Efficacy Study of the LARA Wheelchair System for Subacute Stroke Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy Study of the LARA Wheelchair System for Subacute Stroke Patients (NCT02830893), a randomized na study. The primary outcome is Fugl-Meyer (FM) Motor Assessment of the Upper Extremity.

2. Clinical Question

3. Trial Design

The study is listed as randomized, single-masked, and parallel-group. Participants were assigned to LARA therapy or standard therapy. The registry record does not identify who was masked, so the meaning of “single-masked” for outcome assessment or treatment delivery is not specified.

The study description places the intervention in the acute rehabilitation unit of UC Irvine Douglas Hospital. The LARA arm was to use the LARA system for wheelchair propulsion and affected-arm video-game practice. The standard-therapy arm was to use a standard wheelchair and perform graded, table-supported arm exercises. The described daily practice duration was 30 minutes in each arm. The registry record names University of California, Irvine as sponsor.

The listed enrollment is 23. The brief study description states that investigators planned to recruit 44 subjects. These figures describe different aspects of the record: the former is the listed enrollment, while the latter is the recruitment target in the study description. The registry record does not explain the difference.

Assessments were planned at baseline, at 3 weeks after therapy or sooner upon discharge from the acute rehabilitation unit, and at 3-month follow-up. The primary outcome description specifies a change from baseline to the 3-month follow-up. The record also lists the Modified Ashworth Spasticity Scale, Timed 10-meter Walk, and Box and Blocks Test as secondary outcomes. The record status is completed, but completion status alone does not provide evidence about the comparative 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.

Before assignment: 23 study participants were screened and all 23 study participants were randomized.

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 Fugl-Meyer (FM) Motor Assessment of the Upper Extremity, measured over Baseline, Post-intervention evaluation at 3 weeks, and 3-month evaluation after the end of intervention.

The primary endpoint is the change in the Fugl-Meyer Motor Assessment score for the upper extremity from baseline to the 3-month evaluation after the intervention ended. The registry describes this as a 66-point scale measuring upper-extremity movement patterns; the study analyzes the total score, and higher scores indicate a better outcome. The unit is a score on a scale.

A change score expresses how a participant’s measurement differs from their own baseline. Comparing these changes between randomized groups can address whether the groups followed different average trajectories over the specified period. It is not the same question as comparing only their follow-up scores, because baseline measurements are part of the stated endpoint.

The scale is used to quantify motor impairment in a structured way, allowing a numerical assessment of upper-extremity movement. The registry record does not report a threshold for a clinically important change, nor does it provide the primary endpoint’s group means, standard deviations, estimated between-group contrast, or confidence interval. It therefore describes what the study intended to measure but does not establish the size or precision of any observed difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the trial as randomized, single-masked, and parallel-group. These labels describe broad design features, not the details of the statistical analysis. The registry record does not report the randomization procedure, the identity of the masked party, the primary analysis model, or a statistical analysis plan. It also does not state how the primary analysis handled baseline scores, missing measurements, or departures from assigned treatment.

What does a change score represent?

The stated primary endpoint is change in the Fugl-Meyer upper-extremity total score from baseline to the 3-month evaluation. In general, a change score is calculated for each participant by comparing a later measurement with that participant’s baseline measurement. A group mean change describes the average within-person change in that group. A between-group comparison of mean changes then contrasts these group averages. The registry gives no means or standard deviations for these changes, and no contrast is reported.

In general, a mean summarizes the center of a numerical distribution, while a standard deviation describes how spread out individual measurements are around that mean. The registry identifies the primary outcome as a mean with standard deviation, but this does not provide the actual values. Neither the mean nor the standard deviation alone describes the uncertainty in a between-group comparison; an uncertainty interval for the contrast would be needed for that purpose.

How should a confidence interval be understood?

In general, a confidence interval gives a range of estimates compatible with the observed data and the method used to calculate it. A narrower interval indicates greater precision than a wider interval, though precision does not by itself determine whether a difference is important. The registry record does not report a confidence interval for the primary outcome. It also does not report a p-value for that comparison. Without an estimate and its uncertainty, the direction, size, and precision of a possible group difference cannot be assessed.

What can randomization establish?

In general, random assignment reduces systematic differences in treatment assignment and supports a causal comparison when the trial is conducted and analyzed appropriately. It does not guarantee that every baseline characteristic will be balanced, especially in a small study, and it cannot resolve bias from missing outcomes or analyses that exclude participants in ways related to their outcomes. The registry record does not give baseline summaries or describe the analysis population, so these aspects cannot be evaluated from the record.

The parallel design means the listed groups represent different assigned treatment strategies rather than a sequence in which each participant receives both treatments. This interpretation follows the design label; the record does not report further design details. “Single-masked” is also listed, but the masked person or role is not reported in the registry record, so the potential protection against measurement or performance bias cannot be characterized further.

Why does over-dispersion matter?

In general, over-dispersion means that variation in the data is greater than a statistical model assumes. If an analysis assumes too little variation, its standard errors may be too small and its confidence intervals too narrow. This concept is relevant to some count or event outcomes, but the primary endpoint is described as a continuous score summarized by a mean and standard deviation. The registry record does not report a model or indicate that over-dispersion was assessed, so it would be inappropriate to claim that a particular adjustment was used or needed for this trial.

What analysis details are unavailable?

The registry record does not report whether the primary comparison used change scores, follow-up scores adjusted for baseline, or another model. These approaches can yield different estimates and rely on different assumptions. It also does not report covariate adjustment, handling of repeated assessments, missing-data methods, a definition of the analysis population, or an approach to multiplicity. These details are not interchangeable; they affect how readers should understand an estimate and its uncertainty.

No primary outcome analysis is reported in the registry record, so there are no posted summary statistics from which to make a simple unadjusted recalculation. The record’s stated completion status does not fill this gap. The statistical interpretation is therefore limited to the planned endpoint and design, rather than an inference about treatment-group differences.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and three secondary outcomes: the Modified Ashworth Spasticity Scale, Timed 10-meter Walk, and Box and Blocks Test. It does not report a multiplicity plan, such as whether the primary comparison was treated as the single confirmatory test or whether adjustment was planned across outcomes or assessment times. In general, testing multiple outcomes or time points can increase the chance of at least one apparently unusual result, so a prespecified strategy helps readers distinguish primary evidence from exploratory findings. No such strategy is reported in the registry record.

The primary outcome description includes baseline, a post-intervention assessment at 3 weeks, and a 3-month evaluation, while specifying baseline-to-3-month change as the primary comparison. The record does not report how the intermediate assessment was analyzed or whether additional comparisons were planned. It does not report an analysis plan for the secondary outcomes.

Missing-data methods and analysis populations are also not reported in the registry record. It is not clear whether the primary analysis was intended to include all randomized participants, only participants with observed follow-up data, or another population. The record does not describe missing assessments, reasons for missingness, imputation, sensitivity analyses, or protocol deviations. These omissions matter because a complete-case comparison can differ from an analysis that accounts for missing outcomes, particularly when missingness is related to participant status or outcome.

Although the trial is marked completed, that status does not reveal which participants contributed to each analysis. The record lists no analysis results, so readers cannot determine the number included in the primary comparison or assess how missing data might have influenced an estimate.

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 reports safety figures separately for the two treatment groups. For LARA therapy, 12 participants were listed as at risk for serious adverse events and 0 as affected; the record also lists 12 at risk for other adverse events and 0 affected, with 0 deaths. For standard therapy, 11 were listed as at risk for serious adverse events and 0 as affected; 11 were listed as at risk for other adverse events and 0 affected, with 0 deaths.

These entries mean that the registry record reports zero affected participants in each of these categories. They should not be read as proof that no adverse experiences of any kind occurred. The record does not report the event definitions, collection procedures, observation window, severity breakdown beyond the serious-event category, or detail about events not represented in these counts. It also does not provide a comparative safety analysis or an uncertainty estimate.

Adverse-event counts describe safety reporting, not the primary motor outcome. The absence of reported affected participants in these registry fields does not establish that the interventions are equally safe, and it does not resolve the missing efficacy analysis.

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

The registry record establishes that this study was designed as a randomized, parallel-group comparison of LARA therapy and standard therapy for subacute stroke patients. It describes the intended practice approaches, the assessment schedule, and the primary outcome. It also identifies several secondary measures and reports safety counts for each group.

It does not report the primary outcome comparison. There is no posted group mean change, between-group estimate, confidence interval, or p-value in the registry record. Therefore, the record does not show whether the groups differed in upper-extremity Fugl-Meyer change, in which direction any difference went, or how precisely it was estimated. The study’s completed status cannot be substituted for these results.

The endpoint is a score-based measure, with higher scores described as better. That information gives the scale’s direction, but not the size of an observed change or the importance of such a change. The registry does not report a threshold for clinical importance. It also does not provide a primary analysis population or explain how missing assessments were addressed.

In general, a randomized design can support a comparison of assigned strategies, but interpretation depends on the outcome data, analysis methods, and completeness of follow-up. Here, the registry record does not contain the information needed to evaluate those elements. The listed safety counts are limited to the categories and participants recorded; they do not establish the absence of all possible adverse events.

Accordingly, the defensible conclusion is about reporting, not treatment effect: the record describes a completed randomized study and its intended endpoint, but does not provide a result that quantifies the primary comparison. No claim that either therapy improved outcomes, failed to improve outcomes, or was superior is supported by the registry information.

13. Why This Trial Matters Statistically

This trial is statistically notable because it asks a comparative question using a continuous functional measure and a randomized parallel-group design. Its primary endpoint is defined as a change from baseline to 3-month follow-up, making the analysis dependent on both baseline and follow-up measurements. Clear reporting of the group changes and the between-group contrast would let readers distinguish the estimated effect from the variation among individual participants.

The record also illustrates why design labels and outcome descriptions are not enough to interpret evidence. Randomization indicates how treatment assignment was intended to occur, but readers still need the analysis estimate, its uncertainty, the analysis population, and information about missing outcomes. In a small study, the precision of an estimate is especially important; the registry lists enrollment of 23, while the study description gives a recruitment target of 44. The record does not explain the difference.

Prespecification and transparent reporting matter when multiple assessments and outcomes are listed. The primary endpoint identifies the main comparison, but the record does not explain how secondary outcomes or the intermediate assessment were handled statistically. Without that context and without analysis results, readers cannot tell whether findings would be confirmatory or exploratory.

The study is also a reminder that registry completion and registry results are separate matters. The record is marked completed and contains safety counts, yet it does not report the primary efficacy analysis. For statistical readers, this distinction prevents a design description from being mistaken for evidence about the size or precision of an effect.

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 principal limitation for interpretation is that the registry record does not report the primary outcome results. Without group summaries and a comparative estimate, no quantitative assessment of the endpoint is possible. The record also does not give confidence intervals or p-values, so statistical precision and compatibility with a range of effects cannot be assessed.

Several design and conduct details are unavailable. Although the study is listed as single-masked, the masked party is not identified. The record does not describe the randomization procedure, allocation concealment, or whether the planned interventions were delivered as described. The study description gives the planned practice schedule, but the record does not report adherence or actual exposure.

The listed enrollment is 23, whereas the study description states an intention to recruit 44 subjects. The registry record does not explain this difference. It also does not report the number assessed at each time point, reasons for any missing follow-up, the analysis population, or methods for handling missing data. Thus, the completeness of the primary endpoint cannot be judged from the record.

The primary measure is described, but no threshold for a clinically important change is reported. The statistical plan is also not reported: the record does not specify the model, baseline adjustment, multiplicity strategy, or treatment of the intermediate and secondary outcomes. The safety entries provide counts but no event definitions, observation window, or comparative analysis. These limitations restrict interpretation to the stated design and recorded fields rather than the trial’s efficacy or complete safety profile.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Efficacy Study of the LARA Wheelchair System for Subacute Stroke Patients — NCT02830893.
• Registry record last updated 2020-07-21; status last verified 2020-07.
• Results first posted 2020-07-21.
• 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

NCT02830893 is a completed randomized, single-masked, parallel-group study comparing LARA therapy with standard therapy for people with subacute stroke. The listed enrollment is 23; the brief study description states a recruitment target of 44, and the record does not explain the difference.

The primary outcome is change in the upper-extremity Fugl-Meyer total score from baseline to the 3-month evaluation. The registry describes higher scores as better and lists three secondary outcomes. Serious adverse events, other adverse events, and deaths are recorded as zero affected in both groups, with the group-specific at-risk counts reported in the safety entry.

The registry record does not report the primary outcome analysis, an effect estimate, or uncertainty measures. Statistical methods, missing-data handling, analysis populations, and multiplicity procedures are not reported in the registry record. The available information describes the trial design and intended measurements, but does not quantify the primary treatment-group comparison.