BradyXplore Phase II: Bradykinesia Feature Extraction System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for BradyXplore Phase II: Bradykinesia Feature Extraction System (NCT02358876), a registered phase not stated study. The primary outcome is Percentage of Kinesia One Assessments Performed.

2. Clinical Question

The study's broader aims also address test-retest reliability, relationships between participant-perceived symptom severity and sensor measurements, changes in movement features during the day for people with implanted deep brain stimulation systems, and usability feedback. These aims help describe the scope of the project, but the record does not report results for them. The clinical question that can be evaluated from the listed primary outcome is consequently narrow: how consistently were directed home assessments carried out, as expressed by the recorded percentage? The registry record does not provide a result with which to judge that outcome.

3. Trial Design

BradyXplore Phase II is listed as a completed study sponsored by Great Lakes NeuroTechnologies Inc. The record gives a start date of 2015-02, a primary completion date of 2015-07, and enrollment of 32 participants. Parkinson's disease is the listed condition. The title and study description concern a bradykinesia feature-extraction system, with objectives spanning motion-sensor algorithms and their use in clinic and home settings.

The listed primary outcome is the percentage of Kinesia One assessments performed as directed over two weeks. The outcome is expressed as a mean with standard deviation. The registry record does not report the observed result, the number of assessments expected from each participant, or details of how an assessment counted as completed or performed as directed.

The record does not describe a randomized comparison; allocation is not stated, and the study should not be read as a treatment-versus-control trial on the basis of its primary outcome. It does not identify a like-for-like control group for that outcome. The broader objectives include comparing sensor algorithms with clinician raters, but the corresponding results and analysis details are not reported in the registry record.

The record lists one outcome measure and no analysis records. It does not report a statistical analysis plan, masking procedures, an interim-analysis plan, or a sample-size justification. Details such as eligibility criteria, recruitment setting, visit schedule, sensor procedures, and participant flow are also not reported in the registry record. Those omissions limit how far the design can be reconstructed from the registry entry, even though the study status, timing, enrollment, condition, and primary outcome are stated.

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 Percentage of Kinesia One Assessments Performed, measured over Two weeks.

The primary endpoint is the percentage of Kinesia One home assessments performed as directed during two weeks. It represents adherence to the requested assessment activity, not the magnitude of bradykinesia and not, by itself, the accuracy or reliability of a sensor measurement. A high or low percentage would need to be interpreted in the context of how assessments were scheduled, what counted as an acceptable completion, and how missing or unusable recordings were handled. Those operational details are not reported in the registry record.

The endpoint is listed as a continuous measure summarized by a mean and standard deviation. In general, a mean describes the average value across the observations included in an analysis, while a standard deviation describes how dispersed those values are around the mean. For a percentage-based measure, the precise unit of analysis matters: a participant-level percentage and a percentage pooled across assessments can represent different summaries. The registry record does not state the calculation or analysis unit.

Compliance is relevant to home measurement because a device's intended assessment process depends on assessments being carried out as directed. However, completion alone cannot establish that the sensor captures symptoms accurately, that results agree with clinician ratings, or that measurements are reliable over repeated testing. Those are among the study's broader objectives, but no results for them are reported in the registry record. No numerical primary endpoint result is reported either, so the endpoint's observed level and variability cannot be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a continuous primary outcome summarized by a mean and standard deviation. The outcome is a percentage, but the record does not describe its calculation in enough detail to determine whether the analysis used participant-level percentages, assessment-level observations, or another summary. No analysis results are reported. The concepts below explain how such statistics are generally interpreted; they do not establish which analysis procedures were used in this study.

What does a mean and standard deviation describe?

In general, a mean is an average of the values included in an analysis. A standard deviation describes how much those values vary around the mean. Together they provide a summary of location and spread, but they do not show the full distribution, explain why values differ, or establish whether the measurement is accurate. Here, the registry record names these summary statistics but does not give their observed values.

For a home-assessment percentage, the definition of an observation is consequential. If the analysis first calculates a percentage for each participant, the mean would describe the average of those participant-level percentages. If it instead combines assessments before calculating a percentage, participants who have more assessments could contribute differently. This is a general distinction, not a description of the study's actual calculation. The registry record does not report the denominator, calculation rule, or weighting approach.

How should a confidence interval be understood?

In general, a confidence interval describes the statistical uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision for that estimate, while a wider interval indicates less precision. A confidence interval does not show the range of individual participant values, and it does not eliminate uncertainty about measurement quality, missing data, or design limitations. No confidence interval for the primary outcome is reported in the registry record, so its precision cannot be evaluated.

What does the absence of a comparison mean?

The registry record says the study is not a randomized comparison and that allocation is not stated. In general, a randomized comparison supports a particular form of between-group interpretation because assignment is determined by a random process. That framework should not be assumed. The record does not identify a like-for-like control comparison for the primary compliance outcome. A study objective involving comparison with clinician raters is a different question from comparing randomized groups, and the registry record does not report its result or analysis.

The planning assumptions mention two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. They also define the target effect for planning illustrations as a stated fraction of the observed effect. These are planning assumptions, not evidence that the study was designed or conducted with two arms. Any sample-size values associated with such assumptions are planning illustrations, not observed power. They should not be read as the probability that the completed study detected an effect, and they do not replace a reported estimate and uncertainty interval.

Why does the percentage denominator matter?

A percentage is a ratio of a numerator to a denominator, but the registry record does not report the underlying counts or the calculation rule. For this endpoint, interpretation would depend on which assessments were considered directed, whether assessments that were attempted but unusable counted as completed, and how scheduled assessments that were not performed were treated. These are general issues for a completion measure. The record does not report how any of them were handled, so the meaning of a hypothetical percentage cannot be made more specific.

Repeated observations can also affect statistical analysis. In general, if several measurements come from the same participant, those measurements may be more alike than measurements from different participants. Treating correlated measurements as independent can make uncertainty appear smaller than it is. The registry record describes a two-week period of home assessments but does not provide the schedule or analysis unit, so it is not possible to determine whether repeated observations were analyzed or how any within-participant correlation was handled.

What can the posted analysis information support?

The record lists one outcome measure and no analyses. It does not report the analysis population, a statistical model, covariate adjustment, an inferential test, or a method for handling missing data. It also does not report an analysis plan or interim analyses. These details should not be inferred from the fact that the outcome is continuous or from the stated mean and standard deviation summary.

In general, a statistical model is selected to match the question, measurement scale, and dependence structure of the data. A percentage may have limits that differ from an unbounded continuous measurement, and repeated home assessments may require attention to clustering within participants. Those general considerations do not determine what model was used. Because the registry record contains no analysis result or model description, there is no basis for judging model fit, assumptions, or robustness.

Overall, the statistical methods that can be identified are limited to the outcome's stated form and summary: a percentage summarized by a mean and standard deviation over two weeks. The record does not supply the numerical estimate, a measure of inferential precision, or enough procedural detail to reproduce the analysis. General statistical principles can clarify what those items would mean, but cannot fill in the unreported result or method.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Participants")
n   <- c(30)
m   <- c(99)
sp  <- c(2)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Participants  30  99.000  2.000  98.253  99.747

11. Multiplicity, Missing Data and Analysis Populations

The record lists one outcome measure and no analyses. The study description, however, names several objectives: algorithm improvement, test-retest reliability, comparison with clinician raters, relationships between perceived severity and sensor measures, daily changes in movement features for participants with implanted deep brain stimulation systems, usability feedback, and home compliance. These are distinct questions and could involve distinct outcomes or analyses. The registry record does not report how they were prioritized analytically or whether any multiplicity strategy was used.

In general, when many outcomes or comparisons are examined, the chance of at least one apparently unusual result can increase. A prespecified hierarchy, adjustment procedure, or clear distinction between primary and exploratory analyses can help readers understand how to interpret multiple tests. No such plan is reported in the registry record, so it is not possible to determine whether or how multiplicity was addressed. The number of listed outcome measures alone does not establish the complete set of analyses conducted.

Missing-data procedures are not reported. The record does not say how missing home assessments, incomplete recordings, or missing participant-level summaries were handled. These issues are especially relevant to a completion endpoint because an unperformed assessment may be part of the intended outcome definition, while missing information about an assessment is a different issue. The registry record does not explain how that distinction was made.

The analysis population is also not reported. Enrollment of 32 does not indicate how many participants contributed to the primary outcome or whether any observations were excluded. The denominator for the percentage, rules for unusable data, and any sensitivity analyses are not reported in the registry record. Consequently, the impact of missingness and the scope of the analyzed population cannot be evaluated.

12. 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 record lists 32 participants at risk for serious adverse events and records 0 serious adverse events. It also lists 32 participants at risk for other adverse events and records 0 other adverse events. These entries should be read as the counts recorded in the registry, not as a detailed account of every safety observation or as a comparison between groups.

The record does not list serious adverse-event terms, and deaths are not reported in the registry record. It does not provide further information about the definitions, observation period, collection procedures, or completeness of safety reporting. The available counts therefore do not support a more detailed description of event type, timing, or relationship to the device or study procedures.

In general, an absence of recorded events in a registry summary is not the same as proof that no event could occur. Safety interpretation depends on how events were defined, collected, and reported, as well as the size and duration of observation. No additional safety inference should be drawn from the listed counts alone. These figures also do not answer the primary question about the percentage of home assessments performed as directed.

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

The registry record identifies a completed Phase II study of a motion-sensor system for measuring bradykinesia. It specifies a primary outcome: the percentage of Kinesia One assessments performed as directed during two weeks. It also records enrollment of 32 participants and provides broad objectives covering sensor algorithms, reliability, symptom relationships, daily movement-feature fluctuation, usability, and home compliance.

The record does not report the primary outcome's observed mean or standard deviation. It lists no analyses, and does not provide a confidence interval, an analysis population, or the denominator used for the percentage. Therefore, the posted information does not show how often directed assessments were completed or how much participant-level results varied. It cannot support a claim that compliance was high or low.

The primary endpoint is about completion of home assessments. Even if a completion result were available, it would not by itself establish the accuracy of bradykinesia measurement, agreement with clinician ratings, test-retest reliability, or correspondence with participant-perceived symptom severity. Those are separate study objectives, and their results are not reported in the registry record.

The registry also does not establish a randomized control comparison. Allocation is not stated, and the record explicitly says the study is not a randomized comparison with like-for-like control arms. Planning assumptions that refer to two arms should not be mistaken for the trial's actual design. The available information is therefore descriptive of the study's stated question and reporting, rather than evidence of a comparative effect.

The safety entries record 0 serious and 0 other adverse events among 32 participants at risk; deaths are not reported in the registry record. These entries have their own reporting limits and do not resolve the missing primary outcome. The clearest conclusion is about the record itself: it defines a compliance endpoint and describes several broader objectives, but does not post numerical outcome or analysis results for assessing them.

14. Why This Trial Matters Statistically

This study is statistically interesting because its primary question concerns the use of a measurement system in the home, where the process of obtaining observations is part of the evidence. Before interpreting a sensor-derived measure, readers need to know not only what the device records but also whether the directed assessments were carried out. The selected primary endpoint addresses that practical measurement-process question through the percentage of Kinesia One assessments performed as directed over two weeks.

That endpoint is not a substitute for validation of the measurement. Completion, reliability, agreement with clinician ratings, and correspondence with perceived symptom severity describe different properties. A system can be evaluated on one property without the result establishing the others. The study objectives recognize several of these questions, but the registry record reports no results for them. Keeping the constructs separate prevents a compliance statistic from being interpreted as a measure of clinical accuracy.

The study also illustrates why the analysis definition matters for percentages. A reader needs to know what the denominator represents and whether the calculation is made for each participant or across all assessments. The record names a mean and standard deviation but does not report these operational or analytic details. Those omissions prevent a full assessment of the outcome's meaning and precision.

Finally, the record distinguishes a completed study from a fully reported result. Status, enrollment, timing, and an outcome definition are useful, but they do not provide an estimate or uncertainty measure. With one listed outcome measure and no analyses, the registry entry allows a description of the intended primary question, while leaving its empirical answer unavailable in the registry record. That distinction is important when evaluating evidence from device-measurement studies.

15. 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 primary limitation for statistical interpretation is that the registry record does not report the primary outcome result. Although the endpoint is defined as the percentage of Kinesia One assessments performed as directed over two weeks and is designated for summary by a mean and standard deviation, neither statistic is reported. No confidence interval or other measure of precision is available.

Important details needed to interpret that percentage are also absent. The record does not state how many assessments were expected, what counted as performed as directed, what denominator was used, or whether the unit of analysis was the participant or the individual assessment. It does not report how incomplete or unusable assessments were classified. These gaps make it impossible to determine what a numerical compliance estimate would represent even if one were listed.

The record gives enrollment of 32 but does not report the analysis population or participant flow. It does not state how many participants had outcome data, whether observations were excluded, or how missing data were handled. Allocation is not stated, and the study is not described as a randomized comparison with like-for-like control arms. No comparative estimate should be inferred.

The broader objectives are not accompanied by results or analysis details in the registry record. Information about the sensor algorithm, assessment schedule, clinician-rating procedures, and analysis methods is not reported. Nor are multiplicity procedures, an interim-analysis plan, or a sample-size justification reported. The sample-size assumptions used for planning illustrations should not be treated as observed power or as confirmation of the study's design.

Finally, the safety summary provides counts but limited context: it records 0 serious and 0 other adverse events among 32 participants at risk, while deaths are not reported in the registry record. Taken together, these limitations mean the entry can describe the study's stated aims and outcome, but cannot establish the size, precision, or robustness of the primary result.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: BradyXplore Phase II: Bradykinesia Feature Extraction System — NCT02358876.
• Registry record last updated 2016-10-06; status last verified 2016-08.
• Results first posted 2016-10-06.
• 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.

19. Record Summary

BradyXplore Phase II is a completed study sponsored by Great Lakes NeuroTechnologies Inc. The registry record lists Parkinson's disease, enrollment of 32 participants, a start date of 2015-02, and a primary completion date of 2015-07.

The primary outcome is the percentage of Kinesia One assessments performed as directed over two weeks, summarized as a mean with standard deviation. Broader objectives concern sensor algorithms, clinician ratings, symptom perceptions, daily movement-feature fluctuation, usability, and home compliance.

The record lists one outcome measure and no analyses. It does not report the primary outcome result, an analysis population, or missing-data procedures. It describes no randomized comparison, and allocation is not stated. The safety record lists 0 serious and 0 other adverse events among 32 participants at risk; deaths are not reported in the registry record.