Assessment of Laryngopharyngeal Sensation in Adductor Spasmodic Dysphonia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Assessment of Laryngopharyngeal Sensation in Adductor Spasmodic Dysphonia (NCT05158179), a na na study. The primary outcome is Laryngeal Adductor Reflex.

2. Clinical Question

The study’s broader scientific aim was to examine laryngopharyngeal sensation in people with laryngopharyngeal disorders and compare perceptual strength maps with those of healthy controls. The registered study, however, is described as examining patients with spasmodic dysphonia, with no healthy control arm listed. The primary endpoint is a binary observation of the reflex, rather than a direct comparison between groups or a measurement of change over time.

The intervention is listed as sensation testing using a device. The registry’s abbreviated arm description refers to nasal local anesthetic, a channeled laryngoscope, and a monofilament used as an internal perceptual anchor. Further procedural details are not reported in the registry record. A secondary outcome is perceptual strength of sensation on a 1-10 numerical rating scale. The main question addressed by the posted primary result is therefore whether the reflex was observed following the testing stimulus, not whether sensation differed from that in healthy controls.

3. Trial Design

This was a completed, single-group study with an enrollment of 13. The intervention is listed as sensation testing, categorized as a device intervention. The study was conducted at the University of California, San Francisco. The registry records a start date of 2021-08-27 and a primary completion date of 2022-04-29. Its status is completed.

There was no randomized allocation and no masking. The study model is single group, so the participants do not form treatment and control arms for a like-for-like comparison. The registry lists spasmodic dysphonia patients as the study group. Although the brief summary describes a previous series of 22 healthy adults and states an interest in comparing perceptual strength maps with healthy controls, the current record does not list healthy participants as a concurrent study group.

The primary outcome is the presence or absence of a laryngeal adductor reflex immediately after the intervention, with a timeframe of less than 10 seconds. The registry also lists perceptual strength of sensation on a 1-10 numerical rating scale as a secondary outcome. Two outcome measures are listed, but no analysis records are listed. The statistical plan, including any planned hypothesis tests or adjustments, is not reported in the registry record.

The arm description gives some procedural context, including use of nasal local anesthetic and a laryngoscope, but the text available in the registry is incomplete. The complete testing sequence and the planned approach to comparing results across anatomical sites are not reported in the registry record. The record also does not describe a sample-size justification for this study. Any planning illustrations shown elsewhere on the page should be read as hypothetical calculations, not as the documented rationale for the study’s enrollment.

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

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 Laryngeal Adductor Reflex, measured over Immediately after intervention, less than 10 seconds.

The primary endpoint is the presence or absence of a laryngeal adductor reflex after tactile stimulation. The registry describes the reflex as involuntary closure of the vocal folds in response to stimulation, observed during flexible laryngoscopy. The study team recorded whether it was present at the time of testing, and another team member confirmed the observation through later video review.

This is a binary endpoint: each observation is classified as present or absent. It is used to record an immediate, visible reflex response to direct contact by the tactile aesthesiometer. The specified timeframe is immediately after the intervention, less than 10 seconds. The registry says the study examined patients with spasmodic dysphonia and that all of them had the reflex present.

The endpoint is not a measure of how strong a sensation felt, nor does it directly quantify a participant’s perception. The registry lists perceptual strength on a 1-10 numerical rating scale as a secondary outcome, which addresses a different aspect of sensation. The primary endpoint also does not, by itself, establish whether reflex responses differ from those in healthy people: no concurrent healthy comparison group is listed. A numerical count of positive and negative observations in the primary outcome results is not separately reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a binary primary outcome and lists no analysis records. The methods explanation below separates what the record says about the endpoint from general statistical context. It does not infer an unreported analysis plan.

What does a binary endpoint represent?

A binary endpoint has two possible categories. Here they are presence and absence of the laryngeal adductor reflex after stimulation. For each assessment, the outcome is classified rather than measured on a continuous scale. A count of participants in each category can summarize such an endpoint, provided the number assessed in each category is clear. The registry’s narrative says all patients studied had the reflex present, but a separate outcome count and denominator are not reported in the registry record.

Binary data are different from the secondary numerical rating scale outcome. A rating scale can describe gradations of perceived strength, whereas reflex presence records whether a defined response was observed. The two outcomes can inform different questions and should not be treated as interchangeable. The registry lists perceptual strength on a 1-10 numerical rating scale as secondary, but numerical results for that measure are not reported in the registry record.

What does the study design allow?

In general, a single-group study can describe observations among the participants tested. Without a concurrent comparator, it cannot directly estimate a between-group contrast from the study itself. A previous series of healthy adults is mentioned in the brief summary, but the record does not list those adults as a comparator group in this study. Consequently, comparisons with them should not be presented as if they were randomized or measured alongside the patients under the same study design.

Random allocation and masking are both listed as absent. In general, random allocation is used to make comparison groups more comparable on average, and masking can reduce the influence of knowledge about group or treatment assignment. Those concepts are less central to interpreting a single-group descriptive observation, but their absence reinforces that the registered design is not a blinded comparative trial. The registry does not report other measures intended to address observer expectations beyond its statement that another team member reviewed the video.

How should uncertainty be considered?

A confidence interval is a statistical range that conveys the uncertainty around an estimate under specified assumptions. For a binary outcome, an interval could accompany a proportion or another explicitly defined estimate. No such estimate or confidence interval is reported for the primary outcome in the registry record. The narrative finding can therefore be described, but its statistical precision cannot be quantified from the posted primary outcome information.

A hypothesis test would address a specified statistical question, such as whether an outcome differs from a defined reference or comparator. The registry lists no analysis records, and the comparison or null hypothesis for the primary endpoint is not reported in the registry record. It would be inappropriate to infer a p-value or claim statistical significance from the descriptive wording alone.

What do planning calculations mean?

General sample-size calculations estimate how many participants might be needed under specified assumptions to detect a defined effect with a chosen statistical procedure. The planning assumptions described for the page use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the intended effect is a stated fraction of the observed effect. These assumptions describe a planning illustration, not the design rationale documented for this single-group study. The calculation does not represent observed power, and a two-arm illustration should not be mistaken for evidence that this study included a second arm.

The registry does not report the study’s sample-size justification, the effect it was designed to detect, or a prespecified statistical analysis plan. General planning calculations depend on assumptions about the outcome, effect, allocation, and analysis. They cannot supply missing protocol details or convert a descriptive result into a comparative finding.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability is greater than a statistical model expects. It can affect standard errors and the reliability of model-based inference, especially when counts or repeated observations are analyzed. The record does not describe a count model, repeated-measures analysis, or any assessment of over-dispersion. It is therefore a general methodological consideration, not an identified issue in the posted analysis.

More broadly, the endpoint is an immediate observed reflex, while the study’s stated wider interest includes perceptual strength maps at laryngopharyngeal structures. To interpret those maps statistically, a report would need to specify the observations collected, how within-participant measurements were handled, and what comparisons were planned. Those details are not reported in the registry record. The posted primary description supports a limited descriptive account of reflex presence, not a reconstruction of unreported analyses.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Spasmodic Dysphonia Patients")
n      <- c(13)
events <- c(13)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Spasmodic Dysphonia Patients  13  13  100.0  75.3  100.0  77.2  100.0  76.8  99.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary laryngeal adductor reflex endpoint and a secondary measure of perceptual strength on a 1-10 numerical rating scale. It does not report a statistical analysis plan, a hierarchy of secondary analyses, or a procedure for addressing multiple comparisons. Multiplicity refers generally to the increased chance of chance findings when many outcomes or comparisons are examined. Whether any adjustment was appropriate cannot be determined without the planned analyses, which are not reported in the registry record.

The record contains no analysis entries. This limits the ability to determine whether results were analyzed according to a prespecified plan, whether all outcomes were reported, or whether analyses were exploratory. The absence of registry analysis entries does not prove that no analysis was conducted; it means the registry record does not document one.

Missing-data handling and the analysis population are also not reported in the registry record. The enrollment is listed as 13, but the primary outcome narrative does not state a separate denominator, explain whether any enrolled participants lacked an assessable outcome, or identify an analysis set. The endpoint description says all patients with spasmodic dysphonia in the study had a present reflex, but the record does not provide enough detail to determine how that statement relates to enrollment or any exclusions.

In general, missingness can affect interpretation when participants or measurements without recorded outcomes differ from those with observed outcomes. The extent of any such issue cannot be assessed because the registry does not report missing observations or their handling. The posted result should therefore be read as a registry narrative, not as a complete statistical account of outcome availability or analysis populations.

12. 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 adverse-event record lists 13 participants at risk for serious adverse events and 0 affected. It also lists 13 at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse-event terms are listed.

These are registry counts for the recorded study group. They describe what was entered in the adverse-event section; they do not establish that every possible event was measured or that an event could not occur. The record does not provide additional information about how events were solicited, how long safety follow-up lasted, or how events were defined beyond the serious and other categories displayed.

The safety figures should be kept separate from the primary endpoint. A present laryngeal adductor reflex is an outcome of the sensory testing procedure, not an adverse-event count. Likewise, zero recorded events should not be interpreted as a comparison with another intervention, because the study has no concurrent control arm. The figures are descriptive registry entries, and the registry record does not report further safety analyses.

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

The result supports a narrow descriptive statement: the registry reports that the laryngeal adductor reflex was present in all patients with spasmodic dysphonia examined in this study after tactile stimulation. The reflex was assessed immediately after the intervention, within less than 10 seconds, and the registry says observations were confirmed on video review by another team member.

This finding does not establish how often the reflex would be observed in other populations or settings. The study is a single-group study, and no concurrent healthy comparison group is listed. The earlier series of 22 healthy adults mentioned in the brief summary is background, not a control arm for the registered study. The record therefore does not support a direct estimate of a difference between patients and healthy adults.

The finding also does not, on its own, quantify the strength or distribution of perceived sensation. The registry lists perceptual strength on a 1-10 numerical rating scale as a secondary outcome, but does not report its numerical results. Nor does the primary endpoint report how sensation varies across laryngopharyngeal subsites. The broader stated aim of examining perceptual strength maps should not be confused with the narrower information available in the primary outcome description.

No confidence interval, test result, or separate primary-outcome count is reported in the registry record. As a result, the precision of the observation cannot be evaluated statistically from this entry. The registry also does not document a statistical plan or a sample-size justification. These gaps do not negate the reported observation, but they limit the conclusions that can be drawn from it.

The record is most useful as a description of an immediate reflex response observed during sensory testing in this group. It should not be read as evidence of comparative effectiveness, as a causal comparison, or as a complete account of sensory differences between patients and healthy people.

14. Why This Trial Matters Statistically

This study raises a statistical distinction that matters in clinical research: an observed response in a single group is not the same as a comparative effect. The registry reports reflex presence among the patients examined, but it does not include a concurrent control group. Even when a study’s broader motivation involves comparison with healthy controls, the design and results posted for the particular study determine which comparisons can be made.

The primary endpoint is also distinct from the broader sensory question. A binary reflex observation captures whether a visible response occurred immediately after stimulation. A numerical rating scale captures perceived strength, and anatomical mapping could address how perception differs by site. These measures answer different questions. Keeping them separate helps prevent a simple present-or-absent result from being interpreted as a complete measure of laryngopharyngeal sensation.

Statistical transparency is important for interpreting even a descriptive finding. A denominator, analysis population, uncertainty estimate, and analysis plan would help readers understand how precisely the result is known and how the outcome data were handled. Those details are not reported in the registry record. The absence of registered analyses also makes it important to distinguish the posted narrative from formal statistical inference.

The planning illustrations shown with the page should be understood as hypothetical calculations based on stated assumptions, not as observed power or as the documented justification for enrollment. Their two-arm assumptions do not change the study’s single-group design. This is a useful reminder that sample-size calculations depend on a specific comparison and analysis; they do not independently establish that a study has answered that question.

Overall, the study illustrates why design, endpoint definition, and reporting detail must be considered together. Its posted primary finding is informative as a description of the reflex observation, while the lack of comparative data and statistical detail places clear limits on broader inference.

15. 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 study’s single-group design is the main limitation for comparative interpretation. No concurrent control group is listed, and no randomized allocation is reported. Although the brief summary discusses interest in comparing patients with healthy controls and mentions an earlier series of 22 healthy adults, that series is not a like-for-like control arm in this study record.

The registry lists an enrollment of 13, but does not provide a separate denominator for the primary outcome or an outcome count in the primary results description. It states that all patients with spasmodic dysphonia studied had the reflex present. The relationship between that wording and the enrolled population, including any exclusions or unavailable assessments, is not reported in the registry record.

Statistical detail is limited. No analysis records, confidence interval, hypothesis test, analysis population, or sample-size justification are reported. The registry does not explain how missing observations would be handled or identify a plan for multiple outcomes or comparisons. These omissions prevent an assessment of statistical precision and of whether analyses followed a prespecified plan.

The primary endpoint captures the presence or absence of a reflex, not the strength of sensation. Although a numerical rating scale is listed as a secondary outcome, its numerical results are not reported in the information. The registry’s broader aim refers to perceptual strength maps, but site-specific results and their analysis are not reported in the registry record.

The intervention description is also incomplete in the registry entry. It mentions nasal local anesthetic, a laryngoscope, and tactile testing, but the full procedure and testing sequence are not available. Safety counts are listed, but further details about event collection and follow-up are not reported in the registry record. These limitations constrain interpretation of both the methods and the scope of the findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Assessment of Laryngopharyngeal Sensation in Adductor Spasmodic Dysphonia — NCT05158179.
• Registry record last updated 2024-01-11; status last verified 2024-01.
• Results first posted 2024-01-11.
• 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.

19. Record Summary

This completed, single-group study assessed laryngopharyngeal sensation in patients with spasmodic dysphonia using sensation testing with a device. The registry lists an enrollment of 13 and identifies the primary endpoint as presence or absence of the laryngeal adductor reflex immediately after stimulation, within less than 10 seconds.

The primary outcome description reports that the reflex was present in all patients with spasmodic dysphonia studied. A secondary outcome is perceptual strength on a 1-10 numerical rating scale, but its numerical results are not reported. No concurrent control group, analysis records, confidence interval, or statistical plan is listed. Serious adverse events and other adverse events are each recorded as affecting 0 participants among 13 at risk; deaths are recorded as 0.

The record supports a descriptive account of an immediate reflex observation. It does not provide a comparative estimate against healthy controls or a complete statistical account of sensory outcomes.