Vascular Inflammation and Anti-inflammatory Supplements After Adverse Pregnancy Outcomes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vascular Inflammation and Anti-inflammatory Supplements After Adverse Pregnancy Outcomes (NCT04633551), a randomized na study. The primary outcome is Blood Pressure (mmHg).

2. Clinical Question

The study’s broader motivation was to examine vascular measures and inflammation after an adverse pregnancy outcome. The registry summary describes a comparison of blood pressure, arterial stiffness, blood vessel reactivity, and blood markers of inflammation, as well as interest in participants’ attitudes toward supplementation and dose-taking. Those broader aims provide context, but the primary result is the blood pressure outcome. The available result is a pair of arm-level means with standard errors, not an estimate of the treatment effect with a confidence interval or hypothesis-test result. It therefore addresses the recorded measurements descriptively, while leaving the uncertainty around a between-arm effect unresolved.

3. Trial Design

This was a randomized, single-masked, parallel-group study. Randomization means that allocation to the intervention or control group was assigned by chance, rather than chosen by participants or investigators. The record does not describe the method used to generate the allocation sequence or whether allocation was concealed before assignment. It reports single masking but does not identify which people were masked. The phase is listed as not applicable.

The intervention was a commercially available anti-inflammatory supplement. The control group did not receive the supplement and was described in the study summary as a time control. The primary endpoint timeframe was 1 month. The study was conducted by the University of South Carolina. The recorded start date was 2020-10-01, the primary completion date was 2021-06-30, and the status is completed.

Enrollment was 9. For the primary blood pressure result, the registry reports 5 participants in the intervention arm and 3 in the control arm. These are the numbers attached to the posted arm summaries; the record does not explain the difference between total enrollment and the numbers in those summaries. The primary outcome population is defined as participants who completed Visit 2.

The study also listed inflammatory vascular biomarkers, acceptability assessed with Likert scales and free-text fields, and perceptions assessed through interviews. The summary additionally describes goals related to attitudes and whether participants receiving the supplement took all or most doses. The registry record does not report a detailed protocol, a sample-size justification, or a full statistical analysis plan. Randomization supports a comparative design in principle, but the small enrollment and absence of a reported comparison estimate limit what can be concluded from the posted primary 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

Analysis population for the primary outcome, as defined in the registry: Participants who completed Visit 2.

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.

Population: There were 6 participants enrolled in the Intervention. One participant was lost to follow up and did not complete Visit 2. we analyzed data for those who completed Visit 2.

6. Primary Endpoint

The registry lists the primary outcome as Blood Pressure (mmHg), measured over 1 month.

The primary endpoint is blood pressure, measured in mmHg, at a timeframe of 1 month. The description states that investigators measured blood pressure in the arm and used applanation tonometry to estimate aortic blood pressure. The registry identifies the reported summary parameter as a mean and the accompanying dispersion measure as a standard error. The listed analysis population is participants who completed Visit 2.

Blood pressure is a continuous measurement, so a mean gives a compact description of the observed values in each arm. Comparing arm-level means can describe the direction and size of a difference, but inference about a treatment effect also requires an estimate of uncertainty for the between-arm contrast. Separate standard errors for the means do not themselves provide that contrast or establish whether it is statistically distinguishable from chance variation.

As general context, measuring blood pressure is one way to characterize a vascular outcome. It does not, by itself, establish a change in other vascular measures or in clinical outcomes. The trial summary identifies several broader vascular and inflammatory aims, but the primary result concerns the recorded blood pressure measure. The exact blood pressure component represented by the posted values, including whether they refer to arm pressure or the estimated aortic measure, is not further specified in the registry record.

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 blood pressure, the mean is the arithmetic average of the observed measurements in a group. It provides a single summary of the group’s central level. In this trial, the registry reports a mean for each arm. A mean is useful for describing the measurements, but it can conceal variation among individual participants. It also does not show the full distribution of measurements or whether values were concentrated near the average.

In a randomized comparison, an arm-level mean is often paired with a between-arm contrast. That contrast directly describes how far apart the group averages are on the outcome scale. The registry record does not report an estimable two-arm comparison for the primary continuous endpoint. Thus the posted means can be described separately, but the record does not supply the primary comparative estimate that would answer how the group averages differ with statistical uncertainty accounted for.

What does the standard error mean?

The standard error describes the precision of an estimated mean. As general statistical context, it reflects how much the estimated mean would tend to vary across repeated samples under a statistical model. It is not the same as the spread of individual participants’ measurements. A standard deviation describes participant-to-participant variability; a standard error describes uncertainty in the estimated mean. The registry reports standard errors, not standard deviations, for these arm summaries.

A standard error should be interpreted alongside the sample size and the study design. Here, the arm summaries are based on 5 participants and 3 participants, respectively. The standard errors of 9.0 in both arms indicate that the estimated means are not infinitely precise. They do not tell a reader exactly where the true population means lie, and they do not provide a confidence interval unless further statistical assumptions and calculations are made. No confidence intervals for the means are reported in the registry record.

Why is a comparison estimate important?

The question of whether two observed averages differ is distinct from the question of whether the difference is estimated precisely. A treatment-effect estimate would describe the between-arm contrast; an interval around it would show the range of values compatible with the data and the analysis assumptions. A test result, when reported, would summarize evidence against a specified null hypothesis under its assumptions. None of these comparative quantities is posted for the primary endpoint in this registry record.

It would be inappropriate to infer a p-value or confidence interval from the arm summaries alone and present it as the trial’s analysis. A simple unadjusted recalculation from summary statistics, if available in another context, would not replace the sponsor’s own analysis. In this record, no recalculated comparison is reported, and the record identifies the two-arm continuous comparison as missing or not estimable. The interpretation should therefore remain descriptive rather than claim a statistically established difference.

How should the sample size be understood?

Enrollment and endpoint analysis counts serve different descriptive roles. Enrollment is recorded as 9, while the posted primary summaries include 5 intervention participants and 3 control participants. The primary endpoint population is described as participants who completed Visit 2. The record does not explain why the counts differ, and no reason should be inferred from the totals alone.

General sample-size planning asks how many participants would be needed to detect a specified effect under assumptions about the outcome, allocation, significance level, and analysis. A planning illustration based on an observed effect is not the same as the trial’s original sample-size justification. It is also not observed power: observed power is not a substitute for reporting an effect estimate and its uncertainty. The registry record does not report the study’s own sample-size justification or detailed design assumptions. Any planning illustration should be read as a hypothetical calculation under stated assumptions, not as evidence that the trial was adequately sized or that a particular effect was present.

Why do small groups call for restraint?

With few observations, each participant’s measurement can have substantial influence on a group mean. General statistical reasoning therefore treats small samples as a setting in which estimates can be imprecise and sensitive to individual values. This does not establish that the reported summaries are wrong; it limits how confidently they can be generalized beyond the participants measured. It also makes transparent reporting of the analysis population, missingness, and uncertainty especially important.

The registry reports only the mean and standard error for the primary arm summaries. It does not provide individual-level measurements, a distributional summary, a confidence interval, or the details needed to assess model assumptions. The analysis description does not state whether any covariate adjustment, transformations, or other modeling choices were used. The most defensible reading is consequently narrow: these values describe the posted group summaries at the specified timeframe, while the treatment-effect analysis and its precision are not reported.

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("Intervention", "Control")
n   <- c(5, 3)
m   <- c(122, 116)
sp  <- c(9, 9)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
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  Intervention  5  122.000  20.125  97.012  146.988
CARM  Control  3  116.000  15.588  77.276  154.724

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 7 outcome measures and 3 posted secondary outcomes: inflammatory vascular biomarkers, acceptability of the intervention, and perception of the intervention. The study summary also describes several vascular measures and goals concerning participants’ attitudes and dose-taking. Examining several outcomes creates a general multiplicity issue: when many statistical questions are tested, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that possibility.

The registry record does not report whether multiplicity adjustments were planned or applied, how outcomes were prioritized beyond identifying blood pressure as primary, or which analyses were prespecified. It lists 0 analyses. This does not establish that no analyses were conducted; it means that analysis results are not posted in the record. The significance level and analysis procedures used for a reported primary comparison are not available, and no primary comparison result is posted.

Missing-data handling is also not reported in the registry record. The primary population is defined as participants who completed Visit 2, and the summary counts differ from total enrollment. The record does not state why some enrolled participants are absent from the posted arm summaries, whether measurements were unavailable, or how missing outcomes were handled. It does not specify whether the primary analysis followed an intention-to-treat principle or another analysis population. These omissions prevent assessment of the potential impact of missing observations or departures from assigned treatment.

As general context, missing outcome data can affect both the estimate and the precision of a comparison, particularly when the reasons for missingness relate to participant characteristics or outcomes. The record does not provide enough information to determine whether that concern applies in a particular way. Readers should distinguish what is directly reported—the completion-based population description and arm summary counts—from explanations or analysis choices that are not reported.

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 events for 0 of 6 participants at risk in the intervention group and 0 of 3 participants at risk in the control group. It reports other adverse events for 0 of 6 participants at risk in the intervention group and 0 of 3 participants at risk in the control group. Deaths are reported as 0 in each group. No top serious adverse event terms are listed.

These are event counts within the participants recorded as at risk, not estimates of comparative safety. In general, observing no reported events does not prove that an event cannot occur or that two groups have identical safety profiles. With small groups, the absence of observed events provides limited information about less common outcomes. The registry record does not give further details on event definitions, ascertainment procedures, observation time for safety, or whether adverse-event reporting was complete for every enrolled participant.

The at-risk counts used for adverse-event reporting are not identical to the primary-outcome summary counts. The record does not explain the difference, so no reason should be inferred. These safety figures should be read as the registry’s posted counts, without extrapolating them to a larger population or treating them as evidence of a causal safety difference.

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

The result establishes that the registry contains arm-level mean blood pressure summaries at the one-month timeframe for participants who completed Visit 2. The intervention group mean is 122.0 mmHg with a standard error of 9.0 among 5 participants; the control group mean is 116.0 mmHg with a standard error of 9.0 among 3 participants. The intervention-arm value is numerically higher. Those details describe the reported data and nothing more than the summaries can support on their own.

The posted record does not include an estimable two-arm comparison for this continuous outcome. It therefore does not quantify the treatment-effect estimate, its confidence interval, or a p-value. Without those, the arm means do not establish whether any observed separation is compatible with random variation or represents a precise between-group effect. No claim that the supplement did or did not change blood pressure is supported by these summaries alone.

The result also does not answer the study’s other scientific questions. It cannot be used as a substitute for results on inflammatory biomarkers, arterial stiffness, blood vessel reactivity, acceptability, or perceptions. The registry lists some secondary outcomes, but no associated findings are included in the registry record. Nor do the blood pressure results establish any longer-term outcome: the posted primary timeframe is 1 month.

As general interpretation, a randomized design is useful for estimating causal effects when the comparison is fully reported and the analysis is appropriately conducted. Here, random allocation is recorded, but a comparative estimate is unavailable. The appropriate conclusion is consequently limited to describing the observed arm summaries and noting the missing inferential result. More detailed conclusions would require outcome and analysis information not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between a study’s design and the result available for interpretation. It was randomized and parallel-group, and it reports a primary endpoint with arm-specific means and standard errors. Yet the registry record does not give an estimable two-arm comparison. A reader therefore has descriptive values but not the treatment-effect estimate needed to assess the comparative question directly.

The small enrollment and the even smaller numbers attached to the primary summaries also make clear why sample size and precision need to be read together. A mean can be reported to a decimal place without being precise enough to support a strong comparative conclusion. Standard errors provide information about uncertainty in each estimated mean, but they do not replace an interval for the contrast. Reporting group summaries without the primary comparison leaves an important statistical question unanswered.

The record also highlights the importance of transparent reporting around analysis populations and missing observations. Total enrollment, primary-outcome summary counts, and safety at-risk counts are all reported, but their relationship is not explained. A clear account of who contributed to each analysis and how missing data were handled would help readers understand the scope of each result.

More broadly, studies that assess several vascular, inflammatory, and acceptability outcomes need clear outcome prioritization and analysis reporting. The registry lists multiple outcomes, but does not describe a multiplicity strategy or detailed statistical plan. This does not imply that the study was conducted improperly; it means that the record does not permit readers to evaluate those statistical choices. The central lesson is to distinguish observed summaries from comparative inference and to treat unreported analyses as unknown, not as evidence for either direction.

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 main trial-specific limitation is that the primary two-arm comparison is recorded as missing or not estimable. Separate means and standard errors do not resolve that gap. There is no reported treatment-effect estimate, confidence interval, or p-value for blood pressure, so the comparative question cannot be evaluated with the posted result.

The primary-outcome summaries involve 5 participants in the intervention arm and 3 in the control arm, while total enrollment is 9. The record does not explain the difference. The endpoint population is defined as participants who completed Visit 2, but no details are given about the number of participants who did not complete that visit, the reasons, or missing-data handling. These limits affect the assessment of who is represented by the primary summaries.

The blood pressure description refers to measurement in the arm and estimation of aortic blood pressure using applanation tonometry, but the record does not clarify which specific component the posted means represent. The primary endpoint timeframe is 1 month, so the posted result does not describe longer-term measurements. Details about measurement procedures beyond the brief description are not reported.

The record does not identify the supplement product or dose, the specific masking roles, allocation-sequence methods, or allocation concealment. It also does not report a sample-size justification, full statistical analysis plan, multiplicity approach, or detailed analysis population. The stated study aims cover several outcomes, but results for those outcomes are not included in the information available. Safety counts are small and have limited ability to characterize uncommon events. Together, these limitations call for a narrow, descriptive interpretation of the posted primary blood pressure summaries.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Vascular Inflammation and Anti-inflammatory Supplements After Adverse Pregnancy Outcomes — NCT04633551.
• Registry record last updated 2023-09-21; status last verified 2023-09.
• Results first posted 2023-09-21.
• 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

NCT04633551 is a completed, randomized, single-masked, parallel-group study sponsored by the University of South Carolina. It enrolled 9 participants and compared a commercially available anti-inflammatory supplement with a control group that did not receive the supplement. The recorded start date was 2020-10-01 and the primary completion date was 2021-06-30.

The primary outcome was mean blood pressure in mmHg at 1 month among participants who completed Visit 2. The intervention summary was 122.0 with a standard error of 9.0 among 5 participants; the control summary was 116.0 with a standard error of 9.0 among 3 participants. A two-arm comparison for the continuous endpoint is not reported as estimable. The registry lists inflammatory vascular biomarkers, acceptability, and perception among secondary outcomes. Serious and other adverse events are recorded as 0 in each group, and deaths as 0. Detailed analysis methods, missing-data handling, and a sample-size justification are not reported in the registry record.