CHANGE Feasibility Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for CHANGE Feasibility Study (NCT02671032), a na na study. The primary outcome is Report on Degree of Hearing as Measured by Pure Tone Audiogram.

2. Clinical Question

The study also sets out to examine speech perception and safety, including adverse events and adverse device effects. Secondary outcomes named in the registry record include the Speech, Spatial and Qualities of Hearing Scale (SSQ) and Glasgow Benefit Inventory (GBI). These measures could describe participants’ reported hearing experiences and perceived benefit, but their results are not reported in the registry record.

The primary question is descriptive: it concerns audiological measurements after implantation within a group receiving the same device. Without a separate control group, the study does not make a like-for-like comparison between the device and another treatment or no treatment. The registry record does not report a causal comparison or numerical primary-outcome findings. It therefore supports describing the study’s intended measurements and design, not drawing conclusions about the size or certainty of an outcome difference.

3. Trial Design

The CHANGE Feasibility Study is listed as completed and as a single-group study of the Nucleus CI532 cochlear implant. The registry lists enrollment of 12 and describes all participants as receiving the same intervention: implantation with that device. Allocation is recorded as NA, and masking is listed as none. The phase is recorded as NA. The study is sponsored by Cochlear.

The registry lists a start date of 2016-01-05 and a primary completion date of 2019-07-15. These dates describe the study record, but do not establish when each participant was implanted, activated, or assessed. Participant-level timing and any variation in follow-up are not reported in the registry record.

This design is suited to describing observations made in a group receiving the intervention, including audiological measurements and safety events. It does not provide a concurrent control group for separating changes associated with the intervention from other influences, such as changes over time or differences among participants. The record does not describe random allocation, and it should not be read as a randomized comparison.

The stated primary outcome is the number of participants with a degree of hearing measured by pure tone audiogram. Measurements are specified at 6 months and 12 months post activation, using unaided audiograms in the ear to be implanted and the implanted ear. The brief summary also identifies audiometry, speech perception, and safety as study topics. The registry names the SSQ and GBI as secondary outcomes.

The record lists five outcome measures, but it does not report the numerical results for the primary outcome or the secondary measures. It lists zero analyses. The protocol’s detailed analysis plan, including any planned handling of repeated measurements or missing assessments, is not reported in the registry record. The study’s feasibility label describes its stated purpose; it does not by itself establish that a particular statistical method or design objective was used.

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

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 Report on Degree of Hearing as Measured by Pure Tone Audiogram, measured over 6 months and 12 months post activation.

The primary endpoint is titled “Report on Degree of Hearing as Measured by Pure Tone Audiogram.” Its unit is participants, and its parameter is a number. The specified timeframe is 6 months and 12 months post activation. The description calls for an unaided audiogram at the indicated intervals in both the ear to be implanted and the implanted ear.

A pure tone audiogram measures hearing thresholds across tones. In general, audiometric thresholds provide a structured way to describe auditory sensitivity; measuring the ears separately can distinguish the ear intended for implantation from the implanted ear. Repeating the assessment at specified follow-up points can describe the pattern of recorded hearing over time. Those are general features of audiometric assessment, not findings about participants in this study.

The registry’s endpoint wording calls for reporting a number of participants, rather than specifying a mean threshold, a threshold change, or a treatment contrast. The exact response categories or criteria used to classify “degree of hearing” are not reported in the registry record. Nor are the observed counts, individual measurements, or any summary estimates reported. Thus the endpoint’s description identifies what is to be measured and when, but does not show the resulting audiometric values or how they were analyzed.

The endpoint is relevant to the study’s stated audiological focus. It should be interpreted alongside its measurement definition and the absence of a separate comparator; it cannot by itself establish that any observed change was caused by implantation.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods determine how observations are summarized, how uncertainty is represented, and what comparisons can be supported by a study design. For this study, the registry record identifies the broad endpoint and design but does not report a statistical analysis plan or outcome analyses. The explanations below describe general principles; they are not a description of methods confirmed to have been used in the study.

What does a single-group design permit?

In general, a single-group study can describe measurements and events observed among participants receiving the same intervention. It may summarize individual measurements, counts, or changes over time if those data and definitions are available. It does not provide a concurrent comparison group. Without such a group, a difference between measurements at separate times cannot automatically be attributed to the intervention: time, measurement conditions, participant characteristics, or other influences may also contribute. The registry does not report a control group or a randomized comparison.

The record lists allocation as NA, masking as none, and the model as single group. These design features should guide interpretation of any reported estimates. They are not statistical adjustments. The registry does not report whether assessors were blinded, whether any measurements were repeated or independently reviewed, or how potential sources of bias were addressed.

How should the primary endpoint be understood?

The primary outcome is framed as a number of participants with a degree of hearing measured by pure tone audiogram. The measurements are specified for 6 months and 12 months post activation, with an unaided audiogram in the ear to be implanted and the implanted ear. In general, an outcome analysis needs an operational definition: for a categorical count, it should be clear how participants are classified; for a continuous measurement, it should be clear what value or change is summarized. The registry’s endpoint description does not report the classification criteria, detailed audiometric scale, or a numerical result. It is therefore not possible to determine from the record how the audiogram readings were converted into the stated participant count.

Repeated measurements can be analyzed in more than one way. General approaches may describe each time point separately or model the relationship among repeated observations. Such analyses can differ in their assumptions and in how they use incomplete follow-up. The registry record does not report which approach, if any, was used, whether measurements were paired for analysis, or how missing audiograms were handled.

What do event counts and uncertainty mean?

The adverse-event summary reports affected participants and participants at risk for serious and other events, as well as deaths. Counts are descriptive. In general, a count gives the number of recorded participants meeting a definition; by itself, it does not show how precisely an underlying event frequency is known. A confidence interval is a range of values compatible with the data under a specified statistical model and method. It communicates uncertainty around an estimate, rather than proving that the true value lies within a particular range. No confidence intervals for the outcomes are reported in the registry record.

When event data are sparse, estimates can be especially uncertain. General methods for binary outcomes may rely on approximations that behave poorly when counts are small or when an event is absent. Alternative interval methods may be used in such circumstances, but the record does not report an interval method or any interval estimate. It is not appropriate to infer a specific method from the event counts alone.

Over-dispersion is a general concern when outcome variability is greater than an assumed model allows. For example, a model that expects similar event rates across participants may understate uncertainty if participants differ substantially in risk. Accounting for over-dispersion can widen uncertainty estimates or change model-based inference. The registry does not report a model for event counts, a dispersion assessment, or an adjustment for this issue; the concept should not be mistaken for a finding about this study.

How should planning illustrations be read?

The registry describes sample-size illustrations as planning calculations based on the observed effect, not as the trial’s own design. It specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. It says that time-to-event illustrations give total event counts and other illustrations give participants per arm. These are assumptions for hypothetical planning scenarios. They do not describe the actual single-group allocation, and they do not establish that the study was designed or analyzed according to those assumptions.

A planning sample size estimates the amount of information a hypothetical study might need under stated assumptions. It is not a result observed among participants, and it is not “observed power.” The registry record does not report a sample-size justification for the actual feasibility study. Any illustration based on an observed effect should be interpreted cautiously when the underlying outcome estimate and its uncertainty are not reported. A planning calculation cannot substitute for an outcome analysis or resolve the limitations of a single-group design.

What can be concluded about the analysis?

The record lists zero analyses and does not report a statistical plan, analysis population, model specification, confidence intervals, or hypothesis tests. It does not report whether any adjustment for baseline measurements or participant characteristics was planned. These omissions mean that the statistical method behind the intended outcome summaries cannot be reconstructed from the registry record. The endpoint descriptions and safety counts can be reported as registry information, but claims about statistical significance, adjusted effects, or precision would require results and methods that are not reported.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures, names the primary audiometric outcome, and identifies secondary outcomes including SSQ and GBI. It does not report a multiplicity strategy. In general, when several outcomes or time points are tested, the chance of at least one apparently notable result can increase if each is assessed separately. Researchers may address this through a prespecified hierarchy, adjustment, or a primarily descriptive interpretation. The registry does not say whether any such approach was planned or used.

The primary endpoint includes measurements at 6 months and 12 months post activation and refers to both the ear to be implanted and the implanted ear. The analysis plan does not specify whether those measurements were intended as separate summaries, a paired comparison, or a combined endpoint. No inferential results are reported, so the consequences of multiple measurements cannot be assessed from the record.

Missing-data handling is not reported in the registry record. It does not state how many participants contributed audiograms at each time point, whether follow-up was complete, or how unavailable measurements were handled. In general, missing observations can affect both the size and interpretation of an estimate, especially if absence of measurement is related to a participant’s condition or experience. The record does not support an assumption that all planned assessments were available.

The registry also does not define the analysis population or explain exclusions, eligibility for each outcome, or treatment of participants who did not complete follow-up. These details are needed to understand which observations underlie an estimate. The absence of these details is not evidence that data were missing or that a particular analysis population was used; these matters are simply not reported in the registry record.

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 non-serious adverse event terms

The registry’s safety summary lists 12 participants at risk for serious adverse events and 0 affected, 12 at risk for other adverse events and 7 affected, and 0 deaths. These are counts recorded for the single group receiving implantation with the Nucleus CI532 cochlear implant. The registry lists no serious adverse-event terms.

The counts describe what the record reports; they are not a comparison with an untreated group or another device. The figure of 0 for serious adverse events means none were recorded among the participants listed as at risk in this summary. It does not establish that serious events cannot occur, and it does not quantify comparative risk. The count of 7 for other adverse events is also descriptive. The record does not provide event types, timing, severity details for those events, or an analysis relating events to the device or procedure.

In general, adverse-event counts depend on how events are defined, collected, and followed. A participant count may differ from an event count if one participant experiences more than one event; the registry summary’s stated unit is participants. No further event-level detail or uncertainty estimate is reported in the registry record, so the counts should not be read as complete characterization of the nature or frequency of all events.

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

The study record establishes the design and the outcomes the investigators intended to examine: audiological measurements, speech perception, and safety after implantation with the Nucleus CI532 cochlear implant. It also records the primary audiometric assessment at 6 months and 12 months post activation and lists SSQ and GBI among secondary outcomes. These details clarify the study’s focus, but they are not results about how participants’ hearing or reported experience changed.

The registry reports safety counts for the single treatment group: 0 serious adverse events among 12 at risk, 7 other adverse events among 12 at risk, and 0 deaths. These observations describe this group in the registry summary. With no comparator, they do not establish whether event experience differs from another treatment or from what would otherwise have occurred. Missing event descriptions and uncertainty estimates further limit interpretation.

The primary audiometric results, secondary outcome results, and statistical analyses are not reported in the registry record. No effect estimate or confidence interval is available to show the direction, magnitude, or precision of audiological outcomes. A completed study status does not fill this gap. Nor can a planning illustration be treated as an observed outcome or as evidence of statistical power.

In general, a feasibility study can contribute information about the conduct and measurement aims of research, while a controlled comparison is needed to support a stronger causal contrast. The registry record does not report the operational criteria for classifying the primary endpoint or detailed follow-up completeness. These limitations mean that the record can be used to understand what was studied and what safety counts were entered, but not to quantify a treatment effect or make a comparative conclusion about benefit or risk.

13. Why This Trial Matters Statistically

This study is statistically useful to examine because it illustrates the distinction between describing an intervention group and estimating a comparative treatment effect. The registry identifies a single-group feasibility design in which all participants receive the same cochlear implant. Such a design can organize observations on audiometry, speech perception, and safety, but the absence of a separate comparator constrains causal interpretation.

The endpoint description also shows why an outcome definition matters. “Degree of hearing” measured by pure tone audiogram is a clinical measurement concept, while the registry frames the result as a number of participants. The classification criteria and numerical findings are not reported. Without those details, readers cannot tell how audiogram values were translated into a count or assess how the outcome was summarized.

Timing is part of the estimand: measurements are specified at 6 months and 12 months post activation, and in both the ear to be implanted and the implanted ear. Repeated measurements can create choices about which time point or contrast is emphasized and how incomplete follow-up is handled. The registry does not describe these analysis choices, multiplicity handling, or missing-data methods.

The safety summary demonstrates the difference between a recorded count and a comparative risk estimate. Counts of serious and other adverse events provide descriptive information, but no comparator, event-level details, or uncertainty intervals are reported. Statistical interpretation should keep those boundaries visible rather than treating a low or absent count as conclusive evidence.

Finally, the record distinguishes planning assumptions from the study’s actual design. The described sample-size illustrations use a hypothetical two-arm allocation, whereas the study itself is single group. Recognizing that mismatch prevents a planning scenario from being mistaken for an analysis of the enrolled group. The record is therefore a useful example of how design, endpoint definition, reporting, and uncertainty jointly shape what can be inferred.

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 principal trial-specific limitation is the single-group design. All participants are described as receiving implantation with the Nucleus CI532 cochlear implant, and the registry does not list a separate control arm. This prevents a like-for-like treatment comparison and limits attribution of any measured change to the intervention.

The primary outcome description does not specify the audiometric classification rules used to report a number of participants. Although the record identifies unaided audiograms, the ear to be implanted, the implanted ear, and follow-up at 6 months and 12 months post activation, it does not report threshold values or outcome counts. Primary results are not reported in the registry record.

The registry names speech perception, SSQ, and GBI among the outcomes of interest but does not report their numerical results. It lists five outcome measures and zero analyses, without a detailed analysis plan, multiplicity strategy, or statistical model. The analysis population and missing-data handling are also not reported. As a result, the completeness and precision of outcome summaries cannot be evaluated.

Safety reporting is limited to participant counts and does not list serious adverse-event terms. The registry does not provide event-level descriptions, timing, or comparative estimates. The study’s completed status does not address these reporting gaps. These limitations concern what can be inferred from the registry record and should not be taken as evidence that an unreported outcome or analysis had a particular result.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: CHANGE Feasibility Study — NCT02671032.
• Registry record last updated 2021-06-09; status last verified 2021-06.
• Results first posted 2020-11-20.
• 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

The CHANGE Feasibility Study is a completed, single-group study sponsored by Cochlear. The registry lists enrollment of 12 adults with hearing loss and implantation with the Nucleus CI532 cochlear implant. Allocation is recorded as NA and masking as none. The record lists a start date of 2016-01-05 and a primary completion date of 2019-07-15.

The primary outcome is degree of hearing measured by pure tone audiogram at 6 months and 12 months post activation, using unaided audiograms in the ear to be implanted and the implanted ear. The record also identifies speech perception and safety as study aims and names SSQ and GBI as secondary outcomes. Numerical primary and secondary outcome findings and statistical analyses are not reported in the registry record.

The safety summary records 0 serious adverse events among 12 at risk, 7 other adverse events among 12 at risk, and 0 deaths. The design has no separate comparator, so these counts and the stated outcome aims do not provide a comparative treatment-effect estimate.