Bronchiolitis Recovery and the Use of High Efficiency Particulate Air (HEPA) Filters: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bronchiolitis Recovery and the Use of High Efficiency Particulate Air (HEPA) Filters (NCT05615870), a randomized na study. The primary outcome is Number of Caregiver-reported Symptom-free Days (SFDs).

2. Clinical Question

The registry describes a multi-center, parallel, double-blind, randomized controlled trial. Children were assigned to the active-filter or inactive-filter group, and respiratory outcomes were followed over pre-intervention and intervention periods. The brief summary describes a 24-week home intervention following pre-intervention indoor-air-quality measurements.

The primary measure is a count of symptom-free days summarized as a mean. The posted results give the intervention and control group means, their standard deviations, and a comparison of the means. The registry also lists hospitalizations and other unscheduled respiratory-related visits, quality of life, and particulate matter levels as secondary outcomes. Those outcomes provide related but distinct information: they concern healthcare use, quality of life, and indoor air rather than the primary symptom-free-day measure.

3. Trial Design

The record describes a randomized, parallel-group clinical trial with triple masking. It is listed as completed, with a planned enrollment of 230. The condition is bronchiolitis, and the sponsor is the IDeA States Pediatric Clinical Trials Network. The registry lists the start date as 2022-11-07 and primary completion date as 2024-07-05.

Eligible children are described in the brief summary as younger than 12 months and hospitalized with bronchiolitis. The active-filter group used filtration units containing HEPA and carbon filters, while the control group used identical-appearing units without those filters. The intervention description calls for units in the child’s sleep space and a common room. The brief summary describes use of the units for 24 weeks after pre-intervention indoor-air-quality measurements, with respiratory outcomes followed during the pre-intervention and intervention periods.

The primary outcome was caregiver-reported symptom-free days over 24 weeks. The analysis population is described as randomized participants in either group with available outcome data. The registry reports 110 participants with primary outcome data in the intervention group and 109 in the control group. Those outcome-specific counts need not equal the planned enrollment: they describe the participants represented in the posted primary-outcome summaries, not an independently established account of every randomized participant or every analysis.

The record lists four outcome measures and seven analyses overall. It also lists three secondary outcomes, while posted secondary results include quality of life. The registry record does not report the trial’s original sample-size justification, its prespecified statistical analysis plan, or whether interim analyses were conducted. The exact operational details of masking 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.

Before assignment: Two enrolled participants terminated the study prior to randomization due to withdrawal of consent and ineligibility.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The analysis population included all participants who were randomized to either HEPA filtration (intervention group) or inactive filter unit (control group) with available outcome data

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 baseline analysis population includes all participants who are randomized to either the HEPA filtration (intervention group) or the inactive filter unit (control group).

6. Primary Endpoint

The registry lists the primary outcome as Number of Caregiver-reported Symptom-free Days (SFDs), measured over 24 Weeks.

The primary endpoint is the number of caregiver-reported symptom-free days (SFDs) during 24 weeks. An SFD is defined as a 24-hour period without coughing, wheezing, or trouble breathing. The registry reports the outcome as a mean with standard deviation, so the principal group comparison concerns average symptom-free days rather than the proportion of children meeting a threshold.

This measure captures symptoms over a follow-up period rather than at a single assessment. Counting days without the listed symptoms can describe the duration of symptom-free time as reported by caregivers. It is also distinct from a measure of healthcare use, quality of life, or air quality; those appear among the secondary outcomes. The registry does not report a rationale for selecting this primary endpoint or a threshold for interpreting a difference as important to families.

Caregiver reporting is the stated source of the symptom information. General measurement considerations apply: reports gathered over time may depend on how symptoms are recognized and recalled, and a summary mean does not show each participant’s pattern of symptoms. The posted group means therefore describe average reported SFDs in the analysis population, not the experience of every child. The standard deviations describe variability within groups, while the confidence interval for the comparison conveys uncertainty about the estimated difference in group means.

7. Results Posted in the Registry

• Intervention Group (Active Filter): mean 118.01 versus 112.60 on control; difference 5.41 (95% CI -6.39 to 17.21), standardized effect d = 0.12; z-test p = 0.369.

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.

Total Quality of Life (QOL) Score

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Intervention Group (Active Filter): mean 81.34 versus 82.13 on control; difference -0.79 (95% CI -3.70 to 2.12), standardized effect d = -0.08; z-test p = 0.594.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Intervention Group (Active Filter) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes concern healthcare use for respiratory complaints, quality of life, and average particulate matter levels. These measures address different aspects of the intervention and are not interchangeable with the primary outcome of caregiver-reported SFDs. The registry lists three secondary outcomes, and the posted results include a quality-of-life comparison.

The quality-of-life result is a mean difference of -0.80 in the sponsor’s analysis, with a 95% confidence interval from -3.75 to 2.16 and p = 0.598. The interval includes zero and allows for differences in either direction. The record also gives group means and standard deviations for this outcome. Those estimates do not establish a clear group difference in quality of life.

The overall pattern should be read alongside the primary result: the posted primary and quality-of-life analyses do not establish a clear difference between groups. The available information does not support a single combined conclusion across all secondary outcomes. The registry record does not provide posted numerical results for every listed secondary outcome in the registry record for this analysis, so no quantitative conclusion about those other measures is warranted.

In general, when many outcomes or comparisons are examined, the chance of obtaining at least one apparently notable result by chance can increase. A multiplicity adjustment can address some of that issue, but the registry record does not report whether an adjustment was planned or applied. Unadjusted secondary results should therefore carry less weight than a prespecified primary analysis, particularly when considered one at a time. They can be informative as additional evidence, but should not be treated as independent confirmation without considering the full analysis plan and all tested outcomes.

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

• Number of Hospitalizations, Emergency Department or Urgent Care Visits or Other Unscheduled Medical Visits for Respiratory Complaints
• Total Quality of Life (QOL) Score
• Average Particulate Matter (PM2.5) Levels

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous in the registry’s statistical classification and is summarized by a mean and standard deviation in each group. A mean describes the average observed value, while a standard deviation describes how spread out individual observations are around that average. Neither statistic alone describes the full distribution of participant outcomes.

What does the mean difference represent?

The mean difference compares the average SFD value in the intervention group with the average in the control group. Positive values in the posted comparison indicate a higher mean in the intervention group; negative values indicate a lower mean. The comparison is expressed in days, the unit of the primary endpoint. The posted group means are 118.0 and 112.6, and the reported sponsor estimate is 5.41. These are summaries of the analysis population, not predictions for an individual child.

What does the sponsor’s model add?

The registry identifies the sponsor’s primary analysis method as Mixed Models Analysis and its parameter as Mean Difference (Final Values). A mixed model is a general statistical approach that can model outcome data while accounting for specified sources of correlation or structure. The registry record does not report the model formula, included covariates, assumptions, handling of incomplete observations, or other implementation details. It is therefore not possible to determine from the record precisely how the model was specified or what adjustments it made. The reported estimate, interval, and p-value should be read as the posted results of that analysis, not as quantities recreated from the group summaries.

Why is there also an unadjusted calculation?

The simple recalculation compares the posted group means using the posted standard deviations and group counts. It is unadjusted: it does not reproduce a mixed model or account for information not contained in those summaries. Its estimate is 5.41, with a 95% confidence interval from -6.388 to 17.21 and p = 0.369. Such a calculation provides a check on the broad scale of the group comparison, but it is not a replacement for the sponsor’s analysis. The sponsor’s estimate is also 5.41, while its confidence interval and p-value differ. The registry record does not provide enough model detail to attribute that difference to a particular feature of the analysis.

How should the p-value be read?

In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be if that null model and its assumptions were true. It is not the probability that the null hypothesis is true, nor is it a measure of the size or importance of an effect. The sponsor reports p = 0.537 for the primary analysis. The recalculated unadjusted p-value is 0.369. These values do not establish a difference between groups. They also do not prove that there is no difference.

Why does over-dispersion matter?

In general, over-dispersion means observed variability is greater than a statistical model expects. If a model understates variability, standard errors can be too small and confidence intervals too narrow. The primary outcome is a count of days, but the registry summarizes it as a mean with standard deviation and reports a mixed-model analysis. The record does not report an over-dispersion assessment or a particular count-distribution model. It would therefore be inappropriate to assert that over-dispersion was present or that a particular correction was used.

General statistical interpretation also depends on design and data quality. Randomization supports comparison of assigned groups, but the reported analysis population is limited to participants with available primary outcome data. The registry record does not report sufficient detail to assess the impact of missing outcomes, the prespecified model assumptions, or whether the analysis followed an intention-to-treat approach. These are uncertainties about what can be evaluated from the record, not evidence that the analysis was necessarily flawed.

11. Confidence Intervals and Precision

The sponsor’s primary estimate is a mean difference of 5.41 SFDs, with a 95% confidence interval from -11.77 to 22.60. The interval includes zero, the value corresponding to no difference in group means. It also includes negative and positive values. The posted result is therefore compatible with a range of possible group differences, including a lower mean in the intervention group, little or no difference, or a higher mean.

In general, a confidence interval is a range of values generated by a statistical procedure that, over repeated use under its assumptions, would capture the target quantity at the stated rate. A 95% confidence interval is not a statement that there is a 95% probability that this particular interval contains the true effect. It conveys uncertainty in the estimate under the analysis assumptions.

The unadjusted recalculation gives a 95% confidence interval from -6.388 to 17.21. This is narrower than the sponsor’s interval, but it answers a different calculation based on posted summary statistics rather than the sponsor’s mixed model. The intervals should not be treated as interchangeable. The registry record does not provide enough detail about the model to explain why their widths differ.

The quality-of-life sponsor estimate has a 95% confidence interval from -3.75 to 2.16. It also includes zero. Across these outcomes, interval width is important: a point estimate alone can conceal considerable uncertainty. Neither the primary confidence interval nor the quality-of-life interval supports a precise claim that the groups are identical. At the same time, the primary interval does not isolate a single direction or magnitude with high precision. The registry record does not report a threshold for a clinically important difference, so the intervals cannot be used to classify the estimates as clinically important or unimportant.

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 display is a planning illustration based on the observed effect, not the trial’s original design justification. The figures are participants per arm, not total participants or total events. This is a continuous-outcome comparison; the record’s planning note distinguishes these figures from time-to-event displays, which report total events.

The listed planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is the stated fraction of the observed effect. The rows describe planning for 100%, 75%, and 50% of the observed effect. For the primary outcome, planning for 100% of the observed effect lists 1,064 participants per arm for 80% power and 1,424 participants per arm for 90% power. Planning for 75% lists 1,891 participants per arm for 80% power and 2,531 participants per arm for 90% power. Planning for 50% lists 4,254 participants per arm for 80% power and 5,694 participants per arm for 90% power.

In plain language, the 80% power column gives the planned participants per arm for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect is real. The 90% column uses a higher target chance of detection and consequently lists more participants. Smaller effects need more participants to distinguish them from random variation with the same target power. These are planning illustrations, not observed power.

The registry record does not report the trial’s own original sample-size assumptions or justification. These planning figures should not be read as evidence that the trial was designed to detect the observed effect, nor as a retrospective verdict on whether the trial was adequately powered.

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, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 5.410; pooled standard deviation σ = 44.524.
2. n = 2 × (1.96 + 0.842)² × 44.524² / 5.410² = 1,063.3, rounded up to 1,064 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
delta <- 5.41000000000001                      # observed difference in means
sigma <- 44.5243723243301                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^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 (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(5615870)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 1,064 (80% power), 1,424 (90% power)
 75% of observed effect: n per arm = 1,891 (80% power), 2,531 (90% power)
 50% of observed effect: n per arm = 4,254 (80% power), 5,694 (90% power)
power.t.test: 1064.2 
Simulated power at n = 1,064 per arm: 0.803 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-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. Analyses Reported by the Sponsor

The sponsor’s reported primary analysis is a Mixed Models Analysis of the mean difference in final values. It estimates a difference of 5.41 SFDs, with a 95% confidence interval from -11.77 to 22.60 and p = 0.537. This is the trial’s own posted analysis and should be distinguished from the simple unadjusted recalculation.

The recalculation uses the posted group means, standard deviations, and outcome counts. It also estimates a mean difference of 5.41, but its 95% confidence interval is -6.388 to 17.21 and its p-value is 0.369. The matching point estimates do not make the analyses identical: their intervals and p-values differ. The registry record does not report the model specification or enough detail to explain the difference.

The registry’s discrepancy indicator is false. The recalculation is best treated as a separate, summary-statistic-based check, not as a correction to the sponsor’s result. Both analyses have confidence intervals that include zero, and neither establishes a clear difference. The sponsor’s model-based estimate remains the appropriate reference for what the sponsor reported, while the recalculation illustrates how a simpler unadjusted comparison behaves using the posted summaries.

15. Multiplicity, Missing Data and Analysis Populations

The record lists a primary outcome and secondary outcomes, as well as seven analyses overall. It does not report a prespecified hierarchy for the outcomes, a multiplicity adjustment, or how the family of statistical tests was defined. Without those details, the degree to which the reported p-values account for multiple comparisons is not reported in the registry record.

In general, testing several outcomes can increase the chance of at least one apparently unusual result arising by chance. Adjustments can control that risk for a defined set of tests, but they may also affect precision and power. Since the registry record does not state whether such an approach was used, secondary p-values should be treated as exploratory or supplementary rather than as conclusive evidence on their own. This consideration does not change the numerical estimates; it affects how strongly they can support claims across outcomes.

The primary analysis population is described as randomized participants with available outcome data. The posted primary summaries include 110 intervention participants and 109 control participants, while the sponsor’s analysis is described as a mixed model of final values. The registry record does not report the number of randomized participants lacking primary outcome data, reasons for unavailable outcomes, imputation procedures, or sensitivity analyses for missing data. It also does not specify whether the sponsor’s analysis included all randomized participants under an intention-to-treat principle.

Missing outcome data can affect estimates if availability is related to outcomes or group assignment. In general, statistical methods can address some missing-data structures only under assumptions, and those assumptions should be stated and examined where possible. The available record does not permit an assessment of whether missingness could have shifted the observed comparison. Nor does it permit a complete appraisal of adherence, protocol deviations, or the exact analysis set used by the mixed model. These are reporting limitations; their presence in the record does not by itself show that the results are biased.

16. 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: other - bronchiolitis (5.3%), other - bronchiolitis, hospitalization for hypoxia & increased work of breathing, and respiratory di (4.4%), other - respiratory distress, reactive airway disease with wheezing, hypoxemia and nasal congestion (4.3%), medical or emergency department/urgent care visit for respiratory complaint (0.9%), trouble breathing (0.9%).

The registry reports serious adverse event figures by group. In the active-filter group, 17 participants were affected among 113 at risk; in the control group, 12 were affected among 115 at risk. Deaths are reported as 0 in each group. These are event-record summaries, not estimates that establish whether an event was caused by the filtration units.

The listed serious-event terms include bronchiolitis and respiratory complaints, including a medical or emergency department/urgent care visit for a respiratory complaint, trouble breathing, and wheeze. The term-level percentages are reported in the registry. They should be interpreted using the registry’s terminology and reporting categories, not as a complete description of every event or an independently adjudicated causal assessment.

Comparing these figures requires caution. The registry record does not report a statistical comparison for serious adverse events, detailed event timing, severity beyond the serious-event classification, or a causal attribution method. The counts alone do not establish a difference in safety between groups. They describe what was recorded during the trial, with the group-specific numbers at risk as stated in the record.

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

The primary result is an estimate of the difference in mean caregiver-reported symptom-free days between the active-filter and control groups over 24 weeks. The sponsor’s estimate is 5.41 days, with a 95% confidence interval from -11.77 to 22.60 and p = 0.537. The interval includes no difference and values in either direction, so the result does not establish a clear difference in the primary outcome.

This does not mean the groups have been shown to be equivalent. Demonstrating equivalence or noninferiority requires a defined margin and an analysis designed for that purpose; the registry describes the primary analysis as superiority and does not report an equivalence margin. Nor does a nonsignificant result prove that there is no effect. The interval expresses uncertainty and leaves a range of effects compatible with the analysis.

The result is specific to the study population, intervention, comparator, outcome definition, and follow-up described in the registry. The children were younger than 12 months and hospitalized with bronchiolitis; the comparison was between active-filter units and identical-appearing units without HEPA or carbon filters. The primary outcome depended on caregiver reports of days without the listed symptoms. The registry record does not establish how these findings would apply to different populations, settings, or filtration arrangements.

The result also does not settle every question about healthcare use, quality of life, or particulate matter. Those are distinct secondary outcomes, and the available results do not support a unified conclusion about them. The registry’s serious-event summaries similarly do not establish causation or a group difference in safety.

Overall, the posted data are compatible with uncertainty about the size and direction of the primary group difference. They do not justify a claim that the intervention works or does not work, and they are not medical advice. They describe the results of this completed trial as reported in the registry.

18. Why This Trial Matters Statistically

This trial raises several statistical issues that are useful to clinical researchers. First, a mean difference is easy to interpret in the endpoint’s own units, but it should be read with its confidence interval. The primary estimate is 5.41 days, while the sponsor’s interval extends from -11.77 to 22.60. The interval makes clear that the point estimate alone would give an incomplete account of uncertainty.

Second, the registry presents both a sponsor mixed-model analysis and enough group summaries for a simple unadjusted recalculation. The point estimates are the same, but the confidence intervals and p-values differ. This illustrates why matching point estimates do not imply that analyses are interchangeable. The model-based result and the summary-statistic calculation answer related but not identical statistical questions, and the model details are not fully reported in the record.

Third, outcome availability matters. The primary analysis population is described as randomized participants with available outcome data. That qualification should prompt readers to ask how missing outcomes were handled and whether the analysis population preserved the benefits of randomization. The registry record does not provide all the information needed to answer those questions.

Finally, secondary outcomes and multiple analyses require disciplined interpretation. A collection of results across different measures cannot be treated as a single confirmatory finding without a stated analysis plan. The record’s limited reporting on multiplicity and secondary analyses makes the primary result the clearest focus, while leaving important uncertainty about the broader pattern of outcomes.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record does not report the original sample-size justification, the detailed statistical analysis plan, the model formula for the mixed-model analysis, or whether interim analyses were conducted. It also does not report an equivalence margin or a threshold for a clinically important difference in symptom-free days. These omissions limit assessment of the intended operating characteristics and the practical meaning of the estimated difference.

The primary outcome was caregiver-reported. The registry defines an SFD, but the record does not report additional details about symptom collection, caregiver training, validation, or how reports were reconciled when information was incomplete. As a general measurement consideration, a reported mean can obscure variation in individual patterns over the follow-up period.

The analysis population included randomized participants with available outcome data. The record does not report how many randomized participants lacked primary outcome data, why data were unavailable, or whether imputation and sensitivity analyses were used. It also does not provide enough detail to determine the exact analysis set in the sponsor’s mixed model.

The record describes triple masking but does not specify which people were masked or how masking was maintained. It describes the intervention and control units, but the available intervention description is incomplete in its operational details. The registry lists multiple outcomes and analyses without reporting a multiplicity strategy. Finally, numerical results for every listed secondary outcome are not available in the registry record used for this account. These limits constrain evaluation of the broader outcome pattern, but do not by themselves establish that the trial was conducted improperly.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Bronchiolitis Recovery and the Use of High Efficiency Particulate Air (HEPA) Filters — NCT05615870.
• Registry record last updated 2025-10-02; status last verified 2025-09.
• Results first posted 2025-10-02.
• 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.

23. Record Summary

NCT05615870 is a completed randomized, parallel-group trial of home HEPA filtration units in children younger than 12 months hospitalized with bronchiolitis. The active-filter group used units containing HEPA and carbon filters; the control group used identical-appearing units without those filters. The primary outcome was caregiver-reported symptom-free days over 24 weeks.

The sponsor’s mixed-model analysis estimated a mean difference of 5.41 days, with a 95% confidence interval from -11.77 to 22.60 and p = 0.537. The interval includes zero and values in both directions, so the posted primary result does not establish a clear difference. The registry also reports a quality-of-life comparison whose confidence interval includes zero.

Interpretation is limited by incomplete reporting of the statistical model, missing-data handling, multiplicity, and the trial’s original sample-size assumptions. The results describe the posted analyses and do not establish equivalence, causality for adverse events, or effects beyond the studied population and outcomes.