Passive Immunity Trial for Our Nation to Treat COVID-19 in Hospitalized Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Passive Immunity Trial for Our Nation to Treat COVID-19 in Hospitalized Adults (NCT04362176), a randomized phase 3 study. The primary outcome is COVID-19 7-point Ordinal Clinical Progression Outcomes Scale Score.

2. Clinical Question

This is a question about the distribution of clinical status across ordered categories, ranging from being out of hospital with normal activities resumed to death. It is not simply a question about whether a single event occurred. The registry describes the study purpose as testing the safety and efficacy of convalescent plasma in hospitalized adults with COVID-19 and comparing clinical outcomes with placebo.

The comparison is framed by randomized assignment, but the registry record does not report the Day 15 category counts, an estimated treatment contrast, a confidence interval, or a test result for this primary endpoint. Consequently, the direction, size, and precision of the primary comparison cannot be described from the registry information available for this analysis. The study is marked completed; that status does not itself provide the missing endpoint result.

3. Trial Design

PassItOn is a Phase 3, randomized, triple-masked, parallel-group trial sponsored by Vanderbilt University Medical Center. Its official title is Passive Immunity Trial for Our Nation (PassItOn). The registry lists COVID-19, Coronavirus, and SARS-CoV-2 as conditions. Enrollment is recorded as 974. The study start date is 2020-04-24, primary completion is recorded as 2021-07-06, and status is completed.

The intervention was pathogen-reduced SARS-CoV-2 convalescent plasma. The arm description states that clinical or research personnel administered the plasma while the participant was hospitalized on Study Day 0, within 12 hours of randomization, at a rate of 500 mL/hour. The control intervention was 250mL of Lactate Ringers containing multivitamins, administered intravenously on Day 1 as placebo. The registry record does not describe who was masked under the triple-masking designation.

In general, randomization is intended to make assigned groups comparable, on average, with respect to both measured and unmeasured characteristics. Masking can reduce the influence of treatment knowledge on care, outcome assessment, or reporting, depending on who is masked. The record labels this trial randomized and triple-masked but does not give further procedural detail, such as the randomization method or masking roles. The registry record also does not report the allocation ratio.

The primary outcome was the COVID-19 7-point Ordinal Clinical Progression Outcomes Scale score at Study Day 15. Secondary outcomes listed include mortality at 14 and 28 days, survival through 28 days, ordinal clinical status at Study Days 3, 8, and 29, oxygen-free days through Day 28, and ventilator-free days through Day 28. The registry lists 20 outcome measures. Listing outcomes does not establish which analyses were conducted or how they were prioritized beyond the stated primary outcome.

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.

Population: The 14 patients not included in the analysis all withdrew their consent following randomization which removes them from the primary analytical population.

6. Primary Endpoint

The registry lists the primary outcome as COVID-19 7-point Ordinal Clinical Progression Outcomes Scale Score, measured over Study Day 15.

The primary endpoint is clinical status at Study Day 15, measured using the COVID-19 7-point Ordinal Clinical Progression Outcomes Scale. Its ordered categories run from not hospitalized with normal activities resumed, through progressively greater levels of hospitalization and respiratory support, to death. The registry describes categories for not hospitalized but unable to resume normal activities; hospitalized without supplemental oxygen; hospitalized with supplemental oxygen; hospitalized on high-flow nasal oxygen or noninvasive mechanical ventilation; hospitalized on ECMO or invasive mechanical ventilation; and death.

An ordinal scale preserves the ordering of clinical states while distinguishing degrees of severity. In general, this can capture a broader range of patient status than a single yes-or-no endpoint, particularly when outcomes span recovery, ongoing hospitalization, respiratory support, and death. The ordering does not mean that the distance between adjacent categories is equal. A statistical analysis should therefore use a method appropriate to the ordered nature of the outcome, or otherwise explain how the categories were represented.

The endpoint is assessed at a specified time point, Study Day 15. The registry record does not report how the primary comparison handled missing status at that time, whether the categories were analyzed together or in another way, or the results by randomized group. Because the endpoint has multiple ordered categories, the registry record flags it as not reduced to one comparison. Without the category distribution or a reported treatment contrast, the clinical-status comparison cannot be quantified.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods should connect the question, outcome scale, assignment process, and reported estimate. PassItOn is recorded as randomized, triple-masked, parallel-group, and placebo-controlled. Those design labels describe the framework for comparing assigned interventions, but the registry record does not report the detailed randomization procedures, the identities of masked parties, or the statistical analysis plan. Those omissions prevent a reconstruction of the intended primary analysis.

What does an ordinal endpoint represent?

In general, ordinal data consist of categories with a meaningful order but without a guarantee that the gaps between categories are equal. The primary scale orders states from less severe clinical status to death. Its categories include levels of hospitalization and respiratory support, as well as recovery outside hospital. An analysis can use the ordering rather than treating each category as unrelated, but the chosen method requires assumptions about how the ordering is used. The registry record does not report the method selected for this endpoint.

Possible summaries of an ordinal outcome can answer different questions. A full category distribution shows how participants are spread across the states. A model-based summary may express a shift across the ordered scale, subject to its assumptions. A binary simplification would combine categories and answer a narrower question. No such simplification or primary contrast is reported in the registry record; the outcome is specifically flagged as having several categories and not being reduced to one comparison. That makes it especially important not to invent a single effect from the outcome name alone.

Why does randomization matter?

In general, random assignment supports a comparison of groups by reducing systematic differences in baseline characteristics in expectation. It does not guarantee that all characteristics will be identical, nor does it resolve problems from missing outcome data, deviations from assigned treatment, or choices made after seeing results. The record identifies randomized assignment but does not describe the randomization sequence, concealment, adherence, or the analysis population. The statistical implications of those details cannot be assessed from the registry record.

Masking is also a design feature, rather than a result. In general, masking can help limit the influence of knowledge of assignment on behavior or outcome measurement. The registry labels the trial triple-masked, but does not specify which parties were masked or how masking was maintained. No further conclusion about those procedures is warranted from the label alone.

How should uncertainty be understood?

In general, an effect estimate describes the observed contrast under a defined analysis, while a confidence interval communicates its statistical uncertainty. A narrow interval indicates greater precision than a wide interval, but neither the estimate nor its interval can be interpreted without knowing what contrast and population were analyzed. The registry record does not report a primary estimate, confidence interval, or p-value. The enrollment entry and completion status cannot substitute for these quantities, and no observed treatment effect can be inferred from them.

Sample-size calculations are planning exercises, not outcomes. The registry describes a sample-size illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. It also notes that time-to-event illustrations use a total event count, while other illustrations use participants per arm. These are stated assumptions for planning illustrations, not evidence of observed power, and they do not reveal the primary endpoint result. The numerical illustration outputs are not reported in the registry information.

Why can over-dispersion matter?

In general, over-dispersion means that observed variability is greater than a statistical model expects. If a method assumes less variability than the data contain, its uncertainty estimates may be too small. This is a general statistical consideration, not a reported finding for PassItOn. The primary endpoint is ordinal, and the registry does not report a model or a dispersion estimate. It would therefore be inappropriate to claim that over-dispersion was present or that a particular correction was applied.

Similarly, analyses of event counts, mortality, or days without oxygen or ventilation require definitions of the event, time window, censoring or competing events where relevant, and analysis method. The registry lists these secondary outcomes but does not provide those analytic details in the record. A statistical reading should separate the questions named by the outcomes from the methods and results needed to answer them.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and numerous secondary outcomes, including clinical status at several study days, mortality at 14 and 28 days, survival through 28 days, oxygen-free days, and ventilator-free days. When several outcomes or time points are examined, the chance of finding an apparently notable result by chance can increase if no adjustment or prespecified hierarchy is used. In general, multiplicity procedures can control or clarify this issue, but they depend on the analysis plan and the claims being made.

The registry record does not report whether multiplicity was addressed, how outcomes were prioritized beyond identifying the primary endpoint, or whether any interim analyses were planned or performed. It does not report the primary statistical analysis plan. No adjustment method or interim-monitoring approach can therefore be attributed to the trial from this information.

The registry record also does not report the number of participants with observed Day 15 status, the amount or pattern of missing endpoint data, or how missing values were handled. In general, missing outcome data can affect both the precision and interpretation of a randomized comparison, especially if the likelihood of missingness is related to health status or treatment assignment. The endpoint includes death as a category, but the record does not explain how death and other unavailable Day 15 assessments were incorporated into the analysis.

The analysis population is not reported in the registry record. The information does not say whether the primary comparison used all randomized participants, participants who received assigned treatment, or another defined group. These distinctions can affect the estimand, meaning the treatment effect the analysis is intended to describe. Without the population definition, missing-data method, multiplicity strategy, and primary results, the statistical claims that can be supported remain limited.

11. 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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: respiratory failure (1.8%), sepsis (0.4%), acute kidney injury (0.4%), adult respiratory distress syndrome (ards) (0.4%), lung infection (0.4%).

The registry lists serious adverse-event counts and a separate other-event count for each group, alongside the number at risk for each listing. In the convalescent-plasma group, 21 participants were affected by serious adverse events among 495 at risk; the other-event listing records 27 among 495 at risk. The registry lists 89 deaths for this group. In the placebo group, serious adverse events are recorded for 16 among 479 at risk, the other-event listing records 19 among 479 at risk, and deaths are listed as 80.

The serious-event terms reported include Respiratory Failure at 1.8%, and Sepsis, Acute Kidney Injury, Adult Respiratory Distress Syndrome (ARDS), Lung Infection, and Multi-organ failure at 0.4% each. These percentages are reproduced as registry entries; the record does not provide further detail about their calculation or event-specific denominators.

In general, event counts describe what was recorded, but do not by themselves establish causation or a comparative treatment effect. The registry record does not report adjudication details, event timing, severity definitions, or a statistical comparison for these entries. Deaths are listed separately, and their relationship to the adverse-event listings is not specified. These figures should therefore be read as descriptive safety information, not as proof that an intervention caused or prevented an event.

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

The registry record establishes that PassItOn was a completed, randomized, triple-masked, placebo-controlled Phase 3 trial in hospitalized adults with COVID-19. It identifies convalescent plasma as the intervention, placebo as the comparator, and clinical status on the COVID-19 7-point Ordinal Clinical Progression Outcomes Scale at Study Day 15 as the primary endpoint. It also gives descriptions of the assigned interventions and lists secondary outcomes.

Those design details define the question, but they do not answer it. The registry information does not report the primary endpoint distribution by group, an estimated contrast, a confidence interval, or a p-value. It therefore does not establish the direction, magnitude, or precision of any difference in Day 15 clinical status. Completion is a registry status and should not be interpreted as evidence of a particular result.

The available safety entries provide counts for serious events, other events, and deaths, plus a list of serious-event terms and percentages. Descriptive counts can help readers understand what was recorded, but without fuller event definitions, timing, analysis methods, and a comparative assessment, they cannot establish causation. They also do not answer the primary ordinal-outcome question.

In general, a treatment effect is meaningful only in relation to a defined outcome, population, comparison, and analysis. Statistical uncertainty and potential biases also matter. The registry record does not report the analysis population, handling of missing Day 15 data, multiplicity approach, or detailed statistical plan. Thus, conclusions about efficacy, precision, subgroup patterns, or robustness are not supported by the information. The appropriate interpretation is a description of the trial framework and recorded safety information, with the primary clinical comparison unresolved in this registry record.

13. Why This Trial Matters Statistically

This trial is statistically notable for using an ordered clinical-status endpoint rather than defining its primary question only through a single event such as death. The scale spans recovery outside hospital, levels of hospitalization and respiratory support, and death. In general, an ordinal endpoint can retain distinctions across a range of clinical states, but its analysis must respect the ordering and make clear what treatment contrast is being estimated.

Randomized assignment and masking provide an important framework for comparing interventions, while the placebo-controlled design defines the comparator. These design features are relevant to interpretation, but they do not replace the results or statistical methods needed to evaluate the primary question. The registry record does not report the primary category distributions or the analysis used to compare them.

The record also illustrates why registry information should be read in layers. A trial can have a named primary outcome, listed secondary outcomes, completion status, and descriptive safety counts without reporting the analysis details needed to quantify its primary comparison. Multiplicity, missing data, and the analysis population all affect how findings should be interpreted; those details are not reported in the registry record.

For biostatistical readers, the central lesson is to distinguish the trial's design and endpoint from evidence about an effect. The registered scale defines what was intended to be measured, while the absence of an estimate and uncertainty interval prevents an assessment of size and precision. Neither trial phase nor enrollment nor completion can stand in for the missing outcome analysis. That distinction is essential when communicating clinical-trial evidence accurately.

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 principal limitation for interpretation is that the registry record does not report the primary endpoint results by randomized group. It provides no Study Day 15 category counts, treatment-effect estimate, confidence interval, or p-value. The primary comparison's direction, magnitude, and precision therefore cannot be evaluated from this record.

The record also does not report the statistical model or explain how the ordinal categories were analyzed. It does not describe the analysis population, missing-data handling, outcome assessment procedures, or whether participants were analyzed according to assignment. These omissions matter for understanding the exact comparison and its assumptions. The registry record does not report the randomization procedures, allocation ratio, or which parties were masked under the triple-masking designation.

Although multiple secondary outcomes are listed, the registry does not report an approach to multiplicity, an outcome hierarchy beyond the primary designation, or interim analyses. The listed outcomes are not accompanied in this record by their results or analysis details. The adverse-event entries likewise lack further event definitions, timing, attribution, and comparative statistical analyses. They are descriptive counts and should not be treated as causal estimates.

The study is marked completed, but that status does not resolve these information gaps. The registry record does not report enough detail to judge the robustness of the primary analysis or to evaluate whether missing data, analytic choices, or outcome multiplicity could affect conclusions. These are limitations of interpretation of the record, not assertions about procedures the trial did or did not use.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Passive Immunity Trial for Our Nation to Treat COVID-19 in Hospitalized Adults — NCT04362176.
• Registry record last updated 2022-11-03; status last verified 2022-10.
• Results first posted 2022-11-03.
• 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

PassItOn (NCT04362176) is a completed Phase 3, randomized, triple-masked, parallel-group trial sponsored by Vanderbilt University Medical Center. The registry records enrollment of 974 and lists a study start date of 2020-04-24 and primary completion date of 2021-07-06. The study compared pathogen-reduced SARS-CoV-2 convalescent plasma with placebo in hospitalized adults with COVID-19.

The primary outcome was clinical status on the COVID-19 7-point Ordinal Clinical Progression Outcomes Scale at Study Day 15. Listed secondary outcomes include mortality, survival, clinical status at other study days, oxygen-free days, and ventilator-free days. The registry also lists serious adverse-event counts, other-event counts, deaths, and selected serious-event terms.

The primary outcome results and detailed statistical analysis plan are not reported in the registry record. Consequently, the primary treatment contrast and its precision cannot be assessed from this information.