2 analyses. It names the primary outcome as change in RHI and lists change in IkB-alpha as a secondary outcome. It does not report a detailed statistical analysis plan, identify all planned comparisons, state whether the outcomes were tested in a hierarchy, or describe any correction for multiple testing. The impact of multiplicity on interpretation therefore cannot be determined from the record.

As a general matter, testing multiple outcomes or comparisons can increase the chance that at least one result appears noteworthy by chance. Whether and how that concern should be addressed depends on the prespecified questions and analysis plan. No adjustment method or decision rule is reported, so it would be inappropriate to infer one.

The crossover design implies that observations may be linked within participants. The registry does not report the analysis population, the number with complete measurements, missing outcome counts, or how incomplete data were handled. It also does not state whether all randomized participants were included in the analysis or whether any were excluded. Thus, the reported enrollment of 11 cannot be assumed to equal the number contributing data to each outcome.

Information about interim analyses, stopping rules, and any prespecified handling of missing data is not reported in the registry record. These absences limit assessment of the analysis process; they do not establish that a particular method was or was not used. Numerical primary and secondary outcome results are also not reported, leaving no estimates or uncertainty measures to evaluate alongside these design and analysis uncertainties.

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 registry lists two safety groups: change in PAT after consuming beef only and change in PAT after consuming beef with avocado. Each group records 11 at risk, with 0 serious events and 0 other events. The death field is null for both groups, so a numerical death count is not reported in the registry record. No serious adverse-event terms are listed.

These entries describe what is recorded for the listed groups; they do not establish that no event occurred outside the recorded categories or observation period. The registry entries do not specify the safety observation window, event definitions, collection procedures, or whether the group counts reflect complete follow-up. Nor do they explain how the crossover exposure periods were represented in the safety summaries.

Zero recorded events in these entries should not be read as proof that the meals have no risks. The counts concern this trial record and do not establish safety in other populations or settings. They also do not provide evidence about the primary RHI comparison, which is an efficacy-related endpoint rather than an adverse-event count.

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

This record describes a randomized, unmasked crossover study comparing a ground beef patty with avocado against a ground beef patty without avocado in healthy men. Its registered primary endpoint is change in RHI from baseline to 2 hours after ingestion. The endpoint description explains the measurement and its scale, but numerical outcome results are not reported in the registry record.

That distinction is important: a study’s objective and measurement plan are not results. The rationale in the brief summary discusses MDA and potential effects of antioxidants, while the registered primary outcome concerns RHI. The rationale cannot be used to infer what happened to RHI or to claim that avocado changed the endpoint. The numerical estimate, its uncertainty, and any statistical test result are all absent in the registry record.

The safety entries show zero serious events and zero other events in each listed group, with 11 at risk in each. These are limited registry counts and do not establish absence of risk. The null death fields do not report numerical death counts. The record also does not report complete follow-up, missing measurements, or analysis populations.

More broadly, this trial concerns a specific meal comparison and a short-term physiological measurement in healthy male volunteers. The record does not establish effects on disease, longer-term health outcomes, or other populations. The registered threshold and direction of RHI interpretation provide context for the measure, not a substitute for observed data. Without endpoint results and a description of the analysis, the comparative effect and its precision remain unknown from the registry record.

13. Why This Trial Matters Statistically

The trial is statistically interesting because its crossover design is suited to studying short-term responses to different meal conditions within participants. In general, within-participant comparisons can reduce the influence of stable differences between people. They also require careful attention to condition order, potential carryover, and analysis of the paired observations. The registry identifies the design but does not report the details needed to assess those features.

The endpoint connects a defined post-meal measurement to a baseline value. The registry describes RHI, its measurement by PAT, and the interpretation of its scale. That makes the intended outcome clear, but interpretation of the actual comparison depends on estimates and uncertainty, which are not reported in the registry record. The contrast between a clearly specified endpoint and absent numerical findings illustrates why a trial’s registration and results serve different purposes.

The record also highlights the distinction between a biological rationale and an observed clinical-trial result. The brief summary discusses MDA and antioxidant mechanisms, whereas the registered primary endpoint is RHI and the listed secondary outcome is IkB-alpha. Mechanistic motivation can explain why a question was posed, but cannot replace outcome data or establish what the trial found.

For statistical readers, the missing analysis details matter alongside the absent estimates. The record does not describe the paired analysis, missing-data handling, multiplicity plan, or analysis population. Those omissions prevent a full assessment of precision and robustness. The study therefore offers a defined design and endpoint question, while the registry information available does not support a quantitative conclusion about the primary comparison.

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 most important limitation for interpreting this trial record is that numerical primary and secondary outcome results are not reported. Without condition-specific estimates, a comparison, and measures of uncertainty, the observed effect and its precision cannot be assessed. The outcome definitions alone do not reveal the direction or size of any response.

The registry reports enrollment of 11 but does not state how many participants completed each meal condition or contributed usable endpoint data. Participant characteristics beyond healthy male volunteers are not described in the registry record. The sequence of meal conditions, washout arrangements, and possible carryover are also not reported, although these details can be relevant in crossover studies.

The record identifies the study as unmasked but does not explain whether outcome assessors were masked, how allocation was implemented, or how measurement quality was monitored. It does not report an analysis plan, missing-data methods, multiplicity handling, interim analyses, or a sample-size justification. These gaps limit assessment of the analysis and its susceptibility to bias; they do not show that any particular problem occurred.

Applicability is limited by the registered population of healthy male volunteers and the specific meal conditions. The record does not report longer-term outcomes or clinical disease outcomes. The safety entries lack details about observation period and event collection, and the death fields are null. These limitations mean that the listed safety counts should not be generalized beyond what the registry records.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effects of Avocado When Added to a Meat Patty on Inflammation in Healthy Men — NCT01397071.
• Registry record last updated 2019-09-25; status last verified 2019-09.
• Results first posted 2019-09-25.
• 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

NCT01397071 is a completed randomized, unmasked crossover study sponsored by the University of California, Los Angeles. The registry records enrollment of 11 healthy male volunteers and compares a ground beef patty with fresh avocado against a patty without avocado.

The primary endpoint is change from baseline in RHI at 2 hours post-ingestion, measured using PAT. The registry also lists change in IkB-alpha as a secondary outcome. Numerical results for these outcomes, the analysis methods, missing-data handling, and analysis populations are not reported in the registry record.

The safety entries list 0 serious events and 0 other events in each group, with 11 at risk per group. Death counts are null. These entries do not establish an absence of risk or provide a quantitative result for the primary endpoint.