TOlerability of Transcranial Direct Current Stimulation in Pediatric Stroke Survivors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for TOlerability of Transcranial Direct Current Stimulation in Pediatric Stroke Survivors (NCT05812794), a na na study. The primary outcome is Number of Participants Who Complete the Study.

2. Clinical Question

3. Trial Design

The registry describes a completed, single-group study of Transcranial Direct Current Stimulation (tDCS) in childhood stroke survivors. Enrollment is recorded as 5. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. These features mean the record does not describe a randomized, masked comparison between intervention and control groups. A comparator is not reported, so estimates from this study cannot be read as a between-group treatment contrast.

The listed intervention is tDCS, classified as a device. The brief study description also refers to occupational therapy and to assessing arm function in patients receiving tDCS and occupational therapy. Details of how the stimulation or occupational therapy was delivered are not reported in the registry record. The phase is listed as NA.

The study status is COMPLETED. The recorded start is 2023-06-30 and primary completion is 2023-12-11. The primary outcome is the number of participants who complete the study, with a timeframe of 1-week post therapy. Secondary outcomes include side effects documented on a stimulation monitoring sheet, blood pressure monitoring, a decrease in Peg-Board Test score, upper-extremity function measured by the Fugl-Meyer score, and unilateral upper-limb movement measured by the Melbourne Assessment of the Upper Extremity. Outcome results for these measures are not reported in the registry record. The record lists 9 outcome measures and 0 analyses.

With a single group and no comparator, the design is suited to describing the recorded experience of participants in the study, not to estimating a comparative effect against usual care or another treatment. Information on recruitment procedures, follow-up completion, and the detailed analysis plan is not reported in the registry record.

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 Number of Participants Who Complete the Study, measured over 1-week post therapy.

The primary endpoint is the number of participants who complete the study. It is a count outcome: it records how many participants meet the study's completion definition, rather than measuring the size of a change in arm function or the frequency of a particular symptom. The registry gives the measurement timeframe as 1-week post therapy. The exact operational definition of completion—such as which visits or assessments must be finished—is not reported in the registry record.

Completion can be useful in a tolerability study because it describes whether participants remain in the study through the stated endpoint. It is a practical measure of study participation, but it is not interchangeable with a direct measure of tolerability. A participant may complete despite an unwanted event, and completion alone does not establish why a participant did or did not finish. Interpreting it therefore depends on clear definitions and supporting information about withdrawals, reasons for discontinuation, and observed events. Those details are not reported in the registry record.

The registry lists several secondary outcomes that address tolerability and function more directly: reports of side effects, blood pressure findings, a decrease on the Peg-Board Test, the Fugl-Meyer score of upper-extremity function, and the Melbourne Assessment of the Upper Extremity. Their outcome values are not reported in the registry record. The primary completion result is also not reported, so the endpoint's observed value and its precision cannot be described from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods are most useful when they match the study design, outcome type, and question. In this record, the design is SINGLE GROUP, allocation is NA, and masking is NONE. The primary outcome is a count of participants completing the study. No analyses are listed in the registry record, and a detailed statistical analysis plan is not reported in the registry record. The explanations below describe general statistical principles, not methods confirmed to have been used in this study.

What does a count endpoint describe?

A count endpoint reports how many observations meet a definition. For study completion, the count depends on both the definition of completion and the group of participants considered in the analysis. A count is most interpretable alongside a clearly defined denominator and an account of missing follow-up. The record identifies the primary endpoint as the number of participants who complete the study and gives its timeframe as 1-week post therapy, but does not report the completion result, the completion definition, or a denominator for that endpoint. Therefore, the observed completion count and its uncertainty cannot be assessed from the registry record.

Counts and proportions answer related but distinct questions. A count gives an absolute number; a proportion relates that number to an eligible analysis group. Neither should be reconstructed when the necessary outcome result and analysis denominator are absent. No derived completion percentage is reported.

How should uncertainty be understood?

General: an estimate describes the value observed in a study, while a confidence interval describes the range of values compatible with the data and the interval procedure. A narrow interval indicates greater precision than a wide interval, but neither an interval nor a point estimate can correct limitations in the design or data. The registry record does not report confidence intervals for the completion outcome or secondary outcomes. With a small study, uncertainty is especially important: a limited number of observations can leave a wide range of plausible underlying event rates. This is a general statistical point, not an estimate of this study's precision.

For a binary outcome, such as whether any participant endorses a side effect, methods can estimate an event probability. The choice of interval method matters when counts are small or close to the boundaries of what is possible. The record does not report an analysis method or interval estimates for the tolerability measures. The recorded adverse-event counts can be described as counts, but should not be presented as proof of a precise underlying risk.

Why does the study design matter?

General: a comparison group helps distinguish changes associated with an intervention from changes that might occur over time or for other reasons. In a single-group study, observed outcomes describe participants who received the intervention in that study context. Without a comparator, a difference between an initial and later measurement, if one were reported, would not alone identify the intervention as its cause. Here, a registered comparator is not reported. The study purpose mentions occupational therapy alongside tDCS, but details of its use are not reported in the registry record.

Masking can reduce some forms of bias in outcome assessment or reporting, depending on who is masked and how outcomes are measured. Masking is listed as NONE. The record does not explain whether any outcome assessments were conducted by people independent of treatment delivery, so that cannot be inferred.

What do planning illustrations mean?

General: sample-size calculations use assumptions about the design, event rate or effect size, variability, significance level, and desired power. A planning calculation illustrates how many participants might be needed under those assumptions; it is not an observed result, and it does not show the probability that a completed study's conclusion is correct. The stated planning framework uses 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 fraction of the observed effect. It describes time-to-event calculations in terms of total events and other calculations in terms of participants per arm.

Those assumptions do not describe the registered study design, which is single-group and has allocation listed as NA. The record does not report a trial-specific sample-size justification or the numerical planning outputs. Any planning illustration based on an observed effect should be treated as an illustration, not as observed power or as evidence that the study was adequately sized. The sponsor's own analysis would take precedence if a recalculation were discrepant, but no recalculated outcome estimate is reported in the registry record.

Why can over-dispersion matter?

General: for count data, a statistical model may assume that observations vary around an average in a particular way. Over-dispersion means the observed variation is greater than that assumed by a model. If it is ignored, uncertainty can be understated. This consideration is relevant to some count outcomes, but the record does not report a count-model analysis or data that would establish over-dispersion. The primary endpoint is a count of study completers, and no model for that outcome is reported.

Overall, the registry record does not provide enough outcome data or analytic detail to reconstruct an inferential analysis. The methods explain concepts relevant to interpreting such a study; they should not be mistaken for a statistical plan documented for this trial.

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("Transcranial Direct Current Stimulation (tDCS)")
n      <- c(5)
events <- c(5)
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  Transcranial Direct Current Stimulation (tDCS)  5  5  100.0  47.8  100.0  56.6  100.0  54.1  99.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 9 outcome measures and 0 analyses. The primary endpoint is study completion. Secondary outcomes cover side effects, blood pressure, Peg-Board Test changes, upper-extremity function, and unilateral upper-limb movement. The results for these outcomes are not reported in the registry record.

When a study evaluates several outcomes, there are multiple opportunities to observe an apparently notable result by chance. General approaches to this issue include identifying a primary outcome in advance, adjusting statistical thresholds, or interpreting secondary findings as exploratory. Which approach was planned for this study is not reported in the registry record. A multiplicity adjustment or hierarchy of testing is also not reported. Without outcome estimates and an analysis plan, the impact of multiple outcome assessment cannot be evaluated.

Missing-data handling is important because incomplete measurements can change the group represented by an analysis. The primary outcome is completion, but the registry does not report how completion was defined, whether follow-up data were missing, why any participant may not have completed the study, or how missing observations were handled. An analysis population—such as all enrolled participants or only those with observed outcome data—is not reported in the registry record. Those details should not be inferred from the enrollment figure or from the safety counts.

The record also does not report a prespecified statistical analysis plan, interim analyses, or the handling of protocol deviations. No assumptions about those procedures can be made. Accordingly, the listed outcome titles indicate the topics assessed, but do not establish which results were analyzed, how they were analyzed, or how uncertainty and multiplicity were handled.

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 registry records 0 serious adverse events among 5 participants at risk in the tDCS group. It records 5 other adverse events among 5 participants at risk, and 0 deaths. These are the registry's recorded categories; they do not by themselves establish that an event was caused by tDCS. The record does not provide the event-level descriptions, timing, severity, or attribution needed to interpret the nature of the other adverse events. No serious adverse event terms are listed.

The counts should be read as observations within a small single-group study, not as precise estimates of event rates in a broader population. General: absence of recorded serious events in a study does not establish that an event cannot occur, especially when the number of participants observed is limited. Conversely, an adverse event recorded during a study does not alone show that the intervention caused it. Such judgments require clinical and temporal details, assessment of alternative causes, and a suitable comparison where available.

The registry also names specific tolerability outcomes, including side effects documented on a stimulation monitoring sheet and blood pressure findings. Their individual results are not reported in the registry record. The broad other-adverse-event count should not be treated as a substitute for those outcome-specific results. The primary completion result is likewise not reported.

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

This study record is relevant as a description of a completed investigation of tDCS tolerability in childhood stroke survivors. It identifies the intervention, a single-group design, enrollment of 5, and an endpoint focused on study completion at 1-week post therapy. It also lists tolerability and upper-limb function outcomes, and provides adverse-event counts for the intervention group.

However, the primary completion result and the listed secondary outcome results are not reported in the registry record. The record therefore does not show how many participants completed the study or what was observed on the side-effect, blood pressure, Peg-Board, Fugl-Meyer, or Melbourne Assessment measures. A missing result should not be interpreted as a zero, a lack of change, or evidence that an outcome was not assessed.

The adverse-event information is descriptive. There were 0 recorded serious adverse events and 0 deaths, alongside 5 other adverse events in the group of 5 participants at risk. These counts do not establish causation or precisely characterize risk. Event details and attribution are not reported in the registry record.

The single-group design also limits what can be concluded. Without a registered comparator, the record cannot establish whether outcomes differed from what would have occurred without tDCS, or separate effects of tDCS from occupational therapy or other influences. The trial does not provide a randomized treatment contrast. The information supports describing the study design and recorded safety counts, but not a causal conclusion about treatment or a comparative claim about arm function.

In general, this kind of small study may inform feasibility and generate questions for further research, but the conclusions depend on complete outcome reporting and transparent methods. The registry record does not report enough outcome results or analytic detail to assess estimates of benefit, tolerability beyond the stated counts, or their precision.

14. Why This Trial Matters Statistically

Statistically, this study matters because it illustrates the difference between a study's stated purpose and the results available for interpretation. The record describes an evaluation of tDCS tolerability and arm function, but the primary endpoint is the count of participants who complete the study. Completion is useful as a practical outcome, yet it is not a complete substitute for direct tolerability measurements or functional assessments.

The registry identifies several secondary measures that could add context: side effects, blood pressure, Peg-Board performance, the Fugl-Meyer score, and the Melbourne Assessment of the Upper Extremity. But their results are not reported in the registry record. Without those observations, readers cannot evaluate the magnitude or precision of changes, nor how the different outcome domains relate to completion.

The single-group design makes clear why statistical description and causal inference are different tasks. A study can document outcomes among participants who received an intervention, but a comparator is needed to make a direct treatment contrast. With no registered control group, changes over time cannot be uniquely attributed to tDCS. The study purpose also mentions occupational therapy, and the record does not provide details that would separate its contribution.

The modest enrollment recorded and the absence of reported outcome estimates also underscore the role of uncertainty and complete reporting. Counts are informative as observations but are not, by themselves, precise population estimates. Reporting denominators, definitions, event details, analysis populations, and uncertainty would help readers interpret findings and assess what further research could address. The current registry record offers a design and outcome framework, but not the primary or secondary results needed for broader statistical conclusions.

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 trial-specific limitation is the single-group design. Allocation is listed as NA, masking as NONE, and a comparator is not reported. The study can describe outcomes in the group receiving tDCS, but the record does not support a like-for-like comparison with another treatment or no intervention. The study purpose mentions occupational therapy, but its delivery and relationship to the intervention are not detailed in the registry record.

Enrollment is recorded as 5, which limits how broadly the observed experience can represent childhood stroke survivors. In general, a small study also has limited ability to characterize uncommon events or estimate outcomes precisely. The recorded adverse-event counts should therefore be interpreted descriptively rather than as stable estimates of risk.

The outcome reporting is incomplete in the registry record. The primary outcome is the number of participants who complete the study, but its result and operational definition are not reported. Results for the listed secondary outcomes are also not reported. The record does not describe missing observations, reasons for any non-completion, analysis populations, or the approach to missing data. These omissions prevent assessment of whether outcome data represent all enrolled participants or a subset.

Further details not reported in the registry record include the stimulation protocol, treatment schedule, eligibility criteria, outcome assessment procedures, event descriptions, event attribution, statistical analysis plan, and any multiplicity strategy. The record lists 9 outcome measures and 0 analyses, but does not explain the analysis choices. These limitations restrict interpretation of tolerability, functional outcomes, and their precision.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: TOlerability of Transcranial Direct Current Stimulation in Pediatric Stroke Survivors — NCT05812794.
• Registry record last updated 2024-09-26; status last verified 2024-08.
• Results first posted 2024-09-26.
• 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 describes a completed, single-group study of Transcranial Direct Current Stimulation (tDCS) in childhood stroke survivors, with enrollment of 5. Allocation is listed as NA and masking as NONE. The study purpose is to evaluate tolerability and assess arm function; it also refers to occupational therapy. The primary outcome is the number of participants who complete the study at 1-week post therapy.

Secondary outcomes include side effects, blood pressure findings, Peg-Board Test change, upper-extremity function on the Fugl-Meyer measure, and unilateral upper-limb movement on the Melbourne Assessment. The record lists 9 outcome measures and 0 analyses. The primary and secondary outcome results are not reported in the registry record. Safety counts include 0 serious adverse events, 5 other adverse events, and 0 deaths; event descriptions and causal attribution are not reported. The single-group design does not provide a comparative treatment estimate.