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 Study of Anaesthesia Costs and Recovery Profiles (NCT02920749), a randomized na study. The primary outcome is Drug Consumption.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02920749 |
| Phase | NA |
| Condition | Anaesthesia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 120 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Pecs |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people undergoing otorhinolaryngeal surgery with general anaesthesia. The registry record lists anaesthesia as the condition and an enrollment of 120. Further eligibility details, including age, specific operations and exclusion criteria, are not reported in the registry record.
Intervention
Two groups received sevoflurane-based anaesthesia. Group A used sevoflurane at 1-2% end-tidal concentration, with MAC 1.0-1.5, in a mixture of 50% air and 50% oxygen. In Group B, sevoflurane dosing was adjusted to target BIS levels of 40 to 60 and MAP for controlled hypotension within 60-85 mmHg.
Comparator
Two groups received propofol-based anaesthesia. Group C used TIVA with a propofol protocol of 6 to 8 mg/kg/h. Group D had propofol dosing adjusted to target BIS levels of 40 to 60 and MAP for controlled hypotension within 60-85 mmHg. Further details of monitoring in the groups are not reported in the registry record.
Primary question
The registered primary outcome is drug consumption, measured as a mean with standard deviation in milligrams. The outcome description names fentanyl, sevoflurane, propofol 1% and atracurium, and covers one dose at induction and consumption during anaesthesia in mg/1 hour. The registry record does not report numerical outcome results, so it does not establish how consumption differed among the four groups.
3. Trial Design
This was a randomized, single-masked, parallel-group study. The registry lists an enrollment of 120 and describes four groups: two sevoflurane groups and two propofol groups. The adverse-event record lists 30 people at risk in each group. The identity of the person or people who were masked, and further details of the randomization process, are not reported in the registry record.
The study compared anaesthesia approaches in otorhinolaryngeal surgery, with group protocols differing in the anaesthetic and in the stated use of target values for BIS and MAP. Group A received sevoflurane at 1-2% end-tidal concentration, MAC 1.0-1.5, with 50% air and 50% oxygen. Group B used sevoflurane dosing to target BIS levels of 40 to 60 and MAP within 60-85 mmHg for controlled hypotension. Group C used TIVA with propofol at 6 to 8 mg/kg/h. Group D used propofol dosing to target BIS levels of 40 to 60 and MAP within 60-85 mmHg. These descriptions do not establish that all other aspects of care were the same across groups.
The listed phase is NA. The registry record gives a start date of 2014-09, primary completion of 2016-10 and status of completed. The sponsor is the University of Pecs. The brief summary describes a comparison of perioperative hemodynamic parameters, recovery profiles and cost containment. Costs of anaesthesia are listed as a secondary outcome. Numerical results for those measures are not reported in the registry record.
The four groups create more than one possible comparison: sevoflurane versus propofol, or group-by-group contrasts that may also reflect the different dosing descriptions. The registry record does not report which contrast was designated as the main comparative analysis, how the groups were allocated to particular analyses, or whether a formal comparison between the two approaches was prespecified.
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: We studied patients with ASA physical status I or II, their age between was between 18 and 65 years. Individuals with a history of pulmonary, psychiatric, cerebrovascular or congenital neuromuscular disease were excluded from the study. Patients were blocked randomised to one of four anaesthetic treatment groups with closed envelops.
Overall Study
| Stage | Group A | Group B | Group C | Group D |
|---|---|---|---|---|
| STARTED | 30 | 30 | 30 | 30 |
| COMPLETED | 30 | 30 | 30 | 30 |
| NOT COMPLETED | 0 | 0 | 0 | 0 |
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 | Group A | Group B | Group C | Group D | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 30 | 30 | 30 | 30 | 120 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 30 | 30 | 30 | 30 | 120 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 14 | 16 | 19 | 16 | 65 |
| Sex: Female, Male: Male | Participants | 16 | 14 | 11 | 14 | 55 |
| Region of Enrollment: Hungary | participants | 30 | 30 | 30 | 30 | 120 |
6. Primary Endpoint
The registry lists the primary outcome as Drug Consumption, measured over at induction one dose and during anaesthesia mg/1 hour.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | mg |
| Endpoint classification | Continuous Endpoint |
The registered primary outcome is drug consumption, expressed as a mean with standard deviation and measured in milligrams. Its description includes fentanyl, sevoflurane, propofol 1% and atracurium. It specifies one dose at induction and consumption during anaesthesia in mg/1 hour. The registry record does not give the numerical means or standard deviations for any group, nor does it report a single pooled consumption value or a treatment contrast.
Consumption is a process measure: it describes the amount of named drugs used during the anaesthetic care specified by the study. Such a measure can be relevant when comparing anaesthetic protocols because the protocol includes the use and dosing of anaesthetic drugs. It is not, by itself, a direct measure of recovery, hemodynamic status or cost. Those are distinct outcomes, and the record separately lists costs of anaesthesia as a secondary outcome.
The timing description combines an induction dose with consumption during anaesthesia per hour. These are different ways of expressing use, so interpretation depends on the particular drug and time point being summarized. The record indicates multiple drugs and time points but does not report the detailed outcome categories, their individual results, or how a summary measure was constructed. Therefore, the endpoint’s numerical size and the direction or precision of any between-group difference cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a randomized comparison of four anaesthesia groups and names drug consumption as the primary outcome. It also lists costs of anaesthesia as a secondary outcome. However, it does not report the group means, standard deviations, effect estimates or confidence intervals for drug consumption. Numerical results for costs, perioperative hemodynamic parameters and recovery profiles are also not reported in the registry record. As a result, the posted information does not permit an assessment of the magnitude or precision of differences in these outcomes.
The distinction between the four groups matters for interpretation. The sevoflurane and propofol groups have different stated dosing protocols, and Groups B and D include targets for BIS and MAP that are not described for Groups A and C. A difference between groups could therefore reflect the full protocol contrast rather than the anaesthetic drug alone. The registry record does not report a statistical analysis that separates these features or identifies one primary pairwise comparison.
Random allocation can, in general, support comparisons by reducing systematic differences between groups at the start of a study. It does not remove uncertainty from finite sample sizes, missing observations or differences in how outcomes are measured. The registry record does not provide baseline characteristics, participant flow, analysis populations or missing-data information, so those aspects of the comparison cannot be evaluated.
The adverse-event record lists zero serious adverse events among 30 people at risk in each group. It also lists other adverse events affecting 14 in Group A, 15 in Group B, 4 in Group C and 8 in Group D. These are counts, not estimates of comparative risk, and the record does not report confidence intervals, an analysis of between-group differences, event definitions or the observation period. Deaths are not reported in the registry record.
The statistical interpretation is consequently limited to describing the registered design, endpoint and event counts. There is no basis in the registry record for stating that one anaesthesia approach used more or less of a drug, differed in costs or recovery, or had a particular effect on safety. The record’s completed status does not substitute for numerical outcome results.
9. Statistical Methods Explained
The registered primary endpoint is continuous: drug consumption is summarized as a mean and standard deviation. A mean describes the arithmetic average of measured values, while a standard deviation describes how spread out individual measurements are around that average. These are descriptive summaries. To judge a comparison between groups, readers would also need an estimate of the difference and information about its uncertainty, such as a confidence interval. Those numerical results are not reported in the registry record.
A confidence interval, as a general statistical concept, is a range of values compatible with the observed data under a specified statistical procedure. Its width conveys precision: a narrower interval indicates greater precision than a wider interval. An interval is not a guarantee that the true effect lies within its limits. No confidence interval for drug consumption or costs is reported in the registry record, so the precision of any group difference cannot be assessed.
The study is registered as randomized and parallel-group. In a randomized trial, assignment is intended to make comparison groups similar on average at the time of allocation, including with respect to characteristics that are not measured. In a parallel-group design, participants are assigned to a group and the groups are compared. The registry record does not describe the random sequence, allocation concealment, the masking procedure beyond single masking, or which individuals were masked. It also does not report baseline measurements needed to inspect the realized balance between groups.
There are four named groups, with two sevoflurane protocols and two propofol protocols. A general comparison of anaesthetic agents would need to define how the two groups receiving each agent are handled. Alternatively, each group can be treated as a distinct protocol, producing group-level contrasts. Those choices answer different questions and can lead to different interpretations. The registry record does not report a primary contrast, a model for combining groups, covariate adjustment, or the statistical test used.
The endpoint description covers more than one drug and more than one time point: one induction dose and drug use during anaesthesia in mg/1 hour. A mean for each drug and time point would have a different interpretation from a combined measure. The record does not report all categories, their numerical results or a method for combining them. Its note that the primary outcome has several categories or time points and is not reduced to one comparison is important: there is no single primary estimate to interpret from the posted record.
For a continuous endpoint, distributional shape and outliers can matter to the choice and performance of an analysis. The mean is sensitive to unusually high or low observations. A standard deviation summarizes spread but does not show the full distribution. In general, analysts may examine distributions and choose methods suited to the data and trial design; the registry record does not report such checks or the analysis method used. Over-dispersion is most often discussed for count outcomes, where variability exceeds what a chosen count model expects. It is not a conclusion that can be drawn from these drug-consumption fields, and no dispersion assessment is reported.
The record lists two outcome measures and two analyses, but it does not describe the relationship between each analysis and each outcome. When multiple outcomes, time points or group contrasts are examined, the chance of at least one apparently notable result can increase. Statistical methods may address this multiplicity in different ways, depending on the research question. The registry record does not report whether any multiplicity adjustment, hierarchy or distinction between confirmatory and exploratory analyses was used.
The sample-size assumptions describe planning illustrations, not the trial’s original design justification. They use a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation; the effect to detect is a stated fraction of the observed effect. These assumptions do not establish the actual design target, and the registry record does not report the trial’s sample-size justification. Any sample-size illustration based on an observed effect is a planning aid, not observed power. Observed power is not a substitute for an effect estimate and its confidence interval. Numerical planning results are not reported in the registry record.
Statistical significance and clinical importance are separate ideas. In general, a p-value describes how incompatible data are with a specified null model, under the assumptions of the test; it does not measure the size or practical importance of a difference. The registry record does not report p-values for drug consumption, costs, recovery or hemodynamic measures. No conclusion about statistical significance or the practical magnitude of a contrast can therefore be drawn from the listed design alone.
10. Multiplicity, Missing Data and Analysis Populations
The record lists two outcome measures and two analyses. Drug consumption is named as the primary outcome, and costs of anaesthesia as a secondary outcome. The primary outcome description includes several drugs and time points, and the record does not reduce these to one comparison. It does not report which outcome categories or group contrasts were assigned to each analysis, or identify a hierarchy of hypotheses.
When several outcomes, time points or pairwise contrasts are examined, each analysis creates another opportunity for an apparently unusual result. As a general principle, a prespecified hierarchy or a multiplicity adjustment can help control how findings are interpreted. The registry record does not report whether such an approach was used. It also does not report an analysis plan, the statistical tests or models, or whether any analyses were designated as exploratory.
Information about missing observations is not reported in the registry record. There is no account of participant flow by group, withdrawals, exclusions from analysis, reasons for missing measurements or methods for handling missing data. The record also does not identify an intention-to-treat, per-protocol or other analysis population. Without these details, it is not possible to establish how many participants contributed to each endpoint or whether missingness could affect the comparisons.
Randomization and the listed enrollment do not, on their own, resolve these questions. Interpretation of an analysis depends on the population included, outcome availability, prespecified comparisons and the methods used to address multiple testing. Those details are not reported in the registry record.
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 |
|---|---|---|---|
| Group A | 0 | 30 | 0.0% |
| Group B | 0 | 30 | 0.0% |
| Group C | 0 | 30 | 0.0% |
| Group D | 0 | 30 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Group A | 14 of 30 |
| Group B | 15 of 30 |
| Group C | 4 of 30 |
| Group D | 8 of 30 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Group A | Group B | Group C | Group D |
|---|---|---|---|---|---|
| other minor complications of anaesthesia | Cardiac disorders | 13 of 30 | 13 of 30 | 3 of 30 | 7 of 30 |
| vomiting | Gastrointestinal disorders | 1 of 30 | 2 of 30 | 1 of 30 | 1 of 30 |
The registry lists serious adverse events for four groups. It records zero serious adverse events among 30 people at risk in Group A, zero among 30 in Group B, zero among 30 in Group C and zero among 30 in Group D. A recorded zero means no serious event is listed for that group in this record; it does not establish that the underlying risk is zero.
The record separately lists other adverse events affecting 14 people in Group A, 15 in Group B, 4 in Group C and 8 in Group D, with 30 at risk in each group. These are counts. They do not by themselves quantify a reliable difference between groups, and no statistical comparison or uncertainty interval is reported. The record does not define the events, give their severity beyond the serious/non-serious distinction, or specify the observation period and collection method.
Deaths are not reported in the registry record. The listed adverse-event counts should therefore be read as a limited record of reported events, not as a complete comparative safety analysis. They do not establish whether one protocol is safer than another.
12. What the Result Does, and Does Not, Mean
The record identifies a randomized study of sevoflurane- and propofol-based anaesthesia for otorhinolaryngeal surgery, with four protocol groups and an enrollment of 120. It identifies drug consumption as the primary outcome and costs of anaesthesia as a secondary outcome. The available information is useful for understanding the study question and the distinct protocols being compared.
It does not report numerical results for drug consumption, costs, recovery profiles or perioperative hemodynamic parameters. Therefore, the size, direction and precision of any differences in those outcomes cannot be described. The completed status does not itself show what the results were. Without group estimates and comparative analyses, it is not possible to determine whether the groups differed on the registered outcomes.
The group protocols also limit what can be attributed to the anaesthetic agent alone. Groups B and D were dosed to target BIS levels of 40 to 60 and MAP within 60-85 mmHg for controlled hypotension, while those targets are not described for Groups A and C. A contrast between groups could reflect protocol differences as well as the drug used. The registry record does not report an analysis that isolates those components.
The safety information is similarly descriptive: zero serious adverse events are listed in each group, while other adverse-event counts vary across groups. Definitions, follow-up duration and comparative uncertainty are not reported. These counts should not be interpreted as proof of equal safety or as proof of a safety difference.
In general, a clinical trial result is best understood through its effect estimate, uncertainty, outcome definition, analysis population and follow-up. Here, the registry record supports a description of the design and recorded event counts, but not a conclusion about comparative effects or costs. It does not support medical advice or a claim that either approach does or does not work.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it places two anaesthetic approaches in a four-group design rather than presenting only one group for each approach. The sevoflurane and propofol groups have different dosing descriptions, including target BIS and MAP values in Groups B and D. That structure makes the definition of the comparison central: an agent-level question and a protocol-level question are not necessarily the same.
The primary endpoint also contains several kinds of information. It concerns named drugs, an induction dose and drug use during anaesthesia in mg/1 hour. Such a structure highlights why outcome definitions and time points matter. A single label such as drug consumption can encompass distinct measures, and a meaningful statistical summary depends on specifying which measure is being compared.
The record is also a useful example of the difference between a registered design and an interpretable result. Randomization, masking and a completed status describe features of the study, but they do not replace outcome estimates, uncertainty intervals or analysis details. The serious and other adverse-event counts likewise describe what is listed without providing a comparative model or precision.
Finally, the planning assumptions illustrate the difference between a sample-size calculation and an observed finding. A planning illustration based on a fraction of an observed effect is not evidence that the study had a particular power, and it is not a substitute for reporting the effect and its uncertainty. The registry record does not report its own sample-size justification or numerical primary-outcome results. This makes transparent reporting of outcomes, contrasts and analysis populations especially important for statistical interpretation.
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.
A major limitation of the available record is that it does not report numerical results for the primary endpoint or the secondary outcome. There are no group means, standard deviations, effect estimates, confidence intervals or p-values for drug consumption or costs. The brief summary also names recovery profiles and perioperative hemodynamic parameters, but numerical results for those outcomes are not reported in the registry record.
The primary endpoint description covers multiple drugs and time points, yet the record does not provide the detailed outcome categories or a single comparison. This limits clarity about exactly what a summary estimate would represent. The four protocols also differ in their stated dosing targets, so the groups do not permit an unambiguous interpretation of an agent-only contrast from the descriptions alone. The main intended comparison and any method for combining groups are not reported in the registry record.
Important design and analysis details are absent. The identity of the masked party, randomization procedure, allocation concealment, baseline characteristics, statistical model, analysis population and sample-size justification are not reported in the registry record. Participant flow, missing-data handling, follow-up duration and outcome ascertainment procedures are also not reported. These omissions make it difficult to evaluate risk of bias, precision and the influence of missing observations.
The safety record gives event counts but not definitions, observation time, confidence intervals or comparative analyses. Deaths are not reported in the registry record. The record’s status as completed and its enrollment do not resolve these uncertainties or provide evidence about the unreported outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of Anaesthesia Costs and Recovery Profiles — NCT02920749.
- Registry record last updated 2018-02-06; status last verified 2018-02.
- Results first posted 2016-12-06.
- 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
The registry record describes a completed, randomized, single-masked, parallel-group study sponsored by the University of Pecs. It lists enrollment of 120 and a study of sevoflurane- and propofol-based general anaesthesia for otorhinolaryngeal surgery. Four groups are described, with distinct dosing protocols.
Drug consumption is the primary outcome, summarized as a mean with standard deviation and measured in milligrams. The description includes fentanyl, sevoflurane, propofol 1% and atracurium, at induction and during anaesthesia in mg/1 hour. Costs of anaesthesia are listed as a secondary outcome. Numerical results for these outcomes are not reported in the registry record.
The adverse-event record lists zero serious events among 30 people at risk in each group. Other adverse events are listed as affecting 14, 15, 4 and 8 people in Groups A, B, C and D, respectively. Deaths are not reported in the registry record.