NHFOV vs. NCPAP as a Primary Treatment to Neonatal Respiratory Distress Syndrome(NRDS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for NHFOV vs. NCPAP as a Primary Treatment to Neonatal Respiratory Distress Syndrome(NRDS) (NCT03099694), a randomized na study. The primary outcome is Number of Participants Who Required Intubation.

2. Clinical Question

The clinical question concerns initial noninvasive respiratory support and whether participants subsequently met criteria for endotracheal mechanical ventilation during the stated primary-outcome period. The record defines intubation criteria that include severe respiratory acidosis, severe apnea and bradycardia, hypoxia, severe respiratory distress, neonatal pulmonary hemorrhage, and cardiopulmonary arrest without effective resuscitation requiring continued ventilation and rescue. These criteria describe several routes to the primary event rather than a single physiological threshold.

The comparison is randomized and parallel, with nCPAP serving as the control group in the posted comparison. The registry reports 150.0 participants in the nCPAP arm and 152.0 in the nHFOV arm for the primary outcome. Those group-specific figures are the denominators attached to the posted result; the record does not explain how they relate to the overall enrollment figure or state whether every randomized participant was included in this endpoint analysis.

The question is about a group-level difference in the occurrence of intubation, not about the experience or likely outcome of any individual infant. The registry record does not report a prespecified clinically important difference, nor does it explain how the intubation criteria were applied or adjudicated across centers.

3. Trial Design

The study is identified as NCT03099694 and is titled “NHFOV vs. NCPAP as a Primary Treatment to Neonatal Respiratory Distress Syndrome (NRDS).” Its official title describes a multicenter randomized controlled trial of noninvasive ventilation for preterm neonates with respiratory distress syndrome. The design is recorded as randomized, parallel-group, and with no masking. The phase is listed as not applicable.

The registry lists an enrollment of 340 and the status as completed. The recorded start date is 2017-04-27, and the primary completion date is 2018-07-28. The sponsor is Xingwang Zhu. These registry entries describe the study record; they do not establish when every outcome was collected or whether all enrolled participants contributed to every analysis.

One group received nHFOV as primary noninvasive support, and the comparator group received nCPAP as primary noninvasive support. The primary outcome was the number of participants requiring intubation during the first 7 days after birth. The registry also lists secondary outcomes relating to neonatal complications, infant development, and duration of noninvasive ventilation. Numerical details are available for several of those outcomes, but the record does not give a complete statistical analysis plan for them.

No masking was recorded, so the study should be understood as an unmasked comparison. The record does not describe the randomization sequence, allocation concealment, stratification, center-level procedures, or steps taken to limit bias in outcome assessment. It also does not state the original sample-size rationale or the planned primary analysis population. Those omissions limit what can be concluded about the design beyond the features explicitly recorded.

The reported primary outcome denominators are 150.0 for nCPAP and 152.0 for nHFOV. The registry does not explain the difference between these denominators and the enrollment of 340. It is therefore safest to interpret the result using the group-specific denominators attached to the endpoint, without assuming how enrollment, follow-up, exclusions, or missing observations produced them.

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: 1045 Did not undergo randomization * 663 Refused to participate * 382 NHFOV devices not available

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Who Required Intubation, measured over during the first 7 days after birth.

The primary endpoint is the number of participants who required intubation during the first 7 days after birth. It is a binary participant-level outcome: each participant either met the recorded criteria for intubation during the period or did not. The registry reports event counts rather than a continuous measure of respiratory status.

The stated criteria for endotracheal mechanical ventilation include severe respiratory acidosis (PaCO2 > 60 mmHg with pH < 7.20), severe apnea and bradycardia, hypoxia (FiO2 > 0.5 with PaO2 < 50mmHg), severe respiratory distress, neonatal pulmonary hemorrhage, and cardiopulmonary arrest without effective resuscitation needing continued ventilation and rescue. The record describes recurrent apnea with > 3 episodes per hour associated with heart rate < 100/min, or a single episode requiring bag and mask ventilation, within its apnea and bradycardia criteria.

As a general statistical point, a binary endpoint can make the main comparison easy to interpret as the difference in the proportion experiencing an event. The endpoint is relevant to the trial question because it captures escalation from initial noninvasive support to endotracheal ventilation. It is not a complete measure of respiratory course, duration of support, or longer-term infant health. The registry does not report how clinicians determined that the criteria had been met, whether decisions were independently reviewed, or whether the criteria were applied identically across centers.

7. Results Posted in the Registry

• nHFOV: 9.9% (15/152) versus 17.3% (26/150) on control; risk difference -7.5 percentage points (95% CI -15.2 to 0.2), risk ratio 0.57 (0.31–1.03); unadjusted two-proportion z-test p = 0.058.

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.

the Incidence of Intraventricular Hemorrhage (IVH, ≥ Grade Ⅲ)

• 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:
  • nHFOV: 2.6% (4/152) versus 1.3% (2/150) on control; risk difference 1.3 percentage points (95% CI -1.8 to 4.4), risk ratio 1.97 (0.37–10.61); unadjusted two-proportion z-test p = 0.419.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between nHFOV and the control. The interval gives the range of effects that remain compatible with the data.

the Incidence of Pneumothorax

• 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:
  • nHFOV: 2.0% (3/152) versus 0.7% (1/150) on control; risk difference 1.3 percentage points (95% CI -1.3 to 3.9), risk ratio 2.96 (0.31–28.14); unadjusted two-proportion z-test p = 0.321.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between nHFOV and the control. The interval gives the range of effects that remain compatible with the data.

the Incidence of Neonatal Necrotizing Enterocolitis(>Stage II)

• 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:
  • nHFOV: 7.2% (11/152) versus 4.7% (7/150) on control; risk difference 2.6 percentage points (95% CI -2.8 to 7.9), risk ratio 1.55 (0.62–3.89); unadjusted two-proportion z-test p = 0.346.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between nHFOV and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary outcomes spanning severe intraventricular hemorrhage, pneumothorax, neonatal necrotizing enterocolitis, retinopathy of prematurity, developmental scores, bronchopulmonary dysplasia, abdominal distention, and time on noninvasive ventilation. The record indicates 12 posted secondary outcomes, while the available numerical comparisons in the record are limited to selected endpoints. Across the numerical secondary comparisons, event counts are small and the unadjusted confidence intervals include no difference. These outcomes do not provide a clear, precise pattern that resolves the uncertainty in the primary intubation comparison.

Secondary outcomes can complement the primary endpoint by describing other aspects of neonatal course and potential complications. They are not interchangeable with intubation: different outcomes measure different events, may use different observation periods, and may have different levels of clinical judgment or measurement precision. The registry lists, for example, a first-two-months timeframe for severe intraventricular hemorrhage and a period during non-invasive ventilation, up to 7 days, for some other outcomes. Results across distinct timeframes should not be treated as if they came from one common endpoint.

In general, unadjusted secondary results carry less weight when many outcomes are considered because multiple testing can produce apparently notable results by chance. The registry record does not describe a multiplicity strategy, a hierarchy among secondary endpoints, or confirmatory status for these analyses. It also does not report sponsor analyses for the secondary outcomes. Accordingly, their posted unadjusted comparisons are best viewed as descriptive or exploratory rather than as independent proof of a treatment difference.

The secondary record does not materially settle the primary question. It may point to outcomes worth examining in a complete trial report, but the registry alone does not provide the analytic detail needed to assess prespecification, missingness, or consistency across all planned measures. Counts and confidence intervals should be considered alongside those limitations rather than interpreted in isolation.

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

• the Incidence of Intraventricular Hemorrhage (IVH, ≥ Grade Ⅲ)
• the Incidence of Pneumothorax
• the Incidence of Neonatal Necrotizing Enterocolitis(>Stage II)
• the Incidence of Retinopathy of Prematurity (>Stage II)
• The Score of Bayley Scales of Infant Development
• the Incidence of Bronchopulmonary Dysplasia(BPD)
• the Incidence of Abdominal Distention
• The Time of Non-invasive Ventilation

9. Statistical Interpretation

10. Statistical Methods Explained

What does the risk difference express?

The primary comparison is expressed as a risk difference for nHFOV compared with nCPAP. In general, a risk difference subtracts the event proportion in the comparator group from the event proportion in the group being compared. A value below zero therefore indicates a lower observed event proportion in the first-named group. The posted estimate is -0.075. This is an absolute contrast, not a relative measure such as a risk ratio. The registry does not report a sponsor-conducted analysis for the endpoint; the posted comparison is a recalculation from the arm-level counts.

Because the endpoint records whether each participant required intubation during a defined period, it is treated as binary. The estimate uses each arm’s event count and endpoint denominator. It is not an estimate of time until intubation, nor does it account for how long any participant remained on noninvasive support. The registry lists time on noninvasive ventilation as a secondary outcome, but a distinct time-to-event analysis for the primary endpoint is not reported.

How should the confidence interval be understood?

In general, a confidence interval describes the statistical uncertainty around an estimate under the assumptions of the calculation. It gives a range of values compatible with the observed data and the chosen method; it is not a range containing a fixed proportion of individual participant outcomes. The interval for the primary risk difference runs from -0.152 to 0.002. Since zero is within that interval, the estimate is compatible with no difference as well as with differences in either direction close to its limits.

The interval does not account for every possible source of uncertainty. For example, it cannot correct for incomplete outcome reporting, deviations from randomization, or outcome classification problems if those occurred. The record does not describe those issues sufficiently to determine whether they affected the comparison. The interval should consequently be read as uncertainty conditional on the posted counts and the recalculation, not as a guarantee that all design and measurement uncertainties are captured.

What does the p-value add?

In general, a p-value measures how unusual data at least as incompatible with a specified null model would be if that model and the analysis assumptions held. It is not the chance that the treatment groups are truly equal, and it is not a measure of clinical importance. The primary unadjusted p-value is 0.058. The registry’s planning illustration specifies a two-sided significance level of 0.05, but the original trial’s own analysis threshold and inferential plan are not reported in the registry record. The p-value should therefore be described as a posted unadjusted result rather than as confirmation of the trial’s planned decision rule.

Why does the primary endpoint use counts?

The outcome is reported as participants with an event, rather than as a mean or a rate per unit of follow-up. This is appropriate to the endpoint as recorded: whether a participant met intubation criteria during the first 7 days after birth. A general advantage of a binary outcome is that the group contrast can be expressed directly in terms of event occurrence. A limitation is that this format does not convey the timing of an event within the period or the number of repeated events. No recurrent-event or timing analysis is reported for this endpoint.

For binary outcomes, small event counts can make estimates imprecise, especially for relative measures. In general, a risk ratio or odds ratio can vary substantially when there are few events, even when the absolute difference is more directly interpretable. The posted primary result includes a risk difference; no adjustment for covariates is reported. The secondary outcome recalculations also include relative measures, but the record lists no reported analyses for those secondary results.

What is not established by the registry analysis record?

The record reports zero analyses in its analysis count and contains no reported analyses for the listed secondary outcomes. It does not describe a prespecified model, covariate adjustment, handling of multiple centers, missing-data procedures, or the analysis population. It is not possible to infer an intention-to-treat, per-protocol, or modified intention-to-treat analysis from the group denominators alone. The primary comparison is best read as an unadjusted recalculation using the counts and denominators posted for the endpoint.

General statistical interpretation also depends on the design and measurement process. Randomization can help balance prognostic factors across groups, but the sequence-generation and concealment methods are not reported. No masking is recorded. Because the primary outcome depends in part on clinical criteria, knowledge of the assigned support method could be relevant to assessment; the registry does not state whether independent adjudication was used. These limitations do not change the arithmetic of the posted comparison, but they constrain conclusions about how fully it represents a causal effect.

The secondary endpoint comparisons are also unadjusted recalculations. When many outcomes are examined, the chance of at least one apparently unusual result can increase. General methods for addressing multiplicity include prespecifying a primary outcome, controlling an error rate, or treating secondary analyses as exploratory. The registry record does not report which, if any, strategy was planned. Thus, secondary p-values should not be treated as definitive independent tests of treatment differences.

11. Confidence Intervals and Precision

The primary risk-difference estimate is -0.075, and its 95% confidence interval extends from -0.152 to 0.002. The interval includes zero, so the posted data do not distinguish clearly between a lower event proportion with nHFOV, no difference, and a small difference in the opposite direction. Its width also indicates that the magnitude is not estimated with high precision. The uncertainty is important: the point estimate alone would give an incomplete account of the result.

In general, confidence intervals combine the observed estimate with sampling uncertainty under a statistical method. A narrower interval indicates greater precision under that method, while a wider interval leaves more plausible values. This does not mean that every value within the interval is equally likely, nor does it incorporate uncertainty from unreported design choices, missing outcomes, or differences in outcome assessment. Those concerns remain separate from the interval calculation.

The primary arm counts are 26.0 of 150.0 for nCPAP and 15.0 of 152.0 for nHFOV. These counts and denominators are the basis of the posted unadjusted recalculation. The registry does not report confidence intervals from a sponsor analysis, and the recalculation should not be mistaken for an adjusted model. No subgroup confidence intervals or center-specific estimates are reported.

The planning illustrations are distinct from the observed confidence interval. They describe participant requirements under stated hypothetical assumptions and selected effect sizes, not the precision actually achieved by the trial or the probability that its findings are correct. Those planning assumptions are discussed separately. In particular, the registry’s original design assumptions are not reported in the registry record, so the planning illustration cannot be used to establish whether the completed trial met its intended precision target.

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 estimates use the observed effect as a starting point and show the participants per arm for 80% power and for 90% power under the stated assumptions. For the primary endpoint, planning for 100% of the observed effect gives 330 participants per arm for 80% power and 442 participants per arm for 90% power. Planning for 75% of the observed effect gives 621 participants per arm for 80% power and 831 participants per arm for 90% power. Planning for 50% of the observed effect gives 1,473 participants per arm for 80% power and 1,971 participants per arm for 90% power.

These are planning illustrations, not a report of the trial’s original design calculation. The assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set to the stated fraction of the observed effect. The original trial’s own sample-size assumptions and justification are not reported in the registry record. The estimates for these binary outcomes are participants per arm; the separate rule for time-to-event outcomes, which uses total events, does not apply to this primary binary endpoint.

In plain language, the 80% power column gives the modeled number of participants per arm for a design with an 80% chance of detecting the assumed effect if that effect is real and the assumptions hold. The 90% power column uses a higher detection probability and therefore calls for more participants under the same setup. Smaller assumed effects require more participants because they are harder to distinguish from random variation. The estimates are not observed power; they do not measure the probability that this completed trial detected an effect, and they do not replace interpretation of the observed estimate and confidence interval.

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 = 0.173; treatment proportion p₁ = 0.099; average p̄ = 0.136.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.4848 = 0.9502.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4819 = 0.4056.
4. n = (0.9502 + 0.4056)² / (-0.0746)² = 329.8, rounded up to 330 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 <- 0.173333333333333                          # control proportion
p1 <- 0.0986842105263158                          # 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(3099694)
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 = 330 (80% power), 442 (90% power)
 75% of observed effect: n per arm = 621 (80% power), 831 (90% power)
 50% of observed effect: n per arm = 1,473 (80% power), 1,971 (90% power)
power.prop.test: 329.8 
Simulated power at n = 330 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

The registry record does not report a multiplicity plan. It does not state whether investigators adjusted significance levels for testing multiple secondary outcomes, used a hierarchical testing sequence, or treated those analyses as exploratory. This matters because each additional statistical test creates another opportunity for a chance finding. General statistical practice distinguishes a primary endpoint, which anchors the main inference, from secondary endpoints, whose results may be less conclusive when many are examined. The record does not provide enough detail to determine how that distinction was handled in the original analysis.

Missing-data procedures are also not reported. The primary endpoint lists 150.0 participants for nCPAP and 152.0 for nHFOV, while overall enrollment is recorded as 340. The registry does not explain the relationship between these figures, describe any exclusions or missing outcomes, or state whether participants were analyzed according to randomized assignment. No missingness assumptions, imputation methods, or sensitivity analyses are reported. Consequently, it is not possible to determine from this record whether the endpoint counts represent a complete intention-to-treat analysis.

The analysis population is not specified, and the registry records zero analyses. No per-protocol or other analysis population is described. The primary comparison is therefore interpreted as an unadjusted recalculation from the posted group counts, not as a confirmed reconstruction of the trial’s prespecified analysis. No adjusted analysis, center adjustment, or subgroup analysis is reported.

These absences do not prove that multiplicity or missing-data methods were not used in a full study report; they mean only that they are not reported in the registry record. Without those details, p-values from the secondary comparisons deserve particular caution, and the population represented by the endpoint denominators remains uncertain. A complete protocol or analysis report would be needed to evaluate those aspects.

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 adverse-event record lists zero serious adverse events among 152 participants at risk in the nHFOV group and zero among 150 participants at risk in the nCPAP group. It also lists zero other adverse events in each group, with the same group-specific numbers at risk. No serious adverse-event terms are listed. The record separately reports 6 deaths in the nHFOV group and 4 deaths in the nCPAP group.

These entries should be read as registry counts, not as a complete safety comparison. The record does not provide event definitions, attribution, timing, severity details beyond the serious/other categories, or an explanation of how the death counts relate to adverse-event reporting. In particular, deaths should not be assumed to have been caused by an intervention or included in the adverse-event categories without further information. The registry also does not provide comparative safety analyses or confidence intervals. The counts alone cannot establish whether the groups differed in safety.

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

The posted primary result shows fewer observed intubations in the nHFOV group than in the nCPAP group, using the endpoint-specific counts and denominators. The recalculated risk difference is -0.075. Its 95% confidence interval runs from -0.152 to 0.002, and the unadjusted p-value is 0.058. Together, these statistics describe an observed contrast that points toward a lower event proportion with nHFOV, but remains compatible with no difference and with a small difference in the opposite direction.

This result does not establish that either respiratory-support strategy is superior, nor does it show that one strategy has no effect. Statistical uncertainty is substantial, and the registry does not report the original analysis plan, missing-data strategy, or analysis population. The absence of masking and the clinical elements in the intubation criteria also matter when considering the measurement process. These limitations are not resolved by the numerical estimate.

The primary outcome is limited to intubation during the first 7 days after birth. It does not, by itself, describe the duration or intensity of respiratory support, later complications, developmental outcomes, or the overall balance of outcomes. Secondary endpoints offer additional domains, but the available record does not report a multiplicity plan or sponsor analyses for them. Their unadjusted comparisons should therefore not be treated as definitive confirmation or refutation of the primary result.

In general, a trial estimate is most useful when read with its uncertainty, outcome definition, design, and analysis population. Here, the estimate is an unadjusted recalculation from the posted summary counts. The confidence interval reflects uncertainty conditional on that calculation, not every uncertainty about conduct and reporting. The registry record is consequently informative about the observed counts and their statistical imprecision, but it does not support a broad conclusion about clinical effectiveness or safety.

The right interpretation is neither to treat the point estimate as a settled benefit nor to regard a p-value above a conventional threshold as proof of equivalence. The data are inconclusive about the size and direction of the underlying group difference. Further conclusions would require fuller reporting of the trial methods, outcome completeness, and prespecified analyses.

17. Why This Trial Matters Statistically

This trial is statistically informative because it places a clinically concrete event—escalation to intubation—at the center of a randomized comparison of two noninvasive support strategies. The endpoint is defined over the first 7 days after birth, and the registry specifies clinical criteria that can lead to the event. Reporting group counts alongside an absolute risk-difference estimate makes the observed comparison interpretable without relying only on a relative measure.

The result also illustrates why an estimate should not be reduced to a threshold decision. The point estimate is negative, but the confidence interval includes zero and reaches a small positive value. The unadjusted p-value is 0.058. Looking at all three elements makes clear that the observed data favor one direction numerically while leaving substantial uncertainty about the true contrast. That is a more informative account than a binary label of statistical significance or nonsignificance.

The record further highlights the distinction between a trial’s original design calculation and a later planning illustration based on the observed effect. The displayed planning assumptions describe hypothetical participant requirements for specified effect sizes; they are not the documented rationale for enrollment. The registry does not report that rationale. This distinction matters whenever planning figures are used to discuss whether a study could reliably detect an effect.

Finally, the record shows why outcome definitions, analysis populations, and multiplicity plans are integral to interpretation. No masking is recorded, the endpoint includes clinical decision criteria, and details of missing data and analysis methods are absent. Those features do not invalidate the posted counts, but they limit the strength of conclusions drawn from them. A careful statistical reading preserves both what the record establishes—the observed counts and recalculated comparison—and what it leaves unresolved.

18. Limitations

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

Several limitations specific to this record affect interpretation. The study is recorded as having no masking, and the primary event depends partly on clinical criteria such as severe respiratory distress. The registry does not report whether outcome assessors were independent, whether the criteria were applied uniformly across centers, or whether intubation decisions were adjudicated. Because this is a multicenter trial, details of center-level practice and any adjustment for center are relevant but not reported.

The record lists overall enrollment of 340, whereas the primary endpoint denominators are 150.0 for nCPAP and 152.0 for nHFOV. It does not explain this relationship, identify exclusions, or report missing outcomes. The analysis population and intention-to-treat status are therefore unknown. The registry also provides no sponsor-reported analysis for the primary comparison; the posted estimate is an unadjusted recalculation from the summary counts.

Important design and analysis details are not reported in the registry record, including the randomization sequence, allocation concealment, sample-size justification, prespecified statistical model, adjustment plan, and handling of missing data. Multiplicity methods for the secondary outcomes are not described. These omissions make it difficult to assess the extent to which the posted comparisons correspond to a prespecified analysis.

The primary endpoint covers only the first 7 days after birth. Secondary outcomes have different stated timeframes, and the registry does not supply numerical detail for every listed secondary outcome in the comparisons. Safety reporting gives counts but not event definitions, attribution, or timing. These constraints mean that the registry record alone cannot support a comprehensive assessment of longer-term outcomes or overall safety.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: NHFOV vs. NCPAP as a Primary Treatment to Neonatal Respiratory Distress Syndrome(NRDS) — NCT03099694.
• Registry record last updated 2021-03-02; status last verified 2021-02.
• Results first posted 2019-06-10.
• 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

NCT03099694 is a completed, multicenter, randomized, parallel-group trial comparing nHFOV with nCPAP as primary noninvasive respiratory support for preterm infants with respiratory distress syndrome. The record lists no masking and an enrollment of 340. The primary endpoint is the number of participants requiring intubation during the first 7 days after birth.

The posted counts are 26.0 of 150.0 for nCPAP and 15.0 of 152.0 for nHFOV. The recalculated risk difference for nHFOV compared with nCPAP is -0.075, with a 95% confidence interval from -0.152 to 0.002 and an unadjusted p-value of 0.058. The interval includes no difference, leaving the magnitude and direction uncertain.

The registry does not report the original sample-size rationale, analysis population, missing-data methods, multiplicity plan, or a sponsor analysis of the primary outcome. Secondary and safety counts provide additional context but do not remove those limitations. The record supports a description of the posted observations, not a definitive conclusion about comparative clinical effects.