Kick Out Parkinson's Disease 2: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Kick Out Parkinson's Disease 2 (NCT03882879), a randomized na study. The primary outcome is Change in Mobility as Measured by the Timed Up & Go (TUG).

2. Clinical Question

The study record identifies randomized allocation and describes two arms with different timing of karate classes. Its title calls it a Phase Two randomized trial, although the registry phase field is listed as NA. The key interpretive question is therefore how mobility at the stated assessment time compares across the two exercise sequences. Since both arms are scheduled to receive karate, the contrast concerns timing and prior exercise experience as well as participation in classes.

The summary describes the study as a larger randomized group following a pilot study. The pilot is described as involving 15 participants over 10 weeks, but those pilot observations are not the randomized trial's outcome results. The registry lists enrollment of 52 for the trial. The primary outcome description says that pre- and post-intervention TUG scores will be compared, but it does not give the arm-level results or specify a single contrast that resolves the different intervention schedules.

3. Trial Design

The registry describes a randomized, double-masked study with enrollment of 52 and a completed status. Its official title identifies it as a Phase Two randomized trial, while the phase field itself is listed as NA. The design model is recorded as single-group, although the arm descriptions specify Arm 1 and Arm 2 with different exercise sequences. The record does not explain this difference in its design labels.

Arm 1 was scheduled to begin six months of karate classes immediately after pre-intervention study visits. Arm 2 was scheduled to continue its usual exercise routine for six months and then take karate classes for six months. The record lists a pre-intervention study visit, karate classes, bimonthly online surveys, a six-month study visit, and a 12-month study visit. It does not fully describe the timing or content of each survey or visit beyond those labels and the arm descriptions.

The primary outcome is TUG mobility at the 12-month study visit. The primary outcome description says scores at pre- and post-intervention focus groups will be compared, but does not specify how that wording maps onto the two visit schedules or which arm contrast is primary. The record also lists a secondary outcome concerning change in overall well-being measured by the Patient Global Impression of Change scale.

The study started on 2019-03-03, reached primary completion on 2020-03-27, and is marked completed. The registry record does not report the randomization procedure, allocation concealment, who was masked, the rationale for the sample size, or a detailed statistical plan. Although the record says double masked, the roles of the masked parties are not identified. These omissions limit what can be concluded about implementation and analysis from the design description alone.

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: Baseline study visit and assessments completed after enrollment and prior to randomization.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants evaluated at 12 month study visit.

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: Fifty two individuals enrolled; randomized 27 (Arm 1) to 25 (Arm 2)

6. Primary Endpoint

The registry lists the primary outcome as Change in Mobility as Measured by the Timed Up & Go (TUG), measured over 12 months.

The primary endpoint is change in mobility measured by the Timed Up & Go (TUG), recorded in seconds, with assessment at the 12-month study visit. In the test, a participant starts seated in a standard arm chair, stands when instructed, walks at a normal pace to a taped line, turns, returns to the chair, and sits down. A study team member records the elapsed time with a stopwatch. The registry states that a lower TUG result indicates greater mobility.

The TUG is used because it provides a brief, objective measure of functional mobility involving standing, walking, turning, and sitting. These component actions make the measure relevant to a trial focused on mobility and balance. Its continuous scale also allows results to be described using a mean and standard deviation, the summary measure types listed in the registry for the primary outcome.

Interpreting a change requires knowing which measurements and comparison are being contrasted. The record refers to pre- and post-intervention scores, and specifies the 12-month study visit, but it does not report the observed means, standard deviations, change estimates, or a single arm-level primary comparison. It also does not report a threshold for interpreting a change as clinically important. Consequently, the endpoint definition explains what was measured and the direction of better mobility, but not the size or precision of any observed change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary outcome as a continuous measure summarized by a mean and standard deviation. A mean describes the central level of measurements, while a standard deviation describes how spread out participant measurements are around that mean. These summaries can help convey typical TUG performance and variation, but they do not by themselves provide an estimate of the difference between arms or its uncertainty. The registry record does not report the arm-specific primary outcome summaries.

What does randomization contribute?

In general, random assignment is intended to make study groups comparable, on average, with respect to characteristics measured before intervention as well as characteristics not measured. It supports a comparison of assigned strategies, but does not guarantee that groups will be identical in a particular trial. It also does not resolve questions about adherence, missing observations, outcome measurement, or the appropriateness of the analysis. The record identifies randomized allocation but does not describe how the assignment sequence was generated or concealed.

What does the masking label establish?

The registry records double masking. Masking can reduce the influence of expectations on treatment delivery, outcome assessment, or reporting, depending on who is masked. The record does not say which people were masked or how masking was maintained. Because the intervention consists of exercise classes, the detailed practical implications of masking cannot be determined from the registry description alone.

How should the comparison be understood?

The two arm descriptions specify different intervention sequences: immediate karate classes in Arm 1 and usual exercise followed by karate in Arm 2. A between-arm result at a particular visit would reflect those assigned sequences as implemented and analyzed. It would not automatically represent the isolated effect of karate versus never doing karate. The registry does not specify the primary contrast, the exact change score or model to be used, or whether the principal analysis is based on assignment, participation, or another population.

General statistical practice distinguishes an estimate from its uncertainty. An estimated mean difference or change summarizes the observed contrast; a confidence interval conveys the range of values reasonably compatible with the data under specified assumptions. A test statistic or p-value addresses compatibility with a particular null hypothesis, but does not measure clinical importance. The registry record does not report a primary estimate, confidence interval, or test result, so none can be interpreted for the TUG endpoint.

Why can variability matter?

For a continuous measure, variation among participants affects how precisely a group mean or contrast can be estimated. Greater spread generally makes an estimate less precise when other design features are held constant. This is a general statistical point, not a claim about the observed variability in this trial: the primary outcome's arm-level standard deviations are not reported in the registry record.

General methods also need to consider whether the data fit the assumptions of a chosen model. For example, over-dispersion matters when observed variability is greater than a model assumes, because standard errors may then be understated and uncertainty may look smaller than it is. That concept does not imply that over-dispersion applies to a continuous TUG outcome or to this study. The registry does not identify a fitted model or report diagnostics that would permit such an assessment.

What do planning illustrations mean?

Sample-size illustrations based on an observed effect are planning exercises, not observed power and not proof that the original trial was adequately or inadequately sized. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is defined as a stated fraction of the observed effect. The registry record does not report the trial's own sample-size justification or a protocol-based calculation. No planning sample-size values are reported in this registry entry.

These distinctions are especially relevant when the primary result is not reduced to a single comparison. A study can record multiple outcome measures, analyses, categories, or time points, while the scientific interpretation depends on which contrast was designated as primary and how it was analyzed. The registry lists five outcome measures and five analyses, and notes that the primary outcome spans several categories or time points. It does not report a detailed statistical analysis plan that would identify a single primary estimate or describe adjustments for multiple comparisons.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and five analyses. It identifies TUG mobility as the primary outcome and Patient Global Impression of Change as a secondary outcome. The primary outcome is described as having several categories or time points and is not reduced to one comparison. The record does not identify a single primary contrast among those possible comparisons, nor does it report whether or how the analysis accounted for multiple testing.

In general, multiplicity arises when several hypotheses, outcomes, or time points are examined. If many comparisons are treated as confirmatory without an appropriate plan, the chance of finding an apparently notable result by chance can increase. This general concern does not establish that a particular result is invalid; the registry record does not provide the analysis plan or results needed to evaluate that issue in this trial. It also does not report interim analyses or a prespecified hierarchy of outcomes.

Missing-data information is not reported in the registry record. In particular, the record does not state how many participants contributed TUG observations at each assessment, why any observations might be unavailable, or how missing measurements were handled. It does not identify the analysis population, such as whether analyses followed randomized assignment or were restricted by participation or outcome availability. These details matter because an analysis based only on observed measurements may differ from an analysis that accounts for missingness under explicit assumptions.

General statistical interpretation should distinguish the number enrolled from the number with usable measurements for a particular outcome. The record's enrollment figure does not answer that outcome-specific question. Without the missing-data and analysis-population details, the degree to which the reported data represent all assigned participants cannot be assessed from this registry entry.

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: surgery (4.0%), urinary tract infection (3.7%), hyponatremia (3.7%).

The registry reports serious adverse events by arm. Arm 1 has 27 participants listed at risk for serious events and 2 affected; Arm 2 has 25 at risk and 1 affected. The record lists 0 deaths in each arm. For other adverse events, Arm 1 has 27 participants at risk and 0 affected, while Arm 2 has 25 at risk and 1 affected.

The registry also lists surgery at 4.0%, urinary tract infection at 3.7%, and hyponatremia at 3.7% among the leading serious-event terms. The record does not attribute these listed terms to a particular arm in the information. These percentages should not be added together: the registry does not establish that event categories are mutually exclusive or that each percentage refers to a different participant.

These figures are descriptive counts, not a comparison adjusted for differences between groups or a test of whether the intervention caused an event. The registry does not provide further detail about event timing, relatedness to the intervention, or the methods used to collect and classify events. A reported count of zero means no affected participants are listed for that category in that arm; it does not establish that the risk is absent.

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

The registry record describes a randomized study of two sequences involving karate classes and usual exercise, with TUG mobility at the 12-month visit identified as the primary outcome. It also identifies feasibility, objective outcomes, and patient-reported outcomes as study aims. The record therefore provides information about what the study was designed to examine, but it does not report a single primary outcome comparison or its numerical estimate.

Without arm-level TUG results and an uncertainty measure, the direction and magnitude of any mobility difference cannot be established from this record. The fact that a measure is designated primary does not indicate whether its result favored either sequence. Similarly, the listed secondary outcome does not establish a change in overall well-being. No conclusion about whether karate improved or failed to improve mobility or quality of life follows from the design description or safety counts.

The schedule also shapes what a between-arm comparison would mean. Arm 1 began karate after the pre-intervention visit; Arm 2 continued usual exercise before beginning karate. Because both arms were scheduled for karate, an endpoint comparison would reflect the assigned sequences and timing, not a simple contrast of receiving versus never receiving classes. The registry does not report enough analysis detail to determine how the timing was handled in a primary estimate.

In general, a study estimate should be interpreted in light of its precision, the prespecified comparison, missing data, and the population analyzed. Those details are not reported for the primary outcome in this entry. The serious adverse event counts are useful descriptive information, but they do not answer the mobility question and do not show that an event was caused by the intervention.

The appropriate reading is therefore bounded: the registry documents a completed randomized study, its intervention schedules, its stated outcome, and selected safety counts. It does not document a numerical primary result or enough statistical detail to judge the size, precision, or clinical importance of an outcome contrast. The absence of a reported result in this record is not evidence that no effect occurred; it means the effect cannot be characterized from the information recorded.

13. Why This Trial Matters Statistically

This trial is statistically interesting because its intervention is delivered in two different sequences rather than as a simple intervention-versus-no-intervention contrast. Arm 1 begins karate after the pre-intervention visit, while Arm 2 first continues usual exercise and later begins karate. That schedule makes the definition of the primary comparison central to interpretation, especially for a 12-month mobility assessment.

The endpoint is a continuous, objective mobility measure with a stated direction: lower TUG results indicate greater mobility. Such an outcome can describe changes in functional performance, but statistical interpretation still depends on the contrast, variability, and uncertainty. The registry does not report the primary estimate, confidence interval, or a single comparison, so the result's magnitude and precision cannot be assessed from this entry.

The record also illustrates why a randomized label alone is not a complete account of analysis. The registry lists a single-group model while describing two arms, and its note says the primary outcome spans several categories or time points without one reduced comparison. It does not explain the design label or provide a detailed analysis plan. These points make it important to distinguish the trial's stated aims and structure from evidence about an outcome.

Finally, the record lists serious adverse event counts alongside a completed trial status, but the safety data answer a different question from the TUG endpoint. Reading them separately avoids treating descriptive counts as proof of causation or as a substitute for an efficacy estimate. The statistical value of the record lies in its transparency about the intervention schedules and limitations of the registered result, not in a numerical conclusion it does not report.

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 results in a form that supports a single arm comparison. It lacks arm-specific TUG means and standard deviations, a change estimate, a confidence interval, and a primary test result. The note that the primary outcome has several categories or time points and is not reduced to one comparison leaves the intended primary contrast unclear.

The record also has a design-description tension: allocation is recorded as randomized and the arm descriptions specify two schedules, but the model field says single-group. The registry does not explain this label. Although masking is recorded as double, it does not identify who was masked or describe how masking was implemented. Randomization procedures and allocation concealment are not reported.

Details needed to assess interpretation are also absent. The registry does not report participant characteristics, intervention attendance, adherence, the contents of usual exercise, or the number with outcome data at each visit. It does not identify the analysis population or explain missing-data handling. The analysis plan, sample-size justification, multiplicity approach, and interim-analysis details are not reported in the registry record.

The timing of intervention differs between arms, and both are scheduled to receive karate. A 12-month contrast therefore reflects the assigned sequences and their timing; it is not a direct comparison with an arm that never received karate. The record does not specify a single analysis that separates these aspects. Finally, the serious adverse-event terms are not attributed to arms in the listed information, and details on timing and relatedness are not reported. These limitations constrain conclusions about both the outcome comparison and safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Kick Out Parkinson's Disease 2 — NCT03882879.
• Registry record last updated 2024-04-12; status last verified 2023-10.
• Results first posted 2024-04-12.
• 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 registry identifies NCT03882879, titled Kick Out Parkinson's Disease 2, as a completed randomized, double-masked study sponsored by Rush University Medical Center. Enrollment is listed as 52. The study started on 2019-03-03, with primary completion on 2020-03-27. The official title describes a Phase Two randomized trial, while the phase field is listed as NA.

The study concerns Parkinson disease and compares two schedules: Arm 1 begins six months of karate after pre-intervention visits, while Arm 2 continues usual exercise for six months and then takes karate classes for six months. The primary outcome is change in TUG mobility, measured in seconds at the 12-month visit. The record also lists change in overall well-being on the Patient Global Impression of Change scale as a secondary outcome.

The registry record does not report a single primary comparison or its numerical result. It reports serious adverse event counts by arm and lists surgery, urinary tract infection, and hyponatremia among the leading serious-event terms. Additional statistical-plan, missing-data, and analysis-population details are not reported.