Alternative Exercise Program to Improve Skeletal Muscle Function and Fatigue in Cancer Survivors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Alternative Exercise Program to Improve Skeletal Muscle Function and Fatigue in Cancer Survivors (NCT02739620), a randomized na study. The primary outcome is Maximal Calcium-activated Tension Single Muscle Fiber Tension.

2. Clinical Question

The study rationale notes that exercise training may help address some effects of cancer and its treatment, while recognizing that people diagnosed with or being treated for cancer may face barriers to participating in exercise programs. The research goal was to begin evaluating whether training via NMES has beneficial effects on skeletal muscle size and function in cancer survivors. That rationale frames the question; it does not establish what the trial found.

The record names single muscle fiber contractile velocity as a secondary outcome. It lists four outcome measures overall, but does not provide the other outcome names in the available record information. Results for the primary and secondary measures are not reported in the registry record. Consequently, the clinical question can be described, but the effect estimate, its uncertainty, and the direction of any observed difference cannot be assessed from the record.

3. Trial Design

The study is listed as randomized, single-masked, and parallel-group. Participants were assigned to an NMES group or a control group. The record gives an enrollment of 22 and describes the primary-measure sample sizes as the numbers of volunteers with paired data at baseline and 2-month testing. The numbers contributing paired data to that endpoint are not reported in the registry record, so the enrollment figure should not be treated as the endpoint analysis size.

The condition is breast cancer, and the study title and summary frame the participants as cancer survivors. The sponsor is the University of Vermont. The study is marked completed. Its start date is 2017-10-01, and its primary completion date is 2019-12-02. The phase is listed as NA.

The intervention is named neuromuscular electrical stimulation and is classified as a device. Further procedural details—including how often or how long it was used—are not reported in the registry record. The control condition is likewise not described beyond its group label. Although the study is listed as single-masked, the identity of the masked parties and how masking was maintained are not reported in the registry record.

Randomization and a parallel-group structure describe how the comparison was organized, but they do not by themselves explain the allocation procedure, concealment, or analysis population. Those details are not reported in the registry record. The record gives the endpoint timeframe as a difference between baseline and 2-month values. It does not describe follow-up beyond that timeframe or provide a detailed schedule for other assessments.

The primary endpoint concerns a continuous measurement, summarized as a mean with standard error. The registry record does not report a primary-outcome comparison, an effect estimate, a confidence interval, or a test result. Thus, the design and measurement question are identifiable, but the comparative outcome cannot be reconstructed from the record.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The sample sizes reflect the number of volunteers with paired data at both baseline and 2-month testing.

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 Maximal Calcium-activated Tension Single Muscle Fiber Tension, measured over Difference between values at baseline at 2 months.

The primary endpoint is titled maximal calcium-activated tension single muscle fiber tension. It measures tension, described as force per unit muscle-fiber cross-sectional area, in segments of chemically skinned single human muscle fibers. The fibers are assessed under a maximal calcium-activated condition, and fiber type is determined after measurement by gel electrophoresis. The reported unit is milliNewtons per millimeter^2.

This measurement focuses on the contractile force of an individual muscle fiber relative to its cross-sectional area, rather than a whole-body exercise outcome. In general, a measurement expressed per unit area provides a way to describe force while accounting for the size of the measured fiber segment. That general rationale does not establish that the measure captures every aspect of skeletal muscle function or fatigue.

The registry describes the endpoint as a mean and identifies standard error as its dispersion measure. The timeframe refers to the difference between values at baseline and 2 months. The endpoint population is described as volunteers with paired data at both assessments. The number with paired data in each group and the values observed are not reported in the registry record.

The record also names single muscle fiber contractile velocity as a secondary outcome. It does not report a result for that measure. The primary endpoint is relevant to the stated goal of examining muscle function, but it is not itself a direct measure of fatigue, participation, or long-term prognosis. No conclusion about those broader outcomes can be drawn from the endpoint description alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry labels the primary measure as continuous and identifies the summary parameter as a mean with standard error. The following explanations are general statistical context, not a description of an analysis confirmed in the registry. The specific statistical plan, model, and inferential procedures are not reported in the registry record.

What does a mean describe?

In general, a mean is a summary of the central level of a quantitative measurement. For this trial, the endpoint is a laboratory measurement of tension in single muscle fibers, expressed per unit cross-sectional area. A mean can give a compact description of the measured values, but it does not show their full distribution. Individual values may vary around the mean, and the distribution, range, and possible outliers can matter when assessing whether a mean is representative.

The endpoint timeframe refers to the difference between baseline and 2-month values. In general, a change score can be calculated for each participant who has both measurements, then summarized within groups or compared between groups. Alternatively, a model can use repeated measurements directly. These approaches can target related but not identical quantities and may rely on different assumptions. The registry record does not say which method was used or whether any such analysis was conducted.

What does standard error convey?

In general, standard error describes the statistical precision of an estimated quantity, such as a mean. It is not the same as the spread of individual participant measurements: a measure of spread describes variability among observations, while standard error concerns uncertainty in an estimate. The standard errors for this endpoint are not reported in the registry record, so the precision of the group means cannot be assessed.

A confidence interval is a range produced by a statistical procedure to express uncertainty around an estimate. Its width depends on the data and the method used. A narrow interval generally indicates greater precision than a wide interval, though precision alone does not determine whether a difference is important. No confidence interval for the primary endpoint is reported in the registry record.

Why distinguish within-group change from a group comparison?

In general, a change over time within the NMES group does not by itself show that the change differs from what occurred in the control group. Both groups can change over time for reasons unrelated to the intervention, including ordinary variation or features of the testing process. A randomized comparison is typically interpreted through a contrast between groups, with uncertainty around that contrast. The registry record does not report such a contrast for the primary endpoint.

Pairing baseline and 2-month measurements means that the endpoint sample is defined by volunteers with both values. Pairing can account for the fact that measurements from the same person are related. It also means that participants without one of the paired measurements may not contribute to a paired analysis. The record does not report how many were missing, how missing observations were handled, or whether an alternative analysis included participants with incomplete measurements.

What is over-dispersion, in general?

Over-dispersion is a general concern when observed variability is greater than a statistical model expects. It is especially relevant to count or categorical outcomes modeled with assumptions about variability, and can make standard errors or test results unreliable if ignored. The primary endpoint is described as a continuous mean, and no model details or evidence about over-dispersion are reported. It would therefore be inappropriate to claim that over-dispersion was present or that a particular correction was used.

How should the planning illustration be read?

The registry’s planning assumptions describe an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The illustrated effect is framed as a stated fraction of the observed effect. Such calculations can show how planning requirements vary with assumptions about the effect to detect and the desired power. They are not an account of the trial’s original design unless the record says they were, and this record does not say that they were.

Planning calculations are not observed power. Observed power is not a substitute for interpreting an effect estimate and its uncertainty after a study. A planning illustration also does not show that a study was adequately sized for every outcome or analysis. The actual sample-size justification, intended power, and original design assumptions are not reported in the registry record. Numerical planning results are not reported in the record information summarized for this analysis.

Finally, randomization, masking, and the parallel-group structure describe design features, not the full statistical method. The allocation sequence, concealment procedure, masked parties, analysis population, adjustment variables, handling of repeated measurements, and tests are not reported in the registry record. Without those details and the outcome results, the statistical interpretation must remain limited to what the record explicitly describes.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, with maximal calcium-activated tension single muscle fiber tension identified as the primary endpoint and single muscle fiber contractile velocity named as a secondary outcome. Results for these outcomes are not reported in the registry record, and the record lists 0 analyses. The other outcome measure names and their analysis results are not reported in the registry information available for interpretation.

When a study assesses multiple outcomes or performs multiple comparisons, the chance of obtaining at least one seemingly notable result can increase. In general, researchers may address this through a prespecified hierarchy, adjustment procedures, or careful distinction between primary and exploratory analyses. The registry record does not report a multiplicity strategy, a hierarchy beyond the named primary and secondary outcomes, or whether any adjustment was used. It is not possible to infer a strategy from the outcome labels alone.

The primary measure is described as drawing on paired data at baseline and 2-month testing. This indicates that the endpoint population consists of volunteers with both measurements, but does not say how many participants contributed paired values in either group. Missing-data amounts, reasons for missingness, imputation, sensitivity analyses, and rules for inclusion are not reported in the registry record.

The record gives an enrollment of 22, but it does not describe whether the analysis was based on all randomized participants, participants who completed the intervention, or a subset with available paired measurements. The adverse-event at-risk counts should not be treated as the primary endpoint sample sizes, because the record identifies a different basis for the primary measure and does not provide its group-specific counts. Definitions of intention-to-treat, per-protocol, or other analysis populations are not reported in the registry record.

These omissions limit assessment of how missing observations and multiple outcomes may affect interpretation. They do not establish that a particular problem occurred; they mean that the record does not contain enough information to evaluate the issue.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hospitalization (10.0%).

The registry reports serious adverse events and other adverse events by group. In the NMES group, the serious adverse event count is 0 among 12 at risk, and the other adverse event count is 0 among 12 at risk. In the control group, the serious adverse event count is 1 among 10 at risk, and the other adverse event count is 1 among 10 at risk. Deaths are recorded as 0 in both groups. The registry lists hospitalization at 10.0% among its top serious-event terms.

These counts describe what the registry records for the stated groups and at-risk populations. They are not the primary muscle-fiber outcome, and they do not establish whether the groups differ in overall safety. With limited event counts, estimates of event frequency are imprecise; additional context about event definitions, timing, severity, and ascertainment would be needed for a fuller assessment. Those details are not reported in the registry record.

The listed serious-event term should be read as a registry summary, not as a complete narrative of an event or its relationship to the intervention. The record does not report a causal assessment for the events. The at-risk counts are safety denominators and should not be substituted for the paired-data population used to define the primary endpoint.

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

The record establishes that a randomized, single-masked, parallel-group study compared neuromuscular electrical stimulation with a control group among cancer survivors with a breast cancer condition. It specifies a laboratory endpoint intended to assess maximal calcium-activated tension in single muscle fibers, with baseline and 2-month values. Those details identify the research question and measurement approach.

The record does not report the primary endpoint results or an inferential comparison. It therefore does not show whether muscle-fiber tension increased, decreased, or differed between groups. It also does not provide an estimate precise enough to evaluate uncertainty, and it cannot support a conclusion about statistical significance or the size of any effect.

The study goal described in the record concerns whether NMES training may affect skeletal muscle size and function in cancer survivors. A measured single-fiber tension endpoint addresses one aspect of muscle function under a laboratory condition. It does not, by itself, establish effects on fatigue, everyday function, exercise participation, or long-term prognosis. The record’s stated rationale should not be mistaken for an observed result.

The posted planning assumptions are illustrations based on an observed effect, with specified general assumptions about significance level, allocation, and approximation. Such illustrations are planning aids, not evidence that a treatment effect was detected, and not observed power. The original sample-size justification is not reported in the registry record.

The adverse-event counts give limited descriptive safety information. They do not replace a complete safety analysis, nor do they answer the primary efficacy question. In the absence of outcome results, analysis methods, and fuller trial details, the most defensible interpretation is that the registry describes a completed randomized study and its intended measurements, but does not provide enough results to judge the comparative effect of NMES.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it combines randomization with an endpoint measured at the level of individual muscle fibers. The randomized parallel-group design is intended to support a comparison between NMES and a control condition, while the primary measure focuses on contractile tension under a specified laboratory condition. That combination makes clear why the precise definition of the estimand—the quantity the analysis seeks to estimate—matters. A within-person change, a between-group difference in change, and a comparison at follow-up answer related but distinct questions.

The paired-measure description also makes missingness important. Only volunteers with data at both baseline and 2-month testing are included in the stated primary-measure sample-size definition. In general, restricting analysis to paired observations can reduce the available information and can affect interpretation if the reasons for missing observations relate to participant characteristics or outcomes. The registry does not report the number of paired observations, reasons for missingness, or analytic handling, so these issues cannot be evaluated for this trial.

Multiplicity is another consideration because the record lists four outcome measures, while only the primary and one secondary outcome are named in the available information. A prespecified primary outcome can help focus interpretation, but the multiplicity approach and analyses are not reported. The record lists 0 analyses, leaving no outcome results against which to assess uncertainty or consistency across measures.

Finally, registry transparency is part of statistical interpretation. The record provides design labels, a timeframe, measurement details, and safety counts, but not the statistical plan or the primary result. This distinction matters: a detailed endpoint description can clarify what investigators intended to measure, yet does not replace estimates, uncertainty intervals, and analysis methods needed to evaluate what the data show.

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.

Several trial-specific limitations of interpretation follow from the information not reported in the registry record. The primary endpoint results, group-specific paired-data counts, effect estimate, confidence interval, and test result are absent. Without those details, neither the magnitude nor precision of the primary comparison can be assessed. The record also lists 0 analyses, so it does not provide results for the primary endpoint or the named secondary endpoint.

The description identifies a baseline-to-2-month measurement window but does not report further follow-up or a detailed assessment schedule. The registry describes NMES as a device intervention, but does not specify its schedule, intensity, duration, adherence, or implementation. It labels the comparator as control without describing the control condition. These omissions make it difficult to characterize the contrast participants experienced.

The record states that the trial was single-masked but does not identify who was masked or how masking was maintained. Randomization is reported, but the sequence-generation and allocation-concealment procedures are not. Participant characteristics, eligibility criteria beyond the stated condition, and baseline endpoint values are not reported in the registry record. These details would help assess applicability and the conduct of the comparison.

The handling of missing data, the analysis population, the statistical model, covariate adjustment, and multiplicity procedures are also not reported. The endpoint is defined using paired observations, but missingness amounts and reasons are unavailable. The adverse-event information has limited supporting detail about event definitions, timing, ascertainment, and causal assessment. These limitations concern what can be evaluated from the registry record; they do not establish that any particular bias or problem occurred.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Alternative Exercise Program to Improve Skeletal Muscle Function and Fatigue in Cancer Survivors — NCT02739620.
• Registry record last updated 2023-04-11; status last verified 2023-03.
• Results first posted 2023-04-11.
• 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

NCT02739620 is a completed randomized, single-masked, parallel-group study sponsored by the University of Vermont. It enrolled 22 and compared neuromuscular electrical stimulation with a control group in a study concerning cancer survivors with breast cancer. The record lists a start date of 2017-10-01 and a primary completion date of 2019-12-02.

The primary measure is maximal calcium-activated tension in single muscle fibers, expressed in milliNewtons per millimeter^2, with baseline and 2-month values described. The record names single muscle fiber contractile velocity as a secondary outcome and lists four outcome measures overall. It does not report primary or secondary outcome results and lists 0 analyses.

Safety counts are reported by group, including 0 deaths in both groups. The primary analysis population, statistical plan, missing-data handling, and multiplicity strategy are not reported in the registry record. The record therefore supports a description of the design and measurements, but not an assessment of the comparative primary outcome.