N6 Input Processing in Traditional CI Recipients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for N6 Input Processing in Traditional CI Recipients (NCT02239263), a na na study. The primary outcome is Endpoint 1: Evaluation of Signal to Noise Ratio - Noise Reduction.

2. Clinical Question

The practical statistical question is whether scores differ between the two processing conditions in the testing setup described by the registry. The endpoint is defined as the on-versus-off score difference, so its direction and size would describe performance under those test conditions. The record does not state a numerical result, an estimate of the average difference, or the precision of that estimate.

The question is narrower than whether the processor improves everyday communication or benefits every cochlear implant recipient. The endpoint concerns AzBio sentence understanding in noise at a specified signal-to-noise level; it does not, by itself, establish effects in other listening environments or outcomes. Those broader questions are not reported in the registry record.

3. Trial Design

The registry describes a completed, single-group study sponsored by Cochlear. Enrollment was 40. The listed start was 2014-05, and primary completion was 2014-11. The intervention is the Nucleus 6 Sound Processor, and the stated purpose is to evaluate enhanced signal-processing features in existing Nucleus cochlear implant recipients currently using the Nucleus 5 Sound Processor.

The allocation field is NA, and masking is listed as NONE. The study model is SINGLE GROUP. Accordingly, the registry does not describe randomized allocation or a separate, like-for-like control group. The on-versus-off conditions in the primary endpoint are test conditions; they should not be mistaken for two independently randomized trial arms. Details about the order of those conditions, any counterbalancing, or other measures to limit order effects are not reported in the registry record.

The primary endpoint is described as the difference in percent-correct scores for speech understanding in noise, measured at Visit 2, 1 month after baseline testing. It compares AzBio sentences with the SNR-noise reduction algorithm enabled and disabled at a fixed +10 dB signal-to-noise level in each condition. The registry identifies the reported parameter as a mean and the dispersion as a 95% confidence interval.

The record lists 2 outcome measures, but only the primary endpoint is described in the available details. The other outcome measure, secondary outcome definitions, and the analysis population are not reported in the registry record. The record reports no analysis entries. It does not state how many participants completed testing, whether all enrolled participants contributed endpoint data, or whether the study used an intention-to-treat or other analysis population.

Phase is listed as NA. Further information about the protocol, the study setting, eligibility criteria, participant demographics, and sample-size justification is not reported in the registry record. The design details support describing the planned endpoint and broad study structure, but they do not supply an outcome estimate.

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: As of the date of database closure, 34 of the 40 enrolled subjects completed Visit Two (endpoint testing).

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.

6. Primary Endpoint

The registry lists the primary outcome as Endpoint 1: Evaluation of Signal to Noise Ratio - Noise Reduction, measured over Visit 2, 1 month after baseline testing.

The primary endpoint is the mean difference in percent-correct scores for AzBio sentence understanding in noise. The registry describes testing with the SNR-noise reduction algorithm enabled and disabled, at a fixed +10 dB signal-to-noise level in each condition. Scores from the two conditions are subtracted to represent the performance difference associated with having the algorithm on rather than off. The stated timeframe is Visit 2, 1 month after baseline testing.

Percent correct is an interpretable continuous measure: it records the share of test responses scored as correct. Describing the endpoint as a difference places the focus on the contrast between conditions rather than either condition's score alone. A mean difference describes the average contrast across the analyzed participants, while a 95% confidence interval communicates the statistical precision of that estimated mean under the analysis method used.

In general, a confidence interval is a range of values compatible with the observed data and the assumptions of the statistical procedure. A narrower interval indicates greater precision than a wider interval, but it does not show whether the endpoint captures every aspect of listening ability. The registry record does not report the mean difference, its 95% confidence interval, the condition-specific scores, or the method used to calculate the interval. Thus, the endpoint definition is available, but its observed magnitude and precision are not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is continuous because it is a difference in percent-correct scores, and the registry identifies the summary parameter as a mean. In general, a mean summarizes the average value across observations. For this study, the intended contrast is between scores obtained with the noise-reduction algorithm enabled and disabled. The record does not say whether the analysis was performed on participant-level differences, how those differences were summarized when data were incomplete, or whether any adjustment was used.

What does the 95% confidence interval describe?

In general, a confidence interval expresses uncertainty around an estimated quantity. For a mean difference, it gives a range of values consistent with the observed data under the statistical procedure and its assumptions. Its width conveys precision: narrower intervals indicate more precise estimates than wider intervals. The interval is not a guarantee that the true effect lies within its particular endpoints, and it does not describe the range of individual participant responses.

The registry specifies a 95% confidence interval as the dispersion measure, but it does not report the interval's endpoints or the procedure used to calculate it. It is therefore not possible to assess the precision of the primary estimate or check the interval against the observed data. No standard deviation, standard error, or participant-level distribution is reported in the registry record.

Why does the paired-condition structure matter?

In general, when the same participants are assessed under two conditions, the comparison can use the relationship between each participant's two scores. An analysis of participant-level differences can account for the fact that measurements from the same person are related. This is distinct from treating two separate groups as independent. The endpoint description indicates scores are obtained with the algorithm on and off and then subtracted, but the registry record does not specify the statistical implementation, the order of testing, or whether all participants completed both conditions. The fact that a difference is described does not establish which inferential method was used.

The registry lists SINGLE GROUP and allocation NA. The comparison of processing conditions is therefore part of the endpoint definition, not evidence of a randomized two-group design. In general, a within-participant contrast can reduce variation associated with stable differences between people, but it can still be influenced by condition order, familiarity with the test, or other time-related effects. Whether these issues were addressed is not reported in the registry record.

What can be concluded from the analysis record?

The registry reports 2 outcome measures and 0 analyses. This means the record details an endpoint but does not provide a statistical analysis entry or a numerical result for it. The analysis method, model specification, treatment of outliers, handling of missing scores, and any covariate adjustment are not reported in the registry record. No inferential result should be reconstructed in their absence.

In general, analysis plans help readers understand which estimand was targeted, which participants contributed, and how uncertainty was quantified. A prespecified plan can also clarify how multiple outcomes and analysis choices were handled. Here, the statistical plan, including any interim analyses or multiplicity procedures, is not reported in the registry record. No interim analyses should be assumed.

How should planning illustrations be read?

In general, sample-size calculations describe planning scenarios under stated assumptions; they are not observed trial results or evidence of the study's achieved power. The planning assumptions associated with the record describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with target effects defined as fractions of an observed effect. They also distinguish total events for time-to-event outcomes from participants per arm for other outcomes.

Those assumptions are illustrations, not a description of this single-group study's allocation. The record does not report sample-size values for the illustrations, and it does not report a trial-specific sample-size justification. Because the observed endpoint effect is also not reported, the planning illustrations cannot be used to infer the magnitude of the study result. They should not be interpreted as observed power or as evidence that the study was designed around a particular effect size.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures, but only the primary endpoint is described in the available record. The identity and definition of the other measure, its timing, and its analysis are not reported in the registry record. The record gives no analysis entries. It does not state whether there were multiple primary outcomes, multiple comparisons, prespecified testing order, or an adjustment for multiplicity. Without those details, the risk of selective emphasis among outcomes or analyses cannot be assessed.

The endpoint description names Visit 2, 1 month after baseline testing, but does not explain how missing observations were handled. The number of participants with primary endpoint data, reasons for missing data, and any imputation or sensitivity analyses are not reported in the registry record. Enrollment of 40 does not establish that all 40 contributed to the endpoint analysis.

The analysis population is also not reported in the registry record. It is not stated whether the analysis included all enrolled participants, only those completing the relevant testing, or another defined group. The record does not describe exclusions after enrollment or departures from the protocol.

In general, missing data can affect both the estimate and its precision, particularly when the availability of a measurement is related to participant characteristics or outcomes. Multiplicity can also affect how statistical evidence is interpreted when several outcomes or analyses are considered. These are general concerns; the registry does not provide enough information to determine whether either issue affected this study's analysis.

11. Safety Results

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

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 separate safety group entries labelled N6 Input Processing Features - SNR-NR and N6 Input Processing Features - SCAN. Each entry lists 40 participants at risk for serious events and 0 affected by serious events. Each also lists 40 at risk for other events and 0 affected by other events. These are the posted counts for those reporting groups; they do not provide a detailed account of event collection or follow-up.

Deaths are listed as null for both entries. Null is not a reported count of zero, so the death figures should be read as not reported in the registry record. No top serious-event terms are listed. The record does not provide event definitions, severity grading details, relatedness assessments, or information about how the safety groups relate to the timing of the primary endpoint.

In general, a zero count in a registry entry describes what was recorded for that entry; it does not by itself establish that no events occurred under every possible definition or period of observation. The registry record does not report enough detail to assess the completeness of safety ascertainment or to compare safety across randomized treatment groups. The study is identified as single-group, not as a randomized safety comparison.

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

The registry record establishes that the study was completed, enrolled 40 participants, and evaluated Nucleus 6 signal-processing features in existing Nucleus implant recipients using the Nucleus 5 processor. It defines a primary speech-in-noise endpoint based on the difference in AzBio sentence percent-correct scores with the SNR-noise reduction algorithm enabled versus disabled, at a fixed +10 dB signal-to-noise level. The specified measurement time is Visit 2, 1 month after baseline testing.

The record does not report the mean difference, the 95% confidence interval, or the condition-specific scores. It therefore does not show the observed direction, magnitude, or precision of the contrast. It also does not report a p-value or a formal conclusion from the primary analysis. The endpoint description alone cannot establish what the results were.

Even if a numerical difference were available, the endpoint would describe performance in this particular speech-understanding test and testing setup. It would not, without additional evidence, answer every question about listening performance in other settings, longer-term outcomes, or the experience of all cochlear implant recipients. Those broader outcomes are not reported in the registry record.

The single-group design is another boundary on interpretation. The record does not describe random assignment to a separate control group. The on/off comparison is a contrast between test conditions, and the registry does not report details about condition order or other design features that might affect such a contrast. The available information cannot establish that any difference would be attributable solely to the processor feature.

The safety entries list zero affected participants for serious and other events in the two named reporting groups, each with 40 at risk. Deaths are not reported as numerical counts. These records should be interpreted as the entries presented, without extending them to claims about all possible events or periods.

Overall, the registry supports a description of the research question and some design and safety-record details. It does not provide the primary outcome result needed to judge the observed speech-in-noise contrast or its statistical precision.

13. Why This Trial Matters Statistically

This study illustrates why an endpoint definition and an outcome estimate are different kinds of information. The registry states what was measured, under which test conditions, and the planned summary form: a mean difference with a 95% confidence interval. Those details make the statistical question understandable. But without the estimate and interval, readers cannot evaluate the size of the observed contrast or how precisely it was measured.

The study also highlights the importance of distinguishing a single-group design from a randomized comparison. The endpoint contrasts algorithm-on and algorithm-off testing conditions, while the study model is listed as SINGLE GROUP and allocation as NA. Keeping those descriptions separate helps prevent a test-condition contrast from being misread as evidence from two randomized groups.

Enrollment and analysis size are not interchangeable. The record reports enrollment of 40, but does not report the number of participants who contributed endpoint data. This is why clear reporting of analysis populations, missing measurements, and participant flow matters for interpreting a mean and its confidence interval.

Finally, the record lists 2 outcome measures but supplies detail for only one and no analysis entries. Complete reporting of endpoint definitions, analysis choices, and results helps readers assess multiplicity, precision, and the relationship between planned and reported analyses. In this case, those information gaps restrict the conclusions that can be drawn, even though the primary measurement itself is described in specific terms.

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 most direct limitation for interpretation is that the registry record does not report the primary outcome estimate or its 95% confidence interval. No condition-specific scores or p-value are reported either. As a result, the statistical size, direction, and precision of the primary contrast cannot be assessed.

The study is listed as single-group, with allocation NA and masking NONE. The registry does not describe a randomized control group, and it does not provide details about the order of the algorithm-on and algorithm-off tests. Potential testing or order effects therefore cannot be evaluated from the record. The record also does not explain whether the analyst or participants were aware of the condition during testing beyond the masking field.

Enrollment is reported as 40, but the number analyzed for the primary endpoint is not reported in the registry record. Participant characteristics, eligibility criteria, setting, condition-specific distributions, and reasons for any missing measurements are also not reported. This limits assessment of representativeness and of whether the available endpoint data reflect all enrolled participants.

Although 2 outcome measures are listed, the second measure and its results are not described. The statistical analysis plan, handling of missing data, multiplicity procedures, and any interim analyses are not reported in the registry record. The registry's planning assumptions do not substitute for a trial-specific sample-size justification, which is not reported.

The safety entries show zero affected participants in the listed serious and other event categories, but the record does not give detailed ascertainment methods or numerical death counts. These gaps limit interpretation of safety reporting as well as efficacy-related outcomes. The limitations are reporting limitations; they do not establish what the unreported analyses or protocol contained.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: N6 Input Processing in Traditional CI Recipients — NCT02239263.
• Registry record last updated 2021-02-26; status last verified 2021-02.
• Results first posted 2021-02-26.
• 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

NCT02239263 is a completed, single-group study titled “N6 Input Processing in Traditional CI Recipients,” sponsored by Cochlear. It enrolled 40 participants and evaluated the Nucleus 6 Sound Processor in existing Nucleus cochlear implant recipients using the Nucleus 5 Sound Processor. The listed start was 2014-05, and primary completion was 2014-11. Allocation is NA and masking is NONE.

The primary endpoint is the mean difference in percent-correct AzBio sentence scores in noise with the SNR-noise reduction algorithm enabled versus disabled, at a fixed +10 dB signal-to-noise level. The timeframe is Visit 2, 1 month after baseline testing, and the stated dispersion is a 95% confidence interval. The registry record does not report the endpoint result, its interval, or the analysis method. It lists 2 outcome measures and 0 analyses; further details for the other outcome are not reported in the registry record.

Safety entries list 0 affected participants for serious and other events in each of two reporting groups, with 40 at risk in each. Deaths are not reported as numerical counts. The registry does not report the analysis population, missing-data handling, or a trial-specific sample-size justification.