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 Home-based Compression Therapy for Arm and Truncal Lymphedema in Breast Cancer (NCT00880022), a randomized na study. The primary outcome is Arm Volume at End of Study.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00880022 |
| Phase | NA |
| Condition | Arm Lymphedema, Truncal Lymphedema, Breast Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 47 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Vanderbilt University |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns breast cancer survivors with lymphedema. Its brief description distinguishes people with arm and truncal lymphedema from people with arm lymphedema. The primary endpoint population is described as excluding study withdrawals, but the registry record does not report further eligibility details for the endpoint analysis.
Intervention
The intervention was the Flexitouch System. One group received compression involving the arm, trunk and chest. The brief description refers to home use and scheduled treatment sessions, but the registry record does not report the exact treatment schedule or adherence information for the comparison represented by the primary result.
Comparator
The comparison group received arm compression only with the Flexitouch System. The trial was randomized, parallel-group and unmasked. The registry record does not report details of how the random assignment was generated or concealed.
Primary question
At the end of scheduled treatments on day 30, what arm volume was observed in each group, and how much uncertainty surrounds a comparison between those groups? The primary endpoint was arm volume in millilitres, measured by tape and then calculated. The registry record reports medians and interquartile ranges, but no formal between-group estimate, confidence interval or test result for this endpoint.
The posted results describe 21 participants in each result group. Enrollment is listed as 47, while the primary endpoint description says study withdrawals were not included. These details should be kept distinct: the record does not explain how enrollment relates to the endpoint groups or account for the difference. The clinical question is therefore best read as a comparison of the posted endpoint summaries, not as a complete account of every participant’s outcome.
3. Trial Design
This was a randomized, parallel-group trial with no masking. The registry lists the study as completed and identifies Vanderbilt University as the sponsor. It lists an enrollment of 47 and reports results for two groups: Arm Compression Only and Arm, Trunck and Chest Compression. The registry uses “Trunck” in the latter group label; the intervention description refers to trunk and chest compression.
The primary outcome was arm volume at the end of scheduled treatments on day 30 of treatment. The registry describes the measure as tape measurement followed by a volume calculation. Results are reported as medians with interquartile ranges. The Arm Compression Only group has a median of 2377 ml, with an interquartile range from 1935 to 2623. The Arm, Trunck and Chest Compression group has a median of 2540 ml, with an interquartile range from 2168 to 3296.
The primary endpoint description says withdrawals were not included. The registry does not report the number or reasons for withdrawals, whether participants were analyzed according to their randomized assignment, or how endpoint data were handled for participants without a measurement. Although the record gives an enrollment figure and group-specific result counts, it does not explain their relationship.
The brief description presents a two-part study and discusses several proposed measures and hypotheses, while the posted primary outcome is a single arm-volume summary at day 30. Details needed to reconstruct the allocation procedure, treatment adherence, deviations from treatment, or the statistical comparison are not reported in the registry record. The record also does not report a phase beyond “NA.”
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
| Stage | Arm Compression Only | Arm, Trunk and Chest Compression |
|---|---|---|
| STARTED | 23 | 24 |
| COMPLETED | 21 | 21 |
| NOT COMPLETED | 2 | 3 |
Analysis population for the primary outcome, as defined in the registry: Study withdrawals were not included.
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 | Arm Compression Only | Arm, Trunck and Chest Compression | Total |
|---|---|---|---|---|
| Participants analysed | 23 | 24 | 47 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 17 | 20 | 37 |
| Age, Categorical: >=65 years | Participants | 6 | 4 | 10 |
| Age, Continuous | years | 58.0 (SD 9.3) | 52.2 (SD 8.6) | 55.0 (SD 9.4) |
| Sex: Female, Male: Female | Participants | 23 | 24 | 47 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 23 | 24 | 47 |
6. Primary Endpoint
The registry lists the primary outcome as Arm Volume at End of Study, measured over end of scheduled treatments-day 30 of treatment.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | ml |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is arm volume, expressed in millilitres, at the end of scheduled treatments on day 30. The registry says arm volume was measured by tape and then calculated. Volume is a quantitative summary of the size of the measured arm and provides a way to compare the endpoint distribution between the compression groups. The record describes the summary as a median with an interquartile range, rather than a mean with a standard deviation.
A median identifies the middle of an ordered set of measurements. An interquartile range describes the interval from the lower to the upper quartile, covering the middle half of the observed values. These summaries can be useful when a distribution is skewed or contains values far from the center, because the median is less influenced by extreme observations than the mean. That is a general statistical rationale; the registry does not state why this particular summary was selected or report the shape of the underlying distributions.
The endpoint is a measurement at a specified treatment time, not a reported change from baseline. The record does not provide baseline arm-volume summaries or participant-level changes, so the posted endpoint medians alone cannot describe how much individual participants’ arm volumes changed during treatment. The endpoint population excludes study withdrawals according to its description, but the registry does not specify the detailed measurement procedures, assessor procedures, or missing-measurement rules.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary result is descriptive. At day 30, the median arm volume was 2377 ml in the Arm Compression Only group and 2540 ml in the Arm, Trunck and Chest Compression group. The reported interquartile ranges were 1935 to 2623 and 2168 to 3296, respectively. These summaries describe the observed endpoint distributions in the result groups; they do not by themselves estimate the uncertainty in a between-group treatment effect.
The registry does not report a formal comparison for this primary endpoint. No between-group effect estimate, confidence interval, or p-value is posted in the record. As a result, the summaries do not establish whether a difference between the groups is compatible with a range of effects, nor how precisely any such difference has been estimated. Overlap or separation of interquartile ranges is not a substitute for a confidence interval or a prespecified statistical test.
The endpoint is reported at the end of scheduled treatments rather than as a change from baseline. Without baseline summaries or change scores, the posted medians cannot show whether either group’s arm volume increased or decreased over the treatment period. They also do not show how individual participants responded. A group median can differ from the values experienced by many participants, and the record does not provide participant-level data or a distribution plot description in the registry record.
Randomization is relevant because, when implemented and retained in analysis, it can help make groups comparable on average with respect to measured and unmeasured factors. However, the record does not provide allocation-method details or state whether the endpoint analysis followed randomized assignment. Nor does it give a formal adjustment strategy or account of withdrawals. The available endpoint summaries therefore support a limited description of the posted group results, rather than a complete causal estimate.
The result counts are 21 for each group, while total enrollment is listed as 47. The registry states that withdrawals were not included in the primary endpoint population, but does not explain the relationship between enrollment, withdrawals and the reported group counts. This limits assessment of the analysis population and of whether missing endpoint measurements could have influenced the summaries.
In short, the registry reports arm-volume medians and interquartile ranges for two randomized groups at day 30. It does not report a statistical comparison or enough information to quantify precision around a group difference. The posted figures should be read as descriptive endpoint data, not as a definitive estimate of the relative effect of the two compression approaches.
9. Statistical Methods Explained
The registry reports a median and interquartile range for arm volume in each group. These are descriptive statistics: they summarize the observed distribution without, on their own, testing a hypothesis about the difference between groups. The registry record does not report a primary-endpoint test, effect estimate, confidence interval, or statistical model.
What does a median tell the reader?
When observations are arranged from smallest to largest, the median is the central value. It is a measure of location and does not depend strongly on the most extreme observations. In this trial, the median is used to summarize arm volume at the endpoint. It does not describe the full spread of measurements or indicate how much values vary from one participant to another.
What does an interquartile range describe?
The interquartile range runs from the lower quartile to the upper quartile and contains the middle half of the observed distribution. The posted ranges are 1935 to 2623 for Arm Compression Only and 2168 to 3296 for Arm, Trunck and Chest Compression. These ranges indicate variability within each result group. They are not confidence intervals for the median or for a between-group effect. A confidence interval is a general statistical tool that expresses uncertainty in an estimated quantity; no such interval for the group contrast is reported in the registry record.
Why is a direct group comparison important?
Separate summaries do not quantify the difference between groups or the uncertainty associated with that difference. A direct comparison could be reported as an estimated contrast, with a confidence interval and a test result, using a method suited to the endpoint and design. The registry does not report which comparison method, if any, was used for the primary endpoint. The descriptive medians cannot be used to reconstruct that analysis, particularly without participant-level data or additional distributional information.
How should randomization be considered?
Random assignment is intended to reduce systematic differences between groups at the start of a study. In general, this supports a causal comparison when assignment is implemented as intended and the analysis preserves the randomized groups. The registry identifies the study as randomized, but does not report the sequence-generation or concealment methods. It also does not state whether the primary analysis followed assigned groups, how deviations from treatment were handled, or whether any adjustment was made.
What do the planning illustrations mean?
Planning illustrations based on an observed effect are not results from the trial and are not observed power. They can show, under stated assumptions, how many participants per arm might be needed to detect a selected fraction of an observed effect at a chosen significance level and power. Such calculations are conditional on the assumed effect, allocation, approximation and other inputs. The record describes a two-sided significance level of 0.05, equal allocation, a normal approximation, and effect fractions based on the observed effect. It does not report these illustrations as the trial’s original design calculation. No sample-size justification for the trial is reported in the registry record.
For a non-time-to-event endpoint, a planning illustration expressed as participants per arm is a design aid, not an observed count or a statement about the probability that a result is true. The illustrations should not be interpreted as observed power. Observed power calculated from an estimated effect is generally not a useful replacement for reporting the estimate and its uncertainty; the key information for interpretation would be a direct effect estimate and confidence interval, which are not reported for this endpoint.
What can be said about multiplicity and over-dispersion?
The brief description names several proposed measures and hypotheses, and the registry lists one secondary outcome as Symptom Improvement. The record does not report a multiplicity strategy for handling several outcomes or hypotheses. Multiplicity is a general concern when many outcomes or tests are considered, because the chance of a chance-positive result can increase across repeated testing. The absence of a reported analysis plan means the reader cannot determine how such testing was addressed.
Over-dispersion is a general issue for count outcomes when observed variability exceeds what a simple count model expects. It is not directly relevant to the posted primary endpoint as described: arm volume is a continuous measurement, not a count. The registry does not report a model for the primary endpoint, so no claim about model assumptions or diagnostics can be made.
10. Multiplicity, Missing Data and Analysis Populations
The brief study description includes multiple proposed outcomes, including arm swelling, truncal swelling, symptoms and functional assessment. The registry lists one secondary outcome, Symptom Improvement, and two outcome measures overall. It reports zero analyses. The record does not specify a statistical analysis plan, identify which comparisons were prespecified, or describe a multiplicity adjustment. Without those details, it is not possible to assess how multiple outcomes or tests were handled, or whether the posted primary result reflects a prespecified analysis.
For the primary endpoint, the record states that study withdrawals were not included. It does not report how many withdrawals occurred, when they occurred, why participants withdrew, or whether they differed by group. It also does not explain how missing endpoint measurements were handled beyond excluding withdrawals. The registry record does not describe imputation, sensitivity analyses, or other methods for assessing the influence of missing data.
The record lists enrollment as 47 and reports endpoint results for 21 participants in each group. It does not explain the relationship between enrollment and those result counts. In particular, it does not say whether all randomized participants were included in the endpoint results, whether any participants were excluded for reasons other than withdrawal, or whether the reported group counts refer to a particular analysis population.
These omissions matter because missingness and exclusions can affect how representative the analyzed results are of the randomized groups. Without participant flow and analysis-population details, the degree of potential selection bias cannot be assessed from the registry record. No intention-to-treat designation is reported.
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 |
|---|---|---|---|
| Arm Compression Only | 0 | 21 | 0.0% |
| Arm, Trunck and Chest Compression | 0 | 21 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Arm Compression Only | 0 of 21 |
| Arm, Trunck and Chest Compression | 0 of 21 |
The registry reports zero serious adverse events and zero other adverse events in each posted safety group. For both groups, the number at risk is 21 for serious events and 21 for other events. These are counts as recorded for the listed groups; the record does not provide event descriptions or a detailed safety-analysis period.
The deaths field is not populated with a count. Death counts are not reported in the registry record, so a blank field should not be interpreted as a confirmed count of zero. The record also lists no top serious-event terms. This indicates that no terms are presented in that field, not that the registry supplies a full narrative safety assessment.
Zero reported events do not establish that an intervention has no risk. Safety interpretation depends on the number of people observed, the duration and completeness of follow-up, how events were defined and collected, and whether all events were submitted. The registry does not report those details. The listed at-risk counts and event counts should therefore be read as the safety information posted for these groups, not as proof that adverse events cannot occur or as a comparison with adequate precision.
12. What the Result Does, and Does Not, Mean
The posted results establish that the registry contains endpoint summaries for arm volume at the end of scheduled treatments on day 30. The median was 2377 ml for Arm Compression Only and 2540 ml for Arm, Trunck and Chest Compression. The interquartile ranges were 1935 to 2623 and 2168 to 3296, respectively. These are descriptive summaries of the participants included in each reported group.
The results do not establish a statistically reliable difference between the approaches. The registry does not report a direct contrast, confidence interval or p-value for the primary endpoint. It also does not report baseline arm-volume summaries or changes from baseline. Therefore, the endpoint summaries cannot describe the amount or direction of change during treatment, or the uncertainty around a comparison of changes.
The study is identified as randomized, which is an important design feature, but the registry does not describe the allocation procedure or the analysis population in sufficient detail to assess how the randomized design was carried through to the endpoint results. The endpoint description excludes withdrawals, and the relationship between the enrollment figure and the reported group counts is not explained. These gaps prevent a complete account of participant flow and missing-data handling.
The safety record lists no serious or other adverse events in the reported groups, but death counts and details of safety follow-up are not reported in the registry record. These entries should not be taken as proof of zero risk.
Overall, the registry supports a narrowly framed reading: it posts medians and interquartile ranges for arm volume in two compression groups at a stated endpoint. It does not provide enough statistical information to establish the precision or significance of a between-group effect, and it does not resolve the limitations concerning baseline measurements, withdrawals or analysis populations. The results are not a substitute for a complete report of the trial’s methods and analyses.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it compares two related compression approaches in a randomized, parallel-group design and reports a quantitative endpoint at a defined treatment time. A continuous arm-volume measure allows the results to be described using location and spread, and the registry uses medians and interquartile ranges rather than means and standard deviations. Those summaries give readers a basic view of the endpoint distributions without assuming that the values are symmetrically distributed.
At the same time, this record illustrates why descriptive results and comparative inference are different. Group medians alone do not provide an estimate of the between-group contrast or its precision. Reporting an effect estimate and confidence interval would help readers assess the range of values compatible with the data. A p-value, if reported, would answer a different and narrower question about compatibility with a specified null model; it would not replace the estimate and its uncertainty.
The record also highlights the importance of transparent participant accounting. It lists enrollment as 47, reports results for 21 participants in each group, and states that withdrawals were not included in the primary endpoint population. Without an account linking those figures, readers cannot fully judge missingness or the population represented by the summaries. A clear analysis-population definition and participant flow would make the results easier to interpret.
Finally, the brief description contains several proposed outcomes, while the registry provides limited information on analysis methods and multiplicity. That makes it difficult to assess which comparisons were prioritized and how results across outcomes were intended to be interpreted. The lesson is methodological: a randomized label and descriptive endpoint values are useful, but transparent reporting of estimates, uncertainty, missing-data handling and analysis choices is also needed for a complete statistical interpretation.
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’s primary result is limited to endpoint medians and interquartile ranges. It does not report baseline arm volume, change from baseline, a group contrast, a confidence interval, a p-value or a statistical model. Consequently, the size and precision of a comparative effect cannot be assessed from the posted endpoint summaries alone.
Participant accounting is incomplete. Enrollment is listed as 47, while each result group contains 21 participants. The primary endpoint description excludes study withdrawals, but the record does not give the withdrawal count, reasons, timing or group distribution. It does not explain whether other exclusions occurred or how missing measurements were treated. The registry does not identify the primary analysis population or state whether analysis followed randomized assignment.
There is limited information about implementation. The record identifies the trial as randomized and unmasked but does not report allocation generation or concealment, treatment adherence, deviations from the assigned intervention, or measurement-assessor procedures. The endpoint is described as tape measurement followed by volume calculation, but details of the measurement protocol and quality control are not reported in the registry record.
The study description names several hypotheses and measures, yet the registry does not report a statistical analysis plan or a multiplicity strategy. It lists one secondary outcome and zero analyses. The safety record provides event counts but does not report death counts, event narratives or sufficient detail about safety follow-up. Taken together, these limitations restrict interpretation to the posted descriptive results and leave important questions about precision, missing data, analysis choices and completeness unresolved.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Home-based Compression Therapy for Arm and Truncal Lymphedema in Breast Cancer — NCT00880022.
- Registry record last updated 2017-12-05; status last verified 2017-11.
- Results first posted 2012-09-13.
- 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.
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18. Record Summary
NCT00880022 is a completed randomized, parallel-group, unmasked study sponsored by Vanderbilt University. It compares Flexitouch System arm compression only with arm, trunk and chest compression. The registry lists enrollment as 47.
The primary outcome is arm volume in millilitres at the end of scheduled treatments on day 30, measured by tape and then calculated. The registry reports a median of 2377 ml, with an interquartile range from 1935 to 2623, for Arm Compression Only. For Arm, Trunck and Chest Compression, it reports a median of 2540 ml, with an interquartile range from 2168 to 3296. Withdrawals were excluded from the primary endpoint population.
The registry does not report a formal primary-endpoint comparison, confidence interval, p-value, detailed missing-data handling or the relationship between enrollment and the group result counts. Safety entries list zero serious and zero other adverse events in each group; death counts are not reported in the registry record.