Robotic-assisted Therapy to Improve Manual Dexterity in Children With Cerebral Palsy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Robotic-assisted Therapy to Improve Manual Dexterity in Children With Cerebral Palsy (NCT02923167), a na na study. The primary outcome is Change in Quality of Upper Extremity Skills Test (QUEST) Score - Section on Dissociated Movements.

2. Clinical Question

As a pilot study, the record describes an assessment of clinical outcomes and muscle synergies, including whether muscle-synergy measures might relate to training outcomes. That aim is distinct from establishing that the intervention caused a change. In a single-group pre-to-post design, any observed change could reflect the intervention, but could also reflect other influences over time or measurement variation. Without posted outcome estimates and a comparison group, the registry record does not establish the size, precision, or cause of any change.

3. Trial Design

The registry identifies NCT02923167 as a completed intervention study titled “Robotic-assisted Therapy to Improve Manual Dexterity in Children With Cerebral Palsy.” Spaulding Rehabilitation Hospital is listed as the sponsor. The study began on 2017-05-16, and its primary completion date is listed as 2020-08-12. The registry lists enrollment of 6 and a phase of NA.

The design is recorded as single group, with allocation recorded as NA and masking as none. Participants were assessed at baseline, undertook robotic-assisted hand training, and were assessed after the intervention. The study description says training was intended to last 6 weeks. Separately, the primary outcome timeframe is described as data collected at baseline and at completion of the 7-week intervention. These are both stated in the registry record; the reason for the difference in those descriptions is not reported in the registry record.

The intervention is identified as a device-based intervention called robotic-assisted training of the hand. Training was performed with the Amadeo® device, which held the participant’s forearm securely with Velcro straps. The brief description says each session included 30 minutes of active movements, which could be divided into up to 3 bouts of 10 minutes depending on the participant’s tolerance. The record does not give further detail about the total number of sessions or the full training schedule.

The primary outcome was change in the QUEST score for the section on dissociated movements. Secondary outcomes listed include changes in Box and Block Test score, child and caregiver Cerebral Palsy Quality of Life Questionnaire scores, number of muscle synergies, Modified Ashworth Scale score, and synergy similarity. The record lists 8 outcome measures, but does not report results for the primary endpoint. It also does not report a separate control arm, an allocation procedure, or masking beyond the design fields recorded as NA and none.

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

Analysis population for the primary outcome, as defined in the registry: We were unable to collect data from 3 study participants.

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 Quality of Upper Extremity Skills Test (QUEST) Score - Section on Dissociated Movements, measured over Data collected at baseline and at completion of the 7-week intervention.

The primary endpoint is change in the Quality of Upper Extremity Skills Test (QUEST) score for the section on dissociated movements. The QUEST is described as an assessment of the quality of upper-extremity function. Scores for each assessment are reported on a scale from 0 to 100. The endpoint is intended to represent how the score differs between baseline and the post-intervention assessment.

Assessing change within a participant makes the baseline score a reference for interpreting the later score. The dissociated movements section focuses on a specified component of upper-extremity function, rather than treating the QUEST as a single undifferentiated measure. In general, a change score can help describe whether measurements tend to move between assessment times, while the spread of individual changes indicates how consistently participants experienced that pattern. The registry record identifies the endpoint as a mean with standard deviation, but does not report either value.

The endpoint is clinically relevant to the study’s stated focus on hand dexterity and upper-extremity function. However, the registry record does not state a threshold for a meaningful change, and it does not provide the participant-level or group-level results needed to interpret the magnitude of change. It also states that data could not be collected from 3 study participants. The reason for missing data, the number included in the endpoint analysis, and the handling of missing measurements are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is continuous: the QUEST dissociated movements score is measured on a numerical scale, and the registry defines the endpoint as change between baseline and post-intervention. For a continuous outcome, a mean can describe the average value or average change across the participants included in an analysis. The standard deviation describes how spread out individual measurements or changes are around that mean. These quantities answer different questions: the mean describes the center of the observed data, while the standard deviation describes their variation.

The registry identifies the planned summary as a mean with standard deviation. It does not give the numerical mean change or standard deviation, and it does not describe a statistical test for the primary outcome. Therefore, no reported estimate can be checked against the scale range or interpreted as a particular size of change. The fact that the QUEST score ranges from 0 to 100 at each assessment does not reveal the changes observed in this study.

A confidence interval is a general statistical tool for describing uncertainty around an estimate. It gives a range of values compatible with the data and the method used, rather than a guarantee that the true value lies in that particular interval. The width of an interval depends on factors including the amount of information in the data and the variability of the outcome. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be evaluated from a posted interval.

A p-value is commonly used to describe how compatible the data are with a specified statistical null hypothesis, under the assumptions of the analysis. It is not a measure of the size or practical importance of an effect, nor is it the probability that the null hypothesis is true. The registry record does not report a primary-outcome p-value or identify a specific inferential test. It is therefore not possible to characterize the primary result as statistically significant or not statistically significant from this record.

Because this is a single-group pre-to-post study, the natural descriptive contrast is within participants: each available post-intervention measurement is compared with that participant’s baseline measurement. A mean of individual changes can describe the average observed change among those with data. This is not equivalent to a randomized treatment contrast. Without a separate comparison group, a pre-to-post difference can reflect the intervention and other time-related influences, and the design does not provide a direct estimate of what would have happened to the same participants without training.

The record says that the primary change is calculated from the pre-intervention and post-intervention values, but it does not report an outcome estimate or a detailed analysis specification. It does not state whether the analysis used paired observations, how the outcome distribution was assessed, or whether any adjustment was made. These choices can affect how an estimate and its uncertainty are calculated. They should not be inferred from the study’s endpoint description alone.

Several secondary outcomes are listed: Box and Block Test score, the child and caregiver versions of the Cerebral Palsy Quality of Life Questionnaire, number of muscle synergies, Modified Ashworth Scale score, and synergy similarity. The study also names the primary QUEST outcome. When a study considers multiple outcomes, the chance of finding at least one apparently notable result can rise if many tests are performed without an appropriate strategy. This general issue is called multiplicity. The registry record does not report a multiplicity adjustment or a testing hierarchy, so the interpretation of any multiple outcome findings cannot be assessed from the record; in any case, those findings are not posted.

The sample-size material is described as a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It is explicitly not the trial’s own design. Those assumptions do not describe the single-group design recorded for this study, and the illustration cannot be read as an observed power calculation or as evidence about the precision of this trial’s endpoint. Sample-size illustrations are planning aids: they explore how a hypothetical design might perform under specified assumptions. They do not replace the estimate and uncertainty from observed trial data.

Over-dispersion is a general concern when the observed spread is greater than a statistical model assumes. If a model understates variation, its uncertainty estimates may be too small and its intervals may appear too narrow. The registry record does not identify an analysis model for the primary endpoint or report distributional diagnostics, so it is not possible to say whether over-dispersion was relevant to this study. More broadly, no statistical analysis plan, interim analysis, or sample-size justification is reported in the registry record.

The registry lists no analyses. This does not supply a basis for reconstructing an analysis from the endpoint definition. A complete interpretation would require the reported outcome estimate, its variability or uncertainty, the analysis population, and the method used to handle missing observations. Those details are not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Robotic-assisted Training of the Hand")
n   <- c(3)
m   <- c(3.5)
sp  <- c(4.4)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Robotic-assisted Training of the Hand  3  3.500  4.400  -7.430  14.430

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary outcome and lists secondary measures relating to dexterity, quality of life, muscle synergies, and muscle tone. Considering several outcomes raises a general multiplicity issue: when many statistical tests are conducted, some results can look unusual by chance even if there is no underlying effect. Researchers may address this through prespecified outcome hierarchies or adjustments to statistical testing. Whether either approach was used is not reported in the registry record. No outcome-specific statistical results are posted for evaluating these issues.

Missing data are a direct concern for the primary endpoint. The record states that data could not be collected from 3 study participants. It does not say why the data were unavailable, whether missingness occurred at baseline or after the intervention, or whether other outcomes were affected. It also does not report the number included in the primary analysis or explain how missing observations were handled. The enrollment figure should not be treated as proof that every enrolled participant contributed data to each outcome.

Different approaches to missing data rely on different assumptions. A complete-case analysis uses participants with the required measurements, while other methods may use additional information under stated assumptions. Neither an approach nor its assumptions are reported in the registry record, so the effect of missing data on the primary estimate cannot be assessed. The analysis population is not reported in the registry record. No interim analyses or statistical analysis plan are reported either.

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’s safety figures are listed for the robotic-assisted hand-training group. Serious adverse events are shown for 6 participants at risk, with 0 participants affected. Other adverse events are shown for 6 participants at risk, with 1 affected. Deaths are listed as 0. The registry does not list serious adverse-event terms.

These counts describe what the record reports; they do not establish that an event was or was not caused by the intervention. The record does not provide a detailed description of the other adverse event, its severity, timing, duration, or relationship to training. It also does not explain the methods used to collect or classify adverse events. With a small study enrollment, counts alone offer limited information about how often an event might occur in a broader population.

The absence of a reported serious event should be read as a feature of the posted safety record, not as proof that serious harms are impossible. Similarly, the one other adverse event cannot be attributed to the device or training from the figures alone. No medical advice or treatment conclusion follows from these counts.

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

The study addresses a focused research question: whether outcomes, including upper-extremity function, can be assessed before and after robotic-assisted hand training in children with cerebral palsy, and whether muscle-synergy measures may relate to outcomes. The registry specifies the primary QUEST measure, describes the training device, and identifies the single-group design. These details establish what the study set out to examine.

What the record does not establish is the observed result. The primary change estimate and its uncertainty are not reported, and neither are the secondary outcome results. Therefore, there is no quantitative basis in the registry record for describing the magnitude or direction of change in QUEST scores, assessing how consistent changes were across participants, or judging statistical precision. The absence of a result in the registry is not evidence that there was no change.

Even if a pre-to-post change were reported, this design would not by itself show that training caused the change. A single-group study lacks a concurrent control group to distinguish effects associated with the intervention from changes related to time, repeat assessment, or other influences. That limitation is separate from the missing result: the registry record neither reports an effect estimate nor provides a randomized comparison.

The enrollment of 6 and the statement that primary outcome data could not be collected from 3 participants also constrain interpretation. The record does not give the number analyzed, the reasons for missing data, or the method used to address them. As a result, it is not possible to determine whether the participants with available data represent all enrolled participants in a way relevant to the outcome.

The most defensible conclusion is limited to the study’s design and reporting: this was a completed pilot study with a specified functional endpoint, but the registry record does not provide the outcome information required to assess observed change. It should not be treated as proof that the training works, proof that it does not work, or a definitive estimate of effect.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a clearly stated outcome and a reported outcome. The QUEST dissociated movements score is defined, its scale is described, and the planned contrast is a change from baseline to post-intervention. Yet an endpoint definition alone cannot answer whether scores changed or how precisely any change was estimated. Interpretation depends on the observed estimate and its uncertainty, neither of which is reported in the registry record.

The single-group design also makes the target of inference important. A pre-to-post comparison describes change over time within participants; it does not provide the same causal contrast as a randomized comparison with a control group. Recognizing that distinction prevents a descriptive change, if reported, from being interpreted as an isolated intervention effect. In this record, the results are not available even for the descriptive contrast.

Missing primary outcome data matter alongside the design. The record reports that data could not be collected from 3 participants, but does not describe the analysis population or missing-data approach. Those omissions make it impossible to assess how the missing observations may affect representativeness or precision. A pilot study’s small enrollment can make each unavailable observation particularly consequential to the amount of information available, although the registry does not report the resulting endpoint analysis.

Finally, the record distinguishes the study from its planning illustration: the latter uses assumptions for a two-arm design, whereas the trial itself is recorded as single group. Keeping design assumptions separate from observed results is essential. The record can support careful discussion of outcome selection, missingness, and causal limits, but not an estimate of the intervention’s effect.

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 primary limitation is that the registry record does not report the primary outcome result. It gives the endpoint definition and scale but no mean change, standard deviation, confidence interval, or inferential result. The listed secondary outcomes likewise have no reported estimates in this record. This prevents evaluation of the direction, size, consistency, and precision of the observed clinical changes.

The single-group design does not include a concurrent control group. Any reported change over time would therefore be descriptive rather than a randomized estimate of the effect attributable to training. The record also identifies no masking, so assessments were not described as masked. The impact of that design feature on outcome measurement is not reported in the registry record.

Enrollment was 6, and the record says data could not be collected from 3 participants for the primary endpoint. Reasons for missing data, the number included in the analysis, and the handling of missing observations are not reported. The registry also does not report a sample-size justification, a statistical analysis plan, or an interim-analysis approach. The planning illustration is not the study’s own design justification and assumes a two-arm structure unlike the recorded single-group design.

There is a difference between the intervention duration described as 6 weeks and the primary outcome timeframe described as completion of the 7-week intervention. The registry does not explain this difference. The record does not give further details about the full training schedule, the analysis of the secondary outcomes, or the results of the proposed muscle-synergy relationship assessment. These reporting limits make it difficult to assess implementation and outcome interpretation beyond the stated design.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Robotic-assisted Therapy to Improve Manual Dexterity in Children With Cerebral Palsy — NCT02923167.
• Registry record last updated 2021-10-22; status last verified 2021-09.
• Results first posted 2021-09-05.
• 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

NCT02923167 is a completed, single-group pilot study sponsored by Spaulding Rehabilitation Hospital. It enrolled 6 children with cerebral palsy and evaluated robotic-assisted hand training using the Amadeo® device. The primary endpoint was change in the QUEST dissociated movements score, measured on a scale from 0 to 100 at each assessment.

The study description refers to baseline and post-intervention data collection, with training described as 6 weeks and the primary outcome timeframe described as completion of a 7-week intervention. The registry states that data could not be collected from 3 participants for the primary endpoint. It does not report the primary outcome estimate, uncertainty, analysis population, or missing-data method. The record therefore describes the study question and design, but does not permit a quantitative interpretation of the primary result.