The Effect of FES on Children With Spinal Cord Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Effect of FES on Children With Spinal Cord Injury (NCT00291317), a na na study. The primary outcome is Change in Pediatric Quality of Life Inventory Version 4.0 (PedsQL 4.0)Score..

2. Clinical Question

3. Trial Design

This was a completed, single-group device study sponsored by Children's Specialized Hospital. The registry lists the study start as 2006-01 and primary completion as 2008-09. Its phase is listed as NA, its allocation as NA, and its masking as none. The recorded enrollment was six participants. These design details describe a study without a randomized allocation or a concurrent control group; they do not support a like-for-like comparison between treatment groups.

The intervention was exercise using functional electrical stimulation cycling on the RT 300-P FES cycle. The primary outcome was change in the Pediatric Quality of Life Inventory Version 4.0 psychosocial health summary score. The registry describes pre- and post-intervention assessment, with the time frame among participants ranging from 4 to 12 months. This is the reported range for the assessment time frame, not a stated common follow-up period for every participant.

The record says that four participants completed the PedsQL on at least two occasions. At minimum, each of those participants completed the questionnaire at initial evaluation before beginning the cycling program and at or following their last cycling session. It does not say that all six participants contributed two primary-outcome assessments. The specific statistical analysis plan, the handling of incomplete assessments, and any protocol-defined analysis population are not reported in the registry record.

The record lists two outcome measures and no analyses. It gives the primary outcome’s measurement description but does not provide numerical outcome results. The intervention schedule, frequency and duration of cycling sessions, participant characteristics beyond the stated condition and age description, and any eligibility criteria are not reported in the registry record. The completed status indicates the study’s recorded status, but does not substitute for missing outcome results or details of the analysis.

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: Four of the six participants completed the PedsQL on at least 2 occasions. At minimum, each completed the PedsQL at their initial evaluation before beginning the cycling program and at or following their last cycling session.

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 Pediatric Quality of Life Inventory Version 4.0 (PedsQL 4.0)Score., measured over pre- and post-intervention; time frame among participants ranged from 4 to 12 months.

The primary endpoint is change in the Pediatric Quality of Life Inventory Version 4.0 (PedsQL 4.0) score. The registry describes a psychosocial health summary score formed by combining the emotional functioning, social functioning, and school functioning modules. The scale ranges from 0 to 100, with 100 described as the maximum positive outcome. The questionnaire asks how much of a problem each item has been during the past month, using a 5-point response scale.

A quality-of-life measure can capture aspects of daily emotional, social, and school functioning that are not represented by a physical performance measure alone. The within-participant pre- and post-intervention comparison was intended to assess whether the measured psychosocial score changed after participation in cycling. Such a change is a descriptive before-and-after contrast in a single group; without a separate control group, it cannot distinguish an intervention-associated change from other influences over time.

The registry identifies the outcome as a mean and its dispersion as a standard deviation, but gives no corresponding numerical scores, changes, or standard deviations. Therefore, the size and direction of the observed endpoint change, and the precision with which it was estimated, are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a within-participant change measure?

For a continuous outcome such as a score, a change analysis compares measurements from the same participant at different assessment occasions. The PedsQL endpoint was described as a pre- and post-intervention comparison. A mean change would summarize the average direction and size of the paired score differences among the participants included in that analysis. A standard deviation describes how dispersed those differences are across participants. The registry record identifies a mean and standard deviation as the intended summary measures, but does not report their numerical values.

Pairing measurements can be useful because each participant serves as their own reference for describing change. It does not, by itself, create a control group or establish that the intervention caused a change. General factors that may influence a before-and-after comparison include the passage of time, other care or activities, and measurement timing. The registry record does not report how such factors were assessed or accounted for.

What would a confidence interval convey?

In general, a confidence interval gives a range of values compatible with the data and the statistical method used, expressing uncertainty around an estimated effect. Its width reflects both the amount of information and variability in the data, as well as assumptions of the method. A confidence interval for the mean change could help readers judge the precision of the estimated change. No confidence interval is reported in the registry record, so precision cannot be assessed from the posted endpoint information.

A p-value, if reported, would describe how compatible the observed data are with a specified null hypothesis under the chosen statistical model. It would not measure the probability that the intervention works, nor would it describe the size or practical importance of a change. No p-value or test result is reported. The registry also does not state which test or model was planned or used.

What does the planning illustration represent?

The record describes a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. The illustration is not the study’s own design or sample-size justification. It uses a two-arm framework even though the trial is recorded as single-group. No calculated participant counts or observed effect estimate are reported in the information available for this analysis.

Such planning calculations are hypothetical: they ask how many participants per arm might be needed under specified assumptions to detect a chosen effect with a chosen power. They do not tell how likely this completed study was to detect an effect after the fact. They are not observed power. Any interpretation also depends on whether assumptions about the effect, variability, allocation, and analysis are reasonable. The registry record does not report the study’s own sample-size justification, so the planning illustration should not be treated as its original design basis.

Why does over-dispersion matter in general?

Over-dispersion is a general concern when observed variability exceeds what a statistical model assumes. If a model understates variability, its uncertainty estimates may be too small and its intervals or tests may be misleading. This is a general statistical consideration, not a reported feature of this study. The endpoint is continuous, and the record does not provide outcome distributions or model diagnostics that would allow assessment of this issue.

The record’s stated dispersion measure is the standard deviation, which describes spread in scores or changes. It does not indicate the uncertainty in the mean by itself; assessing that uncertainty also requires information about the analyzed sample and the analysis method. Because the numerical outcome summaries and analysis details are absent, neither variability nor model adequacy can be evaluated from the registry record.

What analysis details are absent?

The registry lists no analyses. The specific statistical test or model, any adjustment for baseline values, the handling of missing observations, and the method for constructing uncertainty intervals are not reported in the registry record. Nor is it reported whether the analysis used every available questionnaire or a prespecified subset. These details matter because different analytic choices can change the estimated effect and its uncertainty, particularly when the available paired observations are limited.

The record identifies two outcome measures but does not describe a multiplicity procedure or identify the analysis status of the other measure. General statistical practice distinguishes a prespecified primary outcome from additional outcomes, since examining multiple outcomes can increase the chance of a nominally notable result. The registry’s designation of a primary endpoint is useful context, but does not establish what analyses were actually conducted. No statistical significance claim can be assessed without reported results and methods.

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("FES Cycle Exercise")
n   <- c(4)
m   <- c(7.08)
sp  <- c(8.21)
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  FES Cycle Exercise  4  7.080  8.210  -5.984  20.144

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and identifies the PedsQL change as the primary outcome. It does not report a multiplicity adjustment, a hierarchy among other outcomes, or the statistical analyses conducted; the record lists no analyses. It is therefore not possible to determine whether any procedure was used to account for examining multiple outcomes. In general, when several outcomes are tested, the chance of a false-positive finding can increase unless the analysis plan addresses multiplicity. That general concern does not establish that any particular result in this study is false or statistically significant.

Missing outcome data are relevant because six participants were enrolled, while four completed the PedsQL on at least two occasions. The record does not report why the other participants lacked two assessments, whether there were partially completed questionnaires, or how missing items or incomplete follow-up were handled. It also does not provide a flow of participants through assessment or the number included in any outcome analysis. A complete-case analysis, an analysis using available observations, and other approaches can target different quantities; the registry does not specify which, if any, was used.

The analysis population is not defined beyond the description of four participants completing the questionnaire on at least two occasions. The record does not report an intention-to-treat population, a per-protocol population, or criteria for inclusion in the endpoint analysis. The extent to which the available participants represent all six enrolled participants cannot be assessed from the reported outcome information. These omissions limit interpretation of both the estimated change and its generalizability.

12. 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 5% reporting threshold.

For the FES Cycle Exercise group, the registry records six participants at risk for serious adverse events and zero affected by serious adverse events. It also records six at risk for other adverse events and zero affected in that category. No serious adverse event terms are listed. These figures describe the event counts recorded in the registry, not an estimate of event risk beyond the study’s recorded participants and reporting.

The deaths field is not reported in the registry record. It should not be interpreted as a count of zero deaths. The record also does not provide additional details about the period or procedures used for adverse-event monitoring, or definitions for the reported categories. A zero count in a small study does not establish that an event is impossible or rule out uncommon events. It only indicates that none were recorded in the stated category among the participants at risk in this entry.

These safety counts should be read separately from the primary quality-of-life outcome. They do not provide information about PedsQL score changes, and the absence of recorded events in these categories is not a measure of the intervention’s effect on psychosocial health.

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

The registry record describes a completed single-group study of FES cycling and a planned assessment of psychosocial quality of life before and after the intervention. It also reports that four participants completed the PedsQL on at least two occasions. These registry entries show what the study set out to assess and give limited information about questionnaire completion. They do not reveal the outcome itself: numerical scores and score changes are not reported in the registry record.

Accordingly, the record cannot support a statement about whether PedsQL scores increased or decreased, how large any change was, or how precisely it was estimated. No confidence interval, p-value, or endpoint analysis is reported. This is not evidence that there was no change; it is an absence of numerical results in the registry record.

Even if a numerical before-and-after change were available, the single-group design would describe change over time among participants with data rather than establish that cycling caused it. A separate control group is not listed, and allocation is recorded as NA. The record also does not describe how missing assessments were handled or whether all enrolled participants were included in an analysis.

The safety entry reports zero serious adverse events and zero other adverse events among six at risk in each category, while the deaths field is not reported. Those counts are limited to the recorded categories and participants. They should not be generalized beyond what the registry states.

The most defensible interpretation is therefore descriptive: the record documents a device intervention, a continuous quality-of-life endpoint, a small enrolled group, incomplete repeated questionnaire completion, and recorded adverse-event counts. It does not report enough outcome or analysis information to assess the magnitude, direction, or statistical reliability of the primary endpoint. Any planning illustration based on an observed effect is separate from the actual design and is not evidence of observed power or a trial result.

14. Why This Trial Matters Statistically

This trial illustrates an important distinction between a registered research question and a reported statistical result. The record clearly identifies a continuous primary outcome and describes how the intended pre- and post-intervention comparison relates to the PedsQL. Yet without numerical scores, changes, or uncertainty estimates, readers cannot evaluate the result’s direction or precision. An endpoint definition alone does not answer the clinical question.

The study also highlights the interpretive limits of a single-group design. Repeated measurements can describe within-participant change, but without a concurrent comparison group the analysis cannot separate intervention-associated change from other changes over time. This is a design limitation, not a judgment about whether the intervention has benefit. The registry record also shows why assessment completion matters: six participants were enrolled, but four completed the questionnaire on at least two occasions.

Finally, the record distinguishes a planning illustration from an actual trial design. A hypothetical calculation based on an observed effect and assumptions for two arms is not the same as the sample-size rationale for a single-group study, and it is not observed power. The study’s own sample-size justification and statistical analysis are not reported in the registry record. These distinctions help prevent readers from treating a calculated planning quantity as a trial finding.

For biostatistical interpretation, the record is useful for identifying the outcome construct, the measurement scale, the study structure, and the limits of what can be concluded. It also demonstrates the importance of complete reporting of analysis populations, missing data, estimates, and uncertainty. Without those elements, the reader can characterize the design but cannot evaluate the primary endpoint result.

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 central limitation for interpreting the primary outcome is that no numerical PedsQL results are reported in the registry record. Means, changes, standard deviations, confidence intervals, and test results are absent. The listed outcome measure therefore cannot be used to judge the direction, size, or precision of change.

The study is recorded as single-group, with no separate control group and no masking. Any pre- and post-intervention difference would be descriptive and could not, by design alone, isolate the effect of cycling from other influences. The record does not report a statistical analysis plan or details of how the comparison was performed.

Enrollment was six, and four participants completed the PedsQL on at least two occasions. The registry does not explain the missing repeated assessments, identify the analysis population, or describe the handling of incomplete questionnaire data. The assessment time frame varied among participants from 4 to 12 months, and no participant-level timing or method for accounting for that variation is reported.

The record lists two outcome measures but no analyses, and does not report whether multiplicity was addressed. It also does not report the study’s own sample-size justification. The stated planning assumptions concern a hypothetical two-arm calculation, which differs from the recorded single-group design. Participant characteristics, eligibility criteria, and further intervention-schedule details are not reported in the registry record, limiting assessment of applicability and intervention exposure.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The Effect of FES on Children With Spinal Cord Injury — NCT00291317.
• Registry record last updated 2012-08-13; status last verified 2012-08.
• Results first posted 2012-08-13.
• 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

NCT00291317 is recorded as a completed, single-group device study sponsored by Children's Specialized Hospital, with six participants enrolled. The study dates are listed as 2006-01 for start and 2008-09 for primary completion. Participants exercised using the RT 300-P FES cycle. The primary outcome was change in PedsQL 4.0 psychosocial health summary score, combining emotional, social, and school functioning modules on a scale from 0 to 100.

The registry says four participants completed the PedsQL on at least two occasions, with assessments before and at or following their last cycling session. The time frame among participants ranged from 4 to 12 months. Numerical endpoint results and statistical analyses are not reported in the registry record. The adverse-event entry records zero serious and zero other adverse events among six at risk in each category; the deaths field is not reported.