Enhancing Plasticity in Stroke Patients With Severe Motor Deficit: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Enhancing Plasticity in Stroke Patients With Severe Motor Deficit (NCT02633215), a randomized na study. The primary outcome is Change in Fugl Meyer Assessment Motor Score.

2. Clinical Question

This is a question about the combined treatment packages as described, not a comparison of stimulation in isolation: the two groups are also described as receiving intensive task-oriented training. The registry record identifies random allocation, but does not give further details about the process used to generate or conceal assignments. It also does not identify which individuals or roles were masked under the triple-masking designation.

3. Trial Design

The registry record describes a randomized, parallel-group trial with triple masking. It lists an enrollment of 36 and a completed status. The record gives a start date of 2005-03 and a primary completion date of 2013-12. The phase is listed as NA. These design details identify how the study was classified in the registry, but do not establish how many participants contributed data to any particular outcome analysis.

Two arms are described. Participants in the active stimulation arm received 2 hours of active peripheral nerve stimulation paired with 4 hours of intensive task-oriented upper-extremity training. Participants in the sham arm received 2 hours of sham peripheral nerve stimulation paired with the same stated duration of training. The stimulation description names Erb's point, radial and median nerves. The device entry names an S88 Dual Output Stimulator by Grass Technologies. Further technical details of the stimulation are not reported in the registry record.

The primary outcome is change in Fugl Meyer Assessment Motor Score. The record describes scores after intervention minus baseline and at 1-month follow-up minus baseline. Two secondary outcomes are listed: change in Action Arm Research Test (ARAT) and change in Wolf Motor Function Test (WMFT). The registry lists three outcome measures in total, but does not report outcome estimates, group comparisons, or analysis results. It does not report a statistical analysis plan, allocation ratio, details of masking, or participant flow by arm. The adverse-event denominators list 18 participants at risk in each arm; those denominators should not be treated as confirmation of the number analyzed for the primary outcome.

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

Reasons for not completing this period:

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 Change in Fugl Meyer Assessment Motor Score, measured over baseline, post-intervention, 1-month follow-up.

The primary endpoint is change in Fugl Meyer Assessment Motor Score, a continuous motor score reported in units on a scale. The registry describes the possible score range as 0 to 66, with 66 indicating the best performance. It defines change as the score after intervention minus the baseline score, and the score at 1-month follow-up minus the baseline score. Thus, the measure is intended to express how a participant's score at each later assessment differs from their own baseline score.

Using a motor assessment at more than one time point can describe both change after the intervention and whether the observed score at follow-up differs from baseline. A continuous score retains more gradation than a simple classification of improvement or no improvement. In general, that can be useful when the aim is to compare the magnitude of measured motor-function changes between randomized groups. This general description does not establish that a particular change is important to participants or that the scale is equally sensitive to change in every study population.

The registry record identifies the primary outcome summary parameter as a mean and the dispersion as a standard error. It gives baseline, post-intervention, and 1-month follow-up as the time frame. Numerical means, standard errors, sample sizes for the outcome analyses, and a between-group comparison are not reported in the registry record. The score range and direction alone therefore do not show the amount of change observed in either arm.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group design. In general, random allocation is intended to make the groups comparable at the start of a trial, on average, with respect to both measured and unmeasured characteristics. A parallel-group design means that participants are assigned to one group rather than crossing between the active and comparison conditions. The record does not report the allocation procedure, concealment process, or a statistical analysis plan, so those features cannot be assessed from the registry entry.

What does a mean summarize?

The primary outcome is specified as a mean of a continuous measure. A mean combines participants' measured values into a summary of the group's average score or change. For this endpoint, the defined quantities are changes from baseline at post-intervention and at 1-month follow-up. A group mean change describes the average within-person change among the participants included in that calculation; a comparison of mean changes between groups would address the randomized contrast. The registry record does not report either group means or a between-group estimate.

In general, a mean can be influenced by unusually high or low values. Its interpretation is clearest when the distribution and the study population are understood. Those details, along with the observed score distributions, are not reported in the registry record. The record gives the possible scale range and indicates that a score of 66 represents the best performance, but this does not supply the observed distribution or the size of any change.

What does a standard error describe?

The stated dispersion is the standard error. In general, a standard error describes the uncertainty in an estimated quantity, such as a mean, under the statistical model; it is not the same as the spread of individual participants' scores. Standard errors tend to be smaller when an estimate is more precise, but their interpretation depends on what quantity was estimated and how the analysis was conducted. Because no standard errors are reported for this outcome, the precision of the trial's mean estimates cannot be evaluated from the record.

A confidence interval is generally formed from an estimate and its uncertainty and gives a range of values compatible with the data under the analysis assumptions. It can show the precision and plausible direction of an estimated contrast more informatively than a significance label alone. No confidence interval for the primary outcome comparison is reported in the registry record. No p-value or other test result for that comparison is reported either.

Why are there multiple time points?

The outcome definition includes post-intervention change from baseline and 1-month follow-up change from baseline. These measurements describe different time points, so they answer related but non-identical questions. A contrast shortly after intervention and a contrast at follow-up could differ in magnitude or precision. In general, when several time points or outcomes are examined, the interpretation depends on which comparison was designated primary and how the set of comparisons was handled. The registry record notes multiple categories or time points but does not reduce them to one comparison.

Multiplicity refers, in general, to the increased chance of obtaining at least one apparently notable result when many statistical comparisons are conducted. Methods such as adjustment of significance thresholds or a prespecified hierarchy can address some multiplicity concerns, but the appropriate approach depends on the analysis plan. Whether any adjustment, hierarchy, or other multiplicity strategy was used is not reported in the registry record. The listed primary and secondary outcomes do not reveal how their results were analyzed.

What can sample-size planning illustrations tell readers?

A planning illustration based on an observed effect is not the same as the trial's original sample-size justification. Such an illustration asks, under stated assumptions, how many participants per arm might be needed to detect a specified fraction of an observed effect with a chosen power and significance level. It is a planning calculation, not observed power and not evidence that the trial was adequately powered. The record describes illustration assumptions of a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. It does not report the trial's own sample-size justification. Because the primary outcome effect is not reported, the record does not provide the results needed to interpret an illustration based on that effect.

In general, statistical power is a design property calculated for a specified effect size, variability, analysis, and significance threshold. It is not a measure of whether the observed result is true. Retrospective calculations that use the observed effect are especially difficult to interpret as evidence about the quality of a study; estimates from a completed study are uncertain, and the calculation does not replace an effect estimate with its confidence interval. Any sample-size figures should therefore be read as planning illustrations under their assumptions rather than as observed trial findings.

The registry lists no analyses for the outcome record. This means that the registry entry does not contain an analysis result to interpret; it does not establish whether analyses were conducted outside the registry. The analysis model, covariate adjustments, handling of repeated measurements, assumptions about score distributions, and approach to missing values are not reported in the registry record. Each could affect the numerical estimate and its uncertainty, so the endpoint definition alone is insufficient to reconstruct the intended analysis.

10. Multiplicity, Missing Data and Analysis Populations

The record lists a primary outcome and two secondary outcomes: change in Fugl Meyer Assessment Motor Score, change in ARAT, and change in WMFT. The primary measure has post-intervention and 1-month follow-up change scores. This creates more than one outcome quantity to consider. In general, testing multiple outcomes or time points can make a collection of results harder to interpret unless the analysis plan establishes priorities or accounts for multiplicity. The registry record explicitly notes that the primary outcome includes several categories or time points and was not reduced to one comparison. Whether multiplicity was addressed, and by what method, is not reported in the registry record.

The record does not report the number of participants with primary outcome data at each time point, reasons for missing measurements, or how missing values were handled. It also does not report whether analyses followed an intention-to-treat approach, a per-protocol approach, or another analysis-population definition. These details matter because the set of participants contributing to an estimate and the assumptions used for missing observations can affect both the estimate and its uncertainty. The enrollment count and adverse-event denominators do not resolve these questions.

In general, complete-case analyses use participants with the required observed measurements, while other approaches may use modeling or imputation under explicit assumptions. No particular approach can be attributed to this trial from the registry record. The record also does not report a prespecified primary time point or a plan for handling multiple outcomes. These omissions limit assessment of selective availability and interpretation of any result, even though no outcome estimate is reported in the entry.

11. 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 adverse-event record lists 18 participants at risk in each arm. It reports 0 participants affected by serious adverse events and 0 affected by other adverse events in the active stimulation with motor training group, and the same counts in the sham stimulation with motor training group. These are the event figures recorded for the listed groups; they do not provide a comparison estimate or a statistical test.

The death counts are not reported in the registry record. The record also does not give event definitions, collection procedures, the period covered by adverse-event monitoring, or further detail on event types. No top serious-event terms are listed. Without those details, the zero affected counts should be read narrowly as the registry's reported counts, not as evidence that no events occurred outside the recorded categories or observation period.

In general, safety counts are interpreted alongside the number monitored, the duration and completeness of follow-up, and the rules used to classify events. The listed denominators and counts do not show whether all enrolled participants were monitored for the same period, or whether safety information was available for everyone. The adverse-event record therefore describes the reported counts but does not support a broader assessment of comparative safety.

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

The record identifies a clinically focused randomized comparison: active peripheral nerve stimulation paired with motor training versus sham stimulation paired with motor training in people described as having severe motor deficit after stroke. It specifies a motor-score outcome and measurement times. Those details establish the question the study set out to examine, but they do not reveal the observed answer.

No primary outcome means, standard errors, confidence intervals, or statistical comparisons are reported in the registry record. The direction and size of any difference, and the precision with which it was estimated, therefore cannot be determined. The record also does not report results for the secondary ARAT and WMFT outcomes. The absence of numerical results in this registry entry should not be interpreted as a null effect, a positive effect, or evidence that an analysis was never conducted.

The named outcome measures and the scale range are not substitutes for results. A score range does not show how participants scored, how much their scores changed, or whether groups differed. Similarly, a completed status is a registry status and is not itself an outcome finding. The adverse-event entries report zero affected participants in the listed categories for both groups, but the death counts and details of monitoring are not reported in the registry record.

In general, a trial result is best understood through the estimated between-group contrast, its uncertainty, the population included in the analysis, and the methods used to handle outcomes and missing data. Those elements are not available for the primary comparison in this record. Consequently, no conclusion about the size, statistical precision, or clinical importance of the treatment contrast can be drawn from the registry information.

13. Why This Trial Matters Statistically

This trial is statistically notable for the structure of its question: both groups are described as receiving task-oriented training, while active versus sham peripheral nerve stimulation is the differing component. A well-reported between-group estimate would therefore help readers assess the contrast between those combined regimens. Because the registry does not report that estimate, the design can be described but the comparison cannot be quantified.

The primary outcome is measured at more than one post-baseline time point. This raises a general interpretive issue: researchers and readers need to know which time point is primary, how repeated measurements are analyzed, and how multiple comparisons are handled. The registry record identifies baseline, post-intervention, and 1-month follow-up, and notes that the primary outcome has several categories or time points without reducing them to one comparison. It does not report the analysis plan or a single primary contrast.

The entry also illustrates why an outcome definition is not equivalent to an outcome result. The mean and standard error are named as the summary and dispersion, but no numerical estimates are available. Without the estimate and its uncertainty, readers cannot distinguish a precise contrast from an imprecise one or assess its direction. Similarly, enrollment and adverse-event denominators do not reveal the number contributing to the primary outcome analysis.

These are general lessons in interpreting clinical-trial records: design labels describe planned structure, outcome definitions state what was to be measured, and results are required to assess the observed evidence. Here the registry record supplies the first two kinds of information in part, while the numerical outcome analysis and important analysis details are not reported.

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 trial-specific limitation for statistical interpretation is that the registry record does not report the primary outcome estimates or a comparison between groups. It gives the measurement definition and time points, but not group means, standard errors, confidence intervals, or test results. The two secondary outcomes are named without reported results. As a result, neither the magnitude nor the precision of the observed outcome differences can be assessed.

The primary outcome spans post-intervention and 1-month follow-up change from baseline, and the record notes that it has several categories or time points without reducing them to one comparison. A prespecified primary time point, any multiplicity strategy, and the analysis model are not reported in the registry record. The record also does not report missing-data methods, analysis populations, or numbers contributing outcome data at each time point. These omissions prevent assessment of how the reported outcome would relate to the full enrolled group or how robust an estimate might be to missing measurements.

Although the record lists 36 enrolled participants, the adverse-event denominators of 18 per group are not primary-outcome analysis counts. Participant flow, exclusions, and follow-up completeness are not reported in the registry record. The triple-masking label is present, but which parties were masked and how masking was implemented are not described. Details of allocation generation and concealment are also not reported.

The adverse-event information is limited to affected counts and denominators, with death counts not reported in the registry record. Event definitions and monitoring duration are not specified. These reporting limits do not establish that the trial itself lacked procedures; they mean that those procedures and the numerical efficacy findings cannot be evaluated from the registry entry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Enhancing Plasticity in Stroke Patients With Severe Motor Deficit — NCT02633215.
• Registry record last updated 2017-08-10; status last verified 2017-07.
• Results first posted 2017-08-10.
• 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

NCT02633215 is listed as a completed randomized, parallel-group trial with triple masking and an enrollment of 36. Its primary question concerns active peripheral nerve stimulation paired with motor training compared with sham stimulation paired with motor training in stroke patients described as having severe motor deficit. Each arm description specifies 2 hours of stimulation or sham stimulation and 4 hours of intensive task-oriented upper-extremity training.

The primary outcome is change in Fugl Meyer Assessment Motor Score from baseline after intervention and at 1-month follow-up. Change in ARAT and change in WMFT are listed as secondary outcomes. Numerical outcome results and analyses are not reported in the registry record. The adverse-event entry lists 18 at risk in each arm and zero affected by serious or other adverse events in each; death counts are not reported.