Cochlear Response Telemetry and Hearing Preservation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Cochlear Response Telemetry and Hearing Preservation (NCT03134989), a na phase not stated study. The primary outcome is Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively..

2. Clinical Question

The study is an association-focused investigation, not a treatment comparison. Its central scientific question is whether an electrical response measured while the electrode is inserted corresponds to subsequent changes in natural low-frequency hearing. The registry description frames this as a possible future aid to surgical technique and hearing preservation; it does not establish that telemetry-guided decisions were tested.

The primary outcome uses each subject’s change in average low-frequency thresholds, calculated from thresholds at 500, 750, and 1000 Hz, and relates that change to whether the cochlear microphonic response was compromised or preserved. The record also lists a secondary question about the correlation between preoperative high-frequency thresholds and the number of electrodes inserted when a cochlear microphonic response was detected.

Because the record describes a single group and no randomized comparator, differences between response categories would be observational associations. They would not, by themselves, show that the telemetry response caused a change in hearing. The posted results do not report an estimate of the association or its uncertainty.

3. Trial Design

The study is registered as a single-group investigation of cochlear implant recipients. The intervention is a cochlear implant device, and the group description says participants were candidates already identified for implantation and undergoing surgery. Allocation is listed as not applicable, and masking is listed as none. There is no separate control arm for a like-for-like treatment comparison.

The record gives a planned enrollment of 80. It lists a start date of 2017-12-22, primary completion on 2020-06-18, and status as terminated. The reason for termination is not reported in the registry record. The record does not explain whether the planned enrollment was reached or give a detailed account of recruitment.

The study’s measurement approach combined cochlear implant and sound processor equipment with a sound delivered through an earphone in the ear canal. The telemetry tool was intended to capture a cochlear response during electrode insertion. The primary outcome then links that intra-operative response to audiometric changes measured after surgery.

The primary outcome timeframe compares a preoperative baseline measured within 90 days of cochlear implant surgery with a postoperative measurement 4 to 6 weeks after surgery. The outcome description specifies average thresholds at 500, 750, and 1000 Hz for the implanted ear, and asks whether larger changes are associated with a compromised rather than an uncompromised cochlear microphonic response.

The primary-outcome population note describes exclusions: 19 of the 80 intra-operative responses were excluded, and 18 of the remaining 61 data points were excluded because the cochlear microphonic response was unclear. It then reports N=43 responses categorized as preserved or compromised. The note starts an additional statement about two subjects but does not complete it; their status is not reported in the registry record.

The registry lists three outcome measures and no analysis records. It does not report a statistical analysis plan, a sample-size justification for the trial, interim analyses, or a reason for termination. The design therefore supports an observational association question, while the record does not provide the planned inferential procedures or a complete account of the 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 19 of the 80 ECochG intro-operative responses were excluded from the analysis (reasons are outlined in the CIR). A further 18 of the remaining 61 data points were excluded due to an unclear CM response resulting in N=43 responses categorized as either preserved or compromised. Further, two subjects were excluded from the primary endpoint analysis as there were no FUV1 thresholds collected. Thereby N=41.

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: 19 data points were excluded from the analysis due to a number of reasons (outlined in the CIR), including that surgical intervention occurred during ECochG measurement for 3 patients invalidating the measures, ECochG measures were not captured intraoperatively for 5 patients, 3 patients received CI512 cochlear implant, one patient unable to undergo surgery, 7 patients had issues with the audiometric measurements.

6. Primary Endpoint

The registry lists the primary outcome as Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively., measured over Baseline measurement (pre-operatively) compared to 4 to 6 weeks post-surgery.

The primary endpoint is the change in average low-frequency hearing thresholds in the implanted ear from before surgery to 4 to 6 weeks after surgery. The average is based on thresholds at 500, 750, and 1000 Hz. Baseline is described as a preoperative measurement taken within 90 days of cochlear implant surgery. The outcome description says each subject’s pre-to-postoperative change is of interest.

This endpoint is used to describe whether low-frequency hearing thresholds differ after surgery relative to baseline. The clinical rationale in the record is that preserving natural hearing may matter for people receiving an implant, and that intra-operative cochlear response telemetry might help characterize cochlear responses during electrode insertion. The analysis question is whether the size of the threshold change is associated with the cochlear microphonic response category.

The outcome is specified as a mean with full-range dispersion. Those terms describe how the result is intended to be summarized: a mean represents the average change, while the full range describes the spread from the lowest to the highest observed value. Neither summary, nor a comparison estimate, is reported in the posted results. The registry record therefore defines the measure and timing but does not establish the size, direction, or precision of any observed change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical question links a continuous audiometric measure with a categorical intra-operative response classification. The registry record describes the intended endpoint and some exclusions, but lists no analysis records and does not report the statistical methods used for an outcome comparison. The concepts below explain how such measures are generally interpreted; they should not be read as methods confirmed for this study.

What does a change score represent?

A change score expresses the difference between a follow-up measurement and a baseline measurement for the same person. It uses the within-person pairing of those observations, rather than treating baseline and follow-up values as unrelated samples. In this study, the specified quantity is the change in the average low-frequency threshold for the implanted ear. The registry record does not state the subtraction order or give observed change values, so neither a positive nor a negative direction should be inferred from the description alone.

A change score can make the question easier to state: does the amount of audiometric change vary according to the intra-operative response category? But its interpretation depends on reliable measurements at both time points and on the completeness of follow-up. The record specifies the measurement windows, but does not report the number with paired audiometry or how missing measurements were handled.

How should a mean and full range be read?

A mean is a measure of the average across observed values. The full range conveys the span from the smallest to the largest observed value, so it can reveal whether individual changes vary widely even when the average is modest. A range is sensitive to extreme observations and does not describe how values are distributed between its endpoints. The registry names mean and full range as the intended summary, but does not post the summaries themselves.

When observations vary substantially, an average alone may not represent what is typical for every participant. A reader would ideally consider the distribution and the uncertainty around the estimate as well as the point estimate. No distributional display, confidence interval, or uncertainty estimate for the primary outcome is reported in the registry record.

What does an association comparison establish?

A comparison of threshold changes between preserved and compromised response categories would estimate whether those observed groups differ. Because category membership is not assigned at random in this single-group study, a difference would be an association. It would not establish that the response category caused the hearing change, or that acting on telemetry would change an outcome. Differences in baseline characteristics or other aspects of surgery could also be related to both the response category and the measured change.

Statistical uncertainty matters alongside the estimated difference. A confidence interval is generally used to show a range of effect estimates reasonably compatible with the data and model assumptions. A p-value, when used, describes how unusual the data would be under a specified null model; it does not measure the probability that the null hypothesis is true or the clinical importance of an effect. The registry record gives neither a confidence interval nor a p-value for the primary question.

What can be inferred from the sample-size illustrations?

The record describes planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. These are stated as illustrations, not the trial’s own design. The trial itself is registered as a single-group study, so hypothetical equal allocation does not describe its enrollment or establish that a two-arm comparison was conducted.

Such illustrations indicate how a hypothetical future study might be planned under specified assumptions. They are not evidence that the current study had a given probability of detecting an effect, and they are not observed power. Their interpretation depends on the effect size used and on the assumptions about allocation and statistical model. The registry record does not report a trial-specific sample-size justification or a statistical plan supporting the outcome analysis.

For event-time outcomes, a Schoenfeld-based calculation concerns total events; for other outcomes, the stated illustrations concern participants per arm. These are general distinctions in the record’s planning assumptions, not descriptions of the primary endpoint’s analysis. No event-time primary endpoint is described for this trial.

Why do exclusions affect interpretation?

The primary-outcome note reports that some intra-operative responses were excluded and that unclear response classification led to further exclusions. If response clarity is related to hearing outcomes or participant characteristics, excluding unclear cases could affect the association among the classified responses. This is a general concern about selection into an analysis, not evidence that such bias occurred in this study. The registry record does not explain whether excluded cases differed from included cases or describe sensitivity analyses.

Because the record reports no analysis output, readers cannot assess the estimate, its uncertainty, or the influence of modeling choices. The endpoint definition is informative about what the investigators intended to study, but it cannot substitute for reported results and a clear account of the analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures, including the primary measure of change in low-frequency hearing thresholds and a secondary measure concerning preoperative high-frequency thresholds and the number of electrodes inserted when a cochlear microphonic response was detected. It does not report a multiplicity strategy. In studies with more than one outcome or analysis, testing many questions can increase the chance of a nominally unusual result arising by chance. Methods for addressing that issue, if any, are not reported in the registry record.

The record lists zero analysis records. It does not report which statistical tests were used, whether analyses were adjusted for other variables, how results were selected for reporting, or whether any analyses were prespecified beyond the outcome descriptions. These omissions mean that the evidential role of any potential comparisons cannot be evaluated from the record.

Missing-data handling is also not reported. The primary-outcome note describes exclusions for intra-operative response data, including cases with an unclear response, but does not explain how missing baseline or postoperative audiometry was treated. It does not state whether all participants had measurements at both time points, whether imputation was considered, or whether sensitivity analyses were performed.

The record’s population note reports N=43 responses categorized as preserved or compromised, after the described exclusions, and then begins an unfinished statement about two subjects. It does not clarify the status of those subjects. The distinction between enrolled participants, available audiometric observations, and classified telemetry responses is important: the record does not provide a complete analysis-population flow or enough information to determine which individuals contributed to each outcome.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: sudden onset rotary vertigo (3.3%).

The registry safety figures are presented for the Cochlear Implant Recipients group. The record lists 61 at risk for serious adverse events, with 2 affected, and 61 at risk for other adverse events, with 15 affected. It lists 0 deaths. The most frequently listed serious-event term is “SUDDEN ONSET ROTARY VERTIGO,” with 3.3% shown beside it.

These are descriptive registry counts, not a comparison between treatment groups. There is no separate control group in the registered design, so the figures cannot show whether event occurrence differed from an alternative treatment or from a background rate. The record does not provide event-level timing, severity details beyond the serious-event classification, or a narrative account of causality.

The denominator shown for the safety group should not be assumed to match the primary-outcome analysis population. The primary outcome note describes response-data exclusions, while the safety listing reports its own at-risk count. The registry record does not explain the relationship between those populations or give additional follow-up details. These safety figures should therefore be read as the adverse-event information recorded for this group, not as proof of a causal device effect or as a complete safety assessment.

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

The record establishes that investigators planned to examine whether intra-operative cochlear microphonic responses were associated with subsequent changes in low-frequency hearing thresholds. It defines the audiometric frequencies, the baseline and follow-up windows, and a classification of responses as preserved or compromised. It also describes exclusions that reduced the number of classified response data points.

It does not report the primary outcome’s observed mean change, the comparison between response categories, or an uncertainty estimate. Consequently, the posted results do not establish the direction or magnitude of an association. They also do not show whether any observed association would be precise enough to distinguish a meaningful pattern from chance variation.

Even if a difference between response categories were reported, the single-group observational design would not establish that the cochlear microphonic response caused the hearing change. It would not by itself show that using telemetry to guide electrode insertion preserves hearing. That would be a distinct intervention question requiring evidence about a strategy for using telemetry, rather than an association between a measured response and a later outcome.

The registry summary describes a possible future role for the telemetry tool in improving surgical technique and potentially preserving natural hearing. This is a rationale, not a reported finding. The status is terminated, and the reason for termination and its effect on the collected data are not reported in the registry record.

The most defensible reading is therefore limited: the registry records a clinically motivated association question and an endpoint definition, but not the statistical result needed to answer that question. It supports neither a claim that the tool improves hearing preservation nor a claim that it fails to do so. Those conclusions cannot be drawn from the posted information.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it connects a measurement taken during surgery with a later, patient-level audiometric change. The question is not simply whether a device was used, but whether the intra-operative cochlear response carries information about subsequent low-frequency threshold changes. That makes the choice of measurement timing, response classification, and analysis population central to interpretation.

The record also illustrates why an endpoint definition is not the same as an outcome result. It identifies the frequencies and follow-up window and explains the intended comparison, but the registry has no analysis records and does not report estimates or uncertainty. Without those, readers cannot judge the observed pattern or how precisely it was measured.

The response-data exclusions further matter statistically. Some responses were excluded, including cases with unclear cochlear microphonic classification. Exclusion can affect an association if inclusion is related to the exposure classification or outcome; the record does not report enough detail to determine whether this occurred. Transparent accounting of who contributed data to each analysis is therefore important.

Finally, the single-group design focuses attention on association rather than causal treatment effects. A relation between telemetry response and hearing change could be scientifically informative, but it would not demonstrate that a telemetry-guided surgical strategy changes hearing outcomes. The distinction between a prognostic or correlational signal and evidence for an intervention is essential when interpreting this research question.

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 registry record does not report the primary-outcome estimate, its uncertainty, or an inferential result. With no analysis records listed, it is not possible to assess the size or precision of the association between cochlear microphonic category and low-frequency threshold change.

The reported response-data exclusions create uncertainty about the analysis population. The record says 19 of the 80 intra-operative responses were excluded, then 18 of the remaining 61 data points were excluded because the cochlear microphonic response was unclear, leaving N=43 categorized responses. The population note then begins an additional statement about two subjects but does not finish. The reason for the initial exclusions and the disposition of those subjects are not fully explained in the registry record.

There is no randomized comparator, and the measured response categories are observational. Any association may be influenced by other participant or procedural characteristics. The record does not report adjustment methods, details of possible confounders, or sensitivity analyses.

The registry specifies audiometric timing but does not report completeness of paired measurements, missing-data procedures, or whether the measurement process was consistent across participants. It also does not describe multiplicity control for the listed outcomes. The status is terminated, but the reason and consequences for recruitment or follow-up are not reported in the registry record. Together, these gaps limit evaluation of both the representativeness of the analyzed responses and the robustness of any potential finding.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Cochlear Response Telemetry and Hearing Preservation — NCT03134989.
• Registry record last updated 2021-09-24; status last verified 2021-08.
• Results first posted 2021-09-24.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT03134989, titled “Cochlear Response Telemetry and Hearing Preservation,” is registered as a single-group study of cochlear implant recipients with sensorineural hearing impairment. Its primary question concerns the association between intra-operative cochlear microphonic responses and changes in average low-frequency hearing thresholds from preoperative baseline to 4 to 6 weeks after surgery.

The record lists planned enrollment of 80, a start date of 2017-12-22, primary completion on 2020-06-18, and terminated status. It describes exclusions from response data and reports N=43 responses categorized as preserved or compromised, while leaving an additional statement about two subjects unfinished.

Three outcome measures are listed, but no analysis records or primary outcome estimates are reported. The reason for termination, the statistical analysis plan, and the handling of missing outcomes are not reported in the registry record. The posted information defines the study question and endpoint but does not establish the direction, size, or precision of an association.