This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Comparison of ProSeal Laryngeal Mask Airway to Laryngeal Mask Airway Supreme (NCT00836095), a randomized phase 4 study. The primary outcome is Insertion Time.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00836095 |
| Phase | Phase 4 |
| Condition | Adverse Effect of Unspecified General Anesthetics |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 52 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Milton S. Hershey Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes mechanically ventilated patients undergoing general anesthesia. The brief summary places the airway devices in the setting of routine anesthesia and airway management during surgery. More detailed eligibility criteria and a fuller description of the enrolled population are not reported in the registry record, so the range of patients to whom these results apply cannot be determined from the record alone.
Intervention
The intervention was the Supreme laryngeal mask airway, described as a newer, single-use variant. Device choice was randomized by opening a sealed envelope immediately before induction. The arm description says an experienced attending anesthesiologist would insert the airway blindly. The registry does not report further procedural details, such as how insertion attempts were handled in the primary outcome analysis.
Comparator
The comparator was the Proseal laryngeal mask airway, described as a multiple-use variant. It was assigned through the same envelope-based randomization process. Both devices are described in the registry as variants of the laryngeal mask airway and as used to assure the airway during general anesthesia. The record does not provide a more detailed account of how device handling or the insertion procedure was standardized between arms.
Primary question
The primary question was whether insertion time differed between the Supreme and Proseal devices. Insertion time was defined as the time taken by the anesthesiologist to insert the airway and verify ventilation. The posted mean was 26.0 seconds for Supreme and 18.0 seconds for Proseal. The reported mean difference, comparing Proseal with Supreme, was -8.0 seconds, with a confidence interval from -12.75 to -3.248 and p < 0.001. These results describe the trial’s posted measure; they do not by themselves establish broader device performance or patient benefit.
3. Trial Design
The registry identifies NCT00836095 as a completed, randomized, parallel-group Phase 4 trial sponsored by Milton S. Hershey Medical Center. Enrollment was 52. The listed study period began in 2009-01, and primary completion was in 2013-01. The registry lists masking as none. The study compared the Supreme laryngeal mask airway with the Proseal laryngeal mask airway in mechanically ventilated patients, with device choice randomized before induction.
The arm descriptions state that assignment was determined by opening a sealed envelope immediately before induction. They also describe the airway as being blindly inserted by an experienced attending anesthesiologist. That description appears alongside the registry’s overall masking classification of none; the record does not explain the relationship between these statements or identify which parties, if any, were masked to allocation during measurement or analysis.
The primary outcome was insertion time, a continuous measure reported as a mean and standard deviation in seconds. Its timeframe was during intubation of the patient. The record also lists insertion success rate as a secondary outcome, but numerical results for that outcome are not reported in the registry record. Although enrollment was 52, the primary outcome arm counts are 22 for Supreme and 27 for Proseal. The record does not explain the difference between the overall enrollment and those outcome counts, so it is not possible to determine from the record why the counts differ or what happened to participants without posted primary outcome values.
The registry includes group summaries and an estimated mean difference for insertion time. It does not report a detailed statistical analysis plan, allocation concealment procedures beyond the sealed-envelope description, or a fuller account of how the trial handled deviations from the assigned device. These omissions limit reconstruction of the study conduct and analysis beyond the information in the record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Supreme LMA | Proseal LMA |
|---|---|---|
| STARTED | 22 | 30 |
| COMPLETED | 22 | 27 |
| NOT COMPLETED | 0 | 3 |
Reasons for not completing this period:
| Reason | Supreme LMA | Proseal LMA |
|---|---|---|
| Physician Decision | 0 | 3 |
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.
| Characteristic | Unit | Supreme LMA | Proseal LMA | Total |
|---|---|---|---|---|
| Participants analysed | 22 | 30 | 52 | |
| Age, Continuous | years | 49 (SD 14) | 41 (SD 14) | 45 (SD 14) |
| Sex: Female, Male: Female | Participants | 14 | 18 | 32 |
| Sex: Female, Male: Male | Participants | 8 | 12 | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Insertion Time, measured over During intubation of the patient.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | seconds |
| Endpoint classification | Continuous Endpoint |
The primary endpoint, insertion time, measures the time taken by the anesthesiologist to insert the airway and verify ventilation. It is reported in seconds, with a mean and standard deviation for each device group. This is a continuous process measure: each observation is a duration, and the group summaries describe the average duration and the spread of individual times.
Insertion time was selected to address one stated aim of the study: whether the newer Supreme device is easier to insert than the Proseal device. A time measure captures the duration of the insertion-and-verification process, but it does not on its own cover every aspect of ease or quality. The registry separately identifies insertion success rate as a secondary outcome, which reflects a different question from how long insertion takes. Numerical results for that secondary outcome are not reported in the registry record.
The endpoint’s definition matters when interpreting the numerical difference. The measured interval includes both inserting the airway and verifying ventilation, rather than insertion alone. The record does not report the precise timing procedure, the equipment used to measure time, or whether repeated insertion attempts were included in a particular way. Those details could affect how consistently the duration was measured across participants. The endpoint should therefore be read as the registry-defined time for insertion plus ventilation verification, not as a general measure of all device characteristics or clinical outcomes.
7. Results Posted in the Registry
- Proseal LMA: mean 18.00 versus 26.00 on control; difference -8.00 (95% CI -12.75 to -3.25), standardized effect d = -1.00; z-test p = <0.001.
Mean difference: Proseal LMA
95% CI: -12.75 to -3.25
Recalculated from the posted summary statistics
8. Statistical Interpretation
The posted primary outcome results report a mean insertion time of 26.0 seconds for Supreme and 18.0 seconds for Proseal. The reported mean difference is -8.0 seconds for Proseal relative to Supreme. Because the difference is expressed in that direction, its negative sign indicates a shorter reported mean time in the Proseal group. The confidence interval extends from -12.75 to -3.248, and the reported unadjusted p-value is p < 0.001.
The confidence interval does not include zero. In the context of the reported comparison, that is consistent with the p-value indicating evidence of a difference in mean insertion time under the analysis used to produce the posted result. The interval also conveys uncertainty about the size of that difference: it spans estimates from -12.75 to -3.248 seconds for the Proseal-minus-Supreme contrast. It should not be read as a range containing a known proportion of individual patients’ insertion times.
The group standard deviations are 10.0 seconds for Supreme and 6.0 seconds for Proseal. Standard deviation describes the spread of individual observations around the group mean; it is not the uncertainty of the group mean or the uncertainty of the between-group difference. The reported arm counts for this endpoint are 22 for Supreme and 27 for Proseal. The overall enrollment is 52, and the record does not explain why the primary outcome counts do not account for that enrollment.
The result pertains to the defined endpoint and the analyzed participants represented by the posted summaries. It does not establish how the devices compare on the separately listed insertion success rate, because its numerical result is not reported in the registry record. Nor does insertion time alone establish differences in safety, positioning, or other outcomes. The study’s brief summary describes those broader aims, but the posted primary result is a comparison of time.
The registry identifies the study as randomized, which supports interpreting the groups as assigned by a random process, but the record does not provide enough detail to assess all aspects of conduct or analysis. The masking classification is none, while arm descriptions state that insertion would be blind. The record does not reconcile these descriptions. There is no reported information on analysis populations, missing-data handling, adjustment for other variables, or multiplicity. Accordingly, the posted estimate and p-value should be interpreted as the reported comparison, not as a fully documented analysis whose assumptions and sensitivity can be independently checked from the registry record.
The effect-size planning illustrations use the observed result as their reference point. They are not evidence about the probability that the observed difference is true, and they are not a retrospective measure of the trial’s observed power. Their role is to show how the hypothetical number of participants per arm changes when planning around different fractions of the observed effect.
9. Statistical Methods Explained
The primary outcome is continuous, and the registry reports it using group means and standard deviations. A mean summarizes the center of the observed times within an arm. A standard deviation describes how much individual times vary around that arm’s mean. These summaries answer different questions: the mean describes the average duration, while the standard deviation describes within-group spread. Neither summary alone gives the uncertainty in the comparison between arms.
What does the mean difference describe?
The posted contrast is defined as Proseal relative to Supreme. The group means are 18.0 seconds for Proseal and 26.0 seconds for Supreme, and the reported contrast is -8.0 seconds. The negative direction denotes a lower mean for Proseal under that ordering of the arms. A mean difference preserves the original time unit, so its interpretation remains in seconds rather than an abstract standardized scale. The estimate describes the difference between group averages, not the difference that every individual would experience.
In a randomized comparison, the analysis typically asks whether the observed difference in group means is compatible with a null comparison in which the population means are equal. The record reports an unadjusted p-value of p < 0.001. A p-value is a measure of how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, nor does it express the magnitude or clinical importance of a difference. The registry does not give a detailed account of the test or model used, so that method cannot be specified beyond the reported result.
How should the confidence interval be read?
The confidence interval for the mean difference runs from -12.75 to -3.248. In general, a confidence interval gives a range of values compatible with the data under the method’s assumptions, and conveys the statistical uncertainty around an estimate. It does not describe the range of individual insertion times. Here, its endpoints remain on the negative side of zero, which is consistent with the reported evidence for a difference under the analysis used. The interval also shows that uncertainty remains about the precise size of the average contrast.
General statistical interpretation depends on the assumptions behind the interval and test. For a comparison of means, relevant considerations can include the distribution of observations, independence of participants, and how variability is estimated. The registry does not report diagnostic checks or enough analytic detail to determine how those considerations were assessed. A mean-based summary can be useful for a continuous duration, but the record does not show whether the analysis considered unusual values or departures from model assumptions.
Why distinguish standard deviation from standard error?
The posted standard deviations are 10.0 seconds for Supreme and 6.0 seconds for Proseal. The standard deviations describe participant-level dispersion. A standard error instead describes uncertainty in an estimated quantity, such as a group mean or a difference in means. They are not interchangeable. The registry record includes calculations of group standard errors and a pooled standard deviation for the comparison, but the primary arm summaries are reported as means and standard deviations. The standard errors do not indicate how widely individual insertion times vary.
The standardized effect-size estimate in the comparison statistics is -0.995. A standardized effect expresses a difference relative to a measure of variability, rather than in the original seconds. It can help put a mean difference on a scale independent of the endpoint’s units, but it is less directly interpretable clinically than the difference in seconds. It also depends on the variability estimate used. The registry does not report a clinical threshold for what would count as an important difference in insertion time, so the standardized value cannot establish importance on its own.
What are the limits of the reported analysis?
The comparison is described as unadjusted, and the record does not report a model specification, covariates, or a prespecified statistical analysis plan. The record also does not describe any interim analyses or the rationale used to select the original enrollment target. Those items are not reported in the registry record and should not be inferred from the posted p-value or the later planning illustration. The result can be described as the registry’s reported unadjusted comparison, while the exact inferential procedure and its assumptions remain undocumented in the record.
Random allocation is a design feature intended to make the groups comparable in expectation, but it does not ensure that all observed characteristics are balanced in a particular trial. Baseline characteristics are not reported in the registry record, so the balance of measured or unmeasured characteristics cannot be assessed. The record also does not state how analysis populations were defined or how missing outcome data were treated. Those details are important for judging whether the posted summaries represent all randomized participants or a subset under a particular analysis rule.
Finally, a small p-value and a confidence interval separated from zero address statistical compatibility under a model; they do not resolve limitations in measurement, missingness, generalizability, or outcome selection. Statistical evidence should be read alongside the trial design and the completeness of reporting. For this trial, the endpoint definition, group summaries, and estimated contrast are available, while several aspects needed for a fuller appraisal of the analysis are not reported in the registry record.
10. Confidence Intervals and Precision
The reported mean difference for Proseal relative to Supreme is -8.0 seconds, with a confidence interval from -12.75 to -3.248. The interval describes uncertainty around the estimated difference in group means under the method used to calculate it. It is not a prediction interval for individual insertion times, and it does not imply that each participant’s time lies within its endpoints.
The interval’s endpoints are both negative, in the same direction as the point estimate. Thus the posted interval is consistent with a shorter average insertion time in the Proseal group under the reported contrast. Its range also indicates that the exact magnitude is not known precisely: estimates across the interval remain compatible with the data under the confidence-interval method. The result should be stated with both the point estimate and interval rather than relying only on the p-value.
The confidence interval’s precision reflects factors such as the amount of observed variability and the number of observations contributing to the comparison. The arm counts for the primary measure are 22 and 27, while the group standard deviations are 10.0 seconds and 6.0 seconds. These features contextualize the estimate, but the registry does not report enough detail about its interval procedure to reproduce or assess that procedure independently. The interval should therefore be read as the posted estimate of uncertainty, not as a guarantee that the true difference falls within the endpoints.
Statistical precision is also distinct from practical importance. The registry does not report a threshold for a clinically meaningful difference in insertion time. Therefore, the interval can inform how precisely the average contrast was estimated, but cannot by itself determine whether its values represent an important difference in practice.
11. 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.
| Effect to detect | Participants per arm, 80% power | Participants per arm, 90% power |
|---|---|---|
| 100% of the observed effect | 16 | 22 |
| 75% of the observed effect | 29 | 38 |
| 50% of the observed effect | 64 | 85 |
The sample-size illustrations are planning calculations based on the observed effect, not a report of the trial’s original design calculation. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each planning row uses the stated fraction of the observed effect as the effect to detect. The displayed figures are participants per arm, not total participants or total events; these are not time-to-event outcomes.
The 80% power column gives the number of participants per arm that the illustration estimates would be needed to have an 80% chance of detecting the specified effect under the stated assumptions, if that effect and the assumptions were correct. The 90% power column gives the corresponding planning count for a 90% chance. These are hypothetical design targets for future planning, not a description of what happened in this trial. This is not observed power.
The rows represent planning for 100%, 75%, and 50% of the observed effect. When the planning target is a smaller effect, more participants per arm are needed to distinguish it from random variation under otherwise fixed assumptions. The displayed counts illustrate that relationship. They should not be treated as a recommendation for a future study without considering its own population, endpoint, design, analysis, and chosen assumptions.
The registry record does not report the original sample-size justification or the assumptions used when the trial was designed. The illustrations therefore cannot establish whether the completed enrollment was selected to detect the posted effect or whether the trial met its original target. They are based on an effect estimated from the posted data, so the observed estimate itself is an uncertain input to the planning exercise.
12. 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 z1−α/2 = 1.960) and the desired power (z1−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
- Observed difference Δ = -8.000; pooled standard deviation σ = 8.037.
- n = 2 × (1.96 + 0.842)2 × 8.0372 / -8.0002 = 15.8, rounded up to 16 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 <- -8 # observed difference in means
sigma <- 8.03714779513548 # 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(836095)
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 = 16 (80% power), 22 (90% power)
75% of observed effect: n per arm = 29 (80% power), 38 (90% power)
50% of observed effect: n per arm = 64 (80% power), 85 (90% power)
power.t.test: 16.9
Simulated power at n = 16 per arm: 0.778 (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.
13. Multiplicity, Missing Data and Analysis Populations
The registry lists insertion time as the primary outcome and insertion success rate as a secondary outcome. Numerical results for insertion success rate are not reported in the registry record. No multiplicity strategy is reported. When a study assesses more than one outcome or conducts multiple statistical comparisons, multiplicity can affect how individual p-values are interpreted; without a stated plan, it is not possible to tell whether or how the reported p-value accounts for other analyses.
The primary comparison is reported with an unadjusted p-value. The record does not report whether there were additional outcome definitions, subgroup analyses, repeated looks at the data, or other tests that might be relevant to multiplicity. It also does not report interim analyses. Their absence from the record should not be taken as proof that none occurred; their status is not reported in the registry record.
Missing-data handling and the analysis population are also not described. Enrollment was 52, while the primary outcome arm counts are 22 for Supreme and 27 for Proseal. The record does not explain this difference, identify whether all randomized participants were included in the primary analysis, or state how any unavailable outcome measurements were handled. It is therefore not possible to classify the analysis as intention-to-treat, per-protocol, or another population definition based on the registry record.
These reporting gaps affect interpretation, not the arithmetic of the posted group summaries. Readers can describe the reported means, standard deviations, difference, confidence interval, and p-value, while recognizing that the record does not document the broader analysis framework. Details about missingness, outcome selection, multiplicity, and population definitions would be needed for a more complete assessment of inferential robustness.
14. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Supreme LMA | 0 | 22 | 0.0% |
| Proseal LMA | 0 | 30 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Supreme LMA | 0 of 22 |
| Proseal LMA | 0 of 30 |
The adverse-event record lists serious adverse events for 22 participants at risk in the Supreme group and 30 at risk in the Proseal group. It reports zero serious adverse events in each group. For other adverse events, the record also lists 22 participants at risk in the Supreme group and 30 in the Proseal group, with zero events reported in both groups. Death counts are not reported in the registry record.
These figures describe the safety information posted in the registry; they do not establish that no adverse events of any kind occurred outside the recorded categories or reporting period. The record does not provide serious-event terms, and it does not explain why the at-risk counts differ from the primary outcome arm counts or from overall enrollment. The posted zeros should be interpreted as zero reported events in the listed groups, rather than proof that an event is impossible or that the devices have equivalent safety.
Event counts are also distinct from the insertion-time endpoint. The safety figures do not determine whether one device had a shorter mean insertion time, and the insertion-time result does not establish a safety difference. The registry record does not provide further detail on event definitions, ascertainment, or follow-up duration.
15. What the Result Does, and Does Not, Mean
The posted result supports a precise description of the trial’s primary outcome: mean insertion time was 26.0 seconds for Supreme and 18.0 seconds for Proseal, with a reported Proseal-minus-Supreme difference of -8.0 seconds. The confidence interval runs from -12.75 to -3.248, and the unadjusted p-value is p < 0.001. Under the analysis reflected in the registry, the observed mean insertion times differ, with the lower mean in the Proseal group.
That finding is limited to the endpoint as defined: the time to insert the airway and verify ventilation. It is not a complete measure of ease of use, positioning, success, or overall device performance. The registry lists insertion success rate as a secondary outcome, but its numerical result is not reported in the registry record. Although the study’s summary identifies positioning and ease of insertion as aims, the posted primary result concerns time and cannot answer every stated question.
The result does not establish that one device is better for every patient or setting, and it does not establish medical benefit. The record does not report detailed eligibility criteria, baseline characteristics, missing-data methods, or analysis-population definitions. These gaps limit assessment of how representative the analyzed participants were and how the comparison might apply beyond the trial. The difference is an average group contrast, not a claim that each individual would have the same experience.
Statistical significance and practical importance are separate concepts. The reported p-value and confidence interval concern evidence and precision under an analysis; the registry does not give a threshold for an important difference in seconds. The data can therefore be summarized as showing a between-group difference in reported mean insertion time, but the record alone does not establish whether that difference is meaningful to patients or clinicians. The zero adverse-event counts should likewise be read as the events recorded in the registry, not as a definitive comparison of safety.
16. Why This Trial Matters Statistically
This trial illustrates how a randomized comparison can address a focused operational question using a continuous endpoint. Insertion time is expressed in seconds, and the reported mean difference retains that directly interpretable unit. Alongside the p-value, the confidence interval communicates the range of estimated average contrasts compatible with the data under the method used. Reading these together is more informative than treating a significance threshold as the whole result.
It also highlights why endpoint definitions matter. The registry defines insertion time to include airway insertion and verification of ventilation. That scope differs from a measure of insertion success, which is separately listed as a secondary outcome. A favorable result on duration cannot substitute for information on success, positioning, safety, or other domains. Distinguishing outcomes prevents a narrow result from being generalized to broader claims.
The record demonstrates the importance of transparent reporting. Randomization and an envelope-based allocation description are documented, but the registry does not report the original sample-size rationale, analysis-population rules, handling of missing data, or a detailed statistical analysis plan. In addition, the overall masking designation and the arm-description wording about blind insertion are not reconciled. These gaps shape how confidently readers can assess the path from design to analysis.
Finally, the planning illustrations show how sample-size requirements depend on the effect targeted. Planning for smaller effects requires more participants under otherwise fixed assumptions. Because those calculations use the observed effect and do not reconstruct the original design rationale, they should be understood as illustrations rather than evidence about whether the trial was adequately planned. Together, these considerations show why effect estimates, uncertainty, design details, and reporting completeness all matter in statistical interpretation.
17. 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 leaves several trial-specific questions unresolved. It reports enrollment of 52 but primary outcome counts of 22 for Supreme and 27 for Proseal. The record does not explain the difference, so reasons such as exclusions, unavailable measurements, or analysis rules cannot be inferred. The adverse-event at-risk counts are 22 and 30, which also differ from the primary outcome counts; no explanation is reported.
Eligibility criteria and baseline characteristics are not reported in the registry record. Without those details, readers cannot assess the enrolled population’s characteristics or evaluate whether measured baseline factors were balanced between randomized groups. The summary describes mechanically ventilated patients in general anesthesia, but does not offer enough detail to define the population more narrowly.
The registry lists no masking overall, while the arm descriptions say the airway would be blindly inserted by an experienced attending anesthesiologist. It does not explain how this wording relates to the masking classification or whether outcome timing was assessed by someone unaware of assignment. Measurement procedures beyond the endpoint definition are also not reported.
The statistical analysis plan, original sample-size justification, missing-data procedures, and analysis-population definition are not reported in the registry record. The result is presented as an unadjusted comparison, but the exact test or model is not specified. Insertion success rate is listed as a secondary outcome without numerical results. These reporting limitations do not change the posted insertion-time summaries, but they constrain interpretation of how complete and robust the overall evidence is.
18. Related Tutorials
19. Related Statistical Calculators
20. Sources
- ClinicalTrials.gov: Comparison of ProSeal Laryngeal Mask Airway to Laryngeal Mask Airway Supreme — NCT00836095.
- Registry record last updated 2016-04-15; status last verified 2016-03.
- Results first posted 2014-06-03.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
21. Record Summary
NCT00836095 is a completed, randomized, parallel-group Phase 4 trial sponsored by Milton S. Hershey Medical Center. It enrolled 52 participants and compared the Supreme and Proseal laryngeal mask airways. The primary outcome was insertion time, defined as the time to insert the airway and verify ventilation.
The posted primary outcome means were 26.0 seconds for Supreme and 18.0 seconds for Proseal. The reported Proseal-minus-Supreme mean difference was -8.0 seconds, with a confidence interval from -12.75 to -3.248 and p < 0.001. Insertion success rate was listed as a secondary outcome, but numerical results are not reported in the registry record.
The record reports zero serious adverse events in both groups and zero other adverse events in both groups; death counts are not reported in the registry record. Important details, including the original sample-size rationale, missing-data handling, and analysis-population definitions, are not reported in the registry record.