Use of Dynamic Arm Supports to Promote Activities of Daily Living in Individuals With DMD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Use of Dynamic Arm Supports to Promote Activities of Daily Living in Individuals With DMD (NCT03531788), a randomized na study. The primary outcome is Change in Upper Extremity Activity Counts (Movement) Through Actigraphy.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel trial evaluating two commercially available dynamic arm supports for upper-limb function and activities of daily living in non-ambulatory individuals with Duchenne muscular dystrophy. The intervention arms are Armon Ayura (Kinova) and JAECO WREX. The arm descriptions state that participants trialed their assigned dynamic support. The record lists enrollment of 18, while the primary endpoint summaries include 7.0 participants in the Armon Ayura arm and 3.0 in the JAECO WREX arm. Those outcome-specific counts are not interchangeable with the enrollment figure: the endpoint description says that data were missing for some participants.

The study is listed as a parallel randomized design with no masking. Its status is terminated. The listed start date is 2018-08-30 and the primary completion date is 2020-12-31. The reason for termination is not reported in the registry record, and the status alone does not establish why the study ended or how termination affected data collection.

The primary endpoint is continuous: mean ActiGraph activity counts, summarized by arm as a change score. The record also lists Goal Attainment Scale (GAS) as a secondary outcome. A statistical method for the primary arm comparison is not reported in the registry record. The posted analysis entry has no test method, comparison estimate, confidence interval, or p-value. Consequently, the arm summaries can be described, but they do not by themselves establish a statistical comparison between devices.

The registry record does not report masking procedures, a detailed allocation procedure, a sample-size justification, or a full statistical analysis plan. The recorded enrollment and completed outcome data indicate that the endpoint summaries cover only participants with qualifying actigraphy data, rather than necessarily all enrolled participants.

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: All participants who had completed the testing period while wearing the Actigraph GT9x are reported. All participants were tested, but data are missing due to technology failure or not wearing the ActiGraph during testing. Participants who were not wearing the ActiGraph during testing are not reported. Comparisons between groups (Kinova and WREX) were not analyzed due to small sample sizes in both groups.

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 Upper Extremity Activity Counts (Movement) Through Actigraphy, measured over Collection of activity counts through the ActiGraph GT9x occurred during testing phase with and without the upper extremity arm device..

The primary endpoint is change in upper-extremity activity counts measured with a wrist-worn ActiGraph GT9x during testing items performed with and without the arm support. The monitor records activity counts representing movement of the upper extremity. For each participant, the described calculation uses average counts without the device minus average counts with the device; the arm summaries report the mean and standard deviation of these change scores.

The endpoint is intended to quantify movement during the testing tasks. As described in the registry record, higher activity counts indicate more effort and more movement during item testing without the device compared with using the device. The measure is relevant to the study question because it captures movement while participants complete standardized testing items under device and no-device conditions. It is not, on its own, a direct measure of independence, success in daily activities, comfort, or longer-term participation.

Actigraphy offers a recorded movement measure rather than relying only on a participant’s or observer’s judgment. However, the record notes missing activity-count data due to technology failure or not wearing the monitor during testing. The endpoint therefore reflects participants with usable measurements, and the registry record does not fully describe how missing observations were handled beyond identifying who was reported.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous, and the registry summarizes it using a mean and standard deviation in each device arm. A mean is the arithmetic average of the observed values. It is a useful description of the center of a distribution, but it can be sensitive to unusually large or small observations. A standard deviation describes how dispersed the observed values are around their mean. It does not give the range of the data, identify the shape of the distribution, or show how precisely a treatment contrast has been estimated.

The registry defines each change score as average activity counts without the device minus average activity counts with the device. This direction matters when interpreting signs: positive values correspond to more recorded movement without the device during the testing items, according to the endpoint description. The arm summaries then average those participant-level change scores. This is a within-participant measurement contrast summarized separately within each randomized arm. It is distinct from a between-arm treatment-effect estimate, which would compare outcomes across randomized groups using a specified statistical method.

A confidence interval, when reported, expresses a range of values compatible with the data and the method used, while reflecting sampling uncertainty. A narrower interval indicates greater precision under that method; a wider interval indicates less precision. No confidence interval is reported for either arm summary or for a direct comparison in this registry entry. There is therefore no interval-based assessment of uncertainty for the randomized contrast. Likewise, no p-value is reported for that comparison. The absence of these quantities does not mean that an effect is exactly zero or that the devices are equivalent; it means the registry record does not give those inferential results.

The posted standard deviations show that participant-level change scores vary. In general, variability matters because estimates based on highly dispersed observations are less precise than estimates based on less dispersed observations when other features are comparable. A small outcome-specific sample also limits how well a sample mean can characterize the broader population. These general statistical considerations do not supply an alternative analysis of this trial, and they do not justify assumptions about the unreported distribution of the activity counts.

The analysis entry is classified as OTHER and does not name a method, parameter, estimate, confidence interval, or p-value. The statistical plan is not reported in the registry record. It is therefore not possible to determine whether the sponsor conducted an additional analysis that is absent from the posted entry, what model or adjustment would have been used, or whether any analysis accounted for the randomized design in a particular way. The posted summaries should not be relabeled as an adjusted analysis or a formal test.

The record includes a planning illustration based on the observed effect, with two-sided significance level 0.05, equal allocation between the two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Such calculations are prospective planning illustrations: they ask what sample size could be needed under stated assumptions. They are not observed power, do not add evidence to the trial results, and do not establish that the original study was designed around those assumptions. The trial’s own sample-size justification is not reported in the registry record.

In general, a planning calculation based on an observed effect can be unstable when that effect is estimated imprecisely. A result from a small dataset may be unusually large or small, and using it as the planning target carries that uncertainty into the illustration. This does not invalidate a planning exercise, but its assumptions and purpose should remain separate from observed outcomes. No planning sample-size figure needs to be interpreted as the number of participants actually enrolled or analyzed.

Over-dispersion is a general concern when observed data vary more than a chosen statistical model expects. In that setting, a model that understates variability can produce intervals that are too narrow and tests that are too optimistic. The primary endpoint is continuous and the registry gives standard deviations, but it does not report a model-based comparison or distributional diagnostics. There is no basis in the registry record to claim that over-dispersion was assessed or that a particular correction was used. Here, the practical implication is simply that the reported spread should be considered alongside the means, while the absence of a specified inferential method limits claims about precision.

Randomization is intended to support a fair comparison between assigned groups by reducing systematic differences at allocation. It does not guarantee that every observed sample is balanced, and it does not resolve missing outcome data automatically. The registry identifies randomized allocation, but does not report details of sequence generation, concealment, or an analysis population such as intention-to-treat. No claim about those procedures or analyses can be inferred from the design label alone.

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("Armon Ayura (Kinova)", "JAECO WREX")
n   <- c(7, 3)
m   <- c(270.61, 26.75)
sp  <- c(375.5, 123.04)
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  Armon Ayura (Kinova)  7  270.610  375.500  -76.670  617.890
CARM  JAECO WREX  3  26.750  123.040  -278.898  332.398

11. Multiplicity, Missing Data and Analysis Populations

The registry lists Goal Attainment Scale (GAS) as a secondary outcome and records three outcome measures and three analyses. It does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment for evaluating several outcomes. Without that information, the registry record does not establish how the risk of false-positive findings across outcomes or analyses was considered. The primary outcome entry itself does not include an inferential result.

Missingness is directly relevant to the primary endpoint. The outcome description says all participants were tested, but data were missing because of technology failure or because the ActiGraph was not worn during testing. It states that participants who completed the testing period while wearing the ActiGraph are reported. The registry does not report the number of missing endpoint observations by reason beyond the posted outcome counts, a missing-data method, or sensitivity analyses assessing how missing observations might affect the results.

The endpoint summaries therefore describe the reported actigraphy observations, not necessarily every randomized participant. If missingness is related to participant characteristics, device use, or movement during testing, the observed summaries may not represent the full randomized groups. That is a general concern, not a demonstrated source of bias in this trial: the record does not establish whether missingness was related to the measured outcome.

The registry record does not report a defined primary analysis population or state whether participants were analyzed according to randomized assignment regardless of usable actigraphy data. It also does not report imputation, a complete-case analysis plan, or other handling rules. These gaps limit assessment of both missing-data bias and the connection between randomization and the reported endpoint summaries.

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.

The adverse-event figures are reported separately for the device arms. In the Armon Ayura (Kinova) group, the record lists 12 participants at risk for serious adverse events and 0 affected; it also lists 12 at risk for other adverse events and 0 affected. In the JAECO WREX group, 6 participants were at risk for serious adverse events and 0 affected; 6 were at risk for other adverse events and 0 affected. Deaths are reported as 0 in each group. No serious adverse-event terms are listed.

These figures describe what was recorded in the registry, not proof that no adverse events of any kind occurred. They should be read with the reported at-risk counts and the limits of the record. The registry does not provide further detail about event definitions, ascertainment procedures, follow-up duration, or whether all events were captured. The outcome-specific actigraphy counts should not be substituted for the safety at-risk counts, since they refer to different reported measures.

The absence of recorded events in these summaries does not permit a broad comparison of safety between devices. The record does not report a statistical comparison or precision measure for adverse-event differences. These counts are descriptive registry figures only.

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

The posted data establish that actigraphy-based change scores were summarized for participants with reported testing-period measurements in each randomized device arm. The mean score was 270.6 Activity Counts for Armon Ayura (Kinova) and 26.75 Activity Counts for JAECO WREX, with standard deviations of 375.5 and 123.0, respectively. Because the score is defined as average movement without the support minus average movement with it, positive arm means indicate higher average counts without the device during the testing items.

The summaries do not establish that one device produced a larger effect than the other. A formal between-arm estimate and its uncertainty are not reported. They also do not establish that either device changes activity in everyday life, improves independence, or increases participation in activities of daily living. The measured endpoint is movement counts during testing items, a narrower construct than daily-life function.

The posted data do not establish a statistically significant result, equivalence, or absence of an effect. The primary analysis entry has no reported test, confidence interval, or p-value. Variation in participant scores and missing actigraphy observations further limit precision and generalizability. The record does not explain why the study was terminated, and termination should not be interpreted as evidence for or against a device effect.

Finally, the safety summaries report zero affected participants for the listed serious and other adverse-event categories and zero deaths in the two arms. Those registry figures are descriptive and do not by themselves establish comparative safety or guarantee that no unrecorded event occurred. The most defensible interpretation is limited to the arm-specific summaries, the endpoint definition, and the data-availability information explicitly recorded.

14. Why This Trial Matters Statistically

This trial raises a useful statistical distinction between measuring movement within participants and estimating a randomized difference between treatment arms. The endpoint calculation compares activity counts with and without a device for each participant, then summarizes those changes within each arm. That design can describe task-level movement patterns, but a randomized treatment comparison requires an explicitly reported contrast between arms and an account of its uncertainty. The registry record gives arm summaries without that inferential result.

The record also illustrates why endpoint availability matters. Although the trial lists enrollment of 18, the reported primary outcome counts are 7.0 and 3.0 participants in the respective arms. The endpoint description attributes missing data to technology failure or not wearing the monitor. When measurements are unavailable, the analysis population may differ from the randomized population; without further detail, readers cannot assess the extent or consequences of that difference.

Dispersion is also central to interpretation. The standard deviations show substantial variability in change scores, and the summaries do not include confidence intervals. A difference in reported means, even if visually apparent, would not alone convey how precisely the underlying comparison is estimated. This makes it important to distinguish descriptive patterns from statistical evidence for a between-arm effect.

Finally, the trial focuses on an objective movement measure during testing items, while its stated motivation concerns participation in activities of daily living. Statistical interpretation should preserve that distinction between the measured endpoint and the broader clinical or functional question. The registry entry is informative about the study’s measurement approach and reported data, while leaving key inferential and missing-data details unreported.

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.

Several limitations specific to this record constrain interpretation. The primary endpoint analysis includes 7.0 participants in the Armon Ayura (Kinova) arm and 3.0 in the JAECO WREX arm, compared with the recorded enrollment of 18. The registry explains that some actigraphy data were unavailable because of technology failure or because participants did not wear the monitor during testing, but it does not report a complete accounting of missingness or its distribution by arm and reason.

The primary outcome is a testing-period movement measure rather than a direct assessment of daily-life participation. The registry describes the counts as representing upper-extremity movement and specifies a within-participant with-device versus without-device change score. It does not report how closely those testing items reflect routine activities, or whether the device-use condition was assessed under conditions that make the arm-level summaries directly comparable.

The primary outcome entry provides means and standard deviations but no confidence interval, p-value, or named comparison method. The analysis method, prespecified statistical plan, sample-size justification, and primary analysis population are not reported in the registry record. The listed secondary outcome, Goal Attainment Scale, has no result described in the available record.

The study is listed as terminated, but the reason and implications for data collection are not reported. The registry also does not describe allocation concealment or the detailed process for generating the randomized assignments. These points should be treated as unknown rather than inferred from the randomized design label. Together, the missing methodological details and endpoint-data limitations prevent a complete assessment of treatment-effect precision or potential bias.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Use of Dynamic Arm Supports to Promote Activities of Daily Living in Individuals With DMD — NCT03531788.
• Registry record last updated 2022-02-18; status last verified 2022-01.
• Results first posted 2022-02-18.
• 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 describes a randomized, parallel, unmasked study of Armon Ayura (Kinova) and JAECO WREX dynamic arm supports in non-ambulatory men with Duchenne muscular dystrophy. Enrollment is listed as 18; status is terminated. The primary endpoint is the ActiGraph GT9x activity-count change during testing items, defined as average counts without the device minus average counts with it.

Reported mean changes are 270.6 Activity Counts for Armon Ayura (Kinova) and 26.75 Activity Counts for JAECO WREX, with standard deviations of 375.5 and 123.0 and outcome counts of 7.0 and 3.0, respectively. The primary analysis entry does not report a between-arm estimate, confidence interval, p-value, or method. Missing actigraphy data are attributed to technology failure or not wearing the monitor. Goal Attainment Scale (GAS) is listed as a secondary outcome.