PCC vs. FFP for Post Cardiopulmonary Bypass Coagulopathy and Bleeding: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PCC vs. FFP for Post Cardiopulmonary Bypass Coagulopathy and Bleeding (NCT02557672), a randomized phase 4 study. The primary outcome is Chest Tube Output.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group, unmasked Phase 4 trial sponsored by Mayo Clinic. The registry lists enrollment of 106 and a completed status. The recorded start was 2016-08, and primary completion was 2021-06. The study was described as a prospective randomized trial at a large US medical center. These design features establish the broad comparison, but do not by themselves explain how randomization was generated, concealed, or implemented.

The two assigned interventions were prothrombin complex concentrate and fresh frozen plasma. Masking was listed as none, so the registry does not describe the trial as blinded. The registry includes arm descriptions concerning post-bypass management, protamine, and laboratory measurements, but those descriptions are truncated. The complete intervention protocols and any treatment crossover or adherence information are not reported in the registry record.

The primary outcome was chest tube output over 24 hours. The registry reports a median and inter-quartile range for each arm, and a separate linear regression result expressed as a ratio of geometric means. The analyzed outcome counts shown for this endpoint were 48 for FFP and 51 for PCC. The endpoint description notes that one subject’s data were not collected nor analyzed in the FFP arm. These counts should be read as endpoint-specific information, not as a complete account of every analysis population.

Five outcome measures and five analyses are listed, but the record identifies no posted secondary results. Further details about allocation concealment, prespecified analysis procedures, sample-size justification, interim analyses, and analysis populations are not reported in the registry record. The trial’s randomized design supports a structured comparison, while the missing operational and statistical details limit how fully readers can assess its implementation.

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:

Analysis population for the primary outcome, as defined in the registry: 1 subject's data was not collected nor analyzed for the FFP arm

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 Chest Tube Output, measured over 24 hours.

Chest tube output measures the volume of drainage collected after surgery. The primary endpoint was defined as drainage from after surgery through midnight of the next day, with a 24-hour timeframe, and was measured in mL. Chest tube drainage is used in this trial as a direct measure of postoperative blood loss. It is relevant to the stated question about bleeding after cardiopulmonary bypass, although it represents one aspect of bleeding rather than every possible clinical consequence.

The registry presents the endpoint by arm using medians and inter-quartile ranges. The FFP summary is 1022 mL, with an inter-quartile range from 799 to 1575; the PCC summary is 937 mL, with an inter-quartile range from 708 to 1443. These descriptive summaries show the distribution’s center and middle spread in each group. They do not alone establish a treatment effect or its precision.

The separate reported analysis uses a ratio of geometric means. A geometric-mean comparison and a median summary describe the data in different ways, so they should not be treated as interchangeable. Chest tube output is a continuous measure, and its interpretation depends on the recorded measurement period and completeness of collection. The record does not report further details about measurement procedures or how values were handled in the regression.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary comparison is reported as linear regression with the parameter labeled ratio of the geometric means. The registry gives an estimate of 0.98, a 95% confidence interval from 0.81 to 1.19, and p = 0.84. It identifies the analysis as a superiority test. The full model specification, including any adjustment variables, transformations, or handling of influential observations, is not reported in the registry record.

What does a ratio of geometric means describe?

In general, a ratio compares two quantities on a relative scale rather than describing their absolute difference. A ratio of 1 represents equal geometric means. Values on either side of 1 represent relative differences, with interpretation depending on which group is in the numerator and which is in the denominator. The registry’s analysis lists the two groups but does not explain the ratio’s direction in accompanying text. It is therefore safest to quote the reported estimate without assigning a direction beyond the group comparison as posted.

A geometric mean is based on averaging on a logarithmic scale and then expressing the result on the original scale. In general, this approach can be useful for positive, skewed measurements when multiplicative differences are of interest. The registry does not state why this parameter was selected, whether a transformation was used in fitting the model, or what diagnostics were conducted. The outcome summaries are medians and inter-quartile ranges, which are descriptive statistics and do not directly generate the regression estimate.

How should the confidence interval be read?

In general, a confidence interval communicates uncertainty in an estimate under the assumptions of the analysis. A 95% confidence interval is generated by a procedure that, over repeated studies under its assumptions, would cover the target value at the stated rate. It is not a probability statement about this particular interval or a guarantee about the true effect. The reported interval, 0.81 to 1.19, includes 1. That is consistent with the reported p-value of 0.84 for a test of no ratio difference, though the interval also allows values away from 1.

Statistical compatibility with 1 does not show that the groups are equivalent. Equivalence or non-inferiority requires a prespecified margin and a design and analysis appropriate to that question. Such a margin is not reported in the registry record. The record labels the analysis as superiority, and no equivalence conclusion follows simply from a nonsignificant result.

What does the p-value contribute?

In general, a p-value measures how compatible the observed data are with a specified null model, assuming that model and the analysis assumptions. It is not a measure of the size or importance of an effect. It is also not the probability that the null hypothesis is correct. The p-value of 0.84 should be considered alongside the effect estimate, confidence interval, outcome definition, and study limitations, rather than used alone as a verdict.

Regression may account for specified relationships among variables, but a method label does not reveal which variables were included or whether assumptions were checked. Those details are not reported in the registry record. The reported analysis therefore cannot be independently assessed for covariate selection, model fit, or sensitivity to alternative analytic choices from the record alone.

Why can over-dispersion matter?

In general, over-dispersion means that observed variability is greater than a model expects. When an analysis assumes less variability than the data contain, uncertainty can be understated and tests can appear more conclusive than warranted. This is a general statistical concern, not a reported finding about this trial. The record does not describe a dispersion assessment, and the regression result should not be characterized as having or not having over-dispersion on the available information.

More generally, chest tube output may vary between patients, and descriptive medians and inter-quartile ranges help convey that variation. They are not substitutes for model diagnostics or a full account of the distribution. The record does not report those diagnostics or explain whether the regression method addressed skewness or other distributional features.

How do planning illustrations differ from trial results?

In general, a sample-size illustration asks how many participants per arm might be needed under stated assumptions for a future study. The planning assumptions recorded for these illustrations include a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect defined as a stated fraction of the observed effect. These are planning illustrations, not observed power and not the trial’s own design justification. A calculation based on the observed effect is especially dependent on that estimate and its uncertainty; it should not be treated as evidence that the completed trial was adequately powered. The trial’s own sample-size justification is not reported in the registry record.

10. Analyses Reported by the Sponsor

The registry reports the sponsor’s primary analysis as linear regression, with a ratio of geometric means of 0.98, a 95% confidence interval from 0.81 to 1.19, and p = 0.84. The registry record does not report a separate recalculated comparison from the posted summary statistics. Consequently, there is no second estimate in the record to compare numerically with the sponsor’s result.

The arm summaries are medians and inter-quartile ranges, whereas the regression parameter is a ratio of geometric means. A recalculation from those summaries would not automatically reproduce the model-based ratio: the statistics describe different features of the data, and individual-level observations and model details are not reported. The record also does not provide the covariates or full model specification needed to reproduce the analysis.

No discrepancy between a recalculation and the reported analysis is identified in the registry record. If a recalculated estimate were available and disagreed with the sponsor’s analysis, the sponsor’s own analysis would take precedence under the stated reporting approach. In this record, interpretation should focus on the posted regression estimate, its confidence interval and p-value, and the endpoint-specific descriptive summaries, without implying that an independent recalculation confirms or contradicts them.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and five analyses, but the record does not identify the full hierarchy of outcomes or explain how the analyses relate to one another. It does not report whether the primary outcome was selected in advance in a protocol or statistical analysis plan, or whether secondary outcomes were subject to a multiplicity adjustment. A plan for controlling the chance of false-positive findings across multiple tests is not reported in the registry record. No secondary results are posted in the record.

Multiplicity matters in general because conducting several statistical tests can increase the chance that at least one result appears statistically significant by chance. The extent of that concern depends on which outcomes and analyses were planned, how they were related, and what testing strategy was prespecified. Those details are not available. The reported primary p-value should be read as the result for the stated comparison, not as evidence that any unreported secondary comparison was tested or had a particular result.

For the primary endpoint, the registry notes that one subject’s data were not collected nor analyzed in the FFP arm. It does not report why the data were unavailable, whether the participant was excluded from other analyses, or how missingness was assessed. The primary endpoint summaries list 48 for FFP and 51 for PCC. The adverse-event at-risk counts are different, and the record does not explain the relationship between those populations and the endpoint analysis population.

In general, missing outcome data can affect a comparison if the reasons for missingness are related to treatment or outcome. The direction and magnitude of any effect depend on information not reported. The record does not describe imputation, sensitivity analyses, an intention-to-treat population, or a per-protocol population. It is therefore not possible to determine from the registry record whether the posted analysis included all randomized participants as assigned or how robust it is to the missing endpoint data.

Details about interim analyses, stopping rules, prespecified analysis populations, and a statistical analysis plan are not reported in the registry record. Their absence from the record is a reporting limitation; it is not evidence that such procedures were or were not used.

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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: renal failure (41.2%), prolonged mechanical ventilation (13.7%), re-operation (10.2%), renal failure requiring dialysis (9.8%), ards (8.2%).

The registry reports serious adverse events for the two groups. In the FFP group, 44 participants were recorded as affected among 49 at risk, and 2 deaths were reported. In the PCC group, 45 participants were recorded as affected among 51 at risk, and 1 death was reported. The registry lists no other adverse events in either group. These are event summaries, not a causal assessment of whether an intervention produced an event.

The serious-event terms listed include Renal Failure at 41.2%, Prolonged mechanical ventilation at 13.7%, Re-operation at 10.2%, Renal Failure requiring dialysis at 9.8%, ARDS at 8.2%, and Mesenteric ischemia at 6.1%. The record does not explain the denominator used for these percentages or whether a participant could contribute to more than one term. They should not be treated as mutually exclusive categories or as a complete description of all serious events without further information.

In general, adverse-event counts need context about definitions, timing, severity, and attribution. The registry does not report detailed event-level timing, causal judgments, or a statistical comparison of safety outcomes. The counts should therefore be read descriptively and separately from the primary chest tube output analysis. They do not establish that a treatment caused or prevented any listed event.

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

The primary result is a registry-reported comparison of chest tube output after cardiopulmonary bypass. The regression estimate is a ratio of geometric means of 0.98, with a 95% confidence interval from 0.81 to 1.19 and p = 0.84. The interval includes 1, and the p-value does not indicate strong evidence against the no-ratio-difference model. The result is not proof that the groups are identical, nor does it establish clinical equivalence.

The endpoint summaries provide additional description: median output was 1022 mL in the FFP group and 937 mL in the PCC group, with the reported inter-quartile ranges. These medians are not the regression estimate, and their difference should not be substituted for the model’s ratio parameter. The record does not supply a threshold for a clinically important difference, so the clinical meaning of the range of effects compatible with the interval cannot be resolved from the posted information alone.

The registry’s original question also mentioned transfusion requirements. The primary result is for chest tube output. A result for transfusion requirements is not reported in the registry record, and the record lists no posted secondary results. The primary endpoint should not be used to infer an unreported effect on transfusion.

The trial’s randomized design is relevant to interpreting a treatment comparison, but important details remain unavailable, including the complete protocol, participant characteristics, and statistical analysis plan. The registry notes one missing FFP endpoint observation and does not describe how missing data were handled. The safety summaries are descriptive and do not establish causation. These limits mean that the posted result answers a specific statistical question about a specific endpoint, rather than resolving every question about bleeding, transfusion, safety, or application to other settings.

In general, a nonsignificant result can reflect a small effect, imprecision, or both. The confidence interval is therefore as important as the p-value when considering what values remain compatible with the analysis. Nothing in this result alone is a recommendation about patient care.

14. Why This Trial Matters Statistically

This trial is statistically notable because it directly randomized patients between PCC and FFP for post-cardiopulmonary bypass coagulopathy and bleeding, according to the registry description. Randomization is a design feature intended in general to make treatment groups comparable on average, while a parallel design assigns participants to one of the comparison groups. The record does not include enough implementation detail to assess the randomization process fully, but the design makes the comparative question explicit.

The primary outcome also illustrates why statistical scale matters. Chest tube output is summarized with medians and inter-quartile ranges, while the reported regression analysis estimates a ratio of geometric means. These summaries are not interchangeable. Readers need to distinguish descriptive distributions from model-based estimates and interpret each according to its scale and assumptions.

The reported confidence interval is informative beyond the nonsignificant p-value. It includes 1 while also covering values on either side of 1. In general, this means the data do not provide a clear distinction from a no-ratio-difference value, but the interval also does not demonstrate that only negligible effects are compatible with the result. Without a clinically meaningful threshold, statistical uncertainty cannot be translated into a conclusion about practical equivalence.

The record also highlights the importance of transparent reporting. A missing endpoint observation, absent details about analysis populations and multiplicity, and no posted secondary results limit evaluation of the full evidence. In general, readers need to know how endpoints were selected, how missing data were handled, and how multiple comparisons were addressed to assess the reliability of a trial’s conclusions. These questions are especially important when the registry’s broad question includes more than the posted primary endpoint.

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 registry record gives only partial intervention descriptions. The arm text is truncated, so the complete treatment protocols, dosing details, and any decision rules cannot be reviewed. The record also does not report participant characteristics or detailed eligibility criteria, limiting assessment of how closely the enrolled population represents the intended clinical population or how broadly the result might apply.

The primary endpoint description identifies the measurement period and unit, but does not give further information about collection procedures, measurement reliability, or how the data were checked. One FFP subject’s data were not collected nor analyzed. The reason for missingness and the handling of missing data are not reported. The endpoint analysis counts and adverse-event at-risk counts are not the same, and the record does not explain the analysis populations behind those figures.

The statistical reporting is incomplete for independent evaluation. The record names linear regression and a ratio of geometric means but does not describe model covariates, assumptions, diagnostics, or sensitivity analyses. The summary statistics are medians and inter-quartile ranges, which are not enough to reproduce the reported model estimate. The direction used to form the ratio is not explained in accompanying text.

Although five outcome measures and five analyses are listed, the registry does not provide secondary results or describe a multiplicity strategy. The sample-size justification, interim analyses, and detailed prespecified analysis plan are also not reported in the registry record. These are limits on what can be concluded from the public record, not evidence that the omitted procedures were absent.

Finally, the primary result addresses chest tube output over the stated 24-hour period. It does not provide a posted result for transfusion requirements, despite that outcome appearing in the trial’s broad question. The safety information is limited to aggregate serious-event summaries and selected event terms, without reported causality assessments or a statistical safety comparison.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: PCC vs. FFP for Post Cardiopulmonary Bypass Coagulopathy and Bleeding — NCT02557672.
• Registry record last updated 2022-06-07; status last verified 2022-05.
• Results first posted 2022-06-07.
• 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

The registry describes a completed, randomized, parallel-group, unmasked Phase 4 trial sponsored by Mayo Clinic. It compared prothrombin complex concentrate with fresh frozen plasma for post-cardiopulmonary bypass coagulopathy and bleeding. Enrollment was listed as 106, with a recorded start of 2016-08 and primary completion of 2021-06.

The primary endpoint was chest tube output in mL over 24 hours. Median output was 1022 mL for FFP and 937 mL for PCC. The reported linear regression analysis gave a ratio of geometric means of 0.98, with a 95% confidence interval from 0.81 to 1.19 and p = 0.84. One FFP subject’s endpoint data were not collected nor analyzed.

The registry lists five outcome measures and five analyses but posts no secondary results. Serious adverse-event summaries are reported for both groups, along with selected event terms. Further details about participant characteristics, the full protocol, missing-data handling, multiplicity, and the statistical analysis plan are not reported in the registry record.