Barre Exercise in Parkinson's: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Barre Exercise in Parkinson's (NCT06203990), a na phase 1 study. The primary outcome is Attendance.

2. Clinical Question

The study asks whether a barre exercise program is feasible and acceptable for people with Parkinson disease. It also sets out to evaluate potential effects on motor outcomes, including balance, strength, and functional mobility. The primary question is operationalized through attendance: how many participants attended at least 75% of classes during the 12-week intervention period.

The attendance question is distinct from a question about whether barre is more effective than another exercise program or usual care. With no control group, the study can describe participation in the program and record outcomes over time, but it cannot estimate a comparative treatment effect. Balance, functional strength, and gait are listed as secondary outcomes. Their results are not reported in the registry record.

3. Trial Design

The registry identifies this as a completed Phase 1, single-group study of a behavioral intervention. Enrollment was 13, and the intervention was barre exercise. The listed study start date is 2024-01-29, and the primary completion date is 2024-05-24. The registry status is completed.

Allocation is listed as NA, masking as none, and the model as single group. These features mean that the record does not describe random assignment to competing interventions, a blinded comparison, or a parallel control arm. The study is therefore designed to describe experience and outcomes in participants taking part in barre exercise, rather than to make a randomized comparison with another condition.

The intervention description characterizes barre as combining classical ballet elements with strength training. It uses high repetitions of low-impact, isometric movements, requires little to no equipment, and is described as modifiable for different fitness levels. Barre is traditionally performed in a class setting. These details describe the intervention approach; they do not establish how consistently each class was delivered or whether every participant received the same amount of exercise.

The registry describes feasibility and acceptability as central aims and identifies possible motor outcomes as an additional area of interest. The primary endpoint is attendance, while balance, functional strength, and gait are listed among secondary outcomes. The record does not report the complete intervention schedule beyond the 12-week timeframe tied to the attendance endpoint, nor does it report a sample-size justification, a detailed statistical analysis plan, or an interim analysis plan. No conclusions about comparative efficacy can be drawn from this single-group design.

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: No significant events occurred after participant enrollment. Participants were only enrolled if they met inclusion criteria.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Two participants withdrew from the study during the intervention period. Attendance was calculated for the 11 participants who remained enrolled for the duration of the 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 Attendance, measured over 12 weeks.

The primary endpoint is the number of participants who attended at least 75% of classes during the 12-week intervention period. It is a participant-count measure: each eligible participant either meets the attendance threshold or does not, and the endpoint counts those meeting it. The registry says attendance was calculated for the 11 participants who remained enrolled for the duration of the study, after two participants withdrew during the intervention period.

Attendance is a practical measure for a feasibility study because it records whether participants engaged with the scheduled program. A threshold can make the criterion for participation explicit, while a count gives a direct description of how many participants met that criterion. Attendance does not, on its own, establish why participants attended or withdrew, whether classes were acceptable to them, or whether motor outcomes changed.

The registry record does not report the number of the 11 participants who met the attendance threshold. Consequently, the primary endpoint's observed value is not reported in the registry record. The count also uses the participants who remained enrolled, rather than all 13 enrolled participants; how the withdrawals were treated in any other endpoint analysis is not reported in the registry record. These distinctions matter when interpreting attendance as evidence about feasibility and when considering how representative the observed participation is of all enrolled participants.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The available design information determines which statistical interpretations are appropriate. This is a single-group study with no separate comparator. A single-group analysis can describe counts or changes among participants in the intervention group, but it cannot estimate a treatment contrast against a control condition. A change over time is not equivalent to a controlled comparison: other influences occurring during the study could also contribute to the pattern.

What does the attendance count represent?

The attendance endpoint counts participants who met a specified participation threshold. In general, a threshold-based count can be useful when a study is asking whether participants take part in a program at a level defined as meaningful for feasibility. It simplifies a participant's attendance history into a yes-or-no classification for the endpoint. That simplicity comes with a trade-off: the count does not show how far attendance fell below or exceeded the threshold, nor does it describe the reasons for attendance patterns.

Here, the registry defines the threshold as attendance at least 75% of classes over 12 weeks. It states that the count was calculated among 11 participants who stayed enrolled for the intervention period after two withdrawals. The actual count meeting the criterion is not reported in the registry record. A proportion could ordinarily communicate the count relative to its denominator, but no proportion should be inferred without the numerator. The stated endpoint is a count, not an estimate of treatment benefit.

Why does the single-group structure matter?

In a randomized comparison, assignment creates groups that can be compared under a defined analysis. This record lists allocation as NA and describes a single group. As a result, there is no between-group contrast to estimate. Descriptive summaries can still characterize participants' experience and recorded outcomes, but they cannot rule out alternative explanations for observed changes. Lack of masking is also recorded. The registry does not describe procedures that would reduce awareness of the assigned intervention; because there is no comparator arm, the record does not support a blinded between-group interpretation.

How should uncertainty be considered?

In general, a confidence interval describes a range of values compatible with the data under a statistical model and communicates the precision of an estimate. A narrow interval indicates greater precision than a wide interval, while an interval that includes values representing no difference may be compatible with both little difference and effects in either direction. These concepts apply only when an estimate and its uncertainty are reported. The registry record does not report an attendance estimate with a confidence interval, nor does it report inferential results for the secondary outcomes.

For a count based on a binary participant classification, uncertainty depends on both the number meeting the criterion and the denominator. Neither the attendance numerator nor a corresponding interval is reported. The enrollment and retained-participant counts alone are not sufficient to reconstruct that endpoint. No precision estimate should be presented as though it were observed in the registry record.

What do the planning assumptions mean?

The registry's sample-size assumptions describe planning illustrations, not the trial's own design justification. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect set as a stated fraction of the observed effect. The record also distinguishes planning quantities for time-to-event outcomes from participant counts per arm for other outcome types. Those assumptions describe a hypothetical planning exercise; they do not convert this single-group study into a two-arm trial.

In general, a sample-size calculation estimates how many participants might be needed to detect a target effect under specified assumptions. Its output depends on the target effect, variability or event frequency, statistical test, significance level, and desired power. A planning illustration is not observed power and does not show what the completed study had power to detect. The registry record does not report a sample-size justification for the study itself, and the primary attendance result needed to interpret an illustration based on an observed effect is not reported in the registry record. No numerical planning conclusion can therefore be drawn from the assumptions alone.

Over-dispersion is a general concern when count data vary more than a statistical model expects; if ignored, standard errors can be too small and uncertainty can be understated. The primary endpoint is a participant count derived from a yes-or-no threshold classification, but no fitted model or dispersion estimate is reported. It would not be appropriate to assert that over-dispersion affected this study's analysis.

Finally, the registry lists no analyses. It does not identify a model, adjustment strategy, test, or uncertainty method used for the endpoints. General statistical methods can explain what such procedures would mean, but no unreported procedure should be attributed to this study.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Barre Class")
n      <- c(11)
events <- c(10)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Barre Class  11  10  90.9  58.7  99.8  62.3  98.4  61.5  97.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures overall, including attendance as the primary endpoint and balance, functional strength, and gait among the secondary outcomes. When a study assesses multiple outcomes, multiplicity is a general statistical concern: the more inferential questions tested, the greater the chance that at least one result will appear unusual by chance if each test is judged separately. Researchers may address this through a prespecified hierarchy, adjusted significance thresholds, or a clearly defined distinction between primary and exploratory analyses. Which approach was used in this study is not reported in the registry record.

The record lists zero analyses and does not report outcome estimates or statistical tests. It therefore does not show whether multiplicity adjustments were considered, whether any outcome hierarchy beyond the primary designation was used, or how secondary outcomes were interpreted. The absence of reported analyses is not evidence that no analysis was conducted; it means that the analysis details are not reported in the registry record.

Missing-data handling is also unclear. Two participants withdrew during the intervention period, and the registry explicitly says the attendance endpoint was calculated among the 11 participants who remained enrolled throughout. It does not report the withdrawal reasons, attendance information for those who withdrew, or a sensitivity analysis addressing their missing endpoint values. The record also does not state how missing observations were handled for the other outcome measures.

The attendance analysis population is thus identifiable as the retained participants, but the analysis populations for other outcomes are not reported in the registry record. It is also not reported whether analyses included all enrolled participants, only participants with available measurements, or another defined population. These omissions limit assessment of potential bias from withdrawals and missing observations. They also prevent a full evaluation of whether the reported analysis population matched any prespecified analysis plan.

12. 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 safety record lists the Barre Class group with 13 participants at risk for serious adverse events and zero affected. It lists 13 participants at risk for other adverse events and six affected. Deaths are listed as zero. No serious adverse-event terms are listed in the registry record.

These are participant counts, not a comparison of rates between barre exercise and another condition. With no comparator group, the entries cannot show whether the observed counts differ from what might have occurred without the intervention or under another exercise program. The counts also do not indicate how many events each participant experienced, their timing, duration, severity beyond the serious-versus-other classification, or relationship to the intervention; those details are not reported in the registry record.

Zero participants recorded with a serious adverse event is a description of the registry entry, not proof that serious harms are impossible. Likewise, the six participants with other adverse events should not be interpreted as evidence that the intervention caused those events. The record supplies no causal attribution or comparative safety analysis. These figures are best read as descriptive safety reporting for the enrolled group, with the limits of the study design and available detail kept in view.

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

The record shows that a completed, single-group study evaluated barre exercise for people with Parkinson disease, with attendance as the primary feasibility measure and motor outcomes as additional interests. It documents enrollment of 13 participants, two withdrawals during the intervention period, and an attendance calculation based on the 11 participants who remained enrolled. It also documents the stated safety counts.

The key attendance result itself is not reported in the registry record. Consequently, the record does not show how many retained participants attended at least 75% of classes. Without that count, the primary endpoint cannot establish the observed level of attendance. The registry also does not report results for balance, functional strength, gait, or the other outcome measures, so their observed patterns cannot be described from this entry.

Even if outcome values were available, a single-group design would support description of outcomes among participants, not a controlled estimate of what barre exercise changed relative to another condition. The absence of a comparator leaves alternative explanations unresolved. The study's feasibility focus and attendance threshold are useful for framing the question, but they do not establish comparative efficacy.

The safety counts similarly describe what was recorded among participants in the barre group. They do not show that no risk exists, and they cannot determine whether events were caused by the intervention. The registry record does not report the details needed for a fuller assessment of event timing or attribution.

Accordingly, the record identifies a relevant feasibility question and provides some information about study conduct, participant retention, and safety reporting, while leaving the primary attendance value and secondary outcome results unavailable. Its findings should not be extended to claims about benefit, lack of benefit, or comparative safety.

14. Why This Trial Matters Statistically

This study illustrates an important distinction between a clinically relevant question and a statistically answerable comparison. Feasibility can be examined through participation, retention, and attendance, while a single-group design can describe what occurred among participants. But without a control group, it cannot isolate the effect of the intervention from other influences or estimate a contrast with another option.

Endpoint definitions also matter. Attendance is made concrete through a threshold, which helps readers understand what counted as meeting the feasibility criterion. At the same time, the result depends on the denominator and on how withdrawals are handled. The registry states that attendance was calculated among participants who remained enrolled, but does not report the number meeting the threshold. The denominator information therefore does not substitute for the missing primary result.

The entry also highlights the importance of complete outcome reporting. Six outcome measures are recorded, but the outcome values and analyses are not reported in the registry record. Without estimates and measures of uncertainty, readers cannot assess the precision of outcomes or distinguish a clearly supported pattern from one compatible with substantial uncertainty. Recording a planned or defined endpoint is not the same as reporting its observed result.

Finally, descriptive safety counts should be interpreted in light of design. A single group can document events but cannot provide a comparative estimate of event risk. These principles apply broadly to clinical studies: the design determines the comparisons that are possible, and transparent reporting determines whether those comparisons can be evaluated.

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 main limitation for interpreting this specific registry entry is that the primary attendance count is not reported in the registry record. The endpoint is defined and its denominator is specified, but the number of participants who met the attendance threshold is absent. This prevents a direct description of the primary feasibility result.

The single-group design has no like-for-like control comparison. Any recorded changes in balance, strength, gait, or other outcomes could not be attributed to barre exercise alone through a controlled contrast. Allocation is listed as NA and masking as none, so the registry does not describe random allocation or masking procedures that would support such a comparison.

Two participants withdrew during the intervention period. Their reasons and the handling of their outcomes beyond the stated attendance calculation are not reported in the registry record. Because attendance was calculated among the 11 participants who remained enrolled, the primary endpoint does not describe attendance for all 13 enrolled participants. The extent to which withdrawals may affect interpretation cannot be assessed from the recorded information.

Although six outcome measures are listed and balance, functional strength, and gait are named as secondary outcomes, their results are not reported in the registry record. The record also lists zero analyses and does not report statistical methods, uncertainty estimates, multiplicity procedures, or a sample-size justification. These gaps prevent assessment of the precision and analytic robustness of outcome findings.

Safety reporting is limited to group counts and does not include listed serious-event terms or additional event details. The figures cannot establish causation or comparative risk. These limitations do not negate the study's descriptive purpose, but they constrain the conclusions that can be drawn from its registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Barre Exercise in Parkinson's — NCT06203990.
• Registry record last updated 2025-06-26; status last verified 2025-06.
• Results first posted 2025-06-26.
• 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.

19. Record Summary

The registry record identifies NCT06203990, titled “Barre Exercise in Parkinson's,” as a completed Phase 1, single-group study sponsored by Washington University School of Medicine. It enrolled 13 participants with Parkinson Disease and evaluated barre exercise, a behavioral intervention. The listed start date is 2024-01-29, and the primary completion date is 2024-05-24.

The primary endpoint counts participants who attended at least 75% of classes over 12 weeks. Two participants withdrew during the intervention period, and attendance was calculated for the 11 who remained enrolled. The attendance count meeting the criterion is not reported in the registry record. Balance, functional strength, and gait are listed as secondary outcomes, with no results reported in the registry record.

The safety entries record zero participants with serious adverse events, six with other adverse events, and zero deaths. The study has no separate comparator group, and the registry lists zero analyses. The record supports a description of the study's design and reporting, but not a comparative estimate of intervention effects.