Yoga in Adult Cancer: A Feasibility Trial: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Yoga in Adult Cancer: A Feasibility Trial (NCT02309112), a randomized na study. The primary outcome is Feasibility of Patient Recruitment to Yoga Intervention.

2. Clinical Question

The trial title and brief summary refer to health-related quality of life and to assessing the appropriateness of yoga during cancer treatment. However, the registered primary outcome is the number of participants eligible for randomization. That distinction matters: a recruitment count can inform whether a future study may be feasible, but it does not by itself quantify a change in quality of life or compare clinical outcomes across groups.

The registry lists 15 participants enrolled and describes randomized assignment in a parallel design. It does not report how many people were screened, how many were eligible, or the primary endpoint count. Enrollment therefore should not be treated as the number eligible for randomization or as evidence that a recruitment target was met. The registered question is narrow and practical: whether recruitment of eligible participants to a yoga study during cancer treatment was feasible over the stated timeframe.

3. Trial Design

The registry describes a randomized, parallel-group feasibility trial, with no masking. It lists three yoga groups: Group A, minimum exposure; Group B, medium exposure; and Group C, maximum exposure. The enrollment is 15. The registry status is completed, with a start date of 2014-04 and primary completion of 2014-08. The phase is listed as NA.

The group descriptions indicate progressively labeled exposure packages, but the registry text for the arm descriptions is incomplete. It describes Group A as including 45-minutes of contact time with a trained yoga professional and a Week 1 introductory session focused on pranayama, or breathing techniques. The Group B and Group C descriptions refer to components of Group A and a 30-minute orientation and safety training concerning yoga dhyana, or meditation techniques, and asana, or physical postures. The full descriptions, including all subsequent activities, are not reported in the registry record. The exact contrast in exposure between groups therefore cannot be reconstructed from the record.

Random allocation is intended to reduce systematic differences between groups, while a parallel design assigns participants to groups that are followed alongside one another. These are general design concepts; details of the allocation sequence, concealment, and implementation are not reported in the registry record. Because masking is listed as none, participants and study personnel were not masked according to the registry description. The consequences of that design feature depend on how outcomes were collected, which is not reported in the registry record.

The record lists two secondary outcomes concerning adherence to the yoga intervention and six outcome measures overall. It does not report outcome analyses. The recruitment endpoint is described over 10 weeks, but the registry does not give the number eligible for randomization. Thus, the design information establishes the study's feasibility focus and group structure, while leaving the realized recruitment process and comparative results unreported.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: No wash out or run-in period was allocated. Recruitment ended on June 30, 2014 and participants were randomized on July 1, 2014.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Male (n=4) and female (n=11) adult patients undergoing conventional treatment in Vancouver, Canada for a cancer diagnosis; who have not participated in yoga the past month.

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.

Population: The sample includes male and female (n=11) adult cancer patients receiving conventional treatment in Vancouver, Canada. Patients undergoing one or more treatments of chemotherapy, radiation, hormone therapy or active surveillance were included in the study. Baseline data collection included all types of treatment for a primary cancer diagnosis.

6. Primary Endpoint

The registry lists the primary outcome as Feasibility of Patient Recruitment to Yoga Intervention, measured over 10 weeks.

The primary endpoint is titled “Feasibility of Patient Recruitment to Yoga Intervention.” It measures the number of participants eligible for randomization to yoga intervention during cancer treatment, with a stated timeframe of 10 weeks. The registry describes the intended population as adult patients undergoing conventional treatment in Vancouver, Canada, for a cancer diagnosis, who had not participated in yoga during the past month.

A recruitment count is used in a feasibility study to describe whether the intended population can be identified and enrolled for a later study. It addresses a practical research question: whether eligible participants can be recruited under the study's conditions. This is a general explanation of feasibility endpoints, not a claim about the outcome of this trial.

The registry lists an enrollment of 15, but that figure is not the reported primary endpoint result. The endpoint asks for the number eligible for randomization; enrollment alone does not establish how many people were assessed, met eligibility criteria, or were eligible during the specified period. The result for the primary endpoint is not reported in the registry record.

The trial title and summary also refer to health-related quality of life. The primary endpoint described in the registry is recruitment feasibility, not a reported change in quality of life. No numerical quality-of-life result or analyzed comparison is reported in the registry record. The endpoint can therefore be interpreted as the study's planned recruitment measure, but its observed value and its relationship to any recruitment target remain unknown from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered design and endpoint determine what can be interpreted statistically. The study is described as randomized and parallel, with three yoga groups and no masking. Its primary endpoint is a count of participants eligible for randomization during a 10-week period. The registry does not report a primary endpoint result or any outcome analyses, so statistical concepts can clarify what such results would mean, but cannot replace the missing estimates.

What does random allocation contribute?

General: random allocation assigns participants using a chance-based process. When implemented properly, it is intended to reduce systematic differences between groups in expectation, including differences that might otherwise influence outcomes. Randomization does not guarantee that groups will be similar in every characteristic, especially in a small feasibility study. The registry identifies the allocation as randomized, but the method for generating the sequence, allocation concealment, and group assignment procedures are not reported in the registry record.

A parallel design means participants are allocated to a group and the groups are considered alongside one another. Here, the registered groups are all described as yoga exposure groups. No non-yoga comparator is listed. Accordingly, even a future comparison among these groups would address contrasts among the listed exposure packages, not a yoga-versus-no-yoga contrast. The registry's arm descriptions are incomplete, so the exact content and separation of the exposure packages cannot be fully characterized.

What does an open-label design mean?

The registry lists masking as none. General: when participants or study personnel know the assigned intervention, expectations and awareness may influence behavior, delivery, or reporting, depending on the outcome. This is especially relevant to outcomes that rely on participant reports or study-personnel judgments. The registry lists adherence outcomes but does not report how they were measured or whether outcome assessors were masked. Therefore, the potential influence of the open-label design on those outcomes cannot be assessed from the record.

How should a recruitment count be understood?

The primary endpoint is a count of people eligible for randomization during the specified timeframe. A count is a descriptive measure. To interpret recruitment feasibility fully, readers would generally need the count eligible, a clear description of the recruitment process, and any planned benchmark or target. General: a count without a denominator can be difficult to interpret as a rate, because it does not show the number approached, screened, or assessed. The registry does not report those recruitment details or the primary endpoint value. No recruitment rate can therefore be interpreted from the registry record.

The listed enrollment of 15 is a separate registry figure. It is not interchangeable with the endpoint count: enrollment does not say how many people were eligible for randomization within the 10-week period, nor does it provide a screening denominator. The record also does not report whether enrollment is the number randomized, the number who started an intervention, or the number included in outcome analyses.

What would a confidence interval or p-value add?

General: a confidence interval expresses the statistical uncertainty around an estimated quantity, conditional on the model and sampling assumptions used. A narrower interval indicates greater precision under those assumptions; a wider interval indicates greater uncertainty. A p-value describes how unusual the observed data would be under a specified null hypothesis and statistical model. It does not measure the probability that an intervention is effective, and it is not a direct measure of practical importance. The registry record reports no primary endpoint estimate, confidence interval, or p-value, so none can be interpreted for recruitment feasibility.

For a feasibility count, descriptive reporting may be central, especially when the purpose is to learn about recruitment processes. Whether an inferential comparison is suitable depends on the question and analysis plan. The registry record does not report a statistical analysis plan, a recruitment target, or a sample-size justification. Those details should not be inferred from the design label or the fact that the study is randomized.

How do the planning assumptions relate to sample size?

The registry's planning description characterizes sample-size calculations as planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. These are assumptions for planning illustrations, not evidence of observed power or a report of the trial's own design rationale. The primary endpoint has fewer than two arms for the relevant outcome, and no primary outcome analysis is reported, so the record does not provide a basis for treating a two-arm illustration as an analysis of recruitment feasibility.

General: sample-size planning evaluates how much information a proposed study might collect under stated assumptions. A planning calculation is conditional on the chosen effect, variability, allocation, and analysis method. It does not show the probability that a completed trial has established a result, and it cannot repair missing outcome data or an unreported analysis. Any sample-size values associated with planning should therefore be read as hypothetical design illustrations, not as observed findings from this feasibility trial.

Why can over-dispersion matter?

General: for count outcomes, a statistical model may assume a particular relationship between the average count and its variability. Over-dispersion occurs when the observed variability is greater than that assumption allows. If a model ignores over-dispersion, uncertainty estimates may be too small, making results appear more precise than they are. No count-model specification, dispersion estimate, or inferential analysis for the recruitment endpoint is reported in the registry record. This general issue does not establish that over-dispersion occurred in this trial.

Overall, the design information supports a description of the study's randomized, parallel-group structure and its feasibility focus. The missing endpoint value and analysis details prevent assessment of recruitment performance, precision, or group differences. Statistical interpretation should remain descriptive of what the registry actually records rather than infer results from enrollment or from the planned design.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures in total and names two secondary outcomes: patient adherence to the yoga intervention and patient adherence rate to the yoga intervention. The primary outcome concerns recruitment feasibility. The registry record does not report results for these outcomes or explain how multiple outcomes were handled in an analysis.

General: when an analysis examines multiple outcomes or performs multiple comparisons, the chance of at least one apparently notable result can increase if each is interpreted without regard to the full set of analyses. A prespecified hierarchy, adjustment method, or emphasis on estimation can help readers understand how multiple results should be interpreted. The registry does not report a multiplicity strategy, so it is not possible to determine whether results were adjusted or prioritized according to a prespecified plan. No outcome analyses are listed.

Missing-data procedures and analysis populations are also not described. The record does not say how missing outcome measurements were handled, whether participants were analyzed according to assigned group, or which participants contributed to each outcome. It does not report loss to follow-up, withdrawals, exclusions after randomization, or reasons for missing data. These details are not reported in the registry record.

These omissions limit assessment of the completeness and potential bias of any outcome estimate, but no estimate is posted to evaluate. The 15 participants enrolled should not be assumed to have complete observations for every outcome or to constitute the analysis population. No imputation method, sensitivity analysis, or population definition can be inferred from the registry's design description.

11. 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 0% reporting threshold.

The registry reports serious and other adverse event counts separately for the three yoga groups. Group A lists 4 participants at risk, with 0 serious adverse events and 0 other adverse events. Group B lists 5 participants at risk, with 0 serious adverse events and 0 other adverse events. Group C lists 4 participants at risk, with 0 serious adverse events and 0 other adverse events.

These are descriptive counts for the groups as recorded. A zero count means that no event in that category is listed among the participants at risk; it does not by itself establish that an event was impossible or that the intervention is free of risk. General: safety interpretation depends on how events were defined, how actively they were sought, the observation period, and whether all participants were followed for the same duration. Those details are not reported in the registry record.

The registry does not provide a statistical comparison of adverse events across groups. It also does not report deaths; death counts are not reported in the registry record. The reported counts should therefore be read as limited descriptive safety information rather than as a precise estimate of comparative safety.

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

The record establishes that a randomized, parallel feasibility trial of yoga exposure groups was completed and that 15 participants were enrolled. It identifies a primary recruitment endpoint: the number eligible for randomization during a 10-week period. It also identifies adherence as a secondary outcome area and records adverse event counts for the three yoga groups.

The most important limit is that the primary endpoint result is not reported in the registry record. The enrollment figure cannot fill that gap because it is not the same measure as the count eligible for randomization. There is no reported recruitment denominator, target, or analysis to show whether recruitment met a feasibility benchmark. The record also lists no outcome analyses, and it provides no numerical result for health-related quality of life or adherence.

As a result, the posted information does not establish whether yoga improved health-related quality of life, whether one exposure group differed from another, or whether recruitment met a prespecified standard. It does not identify a non-yoga comparator, so the listed group structure does not yield a yoga-versus-no-yoga comparison. The incomplete arm descriptions also prevent a full account of how the exposure packages differed.

General: a feasibility trial is usually interpreted in terms of whether study procedures can be carried out and whether a later, larger study appears practicable. A feasibility result is not automatically evidence about clinical benefit. In this case, even the primary recruitment result is unavailable in the registry record, so the feasibility question remains unanswered by the posted outcome data.

The safety counts report zero serious and zero other adverse events in each group among the corresponding participants at risk. These counts are useful as descriptive registry information, but the event definitions and follow-up details are not reported. They should not be treated as proof that there were no risks. Overall, the record supports a description of the study's design and its stated questions, but not a conclusion about the effects of yoga or the success of recruitment.

13. Why This Trial Matters Statistically

This trial is statistically interesting because it separates a feasibility question from a clinical-effect question. The stated primary endpoint is the number of participants eligible for randomization during cancer treatment, while the title and summary refer to health-related quality of life. Those questions require different outcomes and different interpretations. A recruitment count can inform the practicality of running a later study; it is not itself an estimate of a treatment effect on quality of life.

The randomized parallel design and three exposure groups indicate an attempt to compare structured yoga packages, but the registry does not report a primary result or any outcome analysis. The enrollment of 15 is informative as a record of study size, but it does not establish the number eligible, the pace of recruitment, or whether a target was reached. For feasibility research, recruitment denominators and process measures can be as important as the total enrolled.

The record also illustrates why a trial's title should not be used as a substitute for its registered endpoint and results. The stated endpoint identifies what was meant to be measured, whereas the posted outcomes determine what can be interpreted. Since the primary result and quality-of-life results are not reported, neither recruitment performance nor a clinical effect can be quantified from this registry record.

General: this distinction matters when planning later trials. Feasibility information can guide decisions about recruitment procedures, intervention delivery, and outcome measurement, but those decisions require reported results and clear operational definitions. In this record, several such details are absent, including the recruitment denominator, a target, full arm descriptions, and the analysis approach. The study remains relevant as a registered feasibility design, while its posted data are insufficient for a statistical evaluation of the central questions.

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 descriptions are incomplete in several areas that are important for interpretation. The yoga arm descriptions end before all intervention details are given. Although the groups are labeled minimum, medium, and maximum exposure and the text mentions breathing, meditation, physical postures, orientation, and safety training, the full intervention schedules and differences between packages are not reported in the registry record.

The primary endpoint is defined as the number of people eligible for randomization during 10 weeks, but the result is not reported. The registry also does not report the number approached or screened, the number found ineligible, reasons for ineligibility, or a recruitment target. The enrollment of 15 cannot substitute for those details. It is not reported how many participants were assigned to each group for outcome analysis or how enrollment relates to randomization.

The registry lists adherence outcomes, but does not report their measurement instruments, definitions, timing, or results. The trial title and summary refer to health-related quality of life, but no numerical quality-of-life result is reported in the registry record. No statistical analysis plan, sample-size justification, missing-data procedure, or analysis-population definition is reported. The registry lists no outcome analyses, so there are no estimates or uncertainty measures for assessing outcome patterns.

The design is unmasked, and the record does not describe whether outcome assessors were masked or how subjective outcomes were collected. The listed adverse event counts lack event definitions and details about ascertainment and follow-up. Death counts are not reported in the registry record. These limitations restrict interpretation of recruitment, adherence, quality of life, and safety, and they prevent a detailed assessment of bias or precision.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Yoga in Adult Cancer: A Feasibility Trial — NCT02309112.
• Registry record last updated 2015-02-10; status last verified 2014-11.
• Results first posted 2015-02-10.
• 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

The registry describes a completed, randomized, unmasked, parallel feasibility trial of yoga in adults undergoing cancer treatment. The enrollment is 15, and three yoga groups are labeled minimum, medium, and maximum exposure. The primary endpoint is the number of participants eligible for randomization during 10 weeks. Two secondary outcomes concern adherence.

The registry does not report the primary endpoint result, outcome analyses, or numerical results for adherence or health-related quality of life. It lists 0 serious and 0 other adverse events among the participants at risk in each group; death counts are not reported in the registry record. The posted information describes the design and intended questions, but does not establish recruitment performance or a comparative clinical effect.