The Effect of IV NSAID's and Corticosteroids on Dysphasia and Dysphonia Following ASDF: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Effect of IV NSAID's and Corticosteroids on Dysphasia and Dysphonia Following ASDF (NCT04650893), a randomized phase 3 study. The primary outcome is Percentage of Patients With Moderate/Severe Bazaz Classification.

2. Clinical Question

3. Trial Design

The registry record identifies this as a Phase 3, randomized, single-masked, parallel-group trial. It lists enrollment of 33 and a status of terminated. The recorded start date is 2021-01-02, and the primary completion date is 2023-12-08. These dates and status describe the record; they do not by themselves explain why the trial ended or how much follow-up was completed.

Three arms are described: control, ketorolac, and dexamethasone. The ketorolac arm is described as receiving a one-time 30mg intravenous dose at closure, while the dexamethasone arm is described as receiving a one-time 10mg intravenous dose at closure. The control-arm description says no steroid or non-steroidal anti-inflammatory drug. Placebo is listed as an intervention, but its relationship to the control arm is not reported in the registry record.

Single masking means the registry identifies one masked party, but which party was masked and how masking was implemented are not reported in the registry record. The method used to generate the random sequence, conceal assignments, and maintain treatment allocation is also not reported in the registry record. The registry record does not give detailed eligibility criteria, baseline characteristics, or a participant-flow account. The posted endpoint counts are smaller than the overall enrollment, but the record does not explain the reasons for this or describe the endpoint analysis population.

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: Study was terminated early, lack of compliance for follow-up intervals.

Overall Study

Reasons for not completing this period:

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.

Population: Baseline was less than desired due to closure of study because follow-up was poor.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Patients With Moderate/Severe Bazaz Classification, measured over one year.

The primary endpoint is the percentage of participants with moderate or severe dysphagia according to the Bazaz classification at one year. The registry description identifies the grading scale as 0-none, 1-Mild, 2-Moderate, and 3-Severe; the endpoint groups the moderate and severe categories together. The endpoint is therefore a binary summary of swallowing difficulty at the specified follow-up time, rather than a measure of the full range of Bazaz scores.

A categorical endpoint can make it easier to describe how often a clinically defined level of a symptom is recorded in each group. It also gives a direct percentage that readers can interpret as the proportion meeting the endpoint definition. However, combining categories discards distinctions between moderate and severe symptoms, and between the lower categories. The posted primary endpoint is specific to dysphagia; it is not itself a measure of dysphonia.

The registry record lists the timeframe as one year. It does not report the assessment schedule, the exact handling of participants without a one-year assessment, or details on who applied the Bazaz classification. Those details matter when interpreting how the categorical outcome was measured and which participants contributed to the reported percentages.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the reported percentage represent?

The primary outcome is a binary-percentage endpoint: it reports the percentage of participants classified as having moderate or severe Bazaz dysphagia at one year. The registry also supplies an endpoint group size for each arm. A percentage is a descriptive summary of the participants contributing to that arm’s endpoint result. It does not, by itself, quantify the uncertainty around the percentage or the size of a treatment contrast.

For this endpoint, the posted values are 20.0% in control, 20.0% in ketorolac, and 0.0% in dexamethasone. The group sizes are 5, 5, and 4, respectively. These values should be retained as separate arm summaries. No new pooled rate or overall total is needed to interpret them, and the record does not provide information that would justify combining groups.

Why is a comparison different from arm summaries?

A treatment comparison asks how the endpoint differs between a specified pair of arms. For a binary outcome, a comparison might be expressed as an absolute difference in percentages or another effect measure. A point estimate describes the observed contrast; uncertainty measures indicate how precisely the contrast is estimated. The registry record does not report an estimable two-arm comparison for this endpoint, so no comparative point estimate or uncertainty interval can be interpreted.

General statistical explanation: when outcome counts are sparse, estimates for binary outcomes can be imprecise, and some methods may not produce a stable or estimable result. This is one reason to distinguish observed arm percentages from an inferential comparison. The registry’s note says values were missing or not estimable for the two-arm comparison, but it does not identify the calculation method or give a reason for that outcome.

What can a confidence interval tell the reader?

General statistical explanation: a confidence interval communicates uncertainty around an estimated quantity under the assumptions of the method used. For a treatment contrast, it helps show which effect sizes remain compatible with the data, rather than presenting only a single estimate. A narrow interval indicates greater precision than a wide interval, although precision alone does not establish clinical importance. No confidence interval for the primary treatment comparison is reported in the registry record.

A p-value, if reported, would address how compatible the observed data are with a specified null model under a statistical procedure. It would not measure the probability that a treatment works, nor would it describe the size or precision of an effect. A primary-comparison p-value is not reported in the registry record. The absence of that result does not establish either equivalence or a difference between arms.

How should the planning illustrations be understood?

The sample-size material is described as a planning illustration based on the observed effect, not as the trial’s original design justification. Its stated assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is defined as a stated fraction of the observed effect. Such calculations are hypothetical planning exercises. They do not show the trial’s observed power, and they do not substitute for an analysis of the trial data.

General statistical explanation: power is a design concept describing the chance that a specified procedure will detect an effect of a particular size under assumed conditions. A post hoc calculation using an observed effect does not change the uncertainty in the observed estimate. When the observed effect is unstable or imprecise, planning values derived from it can also be unstable. The registry record does not report the trial’s own sample-size justification or the assumptions used for its original planning.

Because the endpoint is binary, the analysis method would need to account for the form of the outcome and the available group sizes. The registry record does not describe the model, estimation procedure, treatment of sparse data, or any covariate adjustment. Without these details or a posted comparison, readers cannot assess whether particular model assumptions were checked or how sensitive a result would be to alternative methods.

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("Control", "Ketorolac", "Dexamethasone")
n      <- c(5, 5, 4)
events <- c(1, 1, 0)
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  Control  5  1  20.0  0.5  71.6  3.6  62.4  4.3  64.1
ARM  Ketorolac  5  1  20.0  0.5  71.6  3.6  62.4  4.3  64.1
ARM  Dexamethasone  4  0  0.0  0.0  60.2  0.0  49.0  0.5  52.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two secondary outcomes: the percentage of participants with a clinically significant Voice Handicap Index-10 (VHI-10), and mean Neck Disability Index (NDI). The primary endpoint concerns moderate or severe Bazaz dysphagia. Considering several outcomes can create a multiplicity issue: if many hypotheses are tested, the chance of at least one apparently notable result may increase. General statistical explanation: prespecified outcome hierarchies or statistical adjustments can address this concern, but the approach depends on the trial’s analysis plan.

The statistical plan for handling multiple outcomes, the ordering of outcome tests, and any multiplicity adjustment are not reported in the registry record. The record lists five outcome measures but does not provide an analysis for these outcomes in the information described. It lists no posted analyses. This does not establish that analyses were not performed; it means their methods and results are not reported in the registry record.

Missing-data methods are also not reported in the registry record. The primary endpoint group sizes are 5, 5, and 4, while enrollment is listed as 33. The record does not explain the difference, describe the number of missing one-year assessments, or say whether missing outcomes were excluded, imputed, or handled through another approach. The population used for the primary analysis is not specified. Readers therefore cannot determine from the registry record whether the posted endpoint groups represent all randomized participants, participants with available assessments, or another analysis population.

These limitations affect interpretation of both the arm percentages and any potential comparison. Missing outcomes may matter if availability of follow-up is related to symptoms or treatment group. Without a participant-flow description and analysis-population definition, the direction and extent of any such influence are not reported in the registry record.

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 registry reports serious adverse event counts of 0 in control, 0 in ketorolac, and 0 in dexamethasone. It also reports 0 deaths in each group. The corresponding serious-event groups at risk are 11, 10, and 12. These are the figures recorded for the safety outcomes; they are distinct from the smaller group sizes listed for the primary endpoint.

A zero count means no serious adverse events or deaths were recorded in the listed safety groups in the registry results. It does not demonstrate that an event is impossible, or establish that risks are the same across arms. With limited group sizes, the data provide limited information about uncommon events. General statistical explanation: observing no events can still be compatible with a range of underlying event risks, and a confidence interval would help describe that uncertainty. No safety confidence intervals or comparative safety estimates are reported in the registry record.

The record does not report detailed adverse-event definitions, the safety observation period, or how events were collected and attributed. It also lists no top serious adverse-event terms. The safety figures should be interpreted as registry-reported counts, not as a complete characterization of all possible harms.

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

The registry record documents a randomized comparison of intravenous ketorolac, intravenous dexamethasone, and a control condition for symptoms following ACDF. The primary outcome is the percentage with moderate or severe dysphagia by the Bazaz classification at one year. Posted arm percentages are available, along with endpoint group sizes, and the registry reports no serious adverse events or deaths in the safety groups.

Those observations do not establish that one arm is better or worse than another. The record does not report an estimable two-arm comparison for the primary endpoint, nor a confidence interval or p-value for that comparison. In particular, the posted percentages should not be interpreted as proof of a treatment effect, proof of no effect, or proof that the arms are equivalent. Establishing equivalence would require an appropriate design and analysis, neither of which is described in the posted comparison results.

The endpoint group sizes are limited, and the record does not explain how they relate to the enrollment of 33. The reason for the terminated status, the analysis population, and the handling of missing one-year outcomes are not reported in the registry record. Those uncertainties limit the conclusions that can be drawn from the percentages and make it difficult to assess the completeness and precision of the findings.

The trial’s title and summary address dysphagia and dysphonia, but the primary endpoint described in the results is dysphagia. The listed secondary outcomes concern VHI-10 and NDI; their results are not reported in the registry record. Thus, the available endpoint values do not describe all the symptoms or outcomes named in the trial record. They also do not establish the effectiveness or safety of any intervention for an individual patient.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between descriptive results and comparative evidence. The registry gives an arm-specific percentage for the primary binary endpoint, but reports that a two-arm comparison was missing or not estimable. A set of percentages can describe the observed endpoint groups without answering the inferential question of how precisely outcomes differ between interventions.

The registry also illustrates why denominators and analysis populations matter. Enrollment is listed as 33, while the endpoint group sizes are 5, 5, and 4, and the safety groups at risk are 11, 10, and 12. These figures refer to different reported results, and the registry does not explain how participants moved from enrollment to each analysis. Without that account, readers cannot evaluate endpoint completeness or understand why the denominators differ.

Small endpoint groups make precision especially important. General statistical explanation: a percentage based on a small group can change substantially when the outcome status of a participant changes. Reporting uncertainty intervals alongside arm-specific results and a clearly defined treatment contrast would help readers judge the range of effects compatible with the data. Those comparative results are not reported in the registry record.

Finally, the terminated status and absence of posted analysis details underscore the value of transparent reporting on the reason for stopping, missing outcomes, statistical methods, and prespecified outcome handling. These features do not determine the validity of the observations, but they are needed to assess how far the posted results can support conclusions about the trial question.

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 registry record leaves several trial-specific questions unresolved. Although it identifies a randomized, single-masked, parallel design, it does not describe the randomization procedure, allocation concealment, which party was masked, or whether masking was maintained. It lists placebo as an intervention, while the control arm is described as receiving no steroid or non-steroidal anti-inflammatory drug. The relationship between those descriptions is not reported in the registry record.

The primary endpoint group sizes are 5, 5, and 4, whereas the record lists enrollment of 33. The record does not provide a participant-flow explanation, reasons for missing endpoint data, or a definition of the population included in the endpoint analysis. It also does not report baseline characteristics, detailed inclusion and exclusion criteria, the assessment process for the Bazaz classification, or the timing and completeness of one-year assessments beyond the stated timeframe.

The trial is marked terminated, but the reason for termination and its effect on follow-up or analysis are not reported in the registry record. The registry does not state whether analyses were interim or final, provide a statistical analysis plan, or explain the method behind the unavailable two-arm comparison. Sample-size justification for the original design is not reported in the registry record.

Results for the listed secondary outcomes are not reported in the registry record. The safety results provide counts but not event definitions, observation duration, or uncertainty estimates. Taken together, these gaps limit assessment of the completeness, precision, and robustness of the posted findings. They do not by themselves establish that the results are biased; the extent and direction of any effect cannot be determined from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The Effect of IV NSAID's and Corticosteroids on Dysphasia and Dysphonia Following ASDF — NCT04650893.
• Registry record last updated 2024-08-23; status last verified 2024-08.
• Results first posted 2024-08-23.
• 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

The registry describes a Phase 3 randomized, single-masked, parallel trial with enrollment of 33 and status terminated. It compares a control condition with one-time intravenous ketorolac and dexamethasone at closure following ACDF. The primary endpoint is the percentage with moderate or severe Bazaz dysphagia at one year.

Posted primary endpoint percentages are 20.0% for control, 20.0% for ketorolac, and 0.0% for dexamethasone, with endpoint group sizes of 5, 5, and 4. A two-arm comparison is not reported as estimable. Serious adverse event and death counts are 0 in each safety group. The registry does not report why the trial was terminated, how missing outcomes were handled, or the analysis methods and populations.