Direct Peritoneal Resuscitation Effects in the Damage Control Patient: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Direct Peritoneal Resuscitation Effects in the Damage Control Patient (NCT01771055), a randomized na study. The primary outcome is Number of Participants With Morbidity.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group trial with no masking. Randomization means that assignment to a study arm was intended to use a chance-based process; a parallel-group design means that participants were assigned to one of the arms rather than crossing between them. The registry does not report how the random sequence was generated, how assignments were concealed, or whether any safeguards were used to maintain the allocation process.

The two arms were Galactose and Standard Resuscitation. The registry lists 3.0 participants in the Galactose arm and 4.0 in the Standard Resuscitation arm, with enrollment of 7. It gives the study status as completed. The start date is 2012-01 and the primary completion date is 2016-06. The listed phase is NA, and the sponsor is University of Louisville.

No masking means that the record does not describe a blinded comparison. In general, knowledge of an assigned intervention can affect care, outcome assessment, or reporting, depending on the outcome and the procedures used. The registry does not say whether outcome assessors were kept unaware of assignment or whether morbidity was assessed using a prespecified definition.

The record does not report the recruitment setting, eligibility criteria, participant characteristics, treatment duration, adherence, or follow-up procedures beyond the primary outcome timeframe. It also does not report a protocol-level sample-size justification or a detailed statistical analysis plan. The listed design therefore establishes the broad comparison, but not the operational details needed to assess how assignment, treatment delivery, and outcome ascertainment were carried out.

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

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 Participants With Morbidity, measured over 1 Month.

The primary endpoint is the number of participants with morbidity, assessed at one month. It is recorded as a count of participants with an event, rather than as a continuous measurement. The registry gives a value of 0.0 for the Galactose arm and 0.0 for the Standard Resuscitation arm.

A binary endpoint classifies each participant according to whether the defined event occurred. Counting participants with an event can make a clinical outcome easier to describe across study arms, but interpretation depends on a clear definition of the event and consistent assessment. The registry record does not define which conditions or events count as morbidity, explain how morbidity was assessed, or state whether events were adjudicated by an independent reviewer.

The study summary also raises questions about organ blood flow, tissue swelling, and abdominal closure. Those are not described as the primary endpoint in the posted results. The primary outcome therefore cannot, by itself, answer whether those specific processes changed. The record lists no estimable two-arm comparison for this binary outcome, so the arm-specific counts should be read as descriptive observations rather than as a quantified treatment effect.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does randomization contribute?

In general, randomization uses chance to assign participants to study arms. Its purpose is to reduce systematic differences in assignment, so that an outcome comparison can be interpreted with less concern that clinicians or participants selected the arm according to prognosis. Randomization does not guarantee that the arms will be similar in every characteristic, especially in a small study. The registry identifies the trial as randomized, but the method used to generate and implement assignments is not reported in the registry record. The design label alone cannot establish whether allocation was concealed or whether the process was followed as planned.

What does a parallel-group design mean?

In general, a parallel-group study assigns each participant to an intervention arm and compares outcomes across arms. This differs from a design in which the same participant receives multiple interventions in sequence. The record lists Galactose and Standard Resuscitation as the two arms. It does not report treatment crossover, adherence, or changes in assigned care, so those aspects cannot be assessed from the posted results.

How should a binary endpoint be understood?

A binary outcome records whether a participant did or did not experience a defined event. A count of participants with morbidity is a way to summarize those events. For an informative comparison, the event definition, follow-up period, and method of assessment should be clear and applied consistently. The registry gives the timeframe as one month but does not define morbidity or describe the assessment process. It reports 0.0 for each arm, but the two-arm comparison is marked as not estimable. Thus, the arm counts describe the posted observations without supplying a comparative effect estimate.

Why does uncertainty matter with zero events?

As a general statistical principle, an observed count is not the same as a known underlying event probability. When no events are observed, uncertainty can still be wide, because the study has limited information about events that might occur in a larger population. A confidence interval is a way to express uncertainty around an estimate: it describes a range of values compatible with the data under the method used. No confidence interval is reported in the registry record for this comparison. Without an interval or another inferential result, the precision of any treatment contrast cannot be read from the two zero counts alone.

What can be said about statistical testing?

The record reports no analyses and does not provide a p-value for the primary outcome. It would be inappropriate to infer which statistical test was used or to perform a new test from the limited posted summaries. Different methods can behave differently when event counts are sparse or zero, and the choice of method depends on the analysis plan and the data available. The statistical plan, model, and any adjustment methods are not reported in the registry record. Consequently, there is no reported basis for a claim about statistical significance.

Why do the registry's planning illustrations have a different role?

Sample-size calculations are planning tools for a proposed study. In general, they ask how much information a future study might need to detect an effect under chosen assumptions. The registry describes its planning illustrations as based on the observed effect, equal allocation, a two-sided significance level of 0.05, and a normal approximation; the effect to detect is a stated fraction of the observed effect. Such calculations are not the trial's original design justification unless the record says so, and that justification is not reported in the registry record. They are not observed power and do not show how likely the completed trial was to detect a true effect.

When an illustration uses an effect estimated from a small study, that estimate can be unstable. A planning calculation can therefore be useful as a conditional example while remaining dependent on its assumptions. It should not be treated as a result about clinical outcomes or as evidence that the trial did or did not succeed in identifying a difference. The posted record does not include a statistical analysis that resolves the primary comparison.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Galactose", "Standard Resuscitation")
n      <- c(3, 4)
events <- c(0, 0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Galactose  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Standard Resuscitation  4  0  0.0  0.0  60.2  0.0  49.0  0.5  52.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure: the number of participants with morbidity at one month. It reports no secondary outcomes. A limited set of outcomes can reduce some concerns about multiplicity, which arises when several outcome tests are conducted and the chance of a misleading positive finding can increase. However, the registry does not report a prespecified testing hierarchy, an adjustment for multiple comparisons, or a plan for handling multiple analyses. Those procedures are not reported in the registry record.

The registry lists no analyses, and the two-arm binary comparison is described as missing or not estimable. It does not report an analysis population, such as whether participants were analyzed according to their randomized assignment, or how deviations from assigned care would be handled. The record also does not describe missing outcome data, exclusions from analysis, or imputation procedures. These details matter because the analyzed group and the handling of unavailable outcomes can affect how a comparison is interpreted.

The posted arm counts should not be read as evidence that missing data were absent: the registry does not describe completeness of follow-up or explain how the values were obtained. Nor does the completed status establish that every planned outcome was analyzed. Without a reported analysis plan and analysis population, it is not possible to assess whether the posted result follows prespecified methods or whether alternative analyses were considered.

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's adverse-event figures report no serious adverse events, no other adverse events, and no deaths in either arm. For Galactose, the record lists 0 serious events among 3 participants at risk and 0 other events among 3 at risk, with 0 deaths. For Standard Resuscitation, it lists 0 serious events among 4 participants at risk and 0 other events among 4 at risk, with 0 deaths. No serious-event terms are listed.

These counts describe what the registry reports; they do not show that the underlying risk of an adverse event is zero. The groups are small, and a count of zero cannot rule out events that might occur with more observation. The record does not provide event definitions, collection procedures, or a separate safety analysis. The adverse-event figures should also be kept distinct from the primary morbidity outcome, whose definition is not reported in the registry record. The registry's counts alone do not establish a comparative safety effect.

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

The posted result is descriptive: the registry records 0.0 participants with morbidity in each arm at one month. It also reports zero serious adverse events, zero other adverse events, and zero deaths in each arm. These observations are relevant to understanding what was recorded among the enrolled participants, but they do not establish that either approach has no risk or that the approaches have the same effects.

The registry does not report an estimable two-arm analysis, a comparative estimate, a confidence interval, or a p-value. It therefore does not quantify how different the underlying outcomes might be between the approaches or how precisely such a difference is estimated. With enrollment of 7, the result has limited information about outcomes beyond the participants represented in the record. A lack of observed events in a small group is not proof that events cannot occur.

The endpoint also does not capture every question described in the study summary. The summary raises organ blood flow, tissue swelling, and speed of abdominal closure, but the posted primary outcome is morbidity. No separate result for those other questions is listed. The morbidity definition itself is not reported, which further limits interpretation of what the endpoint includes.

The trial's randomized design is relevant to the intended comparison, but a design label cannot substitute for reported results and analysis details. The registry does not provide the assignment method, analysis population, missing-data approach, or outcome-assessment procedures. The record supports a cautious account of the observed counts, not a conclusion about whether one approach is preferable or whether either approach changes clinical outcomes.

14. Why This Trial Matters Statistically

This trial is statistically instructive because it combines a randomized comparison with very sparse outcome data. Randomization is a useful design principle, but its ability to support a clear comparison depends on the information collected and on how the results are analyzed. The record lists 3.0 participants in the Galactose arm and 4.0 in the Standard Resuscitation arm, with no recorded morbidity events in either group. Those counts illustrate why design labels and outcome counts must be considered alongside uncertainty.

Zero events can look reassuring at first glance, yet the statistical meaning is limited when the groups are small. The same observed count does not establish equal underlying risks, and without an estimable contrast or interval, the precision of a treatment comparison remains unknown. This distinction between an observation and an inference is central to interpreting clinical trial results.

The record also highlights the importance of matching claims to endpoints. The study summary describes questions about organ blood flow, swelling, and abdominal closure, while the primary posted measure is morbidity. Readers need to distinguish motivating questions from outcomes with reported data. A completed study with a listed endpoint is not necessarily accompanied by an analyzable comparison or by results for each clinical question.

Finally, planning illustrations and trial findings serve different purposes. A sample-size illustration based on an observed effect is conditional on its assumptions; it is not a substitute for a reported analysis and is not evidence of observed power. This record offers a concise example of why transparent definitions, analysis methods, and uncertainty estimates are needed to interpret even a randomized study.

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 immediate limitation is the small enrollment: the registry reports 7 participants, with 3.0 in the Galactose arm and 4.0 in the Standard Resuscitation arm. The primary endpoint has no recorded events in either arm, and the registry marks the two-arm comparison as not estimable. As a result, the posted information cannot support a precise estimate of the comparative outcome.

The registry does not define morbidity, describe outcome assessment, or state whether assessment was blinded. It also does not report participant characteristics, injury severity, eligibility criteria, recruitment setting, treatment adherence, or the handling of changes in care. These omissions limit assessment of how applicable the observations may be to other patients and how consistently the intervention and comparator were delivered.

The study summary raises questions about organ blood flow, tissue swelling, and abdominal closure, but the registry lists morbidity as the primary outcome and reports no secondary outcomes. The posted record therefore does not allow those additional questions to be evaluated. The absence of a reported statistical analysis plan, analysis population, missing-data approach, confidence interval, or p-value further limits interpretation. The record's completed status does not fill in these missing methodological details or establish the completeness of outcome follow-up.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Direct Peritoneal Resuscitation Effects in the Damage Control Patient — NCT01771055.
• Registry record last updated 2021-06-16; status last verified 2021-06.
• Results first posted 2021-06-16.
• 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 record describes a completed, randomized, parallel-group study with no masking, sponsored by University of Louisville. It lists Galactose as the intervention and Standard Resuscitation as the comparator. Enrollment was 7; the listed arm sizes are 3.0 and 4.0. The study start is 2012-01 and primary completion is 2016-06.

The primary outcome is the number of participants with morbidity at one month. The record reports 0.0 in each arm and states that a two-arm comparison for the binary endpoint is missing or not estimable. No analyses or secondary outcomes are reported. Adverse-event figures list no serious events, other events, or deaths in either arm. Definitions, detailed methods, and inferential results are not reported in the registry record.