This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Study of an Implantable Functional Neuromuscular Stimulation System for Patients With Spinal Cord Injuries (NCT00004445), a na na study. The primary outcome is Standing Performance.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00004445 |
| Phase | NA |
| Condition | Spinal Cord Injury |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 18 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Case Western Reserve University |
| Results posted | Yes |
2. Clinical Question
The study asked whether an implanted functional neuromuscular stimulation system could be implemented and assessed for standing and transfer functions in people with spinal cord injury. Its stated objectives also included developing quantitative evaluations of system performance and following participants to monitor use outside the laboratory. The registry describes the intended population as people with incomplete tetraplegia or paraplegia, while the listed condition is spinal cord injury.
Population
People with spinal cord injury, with the study objectives referring to incomplete tetraplegia or paraplegia. The enrollment was 18.
Intervention
An implanted eight-channel neuroprosthesis, identified as IRS-8, with surgery and postoperative training and follow-up procedures.
Comparator
No concurrent comparison group is described. The study is listed as a single-group design, with allocation recorded as NA.
Primary question
How long participants could maintain a standing position, assessed at discharge and at a follow-up between 6-12 months follow-up.
This is a question about performance after implantation and training, rather than a randomized comparison of the device with another treatment or with no device. Without a concurrent comparator, observed standing performance would describe the participants’ experience in this study, but would not by itself isolate the effect of the neuroprosthesis from other influences. The registry record does not report the observed standing times or a statistical estimate of change.
3. Trial Design
The registry lists this study as completed, with 18 enrolled participants. The recorded start was 1996-09 and primary completion was 2009-09. Case Western Reserve University is listed as the sponsor. The study title refers to an implantable functional neuromuscular stimulation system for patients with spinal cord injuries; the official title describes an eight-channel implanted neuroprosthesis for exercise, standing and transfers.
The design is single group, with allocation recorded as NA and masking recorded as NONE. The arm is named Implanted Neuroprosthesis. Its description says that qualifying candidates receive the neuroprosthesis and take part in postoperative training and follow-up procedures. The listed interventions are surgery and the IRS-8 device. No randomized assignment or like-for-like control group is described, so the study does not support a direct between-group treatment contrast.
The primary outcome is Standing Performance, measured in minutes and defined as how long an individual can maintain a standing position. Its timeframe is discharge and one follow-up between 6-12 months follow-up. The registry also lists distribution of body weight through the legs and arms while standing as a secondary outcome. Two outcome measures are recorded, but no outcome analyses are listed.
The record does not report a phase beyond NA, a sample-size justification, or a detailed statistical analysis plan. It also does not report the observed primary-outcome values. The enrollment count describes the study as registered, while the safety record gives an at-risk count of 15; the registry does not explain the difference. The design and the missing outcome results are important context for interpreting any description of the study: its record documents a clinical evaluation framework, but does not provide an analyzable estimate of standing performance.
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: Participants will go through a screening process that will determine eligibility for the study. If they don't meet the inclusion or exclusion criteria they will not be invited to continue to the second phase of the study.
Overall Study
| Stage | Implanted Neuroprosthesis |
|---|---|
| STARTED | 18 |
| COMPLETED | 15 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Implanted Neuroprosthesis |
|---|---|
| Physician Decision | 2 |
| Withdrawal by Subject | 1 |
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.
| Characteristic | Unit | Implanted Neuroprosthesis |
|---|---|---|
| Participants analysed | 15 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 15 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 33.7 (SD 7.3) |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 14 |
| Region of Enrollment: United States | participants | 15 |
6. Primary Endpoint
The registry lists the primary outcome as Standing Performance, measured over Discharge, 1 follow-up between 6-12 months follow-up.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | minutes |
| Endpoint classification | Continuous Endpoint |
Standing Performance measures the duration, in minutes, for which an individual can maintain a standing position. The registry describes it as a measure of how long the individual can remain standing, with assessment at discharge and at a follow-up between 6-12 months follow-up. The outcome is continuous: its values can represent differing durations rather than membership in a yes-or-no category. The listed summary parameter is the mean, and the listed measure of dispersion is the standard deviation.
As a functional measure, standing duration addresses a capacity that is directly relevant to the study’s stated interest in an implanted system for standing and transfers. Repeated measurement at discharge and follow-up can describe performance at more than one stage of participants’ study experience. In general, a mean gives a measure of the group’s average outcome, while a standard deviation describes the spread of individual values around that mean. These summaries have different roles: the mean describes the group’s central level, and the standard deviation indicates how varied participants’ durations are.
The registry record does not report the mean, standard deviation, participant-level values, or an analysis comparing the timepoints. It therefore does not establish the size or precision of standing performance in the enrolled group, or whether it changed between discharge and follow-up. The timing also does not, by itself, establish what caused any difference that might have been observed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record identifies an outcome that could describe standing performance, but it does not provide the observed outcome values or an analysis. No mean standing duration, standard deviation, estimate of change, confidence interval, or test result is reported in the registry record. Consequently, the magnitude and precision of standing performance cannot be assessed from this record.
The distinction between a measurement plan and a result is central. A named outcome and a stated timeframe establish what investigators intended to measure; they do not reveal what participants experienced. The record specifies that Standing Performance is measured in minutes and summarized as a mean with a standard deviation. It does not give the actual values at discharge or follow-up. Without those values, a reader cannot tell the group’s average standing duration, how much participant outcomes varied, or how much information is available about any change.
Even if results at both timepoints were available, a single-group comparison over time would remain descriptive of the participants who were measured. General statistical interpretation: a change between observations can be influenced by factors other than the intervention, including changes in participants over time and other aspects of their care or experience. A concurrent control group can help distinguish intervention-associated differences from such influences; this record describes no concurrent control group. Thus, the registered design does not provide a randomized estimate of what standing performance would have been without the implanted system.
The study enrolled 18 participants, but the record lists no outcome analyses. The enrollment count alone does not show how many participants contributed measurements at each timepoint, whether all planned measurements were collected, or how missing observations were handled. Those details are not reported in the registry record. Nor is a confidence interval or another precision estimate reported. General statistical explanation: a confidence interval expresses uncertainty around an estimated quantity; without an estimate and its interval, the degree of statistical precision cannot be judged.
The safety information is separate from the primary performance outcome. The record lists one serious adverse event affected among 15 at risk, zero other adverse events affected among 15 at risk, and infection as a top serious term at 6.7%. It does not give a narrative account linking individual events to specific circumstances. The death count is recorded as null, so deaths are not reported in the registry record; null should not be read as a reported count of zero.
Overall, the registry supports a description of the study’s intended population, intervention, outcome, design, and selected safety counts. It does not support a conclusion about the observed level or change in standing performance, or a comparative estimate of the neuroprosthesis’s effect.
9. Statistical Methods Explained
The registry records Standing Performance as a continuous outcome, expressed in minutes, with a mean and standard deviation as the planned summary. It records no analyses. The statistical concepts below are general explanations of how such information is ordinarily interpreted; they are not claims about analyses conducted in this study.
What does a mean describe?
For a continuous outcome, the mean is the arithmetic average of the observed measurements in the group being described. In this study, it would summarize standing durations for participants measured at a specified timepoint. A mean is useful for describing the group’s central level, but it does not show whether participants had similar or very different durations. It can also be affected by unusually high or low observations. The registry record names the mean as the summary parameter but gives no observed mean.
What does the standard deviation add?
The standard deviation describes how spread out observations are around the mean. A relatively narrow spread would indicate that measurements were closer to the group average, while a wider spread would indicate greater variability. This is a description of variation among observations, not a measure of uncertainty about the mean. A confidence interval, by contrast, is used to express uncertainty in an estimate. Neither the standard deviation nor a confidence interval for Standing Performance is reported in the registry record.
How would the timepoints be interpreted?
The listed timeframe includes discharge and a follow-up between 6-12 months follow-up. General explanation: measurements at multiple times can be described separately, or a change between times can be estimated for participants with relevant observations. A paired analysis uses the within-participant relationship between measurements; an analysis treating observations as independent does not use that relationship and may not answer the same question. The registry record does not specify which approach, if any, was used, and no analysis is listed. It does not report how many participants had measurements at each timepoint or whether the same participants contributed at both times.
A change over time in a single group is not equivalent to a randomized treatment effect. General explanation: participants may change over time for reasons that are not caused by the intervention. Without a concurrent comparison group, an observed difference between discharge and follow-up cannot separate an intervention-associated change from other influences. The study’s single-group design therefore supports descriptive assessment of its enrolled participants, not a controlled estimate of the intervention’s effect.
What can a confidence interval tell a reader?
General explanation: a confidence interval presents a range of values compatible with an estimate under the statistical model and procedure used. Its width reflects precision: a narrower interval generally indicates more precise estimation, while a wider interval indicates more uncertainty. Interpretation depends on the estimated quantity, the method, and the assumptions. No interval or inferential estimate for the primary outcome is reported in the registry record, so its precision cannot be evaluated.
What is over-dispersion?
General explanation: over-dispersion arises when observed variability is greater than a statistical model assumes. It is particularly relevant to outcomes modeled as counts or event rates, where an overly restrictive variance assumption can make uncertainty appear too small. Standing duration is listed as a continuous outcome summarized by a mean and standard deviation; the registry does not report a count model or an over-dispersion assessment. This concept therefore does not establish anything about the analysis of this outcome.
What do planning illustrations mean?
General explanation: a sample-size planning illustration estimates the number of participants that might be needed under stated assumptions about an effect, variability, significance level, allocation, and analysis. It is a planning exercise, not evidence about what happened in a trial. The record’s planning assumptions describe a two-arm illustration with equal allocation, a two-sided significance level of 0.05, a normal approximation, and effects defined as fractions of an observed effect. Those assumptions do not match the registered single-group design. Any planning illustration based on them should not be read as an observed result or as observed power. A study’s observed estimate and its uncertainty are needed to assess what its data show.
The registry record does not report the protocol’s sample-size justification, the statistical analysis plan, interim analyses, or a calculated sample-size result. Their absence prevents a reader from determining whether the planning illustration reflected the investigators’ original design decisions.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures: Standing Performance as the primary outcome and distribution of body weight through the legs and arms while standing as a secondary outcome. It does not report outcome analyses. No multiplicity adjustment, testing hierarchy, or approach to interpreting multiple outcomes is reported in the registry record. General explanation: when several outcomes or comparisons are tested, the chance of at least one apparently notable result can increase if each is interpreted without regard to the others. How that issue should be handled depends on the prespecified analysis plan and the purpose of the analyses; that plan is not reported.
Missing-data methods are also not reported in the registry record. Although the timeframe names discharge and follow-up, the record does not state how many participants had data at each assessment, whether any measurements were missing, why data might be missing, or how missing observations were treated. This matters because the participants with available measurements may not necessarily represent everyone enrolled. General explanation: an analysis based only on available observations can be difficult to interpret if missingness is related to outcome levels or participant circumstances.
The arm description says that candidates are evaluated for appropriateness for inclusion on an intent-to-treat basis and that qualifying candidates receive the implanted neuroprosthesis. This wording does not describe a randomized allocation or clarify which participants were included in any outcome analysis. The record does not report an analysis population definition, exclusions from analysis, or a participant flow accounting for the primary outcome. The enrollment was 18, while the safety at-risk count was 15; the reason for this difference is not reported in the registry record.
There are no listed analyses, so it is not possible to determine how the outcome, missing observations, or multiple outcomes were handled in practice.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Implanted Neuroprosthesis | 1 | 15 | 6.7% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Implanted Neuroprosthesis | 0 of 15 |
Most frequent serious adverse event terms
| Event term | Organ system | Implanted Neuroprosthesis |
|---|---|---|
| Infection | Infections and infestations | 1 of 15 |
Serious events with the highest arm-level rate: infection (6.7%).
The registry lists one serious adverse event affected among 15 participants at risk in the Implanted Neuroprosthesis group. It lists zero other adverse events affected among 15 at risk. Infection is recorded as a top serious term at 6.7%. These are distinct entries in the record; it does not provide enough detail to establish from the listing alone how the serious-event count and the term-level percentage relate at the participant level.
The death field is null. A null entry means deaths are not reported in the registry record; it does not establish that no deaths occurred. The record does not provide event narratives, timing, severity details beyond the serious-event classification, or an assessment of whether events were related to the procedure or device. It also does not explain why the safety at-risk count is 15 when enrollment is 18.
General explanation: safety counts depend on the population monitored, the period of observation, and the definitions used for adverse events. Counts from a single group do not provide a controlled comparison of event rates. The registry’s safety entries should therefore be read as the posted counts and term listing, not as a comparative safety estimate.
12. What the Result Does, and Does Not, Mean
The registry record documents a completed, single-group study of an implanted neuroprosthesis for people with spinal cord injury. It identifies surgery and the IRS-8 device as interventions, describes postoperative training and follow-up, and names Standing Performance as the primary outcome. That outcome measures how long a person can maintain a standing position, in minutes, at discharge and a follow-up between 6-12 months follow-up.
The record does not report the observed standing-performance values, the mean or standard deviation, an estimate of change, or an analysis. It therefore cannot establish the average standing duration observed in the study, the variability among participants, or the precision of any estimate. The absence of reported results is not evidence that the outcome had no change or that participants had no standing performance; the outcome findings are simply not reported in the registry record.
The design also limits what a result could establish. With a single group and no concurrent comparator, descriptions of participants’ outcomes would not isolate the contribution of the implanted system from other influences. A before-and-after or discharge-to-follow-up pattern, if reported, would describe change over time in the measured participants, not a randomized comparison with an alternative.
The safety record lists one serious event affected among 15 at risk, zero other events affected among 15 at risk, and infection at 6.7% among the top serious terms. The death field is null, not a reported zero. The record does not explain the difference between the enrollment count of 18 and the safety at-risk count of 15.
In short, the registry provides study-design and selected safety information, but not primary-outcome results or statistical analyses. It does not support a conclusion about the magnitude, precision, or comparative effect of the intervention on standing performance.
13. Why This Trial Matters Statistically
This study is statistically notable for the gap between a clearly identified functional outcome and the absence of reported outcome analyses. The registry specifies what Standing Performance measures, its units, its summary parameter, and its assessment timeframe. Yet it lists no analyses and provides no observed values. This illustrates why an outcome definition alone is not a result: interpretation also requires the measurements and an account of how they were analyzed.
The single-group design highlights the difference between describing participant outcomes and estimating a comparative intervention effect. General statistical explanation: a within-group description can show the observed experience of those measured, but it cannot by itself identify what would have happened to similar participants under a different condition. A concurrent comparator is one way to address that question. No comparator is described in this registry record.
The record also brings attention to the distinction between enrollment and analysis populations. Enrollment is 18, while the safety at-risk count is 15; the record does not explain the difference. It does not report how many participants contributed to primary-outcome measurements at discharge or follow-up. Without that information, readers cannot assess outcome completeness or the population represented by any analysis.
Finally, the record includes assumptions for a planning illustration that describe a two-arm setup, while the registered study is single group. That contrast reinforces that planning exercises are conditional calculations, not observations from the trial and not proof of achieved statistical power. For this study, the principal statistical limitation is more basic: the posted record does not include the observed primary outcome or its analysis.
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 registry record does not report the primary-outcome results or any outcome analyses. This prevents assessment of the level of standing performance, variation between participants, change across the named timepoints, or statistical precision. It also does not report participant-level data, confidence intervals, or test results.
The single-group design has no concurrent comparator, and allocation is recorded as NA. There is no like-for-like control comparison from which to estimate a randomized contrast. The absence of masking, recorded as NONE, is also relevant to interpretation, although the record does not describe how outcome measurement was conducted or whether assessor procedures were used.
The timeframe includes discharge and a follow-up between 6-12 months follow-up, but the record does not report the number assessed at either timepoint or how missing measurements were handled. It does not give an analysis-population definition or participant flow for the primary outcome. The enrollment count is 18, while the safety record lists 15 at risk; the reason is not reported in the registry record.
The record names a secondary outcome but does not report its results, or how multiple outcomes were considered. A detailed statistical plan, sample-size justification, and interim-analysis information are not reported. The planning assumptions describe an illustration using two arms, whereas the trial design is single group; the record does not establish that those assumptions were used to plan the study.
Safety details are limited to the listed counts and serious-event term. The death field is null, and the record gives no event narratives or relationship assessments. These omissions limit interpretation of both effectiveness-related outcomes and safety; they should not be replaced with assumptions about unreported methods or results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of an Implantable Functional Neuromuscular Stimulation System for Patients With Spinal Cord Injuries — NCT00004445.
- Registry record last updated 2025-05-20; status last verified 2025-05.
- Results first posted 2019-07-22.
- 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.
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18. Record Summary
NCT00004445 is a completed, single-group study sponsored by Case Western Reserve University. The recorded start was 1996-09 and primary completion was 2009-09; enrollment was 18. The study concerned an implanted eight-channel neuroprosthesis for people with spinal cord injury, with surgery and the IRS-8 device listed as interventions. The arm description includes postoperative training and follow-up.
The primary outcome, Standing Performance, is a continuous measure in minutes, summarized by a mean and standard deviation, with assessment at discharge and a follow-up between 6-12 months follow-up. Distribution of body weight through the legs and arms while standing is listed as a secondary outcome. The registry reports no outcome analyses or observed primary-outcome values. It describes no concurrent control group.
The safety record lists one serious adverse event affected among 15 at risk, zero other adverse events affected among 15 at risk, and infection at 6.7% among the top serious terms. Deaths are not reported in the registry record. The reason the safety at-risk count differs from enrollment is not reported.