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 Intratympanic Steroid for Bell's Palsy (NCT03508440), a randomized phase 2, phase 3 study. The primary outcome is Facial Nerve Recovery.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03508440 |
| Phase | Phase 2, Phase 3 |
| Condition | Bell's Palsy, Facial Nerve Paresis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | 3 |
| Lead sponsor | University of Missouri-Columbia |
| Results posted | Yes |
2. Clinical Question
The study asks whether adding intratympanic steroid injections to oral steroids is associated with a different time to complete facial nerve recovery in adults with Bell’s palsy. The primary outcome defines complete recovery as a House Brackman score of 1 and measures the time from diagnosis or treatment start to that point. The eligible population is described as adults over 18 who presented with Bell’s palsy and a House Brackman score of 4 or greater.
The intended treatment groups are oral steroids alone, oral steroids plus intratympanic injections, and intratympanic injections alone for people unable to take oral steroids for medical reasons. The registry describes the first two groups as randomized, while the third group is described separately for those unable to take oral steroids. This distinction matters: the injection-only group is not described as a randomized alternative for the same population that could receive oral steroids.
The clinical question is therefore most directly about the contrast between standard oral steroid care and oral steroids with added injections. The registry’s primary measure is recovery time, not a direct measure of facial function at a single fixed visit. Follow-up was planned until complete recovery or one year after treatment, whichever came first. The registry record does not report a comparative estimate or inferential analysis for the two treatment groups, and the injection-only arm has no posted endpoint participants. Consequently, the listed summaries do not establish a reliable treatment contrast.
3. Trial Design
NCT03508440, titled “Intratympanic Steroid for Bell’s Palsy,” is listed as a phase 2 and phase 3 randomized, parallel-group study with no masking recorded. The sponsor is the University of Missouri-Columbia. The registry lists enrollment as 10. The start date is 2018-01-31, the primary completion date is 2022-11-22, and the status is completed.
The registry describes oral steroids alone as prednisone or prednisolone 60mg per day for 10 days, or 60mg/day for 5 days followed by a 5 day taper. The combined-treatment group received oral steroids as described, plus up to 1cc of 24mg/ml dexamethasone by intratympanic injection, with 3 injections over three weeks. The injection-only group was described as receiving the injections without oral steroids, for people unable to take oral steroids for medical reasons.
The brief summary describes randomization to oral steroids alone or oral steroids plus injections, and a separate group for patients unable to take oral steroids. It also describes video assessments by two blinded investigators and in-person evaluation by the unblinded treating physician. Although overall masking is recorded as none, these assessor details indicate that some outcome assessments were intended to be blinded; the registry record does not explain how these descriptions were reconciled.
For the primary endpoint, the posted group counts are 1.0 for standard of care, 9.0 for standard of care plus injection, and 0.0 for injection only. The record does not explain how these endpoint counts relate to the listed enrollment. It also does not report allocation concealment or further details about randomization procedures.
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 | Standard of Care | SOC + Injection | Injection Only |
|---|---|---|---|
| STARTED | 1 | 9 | 0 |
| COMPLETED | 1 | 9 | 0 |
| NOT COMPLETED | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Adults over the age of 18 that presented with Bell's palsy and a House Brackman score of 4 or greater
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: Injection only was for participants who could not, for medical reasons, receive the SOC treatment. We did not have any patients that met that criteria
| Characteristic | Unit | Standard of Care | SOC + Injection | Injection Only | Total |
|---|---|---|---|---|---|
| Participants analysed | 1 | 9 | 0 | 10 | |
| Age, Continuous | Years | 63 (SD 0) | 52.90 (SD 13.836) | — | 52.90 (SD 13.836) |
| Sex: Female, Male: Female | Participants | 1 | 2 | — | 3 |
| Sex: Female, Male: Male | Participants | 0 | 7 | — | 7 |
| Race and Ethnicity Not Collected | Participants | — | — | — | 0 |
| Region of Enrollment: United States | participants | 1 | 9 | — | 10 |
| House Brackman Score at Diagnosis | units on a scale | 5 (SD 0) | 5.11 (SD 0.928) | — | 5.10 (SD 0.876) |
6. Primary Endpoint
The registry lists the primary outcome as Facial Nerve Recovery, measured over Up to 365 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Days |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean number of days from diagnosis or treatment start to complete facial nerve recovery. Complete recovery is defined in the registry as a House Brackman score of 1. The endpoint is framed as time to an event—recovery—but is summarized as a continuous measure using a mean and standard deviation. The stated follow-up period is up to 365 days, with follow-up ending at complete recovery or one year post-treatment, whichever came first.
Time to recovery is relevant to the clinical question because it reflects how long participants take to reach the registry’s specified recovery state. A mean can describe the average observed recovery time within a group, while a standard deviation describes the spread of observed times around that mean. These summaries do not by themselves show whether groups differ beyond chance or account for participants who did not recover during follow-up.
The posted values are 7.0 days with a standard deviation of 0.0 in the standard-of-care group and 81.56 days with a standard deviation of 47.67 in the standard-of-care-plus-injection group. The injection-only group has no posted endpoint value. Because the standard-of-care group has only one endpoint participant, its summary cannot convey between-participant variation. The registry record does not report a time-to-event analysis, a confidence interval, or a comparative estimate for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary-outcome summaries show a mean recovery time of 7.0 days in the standard-of-care arm and 81.56 days in the standard-of-care-plus-injection arm. Their associated posted counts are 1.0 and 9.0, respectively. No endpoint value is posted for the injection-only arm, whose endpoint count is 0.0. These are descriptive summaries, not a reported estimate of the treatment effect.
The difference in the sizes of the groups sharply limits interpretation. A mean based on one participant describes that observation but gives no meaningful estimate of how recovery times vary among people receiving that treatment. The standard deviation of 0.0 in that group should not be read as evidence that recovery times are consistently the same with standard care. In the combined-treatment group, a standard deviation of 47.67 indicates spread in the observed recovery times, but the registry does not provide a confidence interval or other precision estimate for its mean.
The registry record reports no analysis for a two-arm comparison of this continuous endpoint. It gives no test statistic, p-value, confidence interval, adjusted estimate, or stated conclusion about whether the groups differ. The observed group means alone cannot account for uncertainty, treatment allocation, or possible differences in participant characteristics. In particular, the summaries do not establish that the treatment caused the observed recovery times.
The injection-only arm has no endpoint participants in the posted results, so it cannot inform the outcome question. The study description also places people unable to take oral steroids into that arm, meaning it is not described as a direct randomized comparison against oral-steroid care. No comparison involving that group is available from the endpoint results.
These limitations are especially important because the outcome is recovery time and follow-up could continue until recovery or one year. The record does not say how participants who had not recovered by the end of follow-up were handled in the mean summaries, or how missing outcome data were treated. Without those details and an inferential analysis, the posted values are best read as limited descriptive observations rather than evidence for a treatment contrast.
9. Statistical Methods Explained
The registry reports the primary outcome as a mean and standard deviation. These are descriptive statistics for a continuous measure: the mean represents the average of the recorded recovery times, and the standard deviation describes how dispersed those times are around the mean. They summarize the observed data but do not, on their own, quantify the precision of the mean or establish whether groups differ.
What does the standard deviation convey?
In general, a standard deviation describes variability among observations in a group. It is not the same as a confidence interval, and it does not show how precisely a group mean has been estimated. In this record, the standard-of-care arm has a posted count of 1.0 and a standard deviation of 0.0. With only one observation, within-group variability cannot be estimated from multiple observations; the reported 0.0 should not be interpreted as evidence of uniform recovery times. The combined-treatment arm has a reported standard deviation of 47.67, indicating that its observed recovery times were spread around its mean.
Why is there no comparative estimate?
A treatment comparison needs more than separate group means. An inferential analysis estimates the contrast between groups and quantifies its uncertainty, using an approach appropriate to the endpoint and study design. The registry record reports no analysis for the two-arm continuous endpoint comparison, and the posted results contain no comparative estimate, confidence interval, or p-value. The record identifies values for the separate arms but does not report a statistical conclusion about a difference between them. No difference should be calculated from the group means when describing the registry’s reported analysis.
In general, a confidence interval gives a range of values compatible with the data and the chosen statistical method, under that method’s assumptions. A narrow interval indicates greater precision than a wide interval. No confidence interval is reported for either mean or for a group contrast, so the precision of the observed means cannot be evaluated from interval estimates. A p-value, if reported, would address compatibility with a specified null model; it would not measure the size or clinical importance of an effect. No p-value is reported.
How should the time outcome be considered?
Recovery time is naturally an event-time outcome because recovery occurs at a particular time, and some people might not reach the event during follow-up. General time-to-event methods can use the timing of events while accounting for participants whose event time is not observed within the follow-up period. The registry lists the outcome as a mean with standard deviation, but does not report a time-to-event method or explain how incomplete follow-up was handled. It is therefore not possible to determine from the registry record whether the posted means include only observed recoveries or how any participants without recorded recovery were treated.
Over-dispersion is a general concern when data vary more than a statistical model assumes. A method that understates variability can give overly narrow uncertainty estimates. The registry does not report a statistical model or variance assumptions for a comparative analysis, so it is not possible to assess whether over-dispersion was considered. The observed standard deviation in the combined-treatment arm conveys descriptive variability, but does not identify the model used for inference.
What do the planning illustrations mean?
The registry’s planning assumptions describe illustrations based on a fraction of the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such calculations are planning illustrations, not observed power and not evidence that the completed trial had a particular probability of detecting an effect. The registry record does not report the trial’s own sample-size justification. It also indicates that values for a two-arm comparison of the continuous endpoint are missing or not estimable, so no arm-size planning value for that comparison is available in the posted results.
General sample-size calculations depend on assumptions about the effect to detect, variability, significance level, power, and design. These quantities should not be treated as results observed in participants. In this record, the very uneven endpoint counts and absent injection-only observations further limit what can be inferred from any planning illustration based on the observed effect. There is no reported observed-power result, and no such quantity should be inferred from the group summaries.
Random allocation, when implemented as described, is intended to reduce systematic differences between treatment groups. It does not guarantee balance in a small study, and it cannot compensate for missing outcome data or a very limited number of endpoint observations. The registry record identifies the study as randomized but does not report the allocation procedure, concealment details, or an analysis that accounts for the randomized design. These omissions prevent a fuller assessment of how the design was incorporated into the reported results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and zero posted secondary outcomes. That limits what can be said about multiplicity from the posted results, but the registry record does not report a prespecified testing hierarchy, multiplicity adjustment, or complete statistical analysis plan. It is therefore not possible to determine whether additional outcomes or analyses were planned outside the posted outcome information.
The registry reports zero analyses for the outcome data. It does not report an intention-to-treat population, a per-protocol population, or another analysis-population definition. It also does not explain whether the posted endpoint counts include everyone randomized, only participants with observed recovery times, or another subset. The listed enrollment and the posted arm-specific endpoint counts are not reconciled in the registry record.
Missing-data methods are not reported in the registry record. In particular, it does not describe how participants without a recorded complete recovery by the end of follow-up were handled, whether any outcome observations were missing, or whether sensitivity analyses were performed. This matters because follow-up could end at recovery or one year, and a simple mean may not adequately represent time to recovery if some event times are unobserved.
Interim analyses, stopping rules, and the statistical plan are not reported in the registry record. Their absence from the posted record should not be interpreted as evidence that they were or were not part of the study conduct. Without these details, the outcome summaries cannot be placed in a complete account of prespecified versus exploratory analyses.
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 |
|---|---|---|---|
| Standard of Care | 0 | 1 | 0.0% |
| SOC + Injection | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard of Care | 0 of 1 |
| SOC + Injection | 0 of 9 |
| Injection Only | 0 of 0 |
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 |
|---|---|
| Standard of Care | 0 of 1 |
| SOC + Injection | 0 of 9 |
| Injection Only | 0 of 0 |
The posted adverse-event figures list zero serious adverse events and zero deaths in the standard-of-care group, where the reported at-risk count is 1. The standard-of-care-plus-injection group has zero serious adverse events and zero deaths, with a reported at-risk count of 9. The injection-only group has an at-risk count of 0, so its zero event count does not provide safety information about participants receiving that regimen.
The registry also lists zero other adverse events affecting participants in the groups with reported participants at risk. These counts describe what was recorded in the registry; they do not establish that no adverse events occurred beyond those represented in the posted categories or reporting period. The record does not provide event-level descriptions, exposure-adjusted rates, or detail about how events were collected. No serious adverse-event terms are listed.
Zero recorded events in small groups do not demonstrate that an intervention has no risk. With few participants represented in the posted safety counts, uncommon events may not appear, and estimates of event frequency would be imprecise. The figures should therefore be read as registry-reported counts, not as a comprehensive assessment of safety or as grounds for comparing risks between treatments.
12. What the Result Does, and Does Not, Mean
The registry record documents a randomized study intended to examine recovery time after oral steroid treatment with or without intratympanic injections. The posted primary-outcome summaries contain a mean and standard deviation for standard care and combined treatment, but not for injection-only treatment. The group counts are markedly limited for interpretation, particularly the standard-of-care arm with a posted count of 1.0 and the injection-only arm with a posted count of 0.0.
These summaries do not show whether adding injections changes recovery time. They do not provide a comparative estimate, precision interval, or statistical test, and the registry reports no analysis for the two-arm continuous endpoint comparison. The means should not be interpreted as proof of benefit, lack of benefit, or a causal effect. The especially limited observation count for standard care makes its mean and reported standard deviation inadequate for describing the range of recovery experiences in that group.
The results also do not answer whether injections alone are associated with recovery time, because no endpoint participants are posted for that arm. Since that arm is described for people unable to take oral steroids for medical reasons, it is not presented as a direct randomized comparison with the other two groups.
More broadly, the record does not report missing-data handling, analysis populations, a comparative statistical method, or confidence intervals. These gaps leave uncertainty about how the endpoint summaries were constructed and how precisely they represent the groups. The safety figures likewise record no events in the groups with reported participants at risk, but the counts are too limited to establish the absence of risk. The appropriate reading is descriptive and cautious: the registry contains a small set of outcome summaries, not a conclusive statistical answer to the treatment question.
13. Why This Trial Matters Statistically
This trial illustrates why a registry’s design label and headline outcome do not by themselves determine how much can be learned from posted results. A study can be described as randomized while its endpoint summaries have highly uneven group counts. The number of observations in each group is central to understanding whether a mean is informative and how much uncertainty surrounds it.
The primary endpoint is a time measure, which raises a specific analytic issue: some participants may not have reached complete recovery during follow-up. A mean and standard deviation can describe observed times, but interpretation depends on how incomplete follow-up and unobserved recovery times were handled. Because the registry does not report those methods, readers cannot determine whether the posted summaries capture the intended time-to-recovery question for all participants.
The record also separates the injection-only group from the randomized comparison described for participants able to take oral steroids. That distinction is important for causal interpretation. A group defined by inability to take oral steroids may differ from groups receiving oral steroids for reasons related to eligibility, and its posted endpoint count is zero in any case. The record therefore does not support a direct comparative conclusion involving injection-only treatment.
Finally, reporting no comparative analysis is itself consequential. Descriptive values can prompt questions, but without an effect estimate and uncertainty assessment they cannot establish how the treatment groups compare. The record’s limited endpoint and safety counts show why transparent reporting of analysis populations, missing-data methods, and statistical analyses is essential to interpreting small clinical trials.
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 posted primary endpoint has very limited and uneven group counts: 1.0 for standard care, 9.0 for standard care plus injection, and 0.0 for injection only. The record does not explain how these counts relate to the registered enrollment of 10. The small count in the standard-care arm leaves its mean dependent on one observation, while the empty injection-only arm supplies no endpoint information.
No two-arm comparative analysis is reported for the continuous primary endpoint. There is no confidence interval, p-value, adjusted estimate, or explanation of the inferential method. The registry record does not report a sample-size justification for the trial, nor does it explain whether recruitment or the available endpoint data differed from the original design expectations.
The outcome is recovery time, but the record does not describe how participants who had not reached complete recovery by the end of follow-up were handled. Missing-data methods, censoring methods, and analysis-population definitions are not reported. The registry also does not provide details about randomization procedures or allocation concealment. Although its summary describes blinded video assessors and an unblinded treating physician, overall masking is recorded as none, and the record does not further explain this distinction.
Safety interpretation is similarly constrained by the small posted at-risk counts and by the absence of participants in the injection-only arm. Zero recorded events should not be read as evidence that the treatments have no associated risk. Overall, these registry-specific limitations prevent a precise or complete comparison of the treatment strategies.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Intratympanic Steroid for Bell's Palsy — NCT03508440.
- Registry record last updated 2024-11-05; status last verified 2024-10.
- Results first posted 2024-11-05.
- 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
NCT03508440 is a completed, randomized, parallel-group study listed as phase 2 and phase 3, with no masking recorded. It examined oral steroids alone, oral steroids plus intratympanic dexamethasone injections, and an injection-only regimen described for people unable to take oral steroids. The primary outcome was mean days to complete facial nerve recovery, defined as a House Brackman score of 1, with follow-up up to 365 days.
The posted endpoint results include a mean recovery time of 7.0 days for standard care and 81.56 days for standard care plus injection; the injection-only group has no endpoint value. The record reports no two-arm analysis, confidence interval, or p-value. Its adverse-event figures list zero serious events and zero deaths in the groups with participants at risk, but the posted counts are limited. Missing-data handling and analysis populations are not reported in the registry record.