The Breast Cancer Online Rehabilitation Program: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Breast Cancer Online Rehabilitation Program (NCT02673918), a non-randomized na study. The primary outcome is Recruitment Rate.

2. Clinical Question

The study’s stated purpose was to assess the feasibility and acceptability of a home-based rehabilitation program supported by an online platform before a larger pragmatic trial. This is a feasibility question, rather than a direct test of whether rehabilitation changes health outcomes. Recruitment is relevant because it indicates whether eligible people can be reached and whether they are willing to join a study of this kind. However, recruitment alone cannot establish whether participants used the platform as intended, found it acceptable, or experienced changes in upper-body function.

The registry also lists secondary outcomes concerning motivation for rehabilitation exercises, upper-body mobility, muscle strength, arm circumference, pain, and activities of daily living. Their inclusion describes areas of interest, not evidence that those outcomes improved or worsened. Results for these measures are not reported in the registry record.

3. Trial Design

The registry describes a completed, nonrandomized, parallel study with no masking. It lists an enrollment of 59 and two parts: rehabilitation after surgery for breast cancer, and rehabilitation after radiation for breast cancer. Both parts are described as home-based upper-body rehabilitation with online support. Because there is no randomized allocation and no distinct control intervention described, the parts should not be interpreted as a treatment group and a control group.

The primary objective was to assess feasibility and acceptability before a larger pragmatic trial. The planned test of feasibility took place in 11 municipalities in Denmark. Recruitment was open for 10 weeks for Part 1 and 20 weeks for Part 2. These different recruitment periods matter when interpreting recruitment counts: a count accumulated over a longer period has had more time to accrue. The registry does not provide the recruitment counts needed to assess this in practice.

The record lists the study start as 2016-02 and primary completion as 2016-12, with status completed. It identifies the sponsor as University of British Columbia. The phase is listed as NA. Further details of the study procedures, including the precise timing and delivery of the rehabilitation program, are not reported in the registry record.

Nonrandomized studies can describe the experience of participants who took part, but they do not provide the same protection against selection differences as a randomized comparison. Here, the two parts represent different points in the treatment pathway, not interchangeable groups assigned to competing strategies. Any differences between them could reflect their different circumstances, recruitment periods, or other factors rather than a program effect. The registry record does not report a comparative analysis plan that would address such differences.

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: This was the number of women who were eligible and invited to participate.

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 Recruitment Rate, measured over 10 weeks for part 1 and 20 weeks for part 2.

The primary endpoint is recruitment rate, described as the number and proportion of eligible patients who consented to participate. Its population is women who were eligible and invited. The registry specifies separate recruitment windows: 10 weeks for Part 1 and 20 weeks for Part 2. It does not report the number invited, the number who consented, or the resulting proportions.

Recruitment is used in a feasibility study because it addresses whether a future study can enroll participants from the intended setting. A count indicates how many people joined; a proportion relates that count to the number invited and eligible. These answer different practical questions, so both the numerator and denominator are needed to interpret a recruitment proportion. A total enrollment figure alone cannot supply either the eligible-invited denominator or the consent count for each part.

Recruitment is not a measure of clinical benefit, function, or acceptability by itself. It also does not show whether participants completed exercises or engaged with the online material. Those questions require other measures and their results. The registry lists additional outcomes, but results for them are not reported in the registry record. Consequently, the primary endpoint’s intended role is clear, while its observed performance cannot be evaluated from the available record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What the primary endpoint represents. Recruitment rate is a binary-outcome concept at the level of each invited person: a person either consented to participate or did not. A count of consented participants and a proportion among eligible people invited are complementary summaries. The denominator is essential for a proportion. Without the number eligible and invited, a consent count cannot be interpreted as the fraction of the target group reached. The registry describes this endpoint but does not report its observed counts or proportions.

Why the recruitment windows matter. Part 1 and Part 2 had different stated periods of open recruitment, 10 weeks and 20 weeks respectively. In general, recruitment accumulation depends in part on how long a study is open, so raw counts from unequal periods should not be interpreted as directly comparable rates without suitable context. A rate might also depend on the flow of eligible people and invitation practices. Those details and any rate-based comparison are not reported in the registry record.

What nonrandomized allocation means. General statistical principle: random allocation can make groups more comparable, on average, with respect to measured and unmeasured baseline characteristics. Without randomization, differences between groups can reflect who entered each group, their circumstances, or other factors. This study is described as nonrandomized, and the two parts refer to rehabilitation after surgery and after radiation. They are not a like-for-like control comparison. A simple difference between them would not isolate a program effect, and the registry does not report an adjustment strategy for such a comparison.

Binary outcomes and uncertainty. General statistical principle: a binary outcome records whether an event occurred for each participant. Counts can be presented with the number at risk, while proportions relate event counts to their denominators. Estimates based on limited observations are generally less precise than estimates based on more information. A confidence interval communicates uncertainty around an estimate; it does not guarantee that the true value lies within the particular interval. No confidence interval or recruitment estimate is reported for the primary outcome in the registry record.

Over-dispersion in general. When binary observations are modeled with a simple binomial model, that model assumes a particular relationship between the average event probability and the variability in counts. Over-dispersion means that observed variability is greater than the model expects. If present and ignored, uncertainty can be understated. Whether over-dispersion was considered in any analysis is not reported in the registry record. The primary endpoint is described as counts and proportions, but no model specification is reported.

Adjusted and unadjusted results. General statistical principle: an unadjusted estimate summarizes the observed data without accounting for other measured characteristics. An adjusted estimate uses a statistical model to account for specified covariates, which can be useful when groups differ at baseline. Adjustment cannot guarantee removal of bias from unmeasured factors, particularly in a nonrandomized study. The registry record does not report adjusted or unadjusted estimates, covariates, or a statistical plan for the primary endpoint.

Sample-size planning is not a result. General statistical principle: a sample-size calculation estimates how much information a planned study might need under stated assumptions. It is not an observed outcome and does not measure the probability that a completed study has reached a true conclusion. The planning illustration associated with this study is described as using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. It is explicitly a planning illustration, not the trial’s own design justification. Those assumptions do not establish that the study used that allocation or analysis, and the registry does not report its own sample-size justification or statistical plan.

Interpreting the listed safety counts. General statistical principle: zero observed events does not establish that the underlying event risk is zero. Interpretation depends on the number of people observed, event definitions, how events were collected, and the length of observation. The record lists the numbers at risk and affected for serious and other adverse events, but does not report additional collection or follow-up details. These counts should therefore be read as recorded event summaries rather than as a complete characterization of safety.

What cannot be reconstructed. The registry record does not report the primary recruitment result, analyses of the secondary outcomes, confidence intervals, missing-data methods, analysis populations, or a prespecified statistical plan. It would not be appropriate to infer these details from the enrollment total or the outcome list. Any interpretation beyond the descriptive details recorded would require information not present in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Part 1: Home-based Rehabilitation", "Part 2: Home-based Rehabilitation")
n      <- c(44, 28)
events <- c(35, 24)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Part 1: Home-based Rehabilitation  44  35  79.5  64.7  90.2  65.5  88.8  65.4  88.8
ARM  Part 2: Home-based Rehabilitation  28  24  85.7  67.3  96.0  68.5  94.3  68.3  94.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures and 2 analyses, with recruitment rate identified as the primary outcome and several clinical and behavioral outcomes listed as secondary. Testing many outcomes can increase the chance of at least one apparently unusual result arising by chance. General statistical approaches to this issue include identifying a primary outcome in advance, adjusting for multiple comparisons, or treating secondary findings as exploratory. Which approach, if any, was planned or used is not reported in the registry record. No inferential results are reported for the listed secondary outcomes, so the impact of multiplicity cannot be evaluated.

Missing-data handling is also not reported. General statistical principle: missing measurements can affect interpretation when the participants with observed data differ from those without observed data. The amount and pattern of missingness, the reasons for it, and the method used to handle it are relevant to assessing an estimate. The registry record does not provide these details for recruitment or the listed secondary outcomes.

The analysis populations are not described beyond the primary endpoint’s stated population of eligible women who were invited. It is not reported whether analyses included all enrolled participants, only those with available measurements, or another defined group. No protocol deviations or exclusions are described in the registry record. These gaps limit assessment of whether the outcome definitions, denominators, and analyses were consistent across participants and study parts.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists Part 1 with 35 participants at risk and Part 2 with 24 at risk. In each part, the number affected by serious adverse events is recorded as 0, the number affected by other adverse events is recorded as 0, and deaths are recorded as 0. These are the adverse-event figures reported in the record.

Such entries describe what was recorded under the registry’s event categories; they do not establish that the underlying risk was zero. Zero observed events can still be compatible with uncertainty about uncommon events, and interpretation depends on the period of observation and the way events were solicited, defined, and recorded. Those details are not reported in the registry record. The record also does not provide serious adverse event terms, so no event-specific pattern can be described.

The two groups are study parts, not randomized comparison arms. Their safety entries should not be used to claim that one part was safer than the other or that the rehabilitation program caused or prevented events. The figures are limited descriptive summaries, rather than a comparative safety analysis.

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

The registry record establishes that a feasibility study of individually tailored, online-supported home-based upper-body rehabilitation was completed. It identifies recruitment as the primary outcome and describes a program intended for women after breast cancer surgery, with separate parts after surgery and after radiation. It also lists outcomes related to motivation, function, pain, and daily activities.

What the record does not establish is whether recruitment met a feasibility target, whether participants found the program acceptable, or whether the clinical outcomes changed. The primary recruitment counts and proportions are not reported in the registry record. Nor are results for the secondary outcomes. The enrollment total of 59 does not replace the missing recruitment denominator or indicate how many eligible women consented in each part.

The study is nonrandomized and does not describe a control group. It cannot therefore be read as a randomized test of program efficacy. The two parts occur at different points in care, so a contrast between them would not necessarily reflect an effect of the online rehabilitation program. No comparative efficacy estimate is reported.

The safety entries record zero serious adverse events, zero other adverse events, and zero deaths in both listed groups. These observations should be interpreted within the limits of the event definitions and observation details, which are not reported in the registry record.

In short, the record documents a feasibility-focused study and its intended questions, but does not report the results needed to answer those questions. It supports description of the design and recorded safety counts, not a conclusion about program effectiveness, acceptability, or clinical benefit.

14. Why This Trial Matters Statistically

Feasibility studies address whether a research approach can be carried out before a larger study is attempted. In this case, the registry states that the investigators aimed to assess feasibility and acceptability of an online-supported home rehabilitation program before a future pragmatic trial. Recruitment is an important part of that assessment because it concerns whether eligible people can be invited and enrolled in the intended setting.

Statistically, a recruitment count is not enough to understand recruitment performance. The number eligible and invited, the number who consented, and the period over which recruitment occurred provide different pieces of context. The record states recruitment windows of 10 weeks for Part 1 and 20 weeks for Part 2, but does not report the relevant counts or proportions. This makes the central feasibility outcome impossible to evaluate from the registry record.

The design also illustrates why study structure matters when interpreting results. Nonrandomized parts are not equivalent to randomized comparison groups, especially when they concern different points in care. Statistical comparisons cannot remove this design limitation merely by producing a numerical difference. A future larger study would need clearly defined outcomes, populations, and comparison strategy to support the questions it aims to answer; the registry does not report those details for a future study.

Finally, a listed outcome or a recorded zero is not a complete account of evidence. Results, denominators, uncertainty, missing-data handling, and analysis methods all shape interpretation. The available record is therefore informative about the study’s purpose and structure, while leaving its central feasibility findings unresolved.

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 main limitation for interpreting this trial is that the primary endpoint’s observed recruitment result is not reported in the registry record. Although enrollment is listed as 59, there is no eligible-invited denominator, consent count by study part, or recruitment proportion. It is therefore not possible to determine recruitment performance from the primary endpoint as defined.

The registry lists secondary outcomes but does not report their results or measurement completeness. The number of participants contributing data to each outcome, the timing of assessments, and the handling of missing measurements are not reported in the registry record. This prevents evaluation of the stated clinical and behavioral outcomes.

The nonrandomized design and the distinct post-surgery and post-radiation parts limit any direct comparison between them. Both are described as receiving online-supported home-based rehabilitation, and no randomized control condition is described. The record does not report methods for adjusting comparisons or a statistical analysis plan.

Further limitations include the absence of reported sample-size justification for the study, prespecified analysis details, outcome estimates, and uncertainty intervals. The registry’s planning illustration is not the trial’s own design justification. Safety interpretation is also constrained because details on event definitions, collection, and observation duration are not reported. These omissions do not show that the study was conducted incorrectly; they limit what can be concluded from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The Breast Cancer Online Rehabilitation Program — NCT02673918.
• Registry record last updated 2019-12-13; status last verified 2019-11.
• Results first posted 2019-12-13.
• 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

NCT02673918 is a completed, nonrandomized, parallel feasibility study sponsored by University of British Columbia. The registry lists enrollment of 59, no masking, and a study start of 2016-02 with primary completion in 2016-12. Its stated purpose was to assess feasibility and acceptability of home-based upper-body rehabilitation supported by an online platform before a larger pragmatic trial.

The study had two parts, after breast cancer surgery and after radiation, both described as home-based rehabilitation with online support. Recruitment was open for 10 weeks and 20 weeks, respectively. Recruitment rate was the primary outcome. Results for that endpoint and the listed secondary outcomes are not reported in the registry record.

The registry lists zero serious adverse events, zero other adverse events, and zero deaths in each part. These are descriptive entries and do not establish absence of risk. The record does not report a statistical analysis plan, missing-data approach, or analysis populations.