Effect of Bilateral TENS With TOT on Upper Limb Function in Patients With Chronic Stroke: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Bilateral TENS With TOT on Upper Limb Function in Patients With Chronic Stroke (NCT03112473), a randomized na study. The primary outcome is Fugl Meyer Assessment on Upper Extremity (FMA-UE).

2. Clinical Question

The study is described as randomized, double-masked, and parallel-group, with enrollment of 120. The registry record does not specify which people were masked or how masking was maintained. The four assigned groups allow the stated bilateral approach to be considered alongside unilateral stimulation, bilateral sham stimulation, and a no-active-intervention control. These comparisons address different questions: the sham groups share task-oriented training, whereas the control description does not include an active intervention. No comparative outcome estimates are available in the record, so the design alone cannot answer whether one approach produced a greater change.

3. Trial Design

The registry identifies this as a randomized, double-masked, parallel-group clinical trial. It lists an enrollment of 120 and marks the study as completed. The sponsor is The Hong Kong Polytechnic University. The record gives the start date as 2016-11-24 and the primary completion date as 2020-10-24. These registry entries describe the study's design and status; they do not supply outcome results.

Four groups are described. The bilateral TENS group received task-oriented upper-limb training with bilateral electrical stimulation. The unilateral TENS group received task-oriented training with stimulation on the paretic side and sham stimulation on the non-paretic side. The placebo group received the training with bilateral sham stimulation. The control group is described as receiving no active intervention. For the first three groups, the registry describes 20 sessions of 60 minutes, thrice a week, for 8 weeks. It does not provide comparable detail about the control group's schedule or what activities, if any, accompanied assessments.

Random allocation can help balance measured and unmeasured participant characteristics across groups on average, but it does not guarantee balance in a particular trial. The method used to generate the allocation sequence, how assignments were concealed before enrollment, and whether allocation was stratified are not reported in the registry record. The masking label is double, but the record does not identify the masked roles or describe procedures for keeping assignments concealed after allocation. These omissions limit how fully the implementation of the design can be assessed.

The primary outcome was scheduled for assessment before intervention, at mid-intervention (4 weeks), after intervention (8 weeks), and at follow-up 1 month (12 weeks) and 3 months (20 weeks). The registry also lists secondary outcomes covering function, strength, joint movement, activity, and community integration. The record does not report group-specific outcome summaries, participant flow, adherence, or analysis results. Accordingly, the design and assessment schedule can be described, but comparative effects cannot be reconstructed from 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 Fugl Meyer Assessment on Upper Extremity (FMA-UE), measured over Pre-intervention, Mid-intervention (4 weeks), Post-intervention (8 weeks), Follow-up 1 month (12 weeks), Follow-up 3 months (20 weeks).

The primary endpoint is the Fugl-Meyer Assessment on the Upper Extremity (FMA-UE), recorded as a score on a scale. The registry describes it as an assessment of upper-limb motor control from the proximal to distal parts of the limb and of voluntary movement from synergistic to isolated movement. Its subsections cover shoulder-arm, wrist, hand, and coordination and speed. Their scores are combined into a total score.

The stated maximum total score is 66, based on 33 items, each scored ordinally from 0 to 2. The registry says that a higher FMA-UE score indicates a higher level of upper-limb motor control. This makes the measure relevant to the trial's focus on upper-limb function after stroke: it captures performance across several parts and aspects of motor control rather than focusing on a single joint or task.

The record identifies the outcome as continuous and specifies that the planned summary parameter is the mean with standard deviation. Those summaries can describe the average score and its variability within a group, but the registry record does not contain the group means, standard deviations, or comparative estimates. The assessment schedule spans pre-intervention, mid-intervention (4 weeks), post-intervention (8 weeks), follow-up 1 month (12 weeks), and follow-up 3 months (20 weeks). The record does not identify a single time point as the sole analysis time point or explain how repeated assessments were to be modeled. No primary endpoint result is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the trial as randomized, double-masked, and parallel-group. These labels have statistical implications, but they do not provide all the information needed to assess the methods. Randomization is intended to make treatment assignment independent of prognostic characteristics, reducing systematic differences between groups on average. In practice, confidence in that process also depends on the sequence-generation and allocation-concealment procedures; these are not reported in the registry record. The masking label does not identify who was masked, how masking was implemented, or whether it was assessed.

What would a between-group estimate mean?

For a continuous outcome such as the FMA-UE, an analysis could estimate a difference in average scores between assigned groups. Such an estimate would describe the contrast under the chosen analysis and at the specified assessment time. An estimate by itself does not show precision. A confidence interval would communicate uncertainty around it, while a hypothesis test would assess compatibility with a stated null hypothesis under the model assumptions. The registry record reports no primary-outcome estimate, confidence interval, or test result, so none of these can be interpreted for this trial.

The planned summaries are means and standard deviations. A mean describes the central average score, while a standard deviation describes the spread of individual scores around that average. These summaries can be useful for describing each group, but the change from baseline and the comparison between groups require an analysis specification. A simple comparison at a follow-up visit, a comparison of change scores, and a model incorporating repeated assessments can answer related but non-identical questions. The analysis approach is not reported in the registry record.

How do repeated assessments affect analysis?

The FMA-UE is scheduled before intervention, mid-intervention (4 weeks), after intervention (8 weeks), and at follow-up 1 month (12 weeks) and 3 months (20 weeks). Repeated measurements from the same participant are generally correlated: observations from one person tend to be more alike than observations from different people. General statistical methods for repeated measures account for that dependence rather than treating every recorded score as independent. They can also use information across visits and estimate differences in trajectories, depending on the chosen model. The registry does not state whether such a method was planned or which assessment time would anchor the primary comparison.

Different choices about baseline adjustment, the handling of repeated measurements, and the definition of the treatment contrast can affect the estimate and its uncertainty. A prespecified model can reduce the risk of selecting an analysis after seeing the results. The registry record does not report the planned model, covariates, contrast, or decision rules. It is therefore not possible to evaluate whether any reported analysis followed a prespecified plan, and no analysis is posted to assess in any case.

Why do distributional assumptions matter?

The score is described as a continuous outcome for analysis, although its component items use ordinal scoring and the total is bounded by a stated maximum of 66. General methods based on means often rely on assumptions about the sampling distribution of estimates and the behavior of residuals. A bounded score may have different variability near its limits than around the middle of its scale, and summed ordinal items do not guarantee that all model assumptions hold. These are general considerations, not evidence that the assumptions were violated in this trial. The registry record does not report diagnostics, transformations, or alternative analyses.

Over-dispersion is a general issue when observed variation exceeds what a statistical model assumes. If present, standard errors based on an overly restrictive variance model may be too small, making uncertainty look less than it is. Whether over-dispersion is relevant depends on the model and data; the registry record does not provide either the fitted model or results that would allow it to be assessed. The concept should not be taken as a claim that over-dispersion occurred in this study.

What can a planning illustration tell the reader?

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also describes the effect to detect as a stated fraction of the observed effect. A planning calculation of this kind asks what sample size would be needed under specified assumptions; it is not a measure of the probability that the completed trial found a real effect. It is not observed power. No observed primary-outcome effect or resulting planning count is reported in the registry record, so the illustration's numerical implications cannot be assessed from the posted information. The record also does not give the trial's own sample-size justification.

More generally, power calculations depend on the target effect, outcome variability, significance level, allocation, and analysis method. A calculation based on an observed effect can be especially hard to interpret when that effect is estimated from the same study, because the estimate can be unstable. These are general methodological points, not claims about the calculation or design choices made by the investigators. No sample-size rationale, interim-analysis plan, or detailed statistical analysis plan is reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists the FMA-UE as the primary outcome and includes secondary measures for the Jacket Test, MVC-Peak Torque, ARAT, range of motion of upper-limb joints, Motor Activity Log, Chinese Version of Community Integration Measure, and MVC-Cocontraction Ratio. It also schedules the primary outcome at pre-intervention, mid-intervention (4 weeks), post-intervention (8 weeks), follow-up 1 month (12 weeks), and follow-up 3 months (20 weeks). Considering several outcomes, visits, and group contrasts raises a general multiplicity issue: the more inferences examined, the greater the chance that some apparently notable result arises by chance. Whether and how that concern was addressed is not reported in the registry record.

The record does not identify a single primary time point for the FMA-UE analysis, a hierarchy among secondary outcomes, a multiplicity adjustment, or a strategy for distinguishing confirmatory from exploratory comparisons. It also does not report an analysis plan for repeated measures. These details matter for interpreting any collection of tests, but no analyses are posted to evaluate.

Missing-data handling is not reported in the registry record. The record does not give the number of participants with endpoint data at each assessment, reasons for missing measurements, imputation procedures, or sensitivity analyses. The number enrolled cannot be treated as the number analyzed. Likewise, the analysis populations are not described: it is not stated whether analyses were intended to follow assigned groups regardless of adherence, to include only participants who completed a specified amount of intervention, or to use another population definition. Without participant flow, missingness information, and population definitions, the potential influence of incomplete follow-up or exclusions cannot be assessed.

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.

The registry lists 30 participants at risk in each of the four groups. For the bilateral TENS, unilateral TENS, placebo, and control groups, the posted figures show 0 serious adverse events, 0 other adverse events, and 0 deaths. These are event counts recorded for the groups; they are not estimates of comparative safety, and the registry record does not provide an analysis comparing groups.

A zero count in a registry entry should be read narrowly. It describes no events recorded in that category for the listed group, but it does not by itself establish that the true event risk is zero. The interpretation depends on how events were defined, collected, and monitored, as well as the observation period and the completeness of reporting. Those details are not reported in the registry record. The record also does not describe whether participants had complete safety follow-up or how withdrawals affected safety ascertainment.

The figures therefore support a limited statement about the posted counts, not a broad conclusion that the interventions are free of risk. The registry does not report event narratives, severity definitions, relatedness assessments, or timing. No medical conclusion should be inferred from the zero counts alone.

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

The registry describes a study designed to compare task-oriented upper-limb training paired with bilateral stimulation, unilateral stimulation with sham stimulation on the opposite side, bilateral sham stimulation, and a control group receiving no active intervention. It identifies the FMA-UE as the primary outcome and gives a schedule extending from pre-intervention through follow-up. These details clarify the scientific question and the kinds of measurements the trial intended to collect.

They do not establish what the trial found. The registry record reports no primary-outcome analyses and gives no group-level FMA-UE summaries or treatment-effect estimates. It is therefore not possible to state whether scores rose or fell, whether groups differed, or whether any difference was large or small. The absence of a posted estimate is not evidence that the assigned approaches had the same effect. It is also not a basis for claiming that an approach worked or failed.

Even if a difference had been reported, its meaning would depend on precision, the chosen comparison and time point, missing-data handling, and how the score relates to meaningful functional change. The registry record does not report an interpretation threshold for the FMA-UE or a clinical-importance criterion. No such threshold should be inferred from the score's maximum or item structure.

The results record also does not provide the participant flow or analysis populations needed to understand who contributed data. Enrollment of 120 does not establish that every enrolled participant completed the intervention or contributed measurements at every visit. Details about adherence and follow-up are not reported in the registry record.

The most defensible reading is therefore descriptive: the study was recorded as completed, had a randomized, double-masked, parallel-group design, and planned assessment of upper-limb motor control alongside other outcomes. The posted record does not provide the comparative results needed to estimate an intervention effect or judge its precision. That distinction separates a clearly stated research question from evidence that can answer it.

13. Why This Trial Matters Statistically

This trial is statistically notable for its multi-group design and repeated outcome schedule. The assigned groups represent distinct contrasts: bilateral electrical stimulation alongside task-oriented training, unilateral stimulation with sham on the opposite side, bilateral sham stimulation with training, and a control group described as receiving no active intervention. The comparison with sham groups addresses a different contrast from comparison with a no-active-intervention group. Keeping those questions separate is important when interpreting a randomized study.

The primary outcome is measured repeatedly, from before intervention through follow-up, while the registry also lists several secondary functional and movement measures. This creates a setting in which the analysis needs to define the main time point, the relevant group contrasts, and how repeated observations are handled. It also raises the general issue of multiplicity across outcomes, time points, and comparisons. The registry record does not report those analysis decisions, so the intended design is clearer than the planned inferential strategy.

The record's limitations illustrate why trial registration and outcome reporting serve different purposes. Registration can describe the question, assignment structure, intervention groups, and planned measures. Estimating an effect requires posted outcome data or analysis results, and assessing trustworthiness also requires details such as missing-data handling and analysis populations. Those results and details are not reported in the registry record.

Thus, this study matters statistically as an example of a design that aims to distinguish stimulation approaches while measuring a continuous, bounded score over time. Its registry entry supports discussion of design and analysis needs, but does not support a quantitative conclusion about the treatment contrasts.

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 main limitation for interpretation is that the registry record reports no outcome analyses. It provides no FMA-UE group means, standard deviations, changes, between-group estimates, confidence intervals, or test results. Consequently, neither effect size nor precision can be assessed. The status of completed does not substitute for these results.

The design is described as randomized, double-masked, and parallel-group, but key implementation details are absent. The method for generating the allocation sequence, allocation concealment, identities of masked participants or staff, and maintenance of masking are not reported in the registry record. The record does not describe eligibility criteria in enough detail to assess the population's clinical range or generalizability.

Although repeated primary-outcome assessments and several secondary outcomes are listed, the analysis plan is not reported. The primary comparison and primary assessment time, model for repeated measures, baseline adjustment, multiplicity strategy, and handling of missing values are not specified. The analysis populations, participant flow, adherence, and numbers with available data at each visit are also not reported. These omissions make it impossible to judge how the posted design would translate into an analysis or who would be represented by any estimate.

The intervention descriptions give a schedule for the three training groups, but the record provides limited detail about intervention delivery and does not describe the control group's activities beyond no active intervention. It does not report adherence, treatment fidelity, or additional care. Safety counts are listed, but event definitions, collection procedures, and observation periods are not described. Finally, the registry describes a planning illustration but does not report an observed primary-outcome effect or resulting numerical planning values. These limitations constrain interpretation to the registered design and recorded counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effect of Bilateral TENS With TOT on Upper Limb Function in Patients With Chronic Stroke — NCT03112473.
• Registry record last updated 2021-05-13; status last verified 2021-04.
• Results first posted 2021-04-20.
• 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 registry record identifies NCT03112473 as a completed randomized, double-masked, parallel-group trial sponsored by The Hong Kong Polytechnic University, with enrollment of 120. It describes four groups: bilateral TENS with task-oriented training, unilateral TENS with task-oriented training and sham stimulation on the non-paretic side, bilateral sham stimulation with training, and a control group receiving no active intervention.

The primary outcome is the Fugl-Meyer Assessment on the Upper Extremity, assessed at pre-intervention, mid-intervention (4 weeks), post-intervention (8 weeks), follow-up 1 month (12 weeks), and follow-up 3 months (20 weeks). Secondary outcomes cover upper-limb function, strength, joint range, activity, and community integration. The adverse-event entries list zero serious events, zero other events, and zero deaths in each group, with 30 at risk per group.

No outcome analyses are reported in the registry record. Treatment-effect estimates, precision measures, participant flow, analysis populations, and missing-data methods are not reported. The registry therefore describes the trial's design and planned measurements but does not establish comparative outcome results.