Deep Neuromuscular Block for Laparoscopic Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Deep Neuromuscular Block for Laparoscopic Surgery (NCT03034577), a randomized phase 4 study. The primary outcome is Percentage of Patients Recovered Cognitively at 1 Week.

2. Clinical Question

The trial’s stated rationale was that deep blockade might improve operative conditions and potentially have benefits beyond the operation. The comparison therefore concerns two treatment strategies that differ in both blockade depth and reversal drug. It cannot isolate the effect of blockade depth from the effect of the reversal agent. The registry describes an effort to minimize variation in other anesthetic techniques and drugs, but does not report enough detail to establish how consistently that was achieved.

3. Trial Design

The registry describes a randomized, single-masked, parallel-group phase 4 trial of deep versus moderate neuromuscular blockade for laparoscopic surgery. It lists enrollment of 350 and says the trial was conducted across 4 centres. The registry status is completed. The primary completion date is 2019-02-15. It does not identify who was masked, describe the randomization sequence or allocation concealment, or report the criteria used to select participants.

The assigned strategies combined a blockade target with a reversal drug. The deep-block group received sugammadex; the moderate-block group received neostigmine. As a result, the randomized comparison evaluates the strategies as packages rather than the independent effects of blockade depth and reversal agent. The registry says investigators intended to minimize variation in other anesthetic methods and drugs, but the details of those methods, adherence, and any departures from assigned treatment are not reported in the registry record.

The primary endpoint was the percentage of patients recovered cognitively at 1 week. The registry also describes recovery assessment at multiple time periods using the Postoperative Quality of Recovery Scale. Secondary outcomes listed include recovery across all domains at 3 months, full reversal before extubation, anesthesia duration, surgical satisfaction, and hospital length of stay. Numerical results are posted for only some of these outcomes in the record.

The registry does not report the planned sample-size justification, a statistical analysis plan, the method of analysis for the primary endpoint, or a prespecified approach to missing data. Randomization supports a comparison of assigned groups in principle, but the interpretation of the posted results also depends on how participants were included in each analysis and how missing assessments were handled. Those details are not reported in the registry 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: No participants were excluded from the study prior to surgical procedure

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: There were 31 participants who did not complete the cognitive assessment at 1 week in the moderate neuromuscular blockade group, whereas there were 35 participants who did not complete the cognitive assessment at 1 week in the deep neuromuscular blockade group

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 Percentage of Patients Recovered Cognitively at 1 Week, measured over 1 week.

The primary endpoint measures the percentage of participants categorized as recovered in the cognitive domain at 1 week after surgery. The registry’s description says this time point was chosen because the investigators expected that most acute inflammation would have resolved and analgesia requirements would be minimal. This is the investigators’ stated rationale, not evidence that those conditions were verified for every participant.

A percentage expresses how common the specified recovery state was among the participants included in the endpoint result. It does not show the range of cognitive scores, the size of any change within an individual, or recovery in other domains. The registry identifies the Postoperative Quality of Recovery Scale as the broader instrument used across multiple periods, but the posted primary result is the cognitive domain at 1 week.

The arm entries report 91.8% for moderate blockade and 92.9% for deep blockade. The listed participant counts are 144 and 140, respectively. The outcome description separately reports that 31 participants in the moderate group and 35 in the deep group did not complete the cognitive assessment at 1 week. The registry does not explain how those incomplete assessments were handled when calculating the percentages, or whether the listed counts represent the full analysis population under a prespecified rule.

No interval estimate, p-value, or registry-reported comparative analysis is posted for the primary endpoint. The percentages describe the reported arm results, but the precision of the comparison and its sensitivity to missing assessments cannot be established from these figures alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does an arm percentage describe?

A percentage summarizes the share of participants in a group who meet a defined outcome. For this trial, the primary outcome is cognitive recovery at 1 week. The registry reports an arm percentage and a participant count for each group, but does not provide the comparative statistical analysis. A percentage alone does not reveal uncertainty: estimates based on fewer observed assessments are generally less precise than estimates based on more, and the registry does not explain the analysis population or handling of incomplete assessments.

How should the secondary binary comparison be read?

Full reversal before extubation is a binary outcome: each participant either meets the recorded criterion or does not. The posted recalculation expresses the comparison as a risk difference, which is the rate in the deep-block group minus the rate in the moderate-block group. Its estimate is 0.017, with an interval from -0.042 to 0.077. The interval includes zero, the value representing no difference on this scale. The unadjusted p-value is 0.572. The interval is important because it shows the range of differences compatible with the data under the calculation’s assumptions; the p-value is not the probability that the strategies are equal or that the result occurred by chance.

Other measures of a binary comparison, such as a risk ratio or odds ratio, describe relative rather than absolute differences. Their interpretation depends on the measure and the event rate. They do not resolve limitations in the underlying data or make an unadjusted result confirmatory.

How should the continuous comparisons be read?

For anesthesia duration and hospital length of stay, the posted summaries give group means and standard deviations. A mean is the average observed value, while a standard deviation describes how spread out individual observations are around that average. A mean difference is calculated as the mean for the deep-block group minus the mean for the moderate-block group. Negative estimates therefore indicate a lower mean in the deep-block group on the reported scale.

The anesthesia-duration mean difference is -1.4 minutes, with an interval from -20.78 to 17.98 and an unadjusted p-value of 0.887. The hospital-stay mean difference is -0.8 days, with an interval from -1.39 to -0.21 and an unadjusted p-value of 0.008. An interval that includes zero is compatible with no mean difference as well as differences in either direction. An interval that does not include zero, as in the posted length-of-stay calculation, indicates a result less compatible with zero under that calculation, but does not by itself establish clinical importance or account for multiple outcomes.

The listed standard deviations show that participant values vary within each group. The recalculated mean-difference intervals use the posted summary statistics. A pooled standard deviation and standardized effect are also used for the sample-size illustration, but they do not replace the outcome in its original units. Standardized effects can help express a mean difference relative to variability; their meaning remains dependent on the outcome and the assumptions used.

What do the p-values and intervals tell us?

A p-value summarizes how unusual data at least as incompatible with a specified null model would be if that model and the calculation’s assumptions held. It is not a measure of effect size, a measure of clinical importance, or a direct probability that the null hypothesis is true. The p-values shown for secondary outcomes are unadjusted recalculations. The registry does not report the trial’s own analysis for these comparisons.

An interval estimate conveys uncertainty around an estimated effect. Wider intervals indicate less precision; intervals spanning the no-difference value leave substantial uncertainty about direction and magnitude. Even a relatively narrow interval would not address systematic issues such as missing outcomes, measurement choices, or selective reporting. Here, the primary endpoint has no posted interval estimate, and the secondary intervals should be interpreted in light of the unreported analysis plan and multiplicity handling.

What do the sample-size illustrations mean?

The sample-size section is a planning illustration based on the observed effect, not the trial’s own design or observed power. It uses a two-sided significance level of 0.05, equal allocation, and a normal approximation. The rows show planning for 100%, 75%, and 50% of the observed effect; the table reports participants per arm for 80% power and participants per arm for 90% power. These figures illustrate how planning requirements change when the effect chosen for future planning is smaller than the observed estimate. They do not establish that the original trial was planned using those assumptions, and they should not be read as a retrospective probability that this trial detected an effect.

Planning from an observed effect is especially uncertain when the estimate itself is imprecise. A future design would need a justified target effect, assumptions about outcome variability or event rates, an analysis approach, and provisions for missing data. Those protocol details are not reported in the registry record. The displayed planning values are therefore illustrative rather than recommendations or evidence about the trial’s power.

10. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a statistical analysis plan or describe how the investigators handled multiple outcomes. The study includes a primary cognitive-recovery endpoint and several secondary outcomes, some of which cover different time periods and different aspects of care. Without a documented hierarchy or adjustment strategy, it is unclear which comparisons were intended to support confirmatory conclusions and how the results were to be interpreted as a set. The unadjusted recalculated secondary p-values do not account for the number of outcomes considered.

The record reports incomplete cognitive assessments at 1 week for 31 participants in the moderate-blockade group and 35 in the deep-blockade group. It does not report the reasons for noncompletion, whether the frequency or reasons differed across other participant characteristics, or how missing values were handled. The primary arm entries list 144 and 140 participants, but the relationship between those entries, the missing assessments, and the analysis population is not explained. No imputation method, sensitivity analysis, or assumption about missingness is reported in the registry record.

These gaps limit interpretation because missing outcomes can affect both the estimated recovery percentages and their uncertainty. If participants with incomplete assessments differ systematically in recovery from those assessed, a result based only on observed assessments may not represent the randomized groups as a whole. This is a general statistical concern, not a claim about why participants missed assessments in this trial.

The registry also does not report whether the primary analysis followed randomized assignment, whether participants were analyzed according to treatment received, or how protocol deviations were treated. The secondary posted arm counts are 175 in each group for the outcomes shown, but the analysis populations and handling of any missing secondary measurements are not described. The record gives no basis for assuming that the same population or approach was used across all endpoints. Clear reporting of analysis populations, missing-data methods, and multiplicity decisions would be needed for a fuller assessment.

11. 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 registry lists 175 participants at risk in each group for serious adverse events and other adverse events. It records zero serious adverse events, zero other adverse events, and zero deaths in each group. No serious adverse-event terms are listed.

These are the event counts posted in the registry, not proof that no adverse events occurred outside the registry’s definitions, collection procedures, or observation period. The record does not report the event definitions, the duration or completeness of safety follow-up, or how events were sought and adjudicated. It also does not provide additional detail about the severity or nature of non-serious events.

A zero count can be reassuring as a description of what was recorded, but it cannot establish that an event is impossible or that the strategies have identical safety profiles. Rare events may not appear in a trial, and conclusions depend on how events were collected and reported. The counts should therefore be read as registry safety data, with the limits of the available reporting in mind, rather than as a comprehensive safety assessment.

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

The posted primary endpoint values describe cognitive recovery at 1 week in the two randomized groups: 91.8% for moderate blockade reversed with neostigmine and 92.9% for deep blockade reversed with sugammadex. These are arm-level percentages, not a complete statistical comparison. The registry does not provide a primary confidence interval or p-value, and it reports incomplete cognitive assessments in both groups without explaining how those assessments were handled. The result therefore does not establish that the strategies are equivalent, nor does it quantify precisely how different their effects might be.

The secondary results add some information, but they answer distinct questions. The unadjusted recalculated comparisons for full reversal and anesthesia duration have intervals that include no difference. The length-of-stay calculation shows an estimated difference with an interval that does not include zero, but it remains a secondary result without reported multiplicity handling or a trial-reported analysis. It should not be treated as decisive evidence about the primary endpoint or about overall recovery.

The randomized design is relevant because it was intended to compare assigned strategies. However, the record does not report the randomization method, the analysis populations, or how missing outcomes were addressed. The intervention and comparator also differ in both blockade depth and reversal drug, so the comparison cannot identify the separate contribution of either component.

These data do not show whether the two approaches are clinically preferable, and they do not support medical advice. They describe the outcomes posted for this trial and the uncertainty and reporting gaps around them. A stronger interpretation would require the prespecified statistical plan, the primary comparative analysis, transparent handling of missing assessments, and complete results for the registered secondary outcomes.

13. Why This Trial Matters Statistically

This trial illustrates why reporting the primary result as an arm percentage is not enough to evaluate a randomized comparison. The percentages communicate the observed outcome levels, but a comparative interval estimate and a clearly defined analysis population are needed to understand precision. Here, the registry also notes incomplete primary assessments in both groups, yet does not explain how they were handled. That leaves a gap between the posted arm summaries and the question the randomization was designed to address.

It also shows why secondary findings need to be interpreted in the context of the full outcome set. The posted secondary calculations include estimates with different patterns, but the record does not report a multiplicity strategy or confirmatory hierarchy. An isolated unadjusted result can attract attention without showing whether it was prespecified, robust to analysis choices, or consistent with the primary outcome. Registry reporting of all planned outcomes and analyses makes that context visible.

The trial compares two clinically distinct strategies, each combining a blockade target with a reversal drug. This is an important design feature for interpretation: a difference between assigned groups, if established, would concern the full strategies and could not be attributed to a single component from this comparison alone.

Finally, the sample-size section is explicitly an illustration based on observed effects, not evidence of the original design rationale or retrospective observed power. Distinguishing planning calculations from the trial’s actual protocol helps prevent overconfident readings of sample size and p-values. Together, these issues make the study a useful example of how endpoint definitions, missing data, multiplicity, and the distinction between descriptive and comparative results shape what can be concluded from clinical trial records.

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 for interpreting the primary result is incomplete reporting of its comparative analysis. The registry gives arm percentages and participant counts but no primary interval estimate, p-value, or analysis method. It also reports incomplete assessments in both groups without stating whether missing observations were excluded or otherwise handled. The precision and robustness of the primary comparison therefore cannot be evaluated from the posted information.

The record does not report detailed participant eligibility criteria or baseline characteristics, so the population represented by the trial is not fully. Although the registry identifies the trial as randomized and single-masked, it does not identify who was masked or describe the randomization and allocation procedures. It also does not provide details sufficient to assess adherence to the assigned strategies, departures from protocol, or consistency of other anesthetic techniques across centres.

The assigned groups differ in both neuromuscular blockade depth and reversal drug. Any valid group comparison would estimate the effect of those combined strategies; the design as described cannot disentangle the separate effects of blockade depth and reversal agent. The registry’s description of the moderate-block protocol also ends before fully specifying the target after the majority of surgical excision.

Only some registered secondary outcomes have numerical results in the record. No trial-reported comparative analyses are listed, and the registry does not describe multiplicity control, analysis populations, or handling of missing secondary data. The posted secondary calculations are unadjusted, so any apparently notable result should be interpreted cautiously. Safety counts also lack reported event definitions and follow-up detail. These limitations arise from the information available in the registry record and do not establish that the trial itself lacked additional methods or analyses.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Deep Neuromuscular Block for Laparoscopic Surgery — NCT03034577.
• Registry record last updated 2020-04-22; status last verified 2020-04.
• Results first posted 2019-10-21.
• 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.

18. Record Summary

NCT03034577 is a completed, randomized, single-masked, parallel-group phase 4 trial of deep neuromuscular blockade reversed with sugammadex versus moderate blockade reversed with neostigmine for laparoscopic surgery. The registry lists enrollment of 350 and describes conduct across 4 centres. Its primary outcome is the percentage of patients recovered cognitively at 1 week.

The posted primary arm results are 91.8% for moderate blockade and 92.9% for deep blockade, with listed participant counts of 144 and 140. The registry also reports incomplete cognitive assessments in both groups but does not explain their handling or post a comparative primary analysis. Secondary numerical results include full reversal before extubation, anesthesia duration, and hospital length of stay; the other registered secondary outcomes do not have numerical results in the record. The registry reports zero serious adverse events, other adverse events, and deaths in both groups. Interpretation is limited by the absence of a reported statistical analysis plan, primary uncertainty estimates, and details on missing data, analysis populations, and multiplicity.