Management of Myelomeningocele Study (MOMS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Management of Myelomeningocele Study (MOMS) (NCT00060606), a randomized na study. The primary outcome is Infant Death or Need for Ventricular Shunt by 1 Year of Life.

2. Clinical Question

The clinical question concerns both timing of repair and a combined outcome. Death and need for a ventricular shunt are distinct events, but the registry defines the primary endpoint as participants with either event by the stated age. A participant meeting either part of that definition contributes to the combined endpoint; the posted primary results do not separate the two components.

The study also reports a secondary measure of participants walking independently at examination at 30 months of age. That outcome describes a later functional measure, rather than the primary combined event. It complements the primary question but does not replace it: the endpoints concern different outcomes and different ages. The registry record does not report further details about eligibility criteria or the clinical characteristics of participants, so the population cannot be characterized beyond the information recorded there.

3. Trial Design

MOMS was a randomized, parallel-group trial comparing two surgical approaches for myelomeningocele. The registry lists 183 participants enrolled, with 91 in the prenatal surgery group and 92 in the postnatal surgery group for the primary endpoint. The study is marked completed. Its recorded start is 2003-02, and its primary completion is 2014-02. The listed phase is NA.

The intervention groups differed in the timing of defect closure. The prenatal group received fetal surgery before 26 weeks of gestation and delivery by C-section at approximately 37 weeks of gestation. The postnatal group received standard closure when the baby was medically stable, usually within 48 hours of birth by C-section. These descriptions define the approaches compared; the registry does not report additional procedural details in the outcome information.

The registry records allocation as randomized, masking as none, and the model as parallel. Randomization is intended to make the groups comparable, on average, with respect to factors that could affect outcomes. It does not guarantee that every characteristic is balanced, and the registry entries do not describe baseline characteristics or the randomization procedure. With no masking recorded, the registry does not indicate blinded treatment assignment or outcome assessment.

The primary endpoint is a count of participants who died or needed a ventricular shunt by 12 months of age. A secondary outcome posted in the record counts participants walking independently at examination at 30 months of age. The record lists three outcome measures but posts one secondary outcome; it lists no reported analyses. The statistical analysis plan, original design assumptions, and details of who was included in each analysis are not reported in the registry record.

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 Infant Death or Need for Ventricular Shunt by 1 Year of Life, measured over 12 months of age.

The primary endpoint counts participants who had died or needed a ventricular shunt by 12 months of age. It is a combined, binary outcome: each participant either met the event definition or did not. The endpoint is stated as a participant count, and the posted results give the count and denominator for each randomized group.

A combined endpoint can capture more than one clinically important event in a single summary measure. Its interpretation depends on the events included, because the component outcomes may differ in frequency, severity, and meaning. Here, death and shunt need are combined, and the posted primary results do not report the counts for those components separately. The combined measure therefore cannot establish which component accounts for the group comparison.

The registry specifies the assessment time as 12 months of age. A fixed assessment time makes the comparison about whether an event occurred by that age, rather than about the timing of an event over follow-up. The record does not report further endpoint-adjudication details, the definition used for shunt need, or how deaths and shunt events were handled if both occurred in a participant.

Using a participant-level count is appropriate for a yes-or-no event outcome, but the count alone does not convey uncertainty. The comparative estimate and its confidence interval add information about the size and precision of the group contrast. Neither the composite nor its statistical comparison, by itself, explains the clinical circumstances behind each event.

7. Results Posted in the Registry

• Postnatal Surgery: 97.8% (90/92) versus 72.5% (66/91) on control; risk difference 25.3 percentage points (95% CI 15.7 to 34.9), risk ratio 1.35 (1.18–1.54); unadjusted two-proportion z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Number of Participants Walking Independently at Examination

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Postnatal Surgery: 23.9% (21/88) versus 44.8% (39/87) on control; risk difference -21.0 percentage points (95% CI -34.7 to -7.2), risk ratio 0.53 (0.34–0.83); unadjusted two-proportion z-test p = 0.003.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Postnatal Surgery than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry posts one secondary outcome: the number of participants walking independently at examination at 30 months of age. The observed pattern differs in direction from the primary comparison: the prenatal group has the higher recorded count for this outcome, while the primary composite has the higher event count in the postnatal group. This contrast is not inherently inconsistent, because the endpoints measure different things at different ages.

Independent walking is a later functional measure and is not part of the primary endpoint’s definition. The primary endpoint combines death and need for a ventricular shunt by 12 months. The secondary outcome therefore adds a distinct perspective, but it cannot clarify which primary component accounts for the group difference or substitute for component-specific reporting. Each endpoint should be interpreted according to its own definition, assessment time, and analysis population.

The secondary comparison is unadjusted. When more than one outcome is examined, the probability of observing at least one apparently notable result can rise if no multiplicity strategy is used. Statistical adjustment is not always the only way to address this issue; prespecification and a clear hierarchy of outcomes can also inform interpretation. The registry record does not report whether the secondary outcome was prespecified as confirmatory, how multiple comparisons were handled, or what broader family of analyses was planned.

The record lists three outcome measures, but only one secondary outcome is posted and no reported analyses are listed. That makes it difficult to establish whether the posted secondary result represents the full set of outcomes assessed or only the set registered in the results. Unadjusted secondary findings can be informative as descriptive evidence, but they generally carry less confirmatory weight than a clearly prespecified primary analysis with a reported multiplicity plan. The registry’s limited analysis details mean the secondary pattern should be read as an additional observation rather than as a separate definitive test of the primary question.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Number of Participants Walking Independently at Examination

9. Statistical Interpretation

10. Statistical Methods Explained

The posted primary outcome is binary at the participant level: a participant either had death or ventricular shunt need by 12 months of age or did not. The arm counts and denominators describe how many participants met that definition and how many were included in the reported group totals. Comparing the groups requires a measure of contrast as well as the underlying counts, because the same count can imply different risks when denominators differ.

What does a risk difference describe?

A risk difference subtracts one group’s event risk from the other’s. The posted primary estimate compares postnatal with prenatal surgery and is 0.253. A positive estimate in that orientation means the observed event risk is higher in the postnatal group. The risk difference is an absolute contrast, expressed on the probability scale. It is often easier to connect to differences in event frequency than a ratio measure, though its meaning still depends on the endpoint definition and the population being compared.

How do risk ratios and odds ratios differ?

The registry also posts a risk ratio and an odds ratio for the primary comparison. A risk ratio divides one group’s risk by the other group’s risk. An odds ratio compares the odds of the event between groups, where odds are the event probability relative to the probability of no event. These measures can convey relative contrasts, but they are not interchangeable. In particular, when events are common, an odds ratio can be farther from 1 than a risk ratio and should not be interpreted as if it were a risk ratio.

The primary comparison reports a risk ratio of 1.349 and an odds ratio of 17.05. These measures use the same group outcome data but answer different mathematical questions. They do not establish what happened to the separate components of the composite. As a general statistical point, a ratio measure is also sensitive to the chosen reference group: reversing the comparison changes the direction of the ratio while leaving the underlying group outcomes unchanged.

What does a p-value tell the reader?

The primary unadjusted p-value is <0.001. A p-value measures how unusual results at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The word “unadjusted” indicates that the displayed value is not adjusted for multiplicity in the posted result. The registry record does not report a broader statistical analysis plan or any multiplicity procedure.

The secondary comparison has an unadjusted p-value of 0.003. It concerns independent walking at 30 months, not the primary composite. When several outcomes or analyses are considered, unadjusted p-values do not account for the increased chance of at least one apparently notable result across those tests. How to interpret that issue depends on which outcomes were prespecified and how the study planned to handle multiple comparisons; those details are not reported in the registry record.

Why include a confidence interval?

A confidence interval gives a range of values compatible with the observed data and the statistical method used, under its assumptions. It gives information about precision as well as direction. An interval that includes the null value is compatible with no difference for a risk difference; an interval wholly on one side indicates that the values in that interval point in one direction. It is not a guarantee that the true effect lies within the range, and it does not include every source of uncertainty, such as bias from missing outcomes or departures from the analysis plan.

For the primary risk difference, the reported interval is on the positive side. The registry also gives intervals for the ratio measures. Confidence-level details and the exact methods used to construct these intervals are not reported in the registry record, so the intervals can be interpreted as posted but their construction cannot be independently assessed from the record alone.

What can be inferred about the analysis?

The group comparisons and estimates are posted, but the registry lists zero reported analyses. It does not specify whether the comparisons used an intention-to-treat population, adjusted for covariates, or handled missing observations in a particular way. It also does not report whether any interim analyses took place. These details matter because an analysis method defines which participants and outcomes contribute to an estimate and what assumptions support its uncertainty measures.

The trial is recorded as randomized, which supports interpreting the group contrast as a comparison arising from randomized allocation, subject to the conduct and analysis of the trial. However, the registry entry alone does not give all the information needed to assess allocation concealment, adherence to assigned procedures, crossover, protocol deviations, or outcome ascertainment. The posted counts and comparative statistics should therefore be read as the registry’s recorded results, with these unreported features kept in view.

11. Confidence Intervals and Precision

The primary risk-difference estimate is 0.253, and its reported confidence interval lies wholly above zero. That placement indicates that the interval’s compatible values all point toward a higher event risk in the postnatal group under the comparison orientation used. The interval communicates more than the point estimate alone: it shows the range of uncertainty around the estimated difference according to the method used.

A confidence interval is not a range containing every plausible source of uncertainty. It reflects sampling variability under the statistical method and assumptions used to calculate it. It does not automatically account for missing outcome data, bias in outcome measurement, departures from the assigned treatment, or errors in the registry entry. The statistical method and confidence level are not reported in the registry record, which limits assessment of how the intervals were constructed.

The primary result also includes intervals for the risk ratio and odds ratio. These intervals apply to their respective scales, so their numerical ranges should not be compared directly with the risk-difference interval. The risk difference is an absolute contrast; the ratios express relative contrasts. The primary risk-difference interval staying above zero is consistent with the positive point estimate, while the ratio estimates are oriented above 1 for postnatal relative to prenatal surgery.

Precision is influenced by the number of participants and by how frequently the outcome occurs, among other factors. The primary endpoint was recorded for 91 participants in the prenatal group and 92 in the postnatal group, and the event counts were high in both groups. The registry record does not provide enough information to evaluate whether all randomized participants had complete endpoint data or whether the denominators represent a particular analysis population. Confidence intervals should therefore be read alongside the recorded counts and the limitations in analysis reporting, not as a complete account of uncertainty.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size planning figures for these binary outcomes are participants per arm, not total events. The planning illustration is based on the observed effect and assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It considers detecting the stated fraction of the observed effect. These are planning assumptions for the illustration; the trial’s own original sample-size assumptions are not reported in the registry record.

The 80% power column gives the illustrated number of participants per arm for a design with 80% power under the stated assumptions and chosen effect size. In plain terms, power is the probability that the design would meet its statistical criterion if the assumed effect were the true effect and the other assumptions held. The 90% power column gives the corresponding per-arm planning figure for 90% power. These are design calculations, not outcomes observed in the trial.

For each displayed effect fraction, the figures apply to planning for that fraction of the observed effect. Smaller effects are harder to distinguish from random variation, so detecting them generally requires more participants. The values are illustrations rather than a reconstruction of the MOMS design: the registry does not report the study’s original sample-size calculation, target effect, or design assumptions. This is not observed power.

Because the primary endpoint is binary, the relevant planning unit is participants per arm. The sample-size assumptions also describe a normal approximation and equal allocation; if a design differed in allocation or used other assumptions, its planning requirements could differ. The figures should not be treated as a recommendation or as evidence that the original trial was adequately or inadequately sized. Their role is to illustrate how sample size changes with the target effect and desired power under the stated assumptions.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.725; treatment proportion p₁ = 0.978; average p̄ = 0.852.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5025 = 0.9849.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4696 = 0.3952.
4. n = (0.9849 + 0.3952)² / (0.2530)² = 29.8, rounded up to 30 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.725274725274725                          # control proportion
p1 <- 0.978260869565217                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(60606)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 30 (80% power), 40 (90% power)
 75% of observed effect: n per arm = 64 (80% power), 85 (90% power)
 50% of observed effect: n per arm = 163 (80% power), 217 (90% power)
power.prop.test: 29.8 
Simulated power at n = 30 per arm: 0.877 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes, time points, subgroups, or statistical tests are considered. Even when each test uses a conventional significance threshold, conducting multiple tests increases the chance that at least one result appears statistically notable by chance. A study can address this through a prespecified hierarchy, adjusted testing procedures, or a clearly defined distinction between confirmatory and exploratory analyses. Which approach is appropriate depends on the trial’s aims and protocol.

The registry record identifies one primary endpoint and posts one secondary outcome, while also listing three outcome measures overall. It does not describe the complete set of tests performed, whether the secondary outcome was prespecified, or whether multiplicity was addressed. The reported p-values are unadjusted. The record therefore does not support treating the secondary p-value as adjusted for testing across outcomes, nor does it establish what multiplicity strategy, if any, was part of the trial’s analysis plan.

The registry lists zero reported analyses. Details such as covariate adjustment, subgroup analyses, interim analyses, analysis populations, and protocol deviations are not reported in the registry record. The original statistical analysis plan is also not reported. Without that information, it is not possible to assess whether the posted comparisons match the prespecified analyses or how any additional analyses were interpreted.

Missing data are another important concern for randomized trials. A participant may lack a recorded outcome, and the treatment of that missing result can affect estimates if missingness differs between groups or relates to the outcome. The posted denominators are stated for each outcome, but the registry does not explain whether all randomized participants were assessed, why any outcome records might be absent, or how missing values were handled. It also does not report an imputation method or sensitivity analyses.

These omissions do not demonstrate that multiplicity or missing-data problems occurred. They mean that the registry entry does not provide enough information to evaluate how those issues were handled. A reader can describe the posted counts and unadjusted comparisons while keeping the limits of the analysis reporting explicit.

15. 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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: fetal or infant death (4.4%).

The serious adverse event figures are presented with a number at risk and a number affected for each group. The registry records 4 serious adverse events among 91 participants at risk in the prenatal surgery group and 3 among 92 at risk in the postnatal surgery group. It lists zero other adverse events in each group. The top serious adverse event term is “Fetal or infant death,” recorded as 4.4%.

The registry also records 4 deaths in the prenatal group and 3 in the postnatal group. These death counts are safety information, while the primary endpoint combines death with need for a ventricular shunt. The serious-event counts and primary endpoint counts should not be treated as interchangeable: the primary outcome includes a separate event component and is reported at a specified age.

These figures are descriptive counts, not a formal comparison of safety risks. The registry does not report a statistical safety analysis, event-level detail, severity grading beyond the serious-event category, or attribution of events to a procedure. The counts alone cannot establish whether events were caused by an intervention or whether a difference between groups is meaningful.

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

The posted results describe the randomized groups’ recorded outcomes. For the primary composite, the event count was 66 of 91 in the prenatal group and 90 of 92 in the postnatal group. The reported risk-difference estimate is positive for postnatal relative to prenatal surgery, and its confidence interval remains above zero. This is evidence about the recorded combined endpoint in this trial, under the assumptions of the analysis used.

The result does not identify whether the difference is driven by death, shunt need, or both, because component-specific primary counts are not reported. Nor does the primary endpoint capture every possible dimension of health. The secondary walking outcome concerns a different function at a later age, and its pattern should be interpreted separately rather than folded into the composite result.

A statistically notable comparison is not, by itself, a measure of clinical importance. The risk difference describes an absolute group contrast, while the risk ratio and odds ratio describe relative contrasts. Their interpretation depends on the population, outcome definition, follow-up time, and analysis assumptions. None of these measures alone establishes how an individual participant would fare under either approach.

The trial record identifies random allocation and the two surgical strategies, but it does not provide the complete protocol, analysis plan, missing-data handling, or baseline characteristics. This limits evaluation of how fully the posted results represent all randomized participants and how broadly the findings may apply. The registry also does not report the separate components of the primary composite or details needed to evaluate potential multiplicity.

Accordingly, the posted statistics support a careful description of the observed group comparison, not an all-purpose conclusion about every outcome or every clinical setting. They should not be interpreted as medical advice. The distinction between a recorded association under a randomized comparison and a decision for an individual patient remains important.

17. Why This Trial Matters Statistically

This trial is statistically instructive because it compares randomized groups on a binary composite outcome and reports both group counts and several measures of contrast. Seeing counts alongside a risk difference, risk ratio, and odds ratio helps readers distinguish absolute from relative scales. That distinction is especially important when the outcome is common: an odds ratio should not be read as though it were a direct change in probability.

The primary endpoint also illustrates a key trade-off in composite outcomes. Combining death and ventricular shunt need can produce a single, interpretable participant-level endpoint, but the summary may conceal different patterns in its components. Component-specific results would help explain what contributes to the overall contrast; those results are not reported in the registry record.

The secondary walking measure demonstrates why outcomes should be interpreted in their own context. It reflects a different domain at a later age, and its observed direction is not the same as the primary composite’s direction. That does not make the findings mutually exclusive, but it makes endpoint definitions and follow-up times central to interpretation.

The entry also shows why statistical significance is only one part of a result. Confidence intervals communicate precision, while details about multiplicity, missing data, populations analyzed, and prespecified methods are needed to assess the analysis more fully. Those details are not reported in the registry record. Planning illustrations can explain how sample size relates to target effect and power, but they are not a substitute for the trial’s own design assumptions. Together, these points make MOMS a useful example of reading estimates, endpoint structure, and reporting limits as parts of one statistical interpretation.

18. 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.

Several limitations specific to interpretation of this registry record deserve attention. The primary endpoint combines death with need for a ventricular shunt, but component-specific counts are not posted. The combined event count therefore does not reveal the contribution of either component, nor whether the observed group contrast is similar for both.

The registry posts a secondary outcome for independent walking at 30 months, but it lists three outcome measures overall and does not report further secondary analyses. It is therefore unclear from this record whether the posted outcome represents the full secondary-results set. The record also does not state whether the secondary outcome was prespecified as confirmatory or how multiplicity was handled.

Although the trial is recorded as randomized and unmasked, the registry does not provide baseline characteristics, allocation procedures, adherence information, or outcome-assessment details. The analysis population and treatment of missing outcome data are not reported in the registry record. These gaps limit assessment of comparability after randomization and of whether the posted denominators reflect all randomized participants.

The registry does not report the trial’s original sample-size assumptions, full statistical analysis plan, confidence-interval construction method, or interim-analysis details. The planning illustration is based on the observed effect and should not be mistaken for the original design calculation. In addition, the safety figures are descriptive and are not accompanied by a reported comparative safety analysis or event attribution.

These are limits of the information recorded, not evidence that the trial necessarily had deficiencies in conduct or analysis. They define what can be evaluated from the registry results alone and where interpretation should remain cautious.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Management of Myelomeningocele Study (MOMS) — NCT00060606.
• Registry record last updated 2020-07-07; status last verified 2020-06.
• Results first posted 2020-07-07.
• 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.

22. Record Summary

The registry record describes the Management of Myelomeningocele Study as a completed, randomized, parallel-group trial comparing prenatal and postnatal myelomeningocele repair. Enrollment was 183. Masking is listed as none; the phase is listed as NA. The recorded start is 2003-02 and primary completion is 2014-02.

The primary endpoint counts participants who died or needed a ventricular shunt by 12 months of age. The recorded counts were 66 of 91 in the prenatal group and 90 of 92 in the postnatal group. The posted comparison reports a risk difference of 0.253 and an unadjusted p-value of <0.001. One secondary outcome is posted: participants walking independently at examination at 30 months of age.

The registry also records serious adverse event counts and deaths by group. It does not report a complete analysis plan, missing-data methods, multiplicity handling, or the original design assumptions. The displayed comparisons and safety counts should be interpreted in light of those reporting limits.