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 Fentanyl Test in Children's Adenotonsillectomy (NCT02484222), a registered phase not stated study. The primary outcome is Rescue Morphine Requirement.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02484222 |
| Phase | Phase not stated |
| Condition | Obstructive Sleep Apnea |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 80 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Children's Hospital of Fudan University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns children with obstructive sleep apnea syndrome (OSAS) after adenotonsillectomy. The registry record lists Obstructive Sleep Apnea as the condition and describes the intended population as children with OSAS after surgery. More detailed eligibility criteria, such as age limits or clinical severity requirements, are not reported in the registry record.
Intervention
The registered intervention is fentanyl, classified as a drug. The study title and summary focus on the result of a fentanyl test and whether that result is associated with, or can help predict, postoperative morphine requirements. The procedure for conducting or interpreting the test is not reported in the registry record.
Comparator
A like-for-like control comparison is not described. The registry record does not state an allocation method, and it identifies the study as not being a randomized comparison. The groups, if any, are therefore not established as comparable treatment arms. A specific comparator is not reported in the registry record.
Primary question
The primary question is whether fentanyl test results are associated with the amount of rescue morphine required after adenotonsillectomy, and whether the test result can predict that requirement. The primary endpoint is rescue morphine requirement, measured in mg and summarized using the median and inter-quartile range at an average of 1 hour from extubation. The registry record does not report the observed endpoint values or the result of an association or prediction analysis.
These are related but distinct aims. An association analysis asks whether morphine requirements differ or vary with the test result. Prediction asks whether the test result provides useful information about an individual’s later morphine requirement. General statistical interpretation: an association alone does not establish that a test accurately predicts individual outcomes, and prediction performance requires appropriate evaluation beyond describing a relationship. The registry record does not specify how either aim was assessed.
3. Trial Design
The registry record identifies NCT02484222, titled “Fentanyl Test in Children's Adenotonsillectomy.” Its official title describes the relationship between fentanyl test results and morphine requirements in children with OSAS after adenotonsillectomy. The sponsor is Children's Hospital of Fudan University. The study is marked COMPLETED, with enrollment of 80; its recorded start is 2015-09 and primary completion is 2016-01.
The record classifies the study kind as “other.” It explicitly notes that this is not a randomized comparison, that allocation is not stated, and that the arms are not a like-for-like control comparison. These details matter because comparisons between groups can be influenced by differences between the people in those groups. Random allocation, when used, is one way to reduce such differences; it cannot be assumed for this study.
Fentanyl is listed as a drug intervention. The study’s stated purpose is to discuss the relationship between the fentanyl test result and required morphine dosage, and to evaluate the ability to predict postoperative morphine dosage. The record does not describe the test procedure, how result categories were defined, how the groups were formed, or what care was given beyond the listed intervention. Those design details are not reported in the registry record.
The primary endpoint is rescue morphine requirement. Two secondary outcomes are named: post-operative nausea and vomiting, and number of participants with pulse oxygen saturation less than 95 Percent. The record lists 4 outcome measures in total. It does not report a protocol, sample-size justification, or detailed statistical analysis plan. Completion status indicates the study’s registry status, not that its primary result or conclusions are available 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.
Before assignment: Children at age of 3 - 7 years with OSAS,The exclusion criteria were craniofacial deformities, mental retardation, BMI \> 22 kg/m², a history of bronchial asthma, and a recent history of opioid use.
Overall Study
| Stage | The Result of Fentanyl Test |
|---|---|
| STARTED | 80 |
| COMPLETED | 77 |
| NOT COMPLETED | 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 | The Result of Fentanyl Test |
|---|---|---|
| Participants analysed | 80 | |
| Age, Categorical: <=18 years | Participants | 80 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 5.2 (3.9 to 6.5) |
| Sex: Female, Male: Female | Participants | 65 |
| Sex: Female, Male: Male | Participants | 15 |
| Region of Enrollment: China | Participants | 80 |
6. Primary Endpoint
The registry lists the primary outcome as Rescue Morphine Requirement, measured over average 1 hour from extubation.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | mg |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is rescue morphine requirement, measured in mg. The registry record specifies a median with inter-quartile range as the summary and gives the timeframe as average 1 hour from extubation. It does not provide the observed median or inter-quartile range for any test-result group, so the amount of morphine used cannot be described from the registry record.
Rescue medication requirements can serve as a measure of postoperative medication use. In this study, that endpoint is relevant to the stated question because the researchers sought to examine whether fentanyl test results were related to, or could predict, subsequent morphine requirements. General statistical explanation: the median describes the middle of the observed values when ordered, while the inter-quartile range describes the spread of the central portion of those values. These summaries can be useful when values are skewed or when a few unusually high or low observations make the mean less representative.
The specified median and inter-quartile range describe the intended form of the endpoint summary; they do not themselves show whether test results and morphine requirements are associated. That would require reported group-level values or an analysis estimate, along with suitable uncertainty information. Neither the primary endpoint results nor an estimate of the relationship is reported in the registry record. The precise meaning of “average 1 hour from extubation,” including how the measurement window was applied, is not further described.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states the study’s question and identifies its endpoint, but it does not report the primary outcome values or an analysis of the relationship between fentanyl test results and rescue morphine requirements. Consequently, the posted record does not establish the direction, size, or precision of any association. It also does not show whether the test result predicted morphine requirements. No conclusion about the primary question can be drawn from the endpoint description alone.
The study is marked COMPLETED and records enrollment of 80. Completion and enrollment are details about study status and registration; they are not evidence of a particular result. The record lists no analyses. This means there is no reported analysis result to interpret in the registry record, rather than evidence that no analysis was conducted outside the record.
The record says this was not a randomized comparison and that allocation was not stated. It also cautions that the arms are not a like-for-like control comparison. General statistical interpretation: when groups are formed without random allocation, differences in their outcomes may reflect differences in the groups as well as any relationship with the measured test result. The record does not give enough detail to assess whether potential confounding factors were measured or addressed.
The primary endpoint is specified as a median and inter-quartile range, but the numerical summaries are absent. Without them, the distribution and variability of rescue morphine requirements cannot be assessed. Without an effect estimate and uncertainty interval, readers cannot assess how precisely any observed relationship was estimated. A p-value or a prediction-performance measure is also not reported in the registry record.
The two named secondary outcomes concern post-operative nausea and vomiting and the number of participants with pulse oxygen saturation less than 95 Percent. Their results are not reported in the registry record. The record lists 4 outcome measures, but only those two secondary outcomes and the primary endpoint are described in the available details. Other outcome descriptions are not reported in the registry record.
The adverse-event entries should be read separately from the primary endpoint. The registry record reports figures for serious adverse events, other adverse events, and deaths, but does not provide a fuller account of event definitions, timing, or attribution. These entries do not answer whether fentanyl test results were associated with morphine requirements. Overall, the registry entry provides a study question and selected design and outcome information, but not results sufficient to evaluate its primary statistical question.
9. Statistical Methods Explained
The registry record identifies rescue morphine requirement as the primary endpoint and specifies a median and inter-quartile range. It does not describe the statistical test or model used to compare or relate the endpoint to fentanyl test results. The explanations below are general statistical context, not a description of methods confirmed to have been used in this study.
What does a median and inter-quartile range communicate?
General explanation: the median is the central value after observations are ordered. The inter-quartile range describes the middle spread of the observations, from the lower quarter boundary to the upper quarter boundary. This pair of summaries emphasizes the center and spread without being as strongly influenced by extreme observations as the mean and standard deviation can be. Reporting the pair does not by itself test a hypothesis or quantify an association.
For the endpoint in this study, the registry record specifies the unit as mg and the timeframe as average 1 hour from extubation. It does not give the actual median or inter-quartile range, nor does it explain whether results were reported separately by fentanyl test result. A reader therefore cannot reconstruct the outcome distribution from the registry entry.
How are association and prediction different?
General explanation: an association analysis describes how an outcome varies with a predictor or group. A prediction analysis asks how well information available before or at the time of prediction can forecast an outcome. Evidence that two measures are associated is not, by itself, enough to establish accurate individual prediction. Prediction assessment often requires measures of predictive performance and validation in data not used to build the prediction. The registry record does not specify a prediction model, performance measure, or validation approach.
The study summary names both an association and an ability-to-predict aim. It does not state how the fentanyl test result was represented in an analysis, whether other variables were considered, or what criterion was used to judge predictive ability. These details are not reported in the registry record. It would therefore be inappropriate to infer a particular model or method from the study’s stated aims.
What does the design imply for group comparisons?
The registry record says the study was not a randomized comparison, allocation was not stated, and arms are not like-for-like control groups. General explanation: nonrandomized groups may differ in ways related to the outcome. For example, differences in participant characteristics or clinical circumstances can complicate an unadjusted comparison. Statistical adjustment may address measured factors under appropriate assumptions, but it cannot automatically remove bias from unmeasured or poorly measured factors. The registry record does not report whether any adjustment was performed.
The record classifies the study as kind “other.” It does not describe a randomized allocation scheme or a comparator group. Thus, the equal allocation assumption appearing in the planning illustration should not be mistaken for the actual allocation of participants. It is a planning assumption, not evidence about how participants were assigned or distributed in the completed study.
What can be said about uncertainty and statistical significance?
General explanation: an estimate gives the size and direction of a relationship, while a confidence interval describes uncertainty around that estimate under the assumptions of the analysis. A p-value, when used, measures how compatible the observed data are with a specified null hypothesis under the chosen model; it does not measure the probability that the null hypothesis is true or the importance of a result. The registry record reports no effect estimate, confidence interval, or p-value for the primary question. Statistical significance and precision therefore cannot be evaluated from the registry entry.
A result summarized only by a median and inter-quartile range would describe observed values, but a comparison or predictive question also requires an appropriate analysis. The record does not state whether a rank-based test, regression model, or another approach was used. No such method should be assumed.
How should the planning assumptions be read?
The registry record describes sample-size calculations as planning illustrations based on an observed effect, not as the trial’s own design. The listed assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are assumptions for an illustration. They do not establish that the trial was designed with those parameters or that the actual groups were equally allocated.
The registry record also distinguishes how planning calculations are expressed: time-to-event calculations use total events, while all other calculations use participants per arm. These conventions describe planning outputs, not observed trial results. A planning sample size is not observed power. The registry record does not report the trial’s own sample-size justification, nor does it establish that a planning illustration represents the study’s actual design.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 4 outcome measures and names two secondary outcomes: post-operative nausea and vomiting, and number of participants with pulse oxygen saturation less than 95 Percent. It identifies rescue morphine requirement as the primary endpoint. The remaining outcome descriptions are not reported in the registry record. The record lists no analyses and does not describe which outcomes were tested or how results were analyzed.
General statistical explanation: when several outcomes or hypotheses are examined, the chance of at least one apparently unusual finding can increase if each is assessed separately without accounting for the number of questions. Methods to address multiplicity can include defining a primary outcome in advance, adjusting significance thresholds, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy, so it is not possible to determine how multiple outcomes or analyses were handled.
Missing-data handling is not reported in the registry record. The record does not state whether outcome data were complete, how missing values were addressed, or whether any sensitivity analyses were conducted. Enrollment is recorded as 80, while the adverse-event entries list 77 at risk for each of the serious and other adverse-event categories. The registry record does not explain the relationship between those figures. It would not be appropriate to infer a reason for the different denominators.
The analysis populations are also not reported in the registry record. In particular, the record does not specify which participants contributed to the primary endpoint analysis, whether participants were excluded, or how exclusions were handled. These omissions limit assessment of how the reported endpoint—if analyzed—would relate to the enrolled study population.
11. 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 |
|---|---|---|---|
| The Result of Fentanyl Test | 0 | 77 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| The Result of Fentanyl Test | 0 of 77 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| The Result of Fentanyl Test | 13 of 77 |
Most frequent non-serious adverse event terms
| Event term | Organ system | The Result of Fentanyl Test |
|---|---|---|
| vomiting | General disorders | 13 of 77 |
The registry record lists one group titled “The Result of Fentanyl Test.” For serious adverse events, it reports 77 at risk and 0 affected. For other adverse events, it reports 77 at risk and 13 affected. The recorded number of deaths is 0. The registry record lists no top serious-event terms.
These are the registry’s reported counts, not a complete safety analysis. The record does not explain the difference between enrollment of 80 and the at-risk figure of 77, or give further detail about the population represented by those denominators. It also does not report event descriptions, timing, duration, severity grading, relatedness assessments, or how adverse events were collected. Such information is not reported in the registry record.
General statistical explanation: a count of affected participants is most interpretable when the population assessed, event definitions, observation period, and collection procedures are clear. The figures should not be converted into rates or compared across groups without those details. The listed numbers also do not establish whether events were caused by an intervention. They are descriptive entries in the registry record and do not resolve the study’s primary question about fentanyl test results and morphine requirements.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed study was registered to examine fentanyl test results in relation to postoperative rescue morphine requirements in children with OSAS after adenotonsillectomy. It identifies rescue morphine requirement, measured in mg, as the primary endpoint and specifies a median with inter-quartile range at an average 1 hour from extubation. These details clarify what the researchers intended to study.
They do not establish what the study found. No primary endpoint values, association estimates, prediction results, or uncertainty measures are reported in the registry record. Therefore, the direction and magnitude of any relationship cannot be described, and its precision cannot be assessed. The stated intention to evaluate prediction is not evidence that prediction was successful or that a prediction model was evaluated.
The record also does not establish a causal effect. It identifies the study as not randomized, does not state allocation, and cautions that the arms are not like-for-like control comparisons. General statistical explanation: an observed association can reflect the relationship of interest, differences between groups, or other factors. A nonrandomized comparison needs design and analysis details to assess these possibilities; those details are not reported in the registry record.
Enrollment of 80 and COMPLETED status describe the registered study, not the completeness or quality of every outcome analysis. The adverse-event counts describe registry entries but do not provide a complete account of safety or attribution. Similarly, the two named secondary outcomes have no reported results in the record. The appropriate interpretation is limited to the information documented: the question, endpoint definition, selected design details, and adverse-event counts. Any stronger conclusion about the test, morphine use, or clinical consequences is not supported by the reported information.
13. Why This Trial Matters Statistically
This study is statistically interesting because it frames fentanyl test results as a possible source of information about postoperative morphine requirements. The question combines an association aim with a prediction aim, which require distinct evidence. A relationship between a test result and an outcome may be statistically detectable without being sufficiently precise or useful for prediction. Separating those questions is important when interpreting any study that proposes a test as a predictor.
The primary endpoint also has a distribution-sensitive summary: the median and inter-quartile range. General statistical explanation: this approach describes the center and central spread of outcome values and can be informative when observations are not symmetrically distributed. But the summary alone cannot establish an association, show predictive accuracy, or describe uncertainty around a comparison. The registry record does not provide the values or analysis needed for those further judgments.
The nonrandomized status is another important statistical feature. The record explicitly warns that the arms are not like-for-like control groups and does not state allocation. This makes it essential to know how test-result groups were formed and whether relevant differences were considered. Those details are not reported in the registry record. The study therefore illustrates why design information and analysis details are necessary alongside an endpoint definition.
Finally, the entry distinguishes planning assumptions from the study’s design: its sample-size calculations are described as illustrations, not the trial’s own design. This distinction helps prevent planning quantities from being mistaken for observed results or observed power. The registry record documents a focused research question, but the missing analysis results prevent statistical assessment of the proposed association or prediction.
14. 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 main limitation of interpreting this study from the registry record is the absence of primary results. The record does not provide the median rescue morphine requirement, inter-quartile range, an estimate of association, a confidence interval, or a p-value. It also does not report prediction performance. Statistical strength, direction, and precision therefore cannot be assessed.
Important design details are not reported in the registry record. These include eligibility criteria beyond the broad population description, the fentanyl test procedure, the definition of test-result categories, and how participants or groups were formed. Allocation is not stated, and the record specifically cautions that this is not a randomized comparison with like-for-like arms. Confounding and group comparability cannot be evaluated from the available details.
The analysis plan is also not reported. The registry record does not describe model choice, adjustment for other factors, handling of repeated or unusual values, missing-data procedures, analysis populations, or multiplicity control. It lists 4 outcome measures, but only the primary endpoint and two secondary outcomes are described. Results for the named secondary outcomes are not reported in the registry record.
The adverse-event entries have limited context: the record does not explain the at-risk denominator, event definitions, assessment period, collection method, or attribution. It does not reconcile enrollment of 80 with the adverse-event at-risk figure of 77. Finally, the sample-size information is described as a planning illustration rather than the trial’s design, and the trial’s own sample-size justification is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Fentanyl Test in Children's Adenotonsillectomy — NCT02484222.
- Registry record last updated 2019-07-09; status last verified 2019-06.
- Results first posted 2019-03-11.
- 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.
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18. Record Summary
NCT02484222 is a completed study titled “Fentanyl Test in Children's Adenotonsillectomy,” sponsored by Children's Hospital of Fudan University. The registry record gives enrollment of 80, a start of 2015-09, and primary completion of 2016-01. Its stated aim is to examine the relationship between fentanyl test results and morphine requirements in children with OSAS after adenotonsillectomy, including whether test results can predict postoperative morphine dosage.
The primary endpoint is rescue morphine requirement in mg, summarized as median and inter-quartile range at an average 1 hour from extubation. Fentanyl is listed as a drug intervention. The record identifies the study as not randomized, says allocation is not stated, and cautions that arms are not like-for-like control groups. It lists 4 outcome measures and no analyses. Primary results, analysis details, missing-data methods, and analysis populations are not reported in the registry record.
For adverse events, the record lists 77 at risk and 0 affected for serious events, 77 at risk and 13 affected for other events, and 0 deaths. No top serious-event terms are listed.