Fundamental Asynchronous Stimulus Timing Sound Coding Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Fundamental Asynchronous Stimulus Timing Sound Coding Study (NCT02698787), a randomized phase not stated study. The primary outcome is Change in Open Set Monosyllabic Word Recognition Score.

2. Clinical Question

The study asks whether the FAST sound coding strategy is non-inferior to the commercially available ACE strategy for open-set monosyllabic word recognition in quiet. The registry describes this as a comparison of the percentage of words answered correctly. It also notes possible motivations for FAST, including potential battery-life benefits and improved localization for bilateral patients, but these are not the primary question reported for this trial.

In a non-inferiority question, the goal is to assess whether the experimental strategy's performance is not unacceptably worse than the comparator under a prespecified margin. The registry record does not report a non-inferiority margin or the statistical results needed to evaluate that question. Therefore, the stated objective can be described, but whether the posted findings support it cannot be determined from the registry record.

3. Trial Design

The registry classifies this as a randomized, double-masked, crossover study. It lists enrollment of 11 and a completed status. The study started in 2015-12, and primary completion was 2018-11-19. The sponsor is Cochlear. These registry entries describe the trial's organization; they do not by themselves establish how the outcome data were analyzed.

A crossover design means that participants receive more than one study condition in a sequence, so comparisons may be made within participants rather than only between separate groups. The registry describes two groups with different initial sound coding strategies. Group 1 was assessed at Visit 5 for FAST and Visit 8 for ACE, while Group 2 was assessed at Visit 5 for ACE and Visit 8 for FAST. The listed primary-outcome time points also include Visit 1 as baseline, Visit 5 at 3 months, and Visit 8 at 6 months.

Random assignment to different sequences can help distribute order effects across groups. In a crossover study, however, interpretation can also depend on issues such as period effects, carryover from an earlier condition, and whether each participant has usable observations under both conditions. The registry record does not report details of any washout period, handling of carryover, or analysis of period and sequence effects. Those features should not be assumed.

Double masking indicates that the registry classifies the study as masked at two levels, but the registry record does not specify which parties were masked or how masking was maintained. It also does not report the randomization procedure or allocation concealment details. Although the record lists two interventions and two analysis visits for the groups, it does not include outcome estimates, participant flow by analysis visit, or an account of exclusions. The design can therefore be described, while its implementation and the completeness of the crossover comparisons remain uncertain.

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.

First Intervention (3 Months)

Second Intervention (3 Months)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Group 1 were analysed at Visit 5 for FAST sound coding strategy and at Visit 8 for ACE sound coding strategy. Group 2 were analysed at Visit 5 for ACE sound coding strategy and at Visit 8 for FAST sound coding strategy.

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 Change in Open Set Monosyllabic Word Recognition Score, measured over Visit 1 (baseline), Visit 5 (3 months), Visit 8 (6 months).

The primary endpoint is change in open-set monosyllabic word recognition score, expressed as a percentage of words correct. The test uses 50 words, each consisting of 3 individual speech sounds. A participant repeats each word heard by the audiologist, and the score is based on the percentage answered correctly. The registry lists baseline at Visit 1, a 3-month assessment at Visit 5, and a 6-month assessment at Visit 8.

Word recognition in quiet is used to assess speech understanding under the test conditions described in the registry. A percentage score provides a direct summary of how many test words were repeated correctly, but it represents performance on this particular test and does not cover every aspect of hearing or communication.

The stated primary objective is to determine whether FAST is non-inferior to ACE for this measure. To interpret a non-inferiority result, readers would need the estimated contrast between strategies, its uncertainty, and the prespecified margin defining an acceptable difference. The registry record does not report those items or the observed endpoint values. It names the summary as a mean with full range dispersion, but the values themselves are not reported in the registry record. Consequently, the endpoint and its intended use are clear, while the magnitude and precision of the observed comparison are not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies randomization, double masking, and a crossover model. These design features have distinct roles. Randomization assigns participants to sequences by chance, which can reduce systematic differences between sequence groups. Masking is intended to limit influences on participant behavior, assessment, or reporting, although the registry record does not identify who was masked or give implementation details. Crossover allocation exposes participants to both strategies according to sequence, allowing a comparison that may use within-participant information.

What does non-inferiority mean?

In general, a non-inferiority analysis asks whether an experimental intervention is no worse than a comparator by more than a prespecified clinically acceptable margin. The margin must be defined before interpreting the results; otherwise, readers cannot tell what degree of difference the trial was designed to rule out. The registry states that FAST was to be assessed for non-inferiority to ACE for word recognition in quiet. The margin, analysis procedure, and result are not reported in the registry record. No non-inferiority conclusion can therefore be evaluated from the posted information.

Why does a crossover design need careful analysis?

In general, crossover data can include repeated measurements from the same participant, which are statistically related rather than independent. Analyses should account for that relationship. The sequence in which conditions occur can matter: performance may change over time, and an earlier condition could potentially influence a later measurement. These are general considerations, not claims that such effects occurred in this study. The registry record does not report a model, adjustment strategy, washout details, or tests addressing period, sequence, or carryover effects.

The registry gives the assessed strategy at Visit 5 and Visit 8 by group, alongside a baseline Visit 1. That schedule provides context for the intended measurements, but it does not show how change was calculated or how baseline was incorporated. The outcome is described as a mean with full-range dispersion. In general, a mean summarizes the central value of observed scores, while a full range describes the lowest and highest values. Neither summary nor the participant-level data are reported numerically in the registry record.

How should uncertainty be understood?

In general, a confidence interval describes a range of effect estimates compatible with the observed data under the statistical model and its assumptions. A narrower interval indicates greater precision than a wider interval, while an interval that spans important possibilities may leave the interpretation uncertain. For non-inferiority, the interval must be interpreted in relation to the prespecified margin and the direction of the contrast. The registry record does not report a confidence interval, an effect estimate, or a margin for this outcome.

A p-value, in general, summarizes how unusual data would be under a specified null hypothesis and model. It does not measure the size or clinical importance of an effect. The record has no listed analysis entries and does not report a p-value for the primary outcome. No p-value or statistical significance claim should be inferred from the objective or the design description.

What can be said about planning?

The registry includes a general description of sample-size planning illustrations based on fractions of an observed effect, with a stated two-sided significance level of 0.05, equal allocation, and a normal approximation. It also distinguishes participant-per-arm illustrations from total-event illustrations for time-to-event outcomes. Those statements describe assumptions for planning illustrations, not the trial's own design justification or observed power. No numerical planning results are reported in the registry record. The actual sample-size rationale, power calculation, and any assumptions used for this trial are not reported in the registry record.

In general, planning calculations answer how much information might be needed under specified assumptions; they do not establish the power achieved after a trial is complete. Calculations based on an observed effect can be especially dependent on that estimate and should not be presented as observed power. The record's planning description does not provide a basis for adding numerical estimates or inferring the trial's intended sample size.

Why can over-dispersion matter?

As a general statistical point, over-dispersion occurs when variability in data is greater than a model assumes. If a model fails to account for that extra variability, its standard errors may be too small and its uncertainty estimates too optimistic. This is a general issue for some data types; the registry record does not report that an over-dispersion problem arose or identify a model for which it was assessed.

In short, the registry provides a design label and an endpoint description but not the analysis methods or numerical outcome results. The statistical concepts above explain what would ordinarily be needed to assess a crossover non-inferiority comparison; they do not fill in unreported methods or findings.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures but does not provide a full account of the outcome hierarchy, analysis plan, or statistical testing procedures. The primary outcome is identified, and the record states a non-inferiority objective, but it does not report whether multiple hypotheses, time points, or secondary outcomes were addressed through a prespecified multiplicity strategy. Any such strategy is not reported in the registry record.

Multiplicity is a general concern when several outcomes or comparisons are tested: the chance of at least one apparently notable result can increase as the number of tests increases. Appropriate interpretation depends on which tests were planned and how they were handled. No adjustment or decision rule can be inferred from the registry's outcome descriptions.

Missing-data information is also limited. The record describes an enrollment of 11 and identifies measurements at baseline, 3 months, and 6 months, but does not report the number of observations available at each visit or the number of participants included in each analysis. It does not state how missing scores, withdrawals, or incomplete crossover sequences were handled. The reasons for any missing data are not reported in the registry record.

The analysis population is not defined in the registry record. It is therefore unclear whether the intended analysis included all randomized participants, only participants who completed both strategies, or another population. These distinctions can matter in non-inferiority studies, where different analysis populations may affect interpretation. The registry record does not report sensitivity analyses or how they were used to assess robustness.

These are reporting limitations, not evidence that any particular procedure was or was not used. Without the statistical plan and analysis details, readers cannot assess multiplicity control, missing-data assumptions, or the relationship between the intended and analyzed populations.

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: vertigo/dizziness (9.1%).

The safety record lists adverse-event counts separately for no sound coding strategy, FAST, and ACE, with 11 participants at risk in each group. Serious adverse events are listed as one for no sound coding strategy, zero for FAST, and zero for ACE. Deaths are listed as zero in all three groups. Other adverse events are listed as five for no sound coding strategy, five for FAST, and four for ACE. The registry also identifies vertigo/dizziness as a top serious-event term at 9.1%.

These entries are descriptive counts in the registry record. They do not establish that an event was caused by a particular strategy, and the record does not provide a statistical comparison between groups. The meaning of the no-strategy category in relation to the timing of exposure is not elaborated in the posted safety details. The record also does not provide event-level descriptions, severity grades beyond the serious/non-serious distinction, or timing by treatment period.

Because this is a crossover study, participants may contribute information under more than one condition. The registry's at-risk counts should not be interpreted as independent groups without further details on event definitions and analysis. Counts alone do not show comparative risk, and no safety conclusion beyond the posted event figures is supported by this record.

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

The record documents a randomized, double-masked crossover study intended to compare FAST and ACE sound coding strategies for word recognition in quiet among newly implanted adult cochlear implant recipients. It specifies the primary test, the assessment visits, and the non-inferiority objective. Those details clarify the question researchers planned to address.

The record does not report the primary outcome values, a FAST-versus-ACE effect estimate, a confidence interval, or a statistical test. It also does not report the non-inferiority margin. Consequently, the posted information cannot establish whether the strategies met the stated non-inferiority criterion, nor can it describe how large or precise any observed difference was. Missing numerical results are not evidence of equivalence, benefit, or harm.

The record's enrollment of 11 describes the number enrolled, not necessarily the number contributing complete data to every assessment or analysis. The number analyzed at each visit and the analysis population are not reported. This limits assessment of the completeness and precision of the primary comparison.

The safety counts describe serious and other adverse events across the listed categories, along with zero deaths in each. They do not establish causality or provide a comparative statistical analysis. The registry record does not give sufficient detail to interpret the timing and attribution of events across crossover periods.

Accordingly, the most defensible interpretation is that the registry records the study's design and intended endpoint, but does not post the numerical outcome evidence needed to answer its main statistical question. Any account of the observed efficacy comparison or a conclusion about non-inferiority would go beyond what is reported in the registry record.

13. Why This Trial Matters Statistically

This study is statistically notable because its stated objective is non-inferiority and its design is crossover. These features make the interpretation depend on more than whether two observed scores appear close. A non-inferiority assessment needs a prespecified margin, an estimate of the contrast, and enough information about uncertainty to judge the estimate against that margin. The registry record does not report these elements, which makes transparent outcome reporting especially important.

The crossover structure offers the possibility of comparing strategies within participants, potentially reducing the influence of stable differences between people. At the same time, the analysis must account for repeated measurements and consider whether period or carryover effects could influence comparisons. The registry identifies the sequence-specific assessments, but does not report the statistical model or how these design features were handled.

The study also illustrates why enrollment counts alone cannot convey precision. Enrollment was 11, but the record does not report the number analyzed at each visit or outcome uncertainty. Without these details, readers cannot judge how complete the data were or how much information supported the main comparison.

Finally, the distinction between a stated trial objective and a posted result matters. The registry makes the scientific question and test understandable, while the absent numerical primary findings prevent a conclusion about the objective. This is a limitation of the available record rather than evidence for a particular treatment effect.

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 central limitation is that the registry record does not report numerical results for the primary word-recognition outcome. There are no group means, full ranges, changes from baseline, comparative effect estimates, confidence intervals, or p-values. The main non-inferiority question therefore cannot be assessed quantitatively.

The record does not report the non-inferiority margin, the statistical analysis plan, or the model used for the crossover data. It also does not specify how period, sequence, or possible carryover effects were addressed. The statistical methods and any protocol-level justification for enrollment are not reported in the registry record.

Although 11 participants were enrolled, the record does not report the number contributing data at each visit, completion of both strategies, withdrawals, or reasons for missing observations. It does not define the primary analysis population or describe how incomplete data were handled. These omissions limit assessment of the completeness and robustness of the intended comparison.

The masking and randomization labels are recorded, but implementation details are not reported. The record also does not provide enough detail to interpret event timing and attribution across the crossover periods. Safety figures should therefore be read as posted counts, not as causal or comparative estimates.

Finally, the registry identifies two outcome measures but does not report the broader statistical plan, any multiplicity handling, or analysis entries. These reporting gaps restrict evaluation of both the primary efficacy question and the context for secondary findings. They do not show that the trial lacked methods or analyses; those details are simply not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Fundamental Asynchronous Stimulus Timing Sound Coding Study — NCT02698787.
• Registry record last updated 2021-02-02; status last verified 2021-01.
• Results first posted 2021-02-02.
• 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

NCT02698787 is a completed randomized, double-masked crossover study sponsored by Cochlear, with enrollment of 11. It examines the FAST experimental sound coding strategy against the commercially available ACE strategy in newly implanted adult cochlear implant recipients with sensorineural hearing loss.

The stated primary outcome is change in open-set monosyllabic word recognition score, measured as percentage of words correct. Assessments are listed at baseline, 3 months, and 6 months, with the two groups assessed under FAST and ACE in differing sequences. The primary objective is non-inferiority of FAST to ACE for word recognition in quiet.

The registry lists safety counts, but does not report numerical primary-outcome results, a non-inferiority margin, or statistical analyses. The main comparative result therefore cannot be determined from the registry record.