ABSORB (Amount of Blueberries So Older Adults Reap Benefits): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for ABSORB (Amount of Blueberries So Older Adults Reap Benefits) (NCT05937165), a randomized na study. The primary outcome is Urinary Flavonoid Biomarkers.

2. Clinical Question

This question concerns a short-term biomarker response, not a clinical outcome such as change in depressive symptoms. Inflammatory biomarkers are listed as secondary outcomes: tumor necrosis factor alpha, interleukin 6, and interferon gamma. The registry record does not report results or analyses for those secondary outcomes. Nor does it report an analysis linking any biomarker change to depressive symptoms or other health outcomes. The findings therefore need to be read as preliminary biomarker information from a small pilot study, rather than as a test of a clinical benefit.

3. Trial Design

The registry describes ABSORB as a randomized, unmasked, crossover pilot study. It lists an enrollment of 6 and a completed status. The study dates run from 2023-10-31 to primary completion on 2024-11-25. The listed phase is NA, so the record does not identify a conventional drug-development phase.

In a crossover design, participants receive more than one intervention regimen, and comparisons can be made within a participant as well as between regimens. This can be useful when the response varies substantially from one person to another, because each participant may serve as their own reference. That general design advantage depends on suitable conduct and analysis. The registry record does not report the sequence of regimens, the period structure, whether a washout interval was used, or how possible carryover effects were handled. Those details should not be assumed.

The two intervention descriptions specify 24 g and 48 g of freeze-dried blueberry powder, each consumed for 3 consecutive days. The registry lists one intervention type, categorized as other, and gives the two regimen descriptions as separate arms. The outcome summaries list 5 participants in each arm, while total enrollment is 6. These arm counts do not, on their own, explain how many participants contributed data to each period or how missing observations were handled. The record does not report a participant flow or analysis population definition.

Masking is listed as none. This indicates that the registry does not describe the study as masked; it does not establish which study personnel or participants knew the assigned regimen at each point. Further operational details are not reported in the registry record. The study is explicitly described as a pilot, and its stated aim is preliminary comparison of flavonoid bioavailability and inflammatory biomarkers. A pilot study can help characterize procedures and generate early estimates, but the registry does not report a formal sample-size justification or a prespecified statistical 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 Urinary Flavonoid Biomarkers, measured over Baseline and Day 3 of intervention.

The primary endpoint is urinary flavonoid biomarkers. The registry describes the measure as change in total flavonoid metabolites found in urine, with observations specified at baseline and Day 3 of intervention. It says the metabolite values represent relative abundance rather than absolute quantification. Higher values are described as indicating higher levels of total flavonoid metabolites in urine.

This is a biomarker endpoint: it measures a biological signal related to flavonoid exposure, rather than a symptom, diagnosis, or direct measure of how participants feel or function. Urinary measurements can be used to characterize whether metabolites are present and how their relative abundance changes over a short intervention period. Such a measure may be relevant to a study of bioavailability because metabolites detected in urine provide information about compounds present after consumption. That is a general rationale for this type of endpoint, not evidence that a biomarker change translates into a clinical effect.

The endpoint is labeled unitless, and the registry reports the outcome parameter as a mean with standard deviation. The reported arm summaries are 398900.0 with a standard deviation of 274200.0 for the standard-dose regimen, and 1046000.0 with a standard deviation of 661100.0 for the higher-dose regimen. The registry does not provide a comparative estimate, confidence interval, or statistical test. It also does not make clear in the posted summaries how the reported arm values relate to the endpoint description of change from baseline. That interpretive detail is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

This explanation separates the statistical meaning of the posted summaries from analyses that the registry does not report. The primary outcome is continuous and described using means and standard deviations. The study is randomized and crossover, but the record contains no posted analyses. Consequently, the numerical summaries can be described, while a treatment contrast, uncertainty interval, or significance test cannot be attributed to the registry.

What does a mean describe?

For a continuous measurement, the mean is a summary of the average level across the observations included in that summary. The registry identifies the primary outcome parameter as a mean. The posted mean values are 398900.0 for the standard-dose arm and 1046000.0 for the higher-dose arm. A mean compresses the individual observations into one value and does not show the full distribution. In a small study, individual observations can have a noticeable influence on that summary.

The registry also reports standard deviations of 274200.0 and 661100.0, respectively. A standard deviation describes how dispersed observations are around their mean. It is not a confidence interval and does not express the precision of a comparison between regimens. General statistical interpretation: larger spread means the individual measurements vary more around the average, while uncertainty about a mean or contrast also depends on the amount and structure of available data. In a crossover study, the relation between paired measurements is important to the uncertainty of a within-participant contrast; arm-level means and standard deviations do not reveal that relation.

Why is the crossover structure important?

In general, a crossover design gives participants multiple intervention periods, allowing a comparison of measurements from the same person under different regimens. A paired analysis can use the within-person difference and may account for stable differences between participants. It is not equivalent to treating all observations in the two regimens as unrelated. Appropriate analysis may also need to consider period and sequence effects, and whether a previous regimen could affect measurements in a later period. The registry record does not report the sequence, period, washout, carryover approach, or statistical model. It is therefore not possible to tell whether or how those design features were incorporated in an analysis.

The posted arm summaries list 5 participants per arm, whereas enrollment is 6. In a crossover study, the arm-level counts alone do not identify the number of complete paired observations, explain whether the same participants contribute to both summaries, or show the reasons for any unavailable measurements. Those details are not reported in the registry record. The counts should not be used to infer a particular analysis population.

What can a confidence interval add?

General statistical explanation: a confidence interval expresses uncertainty around an estimated quantity, such as a mean difference or a paired contrast. It gives a range of values that are compatible with the estimate under the analysis assumptions. A narrow interval indicates greater precision than a wide interval, but it does not by itself establish clinical importance. No confidence interval for the primary comparison is reported in the registry record. The arm-level standard deviations are not substitutes for such an interval.

A p-value, when reported, addresses how compatible the observed data are with a specified null model under the assumptions of a statistical test. It is not the probability that the null hypothesis is true, and it does not quantify the size or practical importance of a difference. No p-value or hypothesis test for the primary outcome is posted. Without a stated test, model, and result, it is not appropriate to characterize the comparison as statistically significant or not statistically significant.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when observed variability is greater than a model assumes. If a model understates variability, standard errors can be too small and uncertainty can appear lower than it is. The posted standard deviations show variation in the primary outcome summaries, but the registry record does not report a model or an over-dispersion assessment. No specific over-dispersion problem can be diagnosed from the summaries alone. For a continuous outcome, the choice of model should reflect the distribution and design; that choice is not reported in the registry record.

What do the sample-size illustrations mean?

General statistical explanation: a sample-size calculation is a planning tool that estimates how much information a future study might need to detect a specified effect under stated assumptions. It is not an observed result, and it cannot establish that a completed study had adequate power. The registry record does not report the trial's own sample-size justification. Any planning illustration based on the observed effect is distinct from a prespecified design calculation and should not be interpreted as observed power. The registry record does not report a formal analysis or a sponsor-reported test that would support a power claim for this trial.

For this study, the central statistical limitation is not that a particular analysis is known to be unsuitable; it is that an inferential analysis is not reported. A transparent interpretation can describe the arm summaries and their spread, but cannot recreate a paired crossover estimate without participant-level paired data and a defined analysis. The registry lists 0 analyses. A result-based comparison, interval, and test are therefore not available in the record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Standard Dose Freeze-dried Blueberry Powder", "Higher Dose Freeze-dried Blueberry Powder")
n   <- c(5, 5)
m   <- c(398863, 1045795)
sp  <- c(274183, 661053)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Standard Dose Freeze-dried Blueberry Powder  5  398863.000  274183.000  58419.840  739306.160
CARM  Higher Dose Freeze-dried Blueberry Powder  5  1045795.000  661053.000  224989.289  1866600.711

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 5 outcome measures and identifies urinary flavonoid biomarkers as the primary outcome. It also lists three secondary inflammatory biomarker outcomes: tumor necrosis factor alpha, interleukin 6, and interferon gamma. The record does not report analyses for those secondary outcomes, and it lists 0 analyses overall. No multiplicity strategy is reported in the registry record.

Multiplicity is the statistical issue that arises when several outcomes, time points, or comparisons are tested. In general, conducting more tests can increase the chance of at least one apparently notable result even when there is no corresponding underlying effect. A prespecified hierarchy, adjustment procedure, or clear distinction between primary and exploratory questions can help readers interpret a family of tests. The registry record does not report whether any such approach was planned or used. Since the secondary results are not posted, it is not possible to assess their estimates or how they might relate to the primary question.

Missing-data handling is also not reported in the registry record. Total enrollment is 6, while the primary outcome summaries list 5 participants in each arm. Those counts do not explain whether a participant lacked a measurement, whether observations were excluded, or whether a particular population was used for analysis. The record does not give reasons for missingness, a method for handling missing values, or a participant flow across intervention periods. No assumptions about missingness or imputation should be inferred.

The analysis population is not defined in the registry record. It is therefore unclear whether the posted summaries include all randomized participants, only participants who completed both regimens, or another set. In a crossover study, complete paired data and incomplete period data can have different implications for the analysis. This missing information limits assessment of selection and potential bias, as well as the ability to reproduce or evaluate an inferential result.

12. 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 event counts of 0 among 5 participants at risk for the standard-dose regimen and 0 among 6 participants at risk for the higher-dose regimen. It also reports 0 other adverse events among 5 participants at risk for the standard-dose regimen and 0 among 6 participants at risk for the higher-dose regimen. Deaths are reported as 0 in both groups. No serious adverse event terms are listed.

These figures describe what was recorded in this small study; they do not establish that an adverse event cannot occur. The number of participants at risk is limited, and the registry counts are not a precise estimate of event frequency in a broader population. Zero reported events means that no events of the listed category were recorded in the stated group, not that the intervention is free of risk.

The serious-adverse-event denominators differ between the two regimens, and the record does not explain the difference. Since the design is crossover, these group counts should not be interpreted as independent parallel-group samples without additional information. The record does not report details of adverse-event definitions, monitoring periods, severity grading, or attribution to an intervention. The safety figures should therefore be read as limited descriptive counts, not as a comparative safety analysis.

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

The registry record contributes a small set of descriptive observations from a randomized crossover pilot study in older adults with minor depressive symptoms. Its primary endpoint is a unitless urinary flavonoid biomarker measure, described as relative abundance of metabolites and framed as change over baseline and Day 3. The posted summaries are a mean of 398900.0 with standard deviation 274200.0 for the standard-dose regimen, and a mean of 1046000.0 with standard deviation 661100.0 for the higher-dose regimen. These values show the arm-level summaries that were posted, but they are not a reported estimate of the within-participant treatment contrast.

The record does not provide a confidence interval or test result for the primary outcome. It also does not clarify whether the arm values represent baseline levels, Day 3 levels, changes, or another summary. Without a defined contrast and an account of the crossover analysis, it is not possible to quantify the precision of a regimen difference from the registry record. The means alone should not be converted into a claim about statistical significance, causal effect, or clinical importance.

The study's stated focus is bioavailability and inflammatory biomarkers. It is not a reported trial of depressive symptom change. The three listed secondary inflammatory outcomes have no posted analyses. Thus, the record does not establish whether any biomarker changed, whether the two regimens differed on those secondary measures, or whether a biomarker pattern was related to symptoms.

The safety counts record no serious adverse events, other adverse events, or deaths in the stated groups. Those counts are useful as a factual report of events recorded in this trial, but the small numbers at risk and absence of further monitoring detail limit broader interpretation. Zero events in this study should not be taken as proof of no risk.

Overall, the record supports a cautious description of preliminary biomarker summaries, not a definitive conclusion about the comparative effect of the regimens or a clinical outcome. Information about the crossover analysis, missing observations, and uncertainty would be needed for a stronger statistical interpretation. A pilot result can inform questions for further study, but the registry record does not report a basis for generalizing these summaries beyond the participants studied.

14. Why This Trial Matters Statistically

This trial is statistically interesting because it combines a randomized comparison with a crossover structure and a biomarker endpoint. In general, a crossover design can offer useful within-person comparisons when participants receive multiple regimens. Its interpretation relies on information about pairing, treatment sequence, periods, and possible carryover. The registry's description establishes the broad design but does not report the details needed to evaluate those features or understand how they entered an analysis.

The contrast between the posted arm summaries invites attention, but an apparent difference between means is not the same as an estimated crossover effect. The record reports means and standard deviations, not the paired participant-level contrast, its uncertainty, or a statistical test. This illustrates why descriptive summaries and inferential analyses answer different questions. A mean describes the observed data summarized; a confidence interval and a defined model would communicate uncertainty around a comparison.

The endpoint also raises a measurement-interpretation issue. The registry describes relative abundance rather than absolute quantification and characterizes the outcome as change from baseline, yet the posted values are not clearly identified as baseline, Day 3, or change values. Clear specification of the estimand—the precise quantity a study intends to estimate—is important for understanding a biomarker result. In this record, that quantity cannot be reconstructed from the posted summaries.

Finally, this is a pilot with an enrollment of 6 and no analyses reported. Such a record is a reminder that an exploratory study may yield descriptive data without supplying the uncertainty estimates needed for a reliable comparative conclusion. The stated secondary biomarkers and safety counts add context, but do not substitute for a prespecified analysis. Statistically, the key contribution is to show what can and cannot be concluded from outcome summaries when design-specific analysis and reporting details are absent.

15. 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 is that the registry record does not report a comparative statistical analysis. Although it gives arm-level means and standard deviations for the primary endpoint, it does not report a crossover contrast, confidence interval, p-value, model, or participant-level paired results. The posted summaries therefore cannot establish the precision of the difference between regimens.

The outcome's interpretation is also constrained by ambiguity in the posted values. The endpoint is described as change in total urinary flavonoid metabolites, with a baseline and Day 3 timeframe, but the record does not identify whether the arm summaries correspond to change scores, individual time points, or another statistic. The measure is relative abundance rather than absolute quantification, and its unit is listed as unitless.

Details needed to assess the crossover design are not reported in the registry record. This includes regimen sequence, period structure, any washout interval, and handling of potential carryover. The outcome summaries list 5 participants per arm, while enrollment is 6; the record does not explain the discrepancy, define the analysis population, or report missing-data handling. These omissions make it difficult to assess whether all relevant observations were included and how the design was represented statistically.

The registry lists three secondary inflammatory biomarkers but no analyses for them. A multiplicity approach is not reported, nor is the trial's sample-size justification or a formal statistical plan. The safety counts are descriptive and involve few participants; adverse-event definitions, monitoring details, and attribution methods are not reported. Finally, the pilot enrollment limits how broadly the observed summaries can be generalized. These limitations do not show that a particular result is wrong; they restrict what can be concluded from the public record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: ABSORB (Amount of Blueberries So Older Adults Reap Benefits) — NCT05937165.
• Registry record last updated 2025-12-15; status last verified 2025-12.
• Results first posted 2025-12-15.
• 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.

19. Record Summary

ABSORB is a completed randomized, unmasked crossover pilot study sponsored by Hebrew SeniorLife. The registry lists an enrollment of 6, with study start on 2023-10-31 and primary completion on 2024-11-25. Participants were assigned standard-dose and higher-dose freeze-dried blueberry powder regimens, described as 24 g and 48 g for 3 consecutive days.

The primary outcome is urinary flavonoid biomarkers, measured at baseline and Day 3 and described as change in relative abundance of total urinary flavonoid metabolites. Arm summaries report means and standard deviations, but no comparative analysis is posted. Three secondary inflammatory biomarkers are listed without analyses. The registry records 0 serious adverse events, 0 other adverse events, and 0 deaths in the listed groups. Statistical methods, missing-data handling, and analysis populations are not reported in the registry record.