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 Intraoperative Video Laryngoscopy as Adjunct for Nerve Monitoring (NCT03742141), a na na study. The primary outcome is Frequency of Congruence of Nerve Integrity and Vocal Cord Functions.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03742141 |
| Phase | NA |
| Condition | Vocal Cord Function in Neck Procedures |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 125 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Icahn School of Medicine at Mount Sinai |
| Results posted | Yes |
2. Clinical Question
Population
Participants undergoing neck procedures that place the recurrent or superior laryngeal nerves at risk for injury or postoperative dysfunction. The study description names thyroidectomy and re-operative parathyroidectomy among the procedures of interest. The registered enrollment is 125.
Intervention
Intraoperative video laryngoscopy (IOVL) used alongside routine intraoperative laryngeal nerve monitoring (IOLNM). The device permits visual assessment of vocal-cord movement in response to nerve stimulation. Glycopyrrolate is also listed as an intervention, but its use and role are not described in the registry record.
Comparator
There is no separate control group in the registered design. The study examines IOVL in conjunction with IOLNM, including the potential for IOVL to add information when routine monitoring is ambiguous or equipment malfunctions. This is not a like-for-like comparison of treatment groups.
Primary question
How often do IOVL findings and nerve-monitoring findings agree about nerve integrity and vocal-cord function? The primary outcome is described as the frequency of congruence, with nerves at risk as the unit and a timeframe of up to 3 months post-resection. Its numerical result is not reported in the registry record.
The clinical question focuses on whether direct visualization contributes information alongside the audio signal and visual assessment of external laryngeal muscle movement used in routine monitoring. The registry describes situations in which the added view may be useful: ambiguous monitoring results, equipment malfunction or failure, and limited visualization of external laryngeal muscles. These are the study’s stated motivations, not reported findings about how often those situations occurred or how decisions changed.
IOVL positivity is defined by observed vocal-cord movement during nerve stimulation. The registry defines positive EMG as an NPI value >100 and loss of signal as an NPI value <100. A discordance is a contradictory IOVL and EMG finding for a particular nerve. The outcome therefore concerns agreement at the nerve level, rather than a direct comparison of participant groups. The registry does not report the observed number or proportion of congruent findings.
3. Trial Design
The registry identifies NCT03742141 as a completed, single-group study titled Intraoperative Video Laryngoscopy as Adjunct for Nerve Monitoring. Enrollment is listed as 125. The study began on 2018-10-17, and the primary completion date is 2022-01-18. The listed phase and allocation are NA, and masking is listed as NONE. The record names Icahn School of Medicine at Mount Sinai as sponsor.
The registered group consists of participants undergoing neck procedures. IOVL is used in conjunction with routine IOLNM, rather than being assigned against a separate group receiving routine monitoring alone. The registry explicitly cautions that this is not a randomized comparison and that the arms are not a like-for-like control comparison. Consequently, the design does not support a randomized between-group estimate of the effect of adding IOVL.
The study description identifies thyroidectomy and re-operative parathyroidectomy as examples of procedures in scope. It explains that a disposable fiberoptic laryngoscope is inserted alongside the endotracheal tube following intubation and allows assessment of vocal-cord movement in response to nerve stimulation. The registry lists Glycopyrrolate as an intervention as well, but does not report how it was used, whether its use was uniform, or how it relates to the primary outcome.
The primary outcome timeframe is up to 3 months post-resection. The record describes video-captured vocal-cord movement and the Nerveana Power Index (NPI) audio signal as the information used to classify findings. It does not report a protocol-level schedule of assessments, the number of procedures or nerves assessed, or details of how observations within the same participant were handled. Those design details are not reported in the registry record.
Completed status indicates the registry’s stated study status; it does not, by itself, provide the outcome estimate or establish how complete the posted outcome data are. Although the registry lists 1 outcome measure, it lists 0 analyses. Numerical results for the primary outcome are not reported in the registry record, so the scale and precision of the observed congruence cannot be described from this 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 | Intraoperative Video Laryngoscopy |
|---|---|
| STARTED | 125 |
| COMPLETED | 75 |
| NOT COMPLETED | 50 |
Reasons for not completing this period:
| Reason | Intraoperative Video Laryngoscopy |
|---|---|
| no surgery or post-operative laryngoscopy | 50 |
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 | Intraoperative Video Laryngoscopy |
|---|---|---|
| Participants analysed | 75 | |
| Age, Continuous | years | 52.1 (23 to 81) |
| Sex: Female, Male: Female | Participants | 52 |
| Sex: Female, Male: Male | Participants | 23 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 5 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 13 |
| Race (NIH/OMB): White | Participants | 20 |
| Race (NIH/OMB): More than one race | Participants | 19 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 18 |
| BMI | kg/m^2 | 28.7 (18.5 to 46.3) |
| History of Thyroiditis | Participants | 13 |
| Thyroid Weight | grams | 28.0 (2 to 200) |
| Thyroid Size | cm | 5.4 (2 to 12.9) |
| Indication for surgery: Cancer | Participants | 21 |
| Indication for surgery: Nontoxic Multinodular Goiter | Participants | 15 |
| Indication for surgery: Toxic Multinodular Goiter | Participants | 3 |
| Indication for surgery: Suspicious Nodule | Participants | 14 |
| Indication for surgery: Grave's Disease | Participants | 4 |
| Indication for surgery: Other | Participants | 18 |
| Type of surgery: Right hemithyroidectomy | Participants | 24 |
| Type of surgery: Left hemithyroidectomy | Participants | 18 |
| Type of surgery: Total thyroidectomy | Participants | 33 |
6. Primary Endpoint
The registry lists the primary outcome as Frequency of Congruence of Nerve Integrity and Vocal Cord Functions, measured over up to 3 months post-resection.
| Element | Registry entry |
|---|---|
| Result type | Count Of Units |
| Measure of spread | not applicable |
| Unit | nerves at risk |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled Frequency of Congruence of Nerve Integrity and Vocal Cord Functions. Its unit is nerves at risk, and its timeframe is up to 3 months post-resection. The endpoint concerns whether direct visual assessment of vocal-cord movement agrees with the nerve-monitoring signal for a nerve. The registry calls contradictory IOVL and EMG findings for a particular nerve discordances.
The record defines positive IOVL as observed vocal-cord movement in response to nerve stimulation and negative IOVL as no visible movement. The NPI is described as an index specific to the Nerveana machine, representing nerve or muscle response power as a percentage of the threshold level of response. The registry defines loss of signal as NPI <100 and positive EMG as NPI >100. These definitions describe how signals are categorized; they do not give the frequency of either category or the frequency of agreement.
This endpoint is relevant to the stated study aim because routine monitoring is described as relying on audio cues and visual assessment of external laryngeal muscle movement, while IOVL offers a direct view of vocal-cord movement. Agreement can describe whether the two sources of information point in the same direction for a nerve. Discordance can identify instances where the signals differ, but does not by itself establish which signal is correct or whether a surgical decision changed.
The registry does not report the primary endpoint’s observed count, proportion, or uncertainty interval. It also does not report how missing or uninterpretable nerve observations were treated. Without those details, the endpoint’s numerical magnitude and precision cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the study’s question and outcome definitions, but not a numerical primary outcome result. It therefore does not establish how frequently IOVL and routine nerve monitoring agreed, how often they were discordant, or how frequently IOVL posted confirmatory or additional information. The outcome description explains what the study intended to measure; it is not itself a result.
The outcome is recorded in nerves at risk, not as a participant-level endpoint. This distinction matters when interpreting any reported count: a count of nerves cannot automatically be treated as a count of participants. The registry does not report the number of nerves evaluated or how many observations came from each participant. It also does not describe an analysis that accounts for possible dependence among observations from the same participant. Those points limit what can be inferred about precision if a nerve-level summary is considered on its own.
The study is single-group and has no separate control group. Its stated purpose is to describe the added information from IOVL when used with routine monitoring. It is not a randomized comparison of IOVL against no IOVL. Even if a numerical frequency of congruence were available, that result would describe agreement within the studied setting; it would not by itself estimate a causal effect on surgeon decisions, postoperative vocal-cord function, or other clinical outcomes.
The registry’s definitions distinguish a positive visual finding from a positive EMG signal and define discordance as contradictory findings. Those classifications organize the signal comparison, but agreement is not synonymous with accuracy. Assessing accuracy would require an appropriate reference standard, and the registry description does not identify one for the primary outcome. Nor does it report whether discordant observations were adjudicated or how ambiguous signals were classified.
Precision cannot be judged because the primary numerical estimate and its uncertainty are not reported in the registry record. A confidence interval, when reported, describes the range of estimates compatible with the data and analysis under its assumptions; it does not eliminate concerns about measurement, selection, or design. No confidence interval for the primary endpoint is reported.
The study status is COMPLETED, but completion does not substitute for outcome reporting. The registry lists a primary endpoint and its timeframe, yet the numerical finding is not reported in the registry record. Accordingly, conclusions should remain at the level of the study’s purpose, design, and measurement definitions. Any claim about the observed frequency of agreement, the value of added information, or the impact on decisions would require results that are not reported in the registry record.
9. Statistical Methods Explained
What does the endpoint count?
The primary outcome is a count-type measure with nerves at risk as its stated unit. A count records how many units meet a defined condition; in this study, the condition is described through congruence between nerve integrity and vocal-cord function findings. The unit is important: a nerve-level count is not interchangeable with a participant-level count. If a participant contributes observations for more than one nerve, those observations may be statistically related. The registry does not report how many nerve observations were made or whether the analysis accounted for within-participant dependence.
The outcome description defines signal categories rather than providing a numerical summary. IOVL positivity corresponds to observed vocal-cord movement during nerve stimulation. Positive EMG corresponds to NPI >100, while loss of signal is defined as NPI <100. Discordance means contradictory IOVL and EMG findings for a particular nerve. Such rules make classifications more explicit, but they do not remove the possibility of measurement error, ambiguous observations, or differences in interpretation. The registry does not report how those situations were handled.
How should agreement be interpreted?
Agreement is a measure of whether two methods give matching classifications. It can be informative when the purpose is to describe whether an added measurement confirms another signal or provides a different one. Agreement alone does not establish that either method is correct. If both methods share a source of error, they can agree and still be wrong; if they disagree, an external reference or adjudication may be needed to determine which finding better reflects the underlying condition. The registry description does not report an external reference standard or an adjudication procedure.
A frequency of agreement can be reported as a count or as a proportion of eligible observations. The registry names the outcome as a frequency but does not report the observed count or proportion. No denominator for the primary endpoint is given in the registry record. Without the numerator, denominator, and rules for handling unevaluable observations, the result cannot be reconstructed or interpreted numerically.
What does uncertainty describe?
In general, a confidence interval expresses sampling uncertainty around an estimate under the assumptions of the statistical method. A narrow interval indicates greater precision under those assumptions; a wide interval indicates less precision. It does not account automatically for bias from selection, measurement, missing observations, or an unsuitable analysis. No primary-outcome confidence interval is reported in the registry record, so the precision of the result cannot be evaluated.
Count outcomes can have variability that differs from the assumptions of a simple model. Over-dispersion is a general statistical issue in which the observed variation is greater than a model expects. If present and not handled appropriately, it can make uncertainty estimates too small. This is a general consideration for count data, not a reported feature of this study. The registry record does not identify a statistical model or report a dispersion assessment.
Clustering is another general issue when multiple measurements are contributed by the same participant. Measurements from one participant may be more alike than measurements from different participants. Treating every nerve as independent when the observations are clustered can affect estimated uncertainty. The registry identifies nerves at risk as the outcome unit but does not report whether multiple nerve observations per participant occurred or how any clustering was handled. It would therefore be inappropriate to assume a particular adjustment method.
What analysis is documented?
The registry lists 0 analyses. It does not report a statistical analysis plan, a model for the primary endpoint, an interval-estimation method, or a hypothesis test for congruence. It also does not report an adjusted or unadjusted effect estimate. No analysis method should be inferred from the endpoint definition alone. The absence of an analysis in the registry record does not establish that no analysis was conducted outside the record.
The registry includes planning-illustration assumptions: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and detection of a stated fraction of the observed effect. The record describes these as planning illustrations computed from the observed effect, not as the study’s own design. This matters because the registered study is single-group, not a randomized two-arm comparison. Such illustrations are hypothetical planning quantities; they are not observed power and do not supply evidence about the primary endpoint. No numerical planning estimates are reported in the registry record.
For time-to-event planning illustrations, the registry says the total number of events is used; for other illustrations, it says participants per arm. Those conventions do not change the registered primary outcome’s stated unit, nerves at risk. The registry does not report a time-to-event primary outcome or a two-arm design. Readers should not treat planning conventions as descriptions of the study’s actual analysis.
What can be concluded from the posted record?
The record supports a description of the study’s single-group design, intended population, measurement approach, and endpoint definitions. It does not supply the numerical primary outcome or methods needed to assess its uncertainty. Consequently, a statistical interpretation must distinguish the purpose of measuring agreement from evidence about the observed frequency or precision. Numerical estimates, p-values, and confidence intervals for the primary outcome are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 1 outcome measure and 0 analyses. The record identifies a primary outcome, but does not report a statistical analysis plan or explain whether additional outcomes, subgroup analyses, or exploratory comparisons were planned. The number of analyses listed in the registry does not establish whether analyses were or were not conducted elsewhere.
A multiplicity adjustment addresses the risk of misleading results when many hypotheses are tested. Whether such an adjustment is relevant depends on the planned questions and analysis strategy. The registry record does not report a multiplicity approach, a family of statistical tests, or a hierarchy of secondary analyses. It is therefore not possible to determine whether multiplicity was considered or how it might affect interpretation.
The record does not report the extent of missing outcome data, how missing or uninterpretable signals were defined, or how they were handled. It does not describe whether every eligible nerve observation was included, whether observations were excluded, or whether any imputation method was used. Missingness can affect a frequency estimate if observations that cannot be classified differ from those that can be classified. Without counts and a missing-data strategy, the direction or size of any such effect cannot be assessed.
Analysis populations are not described. The registry does not state whether outcome summaries would use all enrolled participants, only participants with evaluable signals, or another set of observations. It also does not report how observations at the nerve level were mapped to participant-level summaries. These methods are not reported in the registry record, so the population represented by any numerical estimate cannot be verified from this 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 |
|---|---|---|---|
| Intraoperative Video Laryngoscopy | 1 | 75 | 1.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Intraoperative Video Laryngoscopy | 0 of 75 |
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 |
|---|---|
| Intraoperative Video Laryngoscopy | 2 of 75 |
Most frequent serious adverse event terms
| Event term | Organ system | Intraoperative Video Laryngoscopy |
|---|---|---|
| Tracheostomy | Injury, poisoning and procedural complications | 1 of 75 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Intraoperative Video Laryngoscopy |
|---|---|---|
| Transected nerve intraoperatively | Injury, poisoning and procedural complications | 1 of 75 |
| reintubation and a tracheostomy immediately postoperatively | Injury, poisoning and procedural complications | 1 of 75 |
Serious events with the highest arm-level rate: tracheostomy (1.3%).
The registry lists safety information for the Intraoperative Video Laryngoscopy group. It reports 75 at risk for serious adverse events, with 1 affected, and 75 at risk for other adverse events, with 2 affected. Deaths are listed as 0. The top serious adverse event term is Tracheostomy, listed as 1.3%.
These entries should be read as registry safety summaries, not as a comparison between randomized groups. The design is single-group, and the record does not provide a control group for estimating comparative safety. The term Tracheostomy and its listed percentage are registry entries; the record does not specify the denominator for that percentage in the safety summary. No rate should be recalculated from the listed counts.
The record does not explain whether the serious and other adverse event counts refer to distinct participants, whether events could overlap, how events were attributed, or the safety observation window. The figures therefore do not establish causation or provide a complete account of severity, duration, or clinical context. Adverse-event summaries are most informative when their definitions, collection period, denominators, and relationship to the intervention are clear. Those details are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The study addresses a practical measurement question: whether direct visualization of vocal-cord movement can provide confirmatory or additional information when used with routine intraoperative laryngeal nerve monitoring. The registry explains why that question was asked, including the possibility of ambiguous audio cues, equipment malfunction or failure, and limited visibility of external laryngeal muscles. Those motivations describe the rationale; they are not evidence that IOVL changed decisions or improved outcomes.
The primary endpoint is about congruence between findings at the nerve level. A result for this endpoint, if reported, would describe how often two measurements agreed under the study’s definitions. Agreement does not alone prove diagnostic accuracy, identify which signal should be trusted when the methods disagree, or demonstrate that decisions based on the signals lead to better outcomes. The registry does not report an external reference standard for judging accuracy.
The study is single-group and does not include a like-for-like control comparison. It therefore cannot, from this design alone, provide a randomized estimate of what would have happened under routine monitoring without IOVL. Any observed frequency would need to be interpreted as a description of the studied setting, with attention to who was included, which nerves were assessed, and how missing or ambiguous signals were treated. Those analysis details are not reported in the registry record.
The record does not report the numerical primary outcome, its denominator, or an uncertainty interval. It is not possible to characterize the magnitude or precision of the observed congruence from the registry record. Completion status and an outcome definition do not fill that gap. The evidence that can be described is limited to the registered design, intended measurement, and safety entries.
Accordingly, the record does not establish how often IOVL confirmed routine monitoring, how often the methods disagreed, or whether the additional view affected surgeon decisions, postoperative function, or other outcomes. It also does not establish a treatment effect or a comparative safety effect. Those questions require results and methods that are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically distinctive because its primary unit is the nerve at risk rather than the participant. That choice aligns the endpoint with the signal comparison: each nerve has a monitoring result and a visual assessment of vocal-cord movement. At the same time, nerve-level observations may not be independent if a participant contributes more than one nerve observation. The registry does not report whether that occurred or how dependence was handled, making the analysis unit and uncertainty method important to interpretation.
The endpoint also asks about agreement between two measurement approaches, not simply whether an intervention was assigned. Agreement can answer whether signals tend to match under specified classifications. It cannot, without a suitable reference standard, establish which approach is accurate when signals conflict. Clear definitions such as positive IOVL, positive EMG, loss of signal, and discordance help readers understand the intended classification, but do not replace information about the observed data or their quality.
The single-group design makes the distinction between description and causal comparison especially important. The study’s stated goal is to characterize the added information from IOVL alongside routine monitoring. It does not establish a randomized contrast between monitoring strategies. As a result, even a reported frequency of congruence would be evidence about observed signal patterns, not by itself evidence that the device changed clinical decisions or outcomes.
The registry record also illustrates why registration details and results need to be read separately. It names the endpoint and provides measurement definitions, while the numerical endpoint result and analysis methods are not reported in the registry record. A clearly described question is valuable, but statistical precision and the strength of conclusions depend on reported estimates, denominators, uncertainty, and analysis choices.
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 primary limitation for interpreting the registered outcome is that its numerical result is not reported in the registry record. The endpoint description gives the unit, timeframe, and signal definitions, but not the observed count, denominator, proportion, or uncertainty interval. The frequency and precision of congruence therefore cannot be assessed from this record.
The single-group design has no separate control group and is not a randomized comparison. It can describe findings when IOVL is used with routine monitoring, but it does not provide a like-for-like estimate of outcomes under a different monitoring strategy. The record does not report whether IOVL changed surgeon decisions or whether any decision changes were associated with subsequent function.
The outcome is measured in nerves at risk, while enrollment is reported for participants. The number of nerves assessed, the number of observations per participant, and the handling of within-participant dependence are not reported in the registry record. The handling of missing, ambiguous, or technically unusable signals is also not reported. These omissions prevent assessment of the denominator and the precision of a nerve-level summary.
The record does not identify an external reference standard for determining which method is correct when IOVL and EMG disagree. It also does not report a statistical analysis plan, model, confidence interval method, analysis population, or multiplicity strategy. Glycopyrrolate is listed as an intervention, but its role and administration are not described. These details are not reported in the registry record and should not be inferred.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Intraoperative Video Laryngoscopy as Adjunct for Nerve Monitoring — NCT03742141.
- Registry record last updated 2023-10-02; status last verified 2023-08.
- Results first posted 2023-10-02.
- 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
NCT03742141 is a completed, single-group study sponsored by Icahn School of Medicine at Mount Sinai. The registry lists enrollment of 125, a start date of 2018-10-17, and a primary completion date of 2022-01-18. Allocation and phase are listed as NA, and masking is listed as NONE.
The study examines intraoperative video laryngoscopy alongside routine intraoperative laryngeal nerve monitoring during neck procedures. Its primary outcome concerns the frequency of congruence between nerve-integrity findings and vocal-cord function, with nerves at risk as the unit and a timeframe of up to 3 months post-resection. The registry defines the relevant IOVL and EMG signal classifications but does not report a numerical primary outcome, its uncertainty, or the analysis method.
The safety summary lists 75 at risk and 1 affected for serious adverse events, 75 at risk and 2 affected for other adverse events, and 0 deaths. Tracheostomy is listed as the top serious adverse event term at 1.3%. The record does not report details needed to interpret these entries as comparative safety estimates.