Comparative Effectiveness Study of Bubble CPAP Devices in the NICU: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparative Effectiveness Study of Bubble CPAP Devices in the NICU (NCT02392806), a randomized na study. The primary outcome is Number of Participants With Extubation Failure.

2. Clinical Question

The question is about outcomes following initial assignment to one of the devices, with a planned device change for infants who remained extubated. That timing matters: the primary endpoint covers the first 72 hours after extubation, while the planned crossover was after 72 hours and conditional on remaining extubated. The registry record does not report whether every participant completed the planned device sequence or how any deviations were handled.

The result is a comparison of observed event counts in the two randomized groups. It should not be read as a direct estimate of every aspect of device performance: the primary outcome is a defined failure event over a specified period, while the secondary outcome concerns oxygenation measurement. The record does not report a broader clinical endpoint or a detailed protocol for interpreting oxygenation.

3. Trial Design

This was a completed, randomized study with no masking and a crossover model. The registry record gives enrollment as 43 and lists the study start as 2015-01 and primary completion as 2016-08. The condition listed is respiratory distress syndrome. The trial phase is listed as NA, which is consistent with the record identifying device interventions rather than a drug phase.

Participants were randomized to begin bubble CPAP on either the BabiPlus device or the B&B Bubbler. The arm descriptions specify an intended crossover after 72 hours for infants who remained extubated, followed by 24 hours on the other device. The sequence therefore depended on the initial random assignment, and the crossover was conditional on remaining extubated. The registry record does not report how many participants actually crossed over, whether all planned periods were completed, or how data from the two periods were incorporated into the primary analysis.

The primary outcome was the number of participants with extubation failure within 72 hours. The posted group counts are 9 of 22 for BabiPlus and 7 of 21 for B&B Bubbler. These group summaries describe participants by their initial assignment; they do not by themselves explain the handling of crossover or other protocol details.

The registry lists a two-sided t-test for the reported primary analysis, with a result of >0.05. It does not report a test statistic, an exact p-value, a confidence interval for that analysis, or a more detailed statistical plan. The sample-size assumptions used for the original trial design are not reported in the registry record. The planning illustrations discussed separately are not the trial's original design justification.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Extubation Failure, measured over Within 72 hours of extubation.

The primary endpoint counts participants with Bubble CPAP failure within 72 hours after extubation. The registry definition includes either re-intubation or use of non-invasive positive pressure ventilation during that period. The posted result is a count of participants meeting this definition in each randomized group, rather than a continuous measurement such as oxygen saturation.

This endpoint is used to represent an early failure of the non-invasive respiratory support strategy after extubation. Counting participants with an event gives a clinically interpretable summary of how many in each group experienced the specified event, while fixing the observation window makes the comparison specific to the first 72 hours. The endpoint does not capture all possible outcomes after that interval, nor does it measure oxygenation directly.

The registry lists 9 of 22 participants with failure in the BabiPlus group and 7 of 21 in the B&B Bubbler group. The record does not report separate counts for the two components of the endpoint, so it is not possible from these summaries to distinguish failures involving re-intubation from those involving non-invasive positive pressure ventilation. It also does not report details about adjudication or handling of missing outcome data.

The endpoint is binary at the participant level: each participant either met the failure definition within the stated time frame or did not. This supports comparison of event proportions between groups, but the number of events and the resulting uncertainty are important when interpreting the estimate.

7. Results Posted in the Registry

• Bubble CPAP - B&B Bubbler, B&B Medical Technologies: 33.3% (7/21) versus 40.9% (9/22) on control; risk difference -7.6 percentage points (95% CI -36.4 to 21.2), risk ratio 0.81 (0.37–1.79); unadjusted two-proportion z-test p = 0.607.

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.

Oxygenation - Oxygen Saturation Via Pulse Oximetry Recorded Hourly

• 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:
  • Bubble CPAP - B&B Bubbler, B&B Medical Technologies: 23.8% (5/21) versus 22.7% (5/22) on control; risk difference 1.1 percentage points (95% CI -24.2 to 26.4), risk ratio 1.05 (0.35–3.10); unadjusted two-proportion z-test p = 0.933.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Bubble CPAP - B&B Bubbler, B&B Medical Technologies and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists one secondary outcome, described as oxygenation measured through hourly pulse oximetry and assessed over 96 hours. The posted summaries report 5 participants in each group for this outcome. The unadjusted recalculation gives a risk difference of 0.011, with a 95% confidence interval from -0.242 to 0.264 and p = 0.933. This estimate is also imprecise and does not establish a clear group difference.

Across the primary and secondary outcomes, the posted data do not show a precise separation between the groups. That broad pattern is consistent with the uncertainty in the primary comparison, but it does not make the outcomes equivalent or confirm that the devices have the same effects. The secondary outcome has its own definition and timeframe, and it should not be treated as a substitute for the primary failure endpoint.

General statistical explanation: Secondary outcomes are often used to describe other dimensions of a study, but testing multiple outcomes increases the chance of finding an apparently notable result by chance if each is considered independently. Adjustments or a prespecified hierarchy can address some multiplicity concerns. The registry record does not report a multiplicity plan, adjustment, or inferential analysis for the secondary outcome. Its recalculated p-value is unadjusted, so it should carry less weight than a clearly prespecified primary analysis, particularly when the analysis plan is not available.

The record also does not report additional details about how the hourly oxygen saturation measurements were summarized or converted to the posted participant count. The outcome label and summary alone are not sufficient to reconstruct the analysis or its clinical interpretation. The secondary result is best treated as descriptive supporting information, with uncertainty and reporting limitations kept in view.

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

• Oxygenation - Oxygen Saturation Via Pulse Oximetry Recorded Hourly

9. Statistical Interpretation

10. Statistical Methods Explained

What does a risk difference describe?

General statistical explanation: A risk difference compares the proportion of participants with an event in one group with the proportion in another. Zero corresponds to equal observed proportions; a negative or positive estimate indicates the direction of the comparison according to the chosen group order. Here, the reported comparison is B&B Bubbler relative to BabiPlus, and the recalculated risk difference is -0.076. The estimate is based on the posted counts, not on participant-level data.

The risk difference is a direct measure on the event-proportion scale. It does not adjust for other variables or account for information not present in the group counts. The registry record does not report an adjusted estimate for the primary outcome.

What does the confidence interval add?

General statistical explanation: A confidence interval describes the uncertainty around an estimate under the statistical method used. It gives a range of values compatible with the data and method; it is not a guarantee that the true value lies in the interval, nor does it assign a probability to a particular value after the data have been observed. The recalculated 95% confidence interval for the risk difference runs from -0.364 to 0.212. Since it includes zero and values on both sides of zero, it does not pin down the direction of the group difference.

The registry's sponsor-reported analysis does not include a confidence interval in the posted results. The interval above comes from the unadjusted recalculation from group summaries. Its interpretation should therefore remain tied to that simple comparison rather than being attributed to the sponsor's analysis.

How should the p-values be read?

General statistical explanation: A p-value describes how unusual data at least as incompatible with a null hypothesis would be under the assumptions of a specified statistical test. It does not measure the probability that the null hypothesis is true, and it does not quantify clinical importance. The record reports a two-sided t-test with p >0.05. The recalculation from the posted event counts gives p = 0.607. The two results are not identical; the record flags a discrepancy, so the sponsor's own analysis takes precedence.

The registry does not report enough detail to reconstruct the sponsor's test or determine why its reported result differs from the simple recalculation. In particular, it does not provide a test statistic, exact sponsor p-value, or a fuller description of the analysis. The recalculation is not evidence that the sponsor used the same method.

What does the crossover design imply?

General statistical explanation: In a crossover design, participants may receive more than one intervention in a planned sequence. Repeated measurements from the same participant can be related, and analysis may need to account for that within-participant structure when it is relevant to the outcome. For this study, the arm descriptions specify a device change after 72 hours for infants who remained extubated. The primary endpoint is defined within 72 hours after extubation, so the record's timing places that endpoint before the planned crossover for participants following the described sequence. The registry record does not report the analysis details needed to assess how design features were handled.

The primary comparison presented as counts by randomized group is an unadjusted summary. It does not show the individual sequences, whether participants crossed over, or any within-participant comparisons. No conclusion about the sponsor's handling of the crossover should be inferred from the posted counts alone.

Why can sparse event data be uncertain?

General statistical explanation: When the number of participants and events is limited, each event can have a noticeable effect on the estimated group proportions. That can lead to a wide confidence interval and limited precision. The primary result involves 9 events among 22 participants in one arm and 7 among 21 in the other. The wide recalculated interval reflects substantial uncertainty about the size and direction of the difference; it does not establish that the groups are the same.

The primary outcome is binary, so the posted summary is a count of participants with an event. The record does not report a dispersion measure for this endpoint, which is not generally the form of summary used for binary counts. More detailed methods, including any prespecified model or adjustments, are not reported in the registry record.

11. Confidence Intervals and Precision

The recalculated primary risk difference is -0.076, with a 95% confidence interval from -0.364 to 0.212. The interval is wide and includes zero, as well as negative and positive values. Thus, the posted counts do not estimate the difference with enough precision to identify its direction reliably. The estimate is a simple unadjusted recalculation, not the sponsor's reported result.

General statistical explanation: A confidence interval conveys the range of values that remain compatible with the observed data under a specified method. A narrower interval indicates greater precision; a wider interval indicates more uncertainty. Precision is distinct from whether a result passes a significance threshold. An interval that includes zero does not prove equality or equivalence, just as an interval excluding zero would not by itself establish clinical importance.

The size of the groups is relevant to this uncertainty: the posted primary counts are based on 22 participants in the BabiPlus arm and 21 in the B&B Bubbler arm. With this amount of information, the observed event counts leave considerable uncertainty about the underlying difference. The confidence interval should not be interpreted as covering all possible sources of uncertainty, such as missing data or design features that are not represented in the simple recalculation.

The registry's own analysis reports only p >0.05 and does not report a confidence interval. The interval therefore belongs to the unadjusted recalculation from the posted counts. Because the registry flags a discrepancy between the reported and recalculated analyses, the sponsor's analysis takes precedence for interpreting the sponsor-reported result.

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 illustrations express the number of participants needed per arm, not a total across both arms and not a total number of events. They show scenarios using 100%, 75%, and 50% of the observed effect. In each scenario, the columns for 80% and 90% power indicate the participants per arm that a hypothetical study would require to have the stated chance of detecting the chosen effect, under the stated assumptions, if that effect were present.

The stated 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 original trial's own design assumptions and sample-size justification are not reported in the registry record. These calculations are planning illustrations based on the observed effect, not a description of how enrollment of 43 was originally chosen.

For the primary endpoint, the illustrations give 638 participants per arm for 80% power and 853 participants per arm for 90% power when planning for 100% of the observed effect. Planning for 75% gives 1,146 participants per arm for 80% power and 1,533 for 90% power. Planning for 50% gives 2,602 participants per arm for 80% power and 3,483 for 90% power. The pattern reflects a general statistical principle: smaller effects are harder to distinguish from random variation, so they require more participants. The 90% power column requires more participants than the 80% column for the same effect scenario.

These figures are not observed power. They are hypothetical planning requirements calculated under the listed assumptions, using the observed effect as a reference. They do not show that the completed study had the stated power, nor do they establish what effect would be clinically meaningful.

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 = 0.409; treatment proportion p₁ = 0.333; average p̄ = 0.371.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6832 = 1.3391.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6811 = 0.5733.
4. n = (1.3391 + 0.5733)² / (-0.0758)² = 637.2, rounded up to 638 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 <- 0.409090909090909                          # control proportion
p1 <- 0.333333333333333                          # 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(2392806)
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 = 638 (80% power), 853 (90% power)
 75% of observed effect: n per arm = 1,146 (80% power), 1,533 (90% power)
 50% of observed effect: n per arm = 2,602 (80% power), 3,483 (90% power)
power.prop.test: 637.2 
Simulated power at n = 638 per arm: 0.803 (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. Analyses Reported by the Sponsor

The registry reports the sponsor's primary analysis as a two-sided t-test with p >0.05. It does not report an exact p-value, test statistic, confidence interval, or fuller description of the analysis. The posted primary group counts are 9 of 22 for BabiPlus and 7 of 21 for B&B Bubbler.

A simple unadjusted recalculation from those counts gives a risk difference of -0.076, a 95% confidence interval from -0.364 to 0.212, and p = 0.607. The record flags a discrepancy between the sponsor result and the recalculation. Accordingly, the sponsor's own analysis takes precedence when describing the reported trial analysis; the recalculated figures are an additional, unadjusted analysis of the posted summary statistics.

The available information does not establish why the results differ. The registry record does not report whether the sponsor's method incorporated details of the crossover design, participant-level outcomes, or other analysis features that cannot be recovered from group counts. It would be inappropriate to infer a reason for the discrepancy or to treat the recalculation as a correction of the sponsor analysis.

Both entries are compatible with the registry's broad statement that the reported test result is above 0.05, but the p-values are not interchangeable. The recalculation provides an estimate and interval for a simple group comparison; the sponsor's entry is the analysis attributed to the trial record.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary endpoint and one posted secondary outcome. It does not report whether the outcome hierarchy, testing order, or any multiplicity adjustment was prespecified. General statistical explanation: When several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase if all tests are interpreted as though they were the sole test. A prespecified plan or adjustment can help control that issue. Without a reported plan, secondary findings should be treated cautiously rather than as independent confirmation of the primary result.

The record reports no exact sponsor p-value or confidence interval for the primary analysis. It gives a two-sided t-test result of p >0.05 and identifies no test statistic. The registry record does not report the trial's original sample-size justification, detailed statistical analysis plan, interim analyses, or stopping rules. These items cannot be inferred from the planning illustrations or the final posted outcomes.

The registry record also does not report a defined analysis population, such as whether the primary analysis included all randomized participants or only participants with observed outcomes. It does not describe missing-data handling, exclusions after randomization, protocol deviations, or the treatment of incomplete crossover periods. The arm descriptions give the intended sequence but do not establish how closely the sequence was followed or how the crossover affected analysis.

General statistical explanation: Missing outcomes can affect estimates if participants without observed data differ from those with data. Analysis-population definitions also matter because excluding participants after randomization can change the balance created by random assignment. These are general concerns; the registry record does not show whether either issue occurred in this study.

These reporting gaps limit reproducibility and make it difficult to assess whether the sponsor's analysis fully reflects the randomized crossover design. They do not establish that the analysis was flawed; they mean that the relevant details are not reported in the registry record.

16. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists 0 serious adverse events among 22 participants in the BabiPlus group and 0 among 21 participants in the B&B Bubbler group. It also lists 0 other adverse events among 22 and 21 participants, respectively. Death counts are not reported in the registry record.

These figures describe events recorded in the registry for the listed groups. A count of zero means that no events of that category were posted for the relevant participants; it does not establish that an event is impossible or that there is no safety risk. The record does not give further detail about event definitions, collection procedures, follow-up completeness, or how adverse events were attributed to a device.

The absence of posted events should also be interpreted in light of the group sizes. The safety summaries cover 22 participants in one group and 21 in the other. They are not a substitute for a broader assessment of safety, and the registry record does not report additional context that would support such an assessment. No medical advice or conclusion about device safety follows from these counts alone.

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

The posted primary counts show extubation failure in 9 of 22 participants assigned initially to BabiPlus and 7 of 21 assigned initially to B&B Bubbler. The sponsor's reported test is a two-sided t-test with p >0.05. The unadjusted recalculation gives a risk difference of -0.076 with a 95% confidence interval from -0.364 to 0.212, but the registry flags a discrepancy, so the sponsor's analysis takes precedence.

The result does not establish that the devices are equivalent. A finding above a significance threshold is not proof that no difference exists. The confidence interval from the simple recalculation spans values on both sides of zero and is wide, indicating that the posted group counts do not tightly determine the direction or magnitude of the difference.

Nor does the result establish that one device is better or worse. The observed point estimate favors a lower event proportion in the B&B group in this particular comparison, but the uncertainty is substantial, and the sponsor's analysis is reported separately. The registry record does not provide enough detail to resolve the discrepancy or reconstruct the sponsor's methods.

The endpoint concerns a specific event definition and time window: re-intubation or use of non-invasive positive pressure ventilation within 72 hours following extubation. It does not summarize all clinical outcomes, all follow-up, or the oxygenation measurements. The secondary oxygenation outcome is also uncertain and should not be interpreted as definitive confirmation of the primary comparison.

Overall, the posted results describe a small randomized comparison with limited precision and incomplete reporting of analysis details. They do not support a confident conclusion about the presence, absence, or clinical importance of a difference. The statistical findings alone should not be used as medical advice or as a treatment recommendation.

18. Why This Trial Matters Statistically

This study illustrates why a count comparison should be read together with its uncertainty. The primary outcome is easy to state as participant counts, but the estimate based on 9 events in one group and 7 in the other has a wide recalculated confidence interval. The point estimate alone would not convey how uncertain the direction and size of the comparison remain.

It also illustrates the distinction between a sponsor-reported test and an unadjusted recalculation from summary counts. The registry reports a two-sided t-test with p >0.05, while the recalculation yields p = 0.607 and a risk-difference interval. Because the record flags a discrepancy, the sponsor's own analysis takes precedence. Reporting both transparently makes clear what comes from the registry and what comes from a simple recalculation, without pretending that one reconstructs the other.

The crossover design makes reporting of analysis details especially relevant. The arm descriptions specify a conditional device change after 72 hours, while the primary endpoint covers the first 72 hours after extubation. The registry record does not report whether all participants followed the intended sequence or how the sponsor handled crossover and analysis populations. Clear methods reporting is needed to assess the relationship between randomization, outcome timing, and analysis.

Finally, the sample-size illustrations show how planning requirements depend on the effect selected for detection. Smaller effects call for more participants under the stated assumptions. Those illustrations are not the trial's original design rationale and are not observed power. Together, the uncertainty, discrepancy, and reporting gaps demonstrate why statistical interpretation depends on both numerical results and transparent methods.

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 primary comparison rests on 43 enrolled participants, with 22 in the BabiPlus group and 21 in the B&B Bubbler group. The recalculated confidence interval is wide, so the posted counts provide limited precision. The registry's own result is reported only as p >0.05, without an exact p-value, test statistic, or confidence interval.

The record flags a discrepancy between the sponsor's analysis and the simple recalculation from posted counts. It does not give enough information to explain the discrepancy. Consequently, the recalculation should not be treated as a reconstruction of the sponsor's method. The sponsor's reported analysis takes precedence.

The study is described as a randomized crossover, with a planned switch after 72 hours for infants who remained extubated. The registry record does not report completion of crossover, deviations from the intended sequence, or how the crossover structure was handled in analysis. It also does not report the analysis population, missing-data methods, or post-randomization exclusions.

The primary outcome is a combined definition of re-intubation or use of non-invasive positive pressure ventilation, and separate component counts are not reported. The secondary oxygenation summary is described as hourly pulse oximetry over 96 hours, but details of its summary method are not reported. A multiplicity plan and the original sample-size justification are also not reported in the registry record.

These limitations concern precision and the ability to evaluate or reproduce the analysis. They do not demonstrate that unreported methods were absent or that a particular bias occurred. They restrict the conclusions that can be drawn from the posted results.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Comparative Effectiveness Study of Bubble CPAP Devices in the NICU — NCT02392806.
• Registry record last updated 2018-03-09; status last verified 2018-02.
• Results first posted 2017-12-26.
• 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

NCT02392806 is a completed randomized, unmasked crossover study comparing BabiPlus and B&B Bubbler bubble CPAP devices in the NICU. The record lists enrollment of 43 and identifies respiratory distress syndrome as the condition.

The primary endpoint was the number of participants with Bubble CPAP failure within 72 hours after extubation, defined as re-intubation or use of non-invasive positive pressure ventilation. The posted counts were 9 of 22 for BabiPlus and 7 of 21 for B&B Bubbler. The sponsor reports a two-sided t-test with p >0.05. A simple unadjusted recalculation gives a risk difference of -0.076, with a 95% confidence interval from -0.364 to 0.212 and p = 0.607; the record flags a discrepancy, so the sponsor's analysis takes precedence.

The registry also lists an oxygenation outcome and no posted serious or other adverse events in either group. Details of the original sample-size rationale, missing-data handling, analysis population, multiplicity plan, and crossover analysis are not reported in the registry record.