The Effect of Providing Stratification of Low Risk Penicillin Allergies on Penicillin Allergy Label Removal: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Effect of Providing Stratification of Low Risk Penicillin Allergies on Penicillin Allergy Label Removal (NCT03702270), a randomized na study. The primary outcome is Penicillin Allergy Label Removal.

2. Clinical Question

The trial asks whether offering hospital-floor clinicians a penicillin-allergy risk-stratification tool and recommendations is associated with more penicillin-allergy labels being removed from patients’ medical charts by discharge. The target group in the primary outcome description is patients with low-risk penicillin allergy. The comparison is against the current standard of care described in the registry, which typically involves physician judgement about challenges or consultation with an allergy service.

This is a question about a care process and a documented chart outcome within the hospital stay. It is not a direct test of whether participants were allergic, nor does label removal by itself establish the result of an allergy test. The registry describes the intended comparison but does not report detailed eligibility criteria, the method used to establish low-risk status, or how the primary analysis population was defined.

3. Trial Design

The registry describes a randomized, unmasked trial with a sequential model. It records enrollment of 2052 and a completed status. The study began on 2020-11-11, with primary completion on 2021-12-11. The phase is recorded as NA. The sponsor is Vanderbilt University Medical Center.

Participants were assigned to an experimental group with access to a penicillin-allergy best-practices alert or a control group receiving the described standard of care. The posted arm counts are 1018.0 in the experimental group and 1034.0 in the control group. The intervention is an alert and decision-support approach: its description includes a risk-stratification tool and recommendations about an oral amoxicillin test-dose challenge order set for people assessed as low risk. It does not say that every participant received a challenge.

The registry’s description of control care allows physician judgement and allergy-service consultation. It therefore describes usual care as involving clinical decisions rather than a single fixed procedure. The record does not report how often those different approaches were used in the control group, or whether the alert was opened or followed in every eligible case.

Random allocation can help make groups comparable on average, but the record does not describe the allocation sequence, concealment, or procedures used to implement assignment. Masking is recorded as none. The registry does not report whether outcome assessors were masked, how adherence to the intervention was measured, or whether analysis followed assignment regardless of intervention use. Details of the sequential model are not reported in the registry record, so the label alone should not be taken to establish the operational sequence or a particular analysis method.

The primary outcome was assessed at hospital discharge, described as approximately 4 days after admission. The registry also lists outcomes involving safety, communication in discharge summaries, antibiotic use, durability of label removal, risk-stratification assessment, time to label return, penicillin use, and cephalosporin use. The posted descriptions do not provide the same level of numerical detail for all these outcomes.

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.

Only the first 6 of 12 groups are shown.

Control

Intervention

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 Penicillin Allergy Label Removal, measured over Hospital discharge at approximately 4 days after admission.

The primary endpoint is the count of participants whose penicillin-allergy label was removed from the medical chart’s allergy section. The registry describes the measure as the percentage of patients with low-risk penicillin allergy whose labels are removed, assessed at hospital discharge, approximately 4 days after admission. The posted arm results give participant counts for this outcome.

This endpoint captures a documented clinical process: whether the allergy label was removed during the hospital episode. It is relevant to the study’s stated question because the intervention was intended to offer risk stratification and recommendations that could inform label removal. It is not itself a measurement of biological allergy status, and it does not establish whether the label remained removed after discharge. The registry lists durability and time to label return as secondary outcomes, but their numerical results are not included in the detailed results.

For interpreting the comparison, the outcome is binary at the participant level: a participant either had a recorded label removal or did not. The count therefore depends on the outcome definition, the participants included in the denominator, and the documentation available at discharge. The primary population field is empty, and the record does not report detailed eligibility rules, missing-outcome handling, or how a participant’s low-risk status was established. Those details matter when judging how directly the reported count represents the intended low-risk population.

7. Results Posted in the Registry

• Penicillin Allergic Floor Patients- Experimental: 4.4% (45/1018) versus 3.0% (31/1034) on control; risk difference 1.4 percentage points (95% CI -0.2 to 3.1), risk ratio 1.47 (0.94–2.31); unadjusted two-proportion z-test p = 0.088.

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.

Receipt of Risk Stratification Tool Assessment

• 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:
  • Penicillin Allergic Floor Patients- Experimental: 8.4% (86/1018) versus 2.6% (27/1034) on control; risk difference 5.8 percentage points (95% CI 3.9 to 7.8), risk ratio 3.24 (2.12–4.94); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Penicillin Allergic Floor Patients- Experimental than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry lists secondary outcomes covering implementation, safety, communication, antibiotic use, and whether label removal persists or the label returns. These outcomes provide context around the primary question: the trial concerns not only whether labels were removed by discharge, but also whether risk stratification was assessed and what related processes or later outcomes might be tracked.

The detailed secondary comparison concerns receipt of risk-stratification tool assessment. Its direction is consistent with the intervention being designed to make the tool available and encourage its use. Assessment of a tool is an implementation measure, however, and is not the same event as removing an allergy label. A difference in a process measure can help explain whether the intervention reached the intended workflow, but it does not establish that the downstream primary outcome will be estimated with equal precision or that the process caused a particular label decision.

The registry record lists eight secondary outcomes, but numerical results for the remaining listed outcomes are not reported in the registry record. As a result, the broader pattern across all secondary endpoints cannot be judged from the available numerical summaries. In particular, listed outcomes concerning durability, time to label return, antibiotic use, and communication should not be treated as showing a particular direction or magnitude without their results.

Secondary results generally carry less weight when many outcomes are examined, because testing a collection of outcomes creates more opportunities for chance findings. Their interpretation also depends on whether they were prespecified, how missing values were handled, and whether a multiplicity strategy was used. Those plans are not reported. The secondary findings are therefore best used as supportive, descriptive context rather than as independent confirmation of the primary result.

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

• Adverse Events (in Particular, Reported Allergic Events)
• Communication About Penicillin Allergy in Discharge Summary
• Antibiotic Utilization by Patients
• Durability of Penicillin Allergy Label Removal
• Receipt of Risk Stratification Tool Assessment
• Time to Penicillin Allergy Label Return
• Penicillin Utilization by Patients
• Cephalosporin Utilization by Patients

9. Statistical Interpretation

10. Statistical Methods Explained

The numerical summaries compare a binary outcome between two randomized groups. For each group, the posted outcome count indicates how many participants had the label removed, while the arm count gives the denominator used in the comparison. The absolute comparison is expressed as a risk difference: the experimental-group event proportion minus the control-group event proportion. A positive estimate means the observed event proportion is higher in the experimental group; a negative estimate would mean it is lower. Here the reported primary risk difference is 0.014.

What does a risk difference describe?

In general, a risk difference presents an absolute contrast between groups on the outcome scale. It is distinct from a relative measure, which expresses one group in relation to the other. Absolute measures can help readers understand the size of an observed difference without translating it into a ratio. The trial page includes the risk difference and confidence interval in its comparison results; readers should use those posted values rather than reconstructing a result from rounded arm summaries.

What does the confidence interval add?

A confidence interval gives a range of values compatible with the observed data under the method’s assumptions. It reflects sampling uncertainty, not every source of uncertainty. For the primary comparison, the interval runs from -0.002 to 0.031 and includes zero. That means the data do not precisely distinguish the observed comparison from no absolute difference. The interval’s lower and upper limits also show that estimates in different directions and of different magnitudes remain compatible with the data. It does not mean that there is a stated probability that the true effect lies within this particular interval.

How should the p-value be read?

The primary unadjusted p-value is 0.088. In general, a p-value is calculated under a null model and describes how often results at least as incompatible with that model might occur if its assumptions held. It is not the probability that the null hypothesis is true, and it does not measure effect size or practical importance. The record does not report the planned primary testing threshold or enough of the analysis plan to assess whether this p-value was the intended confirmatory test. It is therefore most informative alongside the effect estimate and its confidence interval.

What do unadjusted and adjusted comparisons mean?

An unadjusted comparison is not corrected for other variables in a model. The posted primary p-value is identified as unadjusted. The registry does not report an adjusted primary estimate or describe covariate adjustment. Randomization can support comparability between groups, but it does not remove the need to understand the planned analysis or the handling of missing results. The detailed analysis population and missing-data approach are not reported in the registry record.

What does the design label establish?

The record identifies the study as randomized, unmasked, and sequential. Randomization refers to assignment by chance, but the practical details of sequence generation and allocation concealment are not reported. Unmasked means the design is recorded as having no masking; it does not tell us whether any outcome assessment was performed without knowledge of group assignment. The sequential model is recorded, but its operational meaning and any consequences for analysis are not described. Those labels should not be expanded into assumptions about procedures that the registry does not state.

Why might event counts be difficult to interpret?

Binary outcomes summarize whether an event was recorded, not its severity, timing, or context. For the primary endpoint, the event is removal of a chart label by discharge. This is a different construct from confirmed allergy status. The outcome is also tied to a particular hospital time point, so it cannot alone describe whether removal persisted. Although durability and time to label return are listed as secondary outcomes, detailed numerical results for those measures are not included.

What is the role of the secondary comparison?

The registry also reports a comparison for receipt of risk-stratification tool assessment. This measures an implementation-related event, which is conceptually different from the primary outcome of label removal. In general, an intervention can affect whether a process is carried out without producing a correspondingly precise estimate for a downstream outcome. The secondary comparison can help describe whether the intended tool was assessed, but it does not replace the primary endpoint or establish why a label was or was not removed.

More broadly, analyses of multiple outcomes raise the possibility of chance findings across a collection of tests. The registry lists eight secondary outcomes, but a multiplicity plan is not reported. Without knowing whether outcomes and analyses were prespecified, or whether any adjustment was planned, individual secondary p-values should be treated as descriptive and interpreted with less weight than a prespecified primary comparison. No particular statistical model, correction, interim analysis, or sample-size justification for the trial is reported in the registry record.

11. Confidence Intervals and Precision

The confidence interval is central to judging how precisely the primary comparison is estimated. The reported risk difference is 0.014, and its 95% confidence interval runs from -0.002 to 0.031. The interval includes zero, so the posted data are compatible with no absolute difference. It also includes values on either side of zero, leaving uncertainty about the direction as well as the magnitude of the underlying comparison.

Precision is not the same as whether a result is important. A narrow interval would indicate a more concentrated range of estimates under the calculation’s assumptions; a wider interval would indicate greater sampling uncertainty. Here, readers should retain the full interval rather than focusing only on the point estimate or p-value. The displayed estimate is not an exact description of what would occur in every comparable setting.

The interval addresses uncertainty associated with the statistical comparison, but cannot account for unreported features such as outcome missingness, departures from the planned analysis, or differences between this hospital population and other settings. The primary population field is empty, and the analysis population and missing-data approach are not reported in the registry record. These limitations concern interpretation beyond the interval’s sampling precision.

The interval also pertains to label removal by discharge, not long-term label status or confirmed allergy. The timeframe is approximately 4 days after admission. Other listed outcomes address durability and return of the label, but their detailed numerical estimates are not reported. Consequently, the primary interval should not be extended to those later outcomes.

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 planning table and curve are planning illustrations based on the observed primary effect, not a record of the trial’s original design assumptions. The registry does not report the original sample-size justification. The illustrations assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. They consider detecting the stated fraction of the observed effect. The figures are participants per arm, not a combined total and not total events.

For the primary comparison, the table gives participants per arm for 80% power and participants per arm for 90% power at each effect fraction. For planning for 100% of the observed effect, the figures are 2,771 and 3,708, respectively. For planning for 75% of the observed effect, they are 4,699 and 6,289. For planning for 50% of the observed effect, they are 10,059 and 13,465. These are hypothetical planning quantities under the stated assumptions, not the number enrolled in this completed trial.

In plain terms, 80% power means that a design with the stated assumptions would have an 80% chance of detecting an effect of the specified size using the calculation’s testing framework, if that effect were the true one. The 90% power column uses a higher detection probability under the same kind of assumptions. Planning for a smaller effect requires more participants, because a smaller group difference is harder to distinguish from sampling variation. The curve can be read as the visual counterpart to this relationship: as the target effect becomes smaller, the planned participant count rises.

This is not observed power. The table does not describe the trial’s actual chance of a positive result after completion, and it cannot substitute for the confidence interval around the observed comparison. It is a forward-looking illustration that uses the observed effect as an input.

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 = 0.030; treatment proportion p₁ = 0.044; average p̄ = 0.037.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.2673 = 0.5238.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.2671 = 0.2248.
4. n = (0.5238 + 0.2248)² / (0.0142)² = 2,770.1, rounded up to 2,771 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 <- 0.0299806576402321                          # control proportion
p1 <- 0.0442043222003929                          # 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(3702270)
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 = 2,771 (80% power), 3,708 (90% power)
 75% of observed effect: n per arm = 4,699 (80% power), 6,289 (90% power)
 50% of observed effect: n per arm = 10,059 (80% power), 13,465 (90% power)
power.prop.test: 2770.1 
Simulated power at n = 2,771 per arm: 0.802 (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 a trial evaluates several outcomes or performs several statistical tests. Even when each test is considered separately, examining a collection can increase the chance that at least one result appears notable by chance. The registry lists eight secondary outcomes in addition to the primary outcome. It does not report a plan for controlling multiplicity, identify a hierarchy among the secondary outcomes, or state which analyses were intended to be confirmatory.

The primary comparison is accompanied by an unadjusted p-value. The record does not report whether the primary test was part of a prespecified testing sequence, whether secondary tests were adjusted, or what decision threshold was set for the trial’s own analysis. The planning illustration’s two-sided significance level of 0.05 is a stated assumption for that illustration; it should not be mistaken for a reported analysis-plan threshold for the completed trial.

Missing-data methods are also not reported in the registry record. The arm results provide denominators, but do not explain whether those denominators include every randomized participant, how any unavailable discharge information was treated, or whether participants with missing outcome status were excluded or classified in a particular way. The record does not specify an intention-to-treat, per-protocol, or other analysis population, and does not report sensitivity analyses for missing outcomes.

These omissions do not change the numbers displayed in the results, but they limit assessment of how the estimates were produced and how robust they are to analysis choices. The primary population field is empty, and the criteria for low-risk classification are not described in detail. Without a prespecified analysis plan and information about outcome availability, readers cannot fully assess whether the reported comparison follows the intended population and methods. The registry record also does not report interim analyses or stopping rules.

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 0% reporting threshold.

The serious adverse-event summary records 0 serious adverse events in the experimental group among 1018 participants at risk and 0 in the control group among 1034 participants at risk. It also records 0 other adverse events and 0 deaths in each group. No serious adverse-event terms are listed.

These are the figures recorded in the registry. They indicate that no events in these categories were entered in the posted summary for either arm; they do not establish that no symptoms or events of any kind occurred. The record does not give further details about event ascertainment, reporting completeness, timing, or the definitions used for these summaries. The primary endpoint is label removal, not a safety endpoint, so the adverse-event figures should be read separately from the primary comparison.

Zero recorded events in both groups does not permit a comparative estimate of relative safety from these summaries. It also does not show that the groups are equivalent with respect to uncommon harms. The registry lists adverse events, particularly reported allergic events, among its secondary outcomes, but the detail is limited to the aggregate figures.

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

The posted primary result is a comparison of chart-label removal by hospital discharge between a group offered access to risk stratification and a group receiving the described standard care. The point estimate is higher in the experimental group, but its confidence interval includes zero and the unadjusted p-value is 0.088. The result therefore conveys both a direction in the observed data and uncertainty about the underlying difference.

It does not establish that the approach caused a particular change in every setting, or that a label removed during admission remained removed afterward. Nor does the endpoint establish whether each participant was truly allergic or not. It records a chart outcome at a stated timepoint. Confirming allergy status, assessing later prescribing, and measuring durability are distinct questions.

The trial is randomized, which is an important feature for a comparative study, but interpretation also depends on implementation and analysis details. The record does not describe the allocation procedures, detailed eligibility criteria, low-risk classification rules, primary analysis population, or missing-data approach. Masking is recorded as none. These features matter when considering possible differences in care or outcome documentation between groups.

The trial’s outcome is tied to hospital-floor care and discharge at approximately 4 days after admission. The registry does not provide demographic or clinical subgroup details in the results. It is therefore not possible to determine from this record how the result varies across patient types or how closely other clinical settings match the study context. The control approach itself may involve physician judgement or allergy-service consultation.

Overall, the result should be read as an uncertain estimate for a specific hospital process and timepoint. The secondary tool-assessment comparison offers context about implementation, while the other listed outcomes would be needed to assess additional questions about durability, communication, and antibiotic use. Those outcomes should not be inferred from the primary result.

17. Why This Trial Matters Statistically

This trial is statistically informative because it puts a care-process intervention into a randomized comparison rather than relying only on an observational before-and-after pattern. Randomization can strengthen the basis for comparing assigned approaches, while the confidence interval makes visible the uncertainty that remains around the observed primary difference.

The endpoint also illustrates why outcome definition matters. Removing an allergy label from a chart is a specific documented action at discharge; it is not interchangeable with establishing allergy status or demonstrating persistence of the decision. Distinguishing these constructs helps prevent a process measure from being interpreted as a broader clinical outcome.

The registry includes an implementation-related secondary outcome as well as outcomes involving subsequent care and label durability. This provides a framework for considering how an alert might connect to clinical workflow and later consequences. But the posted numerical details are limited, and the absence of a reported multiplicity plan means secondary findings should be treated cautiously. The primary estimate’s interval, rather than a single p-value alone, is particularly useful for seeing the range of effects that remains compatible with the data.

Finally, the planning illustration shows how sample-size requirements depend on the effect a future study aims to detect. The table makes the trade-off between smaller target effects and larger participant requirements explicit under stated assumptions. It is distinct from the original trial’s design justification, which is not reported in the registry record. Together, these features make the study a useful example of interpreting a randomized process-outcome trial without overstating what a registry summary can establish.

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 are specific to the context and reporting of this trial. The study concerns hospital-floor patients and an outcome recorded at discharge, approximately 4 days after admission. The result may not describe care in other settings or later outcomes. The registry does not report participant characteristics or subgroup results that would allow readers to judge the range of patients represented.

The primary outcome description focuses on patients classified as low risk, but detailed low-risk criteria and the primary analysis population are not reported. The primary population field is empty. The alert recommends use of an oral amoxicillin test-dose challenge order set for patients who stratify as low risk, but the registry does not report the proportion who received a challenge or how clinicians used the recommendations. The control description allows physician judgement or allergy-service consultation, leaving the mix of control practices unspecified.

The design is recorded as unmasked, and details of allocation implementation, outcome assessment, adherence, and missing-data handling are not reported. These omissions make it harder to assess whether awareness of group assignment could have influenced the workflow or chart documentation, and how incomplete outcome information was treated.

The primary result concerns label removal rather than confirmed allergy or durability. Although the registry lists related secondary outcomes, detailed numerical results for most of them are not included. The secondary analysis strategy and multiplicity handling are also not reported. Finally, the serious adverse-event summary contains zero recorded events in both groups, but the record does not explain ascertainment or completeness. These limitations constrain interpretation; they do not by themselves determine the direction of any bias.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: The Effect of Providing Stratification of Low Risk Penicillin Allergies on Penicillin Allergy Label Removal — NCT03702270.
• Registry record last updated 2024-12-18; status last verified 2024-12.
• Results first posted 2024-10-15.
• 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

This completed randomized, unmasked trial evaluated access to a penicillin-allergy risk-stratification alert for hospital-floor patients compared with the described standard of care. The registry records enrollment of 2052, a sequential model, and a primary assessment at hospital discharge, approximately 4 days after admission.

The primary outcome was penicillin-allergy label removal from the medical chart. The posted estimate is a risk difference of 0.014, with a 95% confidence interval from -0.002 to 0.031 and an unadjusted p-value of 0.088. The interval includes zero, indicating uncertainty about the direction and size of the comparison.

One secondary comparison concerns receipt of risk-stratification tool assessment. The registry lists additional outcomes, but detailed numerical results for the other listed measures are not reported in the registry record. Serious adverse-event summaries record zero events in both groups. Analysis-plan details, missing-data methods, multiplicity handling, and the original sample-size justification are not reported in the registry record.