Developing a Virtual Stress Management Intervention for Spousal/Partnered Caregivers of Solid Tumor Cancer Patients.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Developing a Virtual Stress Management Intervention for Spousal/Partnered Caregivers of Solid Tumor Cancer Patients. (NCT04739696), a randomized na study. The primary outcome is Caregiver: Change in Center for Epidemiological Studies Depression Scale (CESD).

2. Clinical Question

The stated research aim is to investigate whether a stress-management psychoeducation program for employed caregivers can mitigate psychological distress and pathophysiology. The summary also describes an expectation that improving caregiver status will be accompanied by reduced depressive symptoms. These are the study’s aims and expectations, not findings: the registry record does not report outcome results demonstrating whether scores changed or whether groups differed.

There are three study arms, so the clinical question is not simply whether an intervention group differs from a control group. It could involve comparisons between either program and treatment as usual, or between the two program formats. Which contrast is designated as primary, and how repeated measurements or multiple contrasts are handled, is not reported in the registry record. The listed secondary outcomes include caregiver anxiety, perceived stress, health care utilization, adrenal activity, and telomere length, as well as patient depression, anxiety, and perceived stress.

3. Trial Design

This is a randomized, parallel-group trial with double masking recorded in the registry. The registry lists an enrollment of 538. The phase is recorded as NA. The listed sponsor is the University of Colorado, Denver. The study began on 2021-02-05, has a primary completion date of 2025-09-30, and is listed as active, not recruiting.

Three groups are described. Caregiver Control includes biomarker analysis, questionnaire and survey administration, and treatment as usual. Caregiver Intervention includes the same listed assessment activities and PEPRR, described as virtual one-on-one psychoeducation and stress management. Caregiver Self-Directed includes those assessment activities and Pep-Pal, described as web-accessible video modules of the psychoeducation and stress-management intervention. The record does not describe the content of treatment as usual in more detail.

Randomization means that allocation to study groups is intended to occur by chance. In general, this can help make groups comparable at the start of a trial, although it does not guarantee that every characteristic will be balanced. A parallel design assigns participants to a group and follows that group over time, rather than having each participant receive every study condition. The registry’s double-masking label does not identify which people were masked or how masking was maintained; those details are not reported in the registry record.

The outcome schedule spans baseline and follow-up through 12 months. The registry describes the analysis population as varying by time point because of withdrawals or missing data. It does not provide the number assessed at each visit in the registry record described for this study, nor does it report a statistical analysis plan, allocation ratio, or detailed sample-size justification. Those design details should not be inferred from the total enrollment or from the presence of three arms.

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: The protocol enrollment number (i.e., 538) represents the total number of individual participants, not the number of dyads enrolled in the study Caregivers and patients completed baseline questionnaires before dyads were assigned to one of three study groups: Intervention, Self-Directed, or Control. Thirty-five caregiver-patient dyads (70 participants) left the study before finishing the initial questionnaires, therefore they were never assigned to any study group.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The analysis population differs from the overall number due to withdrawals or missing data. At each time point, the number analyzed reflects caregivers with a non-missing CES-D; differences across time points reflect attrition and missing data.

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 Overall Number of Baseline Participants include the total number of individual participants (caregivers and patients) in each Arm. Baseline measures are reported separately for caregivers and for patients, and the number analyzed for each measure reflects only the individuals who provided data for that specific measure.

6. Primary Endpoint

The registry lists the primary outcome as Caregiver: Change in Center for Epidemiological Studies Depression Scale (CESD), measured over Baseline, 3 months, 6 months, 9 months, 12 months follow up.

The primary endpoint is change in caregiver depressive symptoms measured with the Center for Epidemiological Studies Depression Scale (CESD). It is a self-report, 20-item measure of current depressive symptoms. The registry describes its total score as ranging from 0-60 and identifies a score at or above 16 as reflecting significant depressive symptomatology. The endpoint is recorded as a mean score with standard deviation.

Repeated scores can describe the course of reported symptoms over time. Measurements are scheduled at baseline, 3 months, 6 months, 9 months, and 12 months follow-up. In general, following a measure at several time points can show whether the group averages change over the observation period, but a pattern of change alone does not establish that an intervention caused it. A comparison between randomized groups is needed to distinguish intervention-associated differences from changes shared across groups or other influences.

The scale’s threshold gives context for interpreting individual scores, but it does not by itself describe the average change or the difference between groups. The registry record does not report CESD means, standard deviations, changes, confidence intervals, or test results. It therefore does not establish the size, direction, or precision of any primary-outcome difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

For a continuous outcome such as a scale score, a common summary is the mean, which represents the arithmetic average of observed scores in the analyzed group. The registry identifies the primary CESD measure as a mean with standard deviation. In general, the standard deviation describes how spread out individual scores are around the group mean; it is not the same as the uncertainty in the estimated mean. The record does not report the actual means or standard deviations for this endpoint.

What does a change score represent?

Change is a comparison between measurements at different times. In this study, the intended schedule includes baseline, 3 months, 6 months, 9 months, and 12 months follow-up. In general, a change from baseline describes how a score differs from its starting measurement, while a comparison of changes between groups asks whether the groups’ trajectories differ. These are related but not interchangeable quantities. The registry record does not state whether the primary analysis uses change scores, follow-up scores adjusted for baseline, or another repeated-measures approach.

Repeated measures from the same caregiver are statistically related: measurements from one person tend to share features because they come from the same person. General methods for repeated data account for that dependence rather than treating every visit as an unrelated observation. The specific model, covariance structure, and handling of visit effects are not reported in the registry record. It would be inappropriate to assume a particular model from the fact that several visits are scheduled.

How should a group comparison be understood?

Random allocation supports comparisons between assigned groups, but the analysis still needs to define the contrast of interest. In this three-arm study, possible questions include a program group versus treatment as usual, the self-directed program versus treatment as usual, or the two program formats compared with each other. These answer distinct questions. The registry record does not identify a single primary contrast or report a group-comparison estimate.

In general, a confidence interval describes a range of values compatible with the data and the analysis procedure at a stated confidence level. Narrower intervals indicate greater precision, while wider intervals indicate greater uncertainty. A confidence interval can help distinguish an estimate that is precise from one that remains uncertain, but it cannot correct for a poorly specified analysis or missing information. No confidence interval for the primary outcome is reported in the registry record.

In general, a significance test evaluates the data relative to a null hypothesis under a specified statistical model. A p-value is not the probability that the null hypothesis is true, and it does not convey the magnitude of an effect. Interpretation should consider the estimated effect and its uncertainty, not a threshold alone. The registry record does not report a significance test or p-value for the primary CESD outcome.

What can the planning assumptions tell readers?

The record describes a planning illustration based on an 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 planning assumptions, not a description of the trial’s original design rationale. In general, sample-size calculations estimate how many participants may be needed under specified assumptions to detect a target effect with a chosen probability. Such calculations do not show that a study had that probability of detecting an effect after data collection, and they are not observed power.

The record’s planning description distinguishes participant counts per arm from total event counts for time-to-event settings. The primary endpoint in this study is continuous, so the stated general convention for non-time-to-event calculations is participants per arm. However, the registry record does not report a primary-outcome effect estimate or a single comparison to use for such a calculation. It is therefore not possible to interpret a specific planning value or to treat it as evidence about the trial’s observed findings.

Why can over-dispersion matter?

In general, over-dispersion occurs when outcome variability is greater than a statistical model assumes. If the model understates variability, estimated uncertainty can be too small and tests can appear more decisive than warranted. This issue is most directly relevant to count outcomes and particular outcome models; it should not be presumed for a continuous CESD score. The statistical distribution and model used for the primary endpoint are not reported in the registry record.

Statistical methods should be evaluated alongside the analysis population, missing-data procedures, prespecified contrasts, and multiplicity handling. The record gives limited information about the changing number of caregivers analyzed over time, but does not provide the detailed model or procedures needed to reconstruct an analysis. The absence of those details means that readers cannot assess model assumptions, reproduce estimates, or determine whether the reported analysis followed a prespecified plan.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint is measured at multiple scheduled visits, and the study has three arms. This creates several possible ways to compare outcomes: across groups at a particular visit, across time within a group, or between groups’ patterns of change. Testing multiple contrasts or time points can increase the chance of finding at least one apparently unusual result by chance. In general, multiplicity procedures define how that risk is addressed, or a prespecified primary contrast can limit the number of confirmatory tests. The registry record does not report a multiplicity strategy or identify a single primary comparison.

The record’s note that the primary outcome has several categories or time points and was not reduced to one comparison means a single primary contrast is not available in the registry results described. Statistical analysis details, including any hierarchy of outcomes or adjustment across comparisons, are not reported in the registry record. The secondary outcomes cover several caregiver and patient measures, but the record does not state how those outcomes would be treated in confirmatory inference.

For missing data, the registry explains that the analysis population differs from the overall number because of withdrawals or missing data. At each time point, the number analyzed reflects caregivers with a non-missing CES-D, and differences across time points reflect attrition and missing data. This is important because the observed participants at later visits may not represent everyone originally enrolled. In general, the consequences depend on why data are missing and on the analysis method.

The registry record does not report visit-specific counts, reasons for missing observations, an imputation method, sensitivity analyses, or assumptions about the missing-data process. It also does not state whether the primary analysis follows an intention-to-treat principle. Without those details and outcome results, the influence of missingness and the robustness of any estimate cannot be evaluated.

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 0% reporting threshold.

The registry lists serious adverse events, other adverse events, and deaths separately for caregivers and patients in each of the three groups. For the Caregiver Control group, the record lists 76 caregivers and 76 patients at risk, with 0 affected by serious adverse events, 0 affected by other adverse events, and 0 deaths in each listed population. For the Caregiver Intervention group, it lists 79 caregivers and 79 patients at risk, again with 0 affected by serious adverse events, 0 affected by other adverse events, and 0 deaths for each population. The Caregiver Self-Directed group likewise lists 79 caregivers and 79 patients at risk, with 0 in each of those event categories for both populations.

These entries describe the figures recorded for the listed groups and populations. They do not establish that no events occurred outside the recorded categories, reporting period, or people included in these counts. The registry record does not provide event descriptions, follow-up duration for safety, or further detail about how the counts were collected. Zero recorded events should therefore be read as a registry entry, not as a general guarantee of safety or a comparison proving that one group is safer than another. No treatment recommendation follows from these figures.

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

The record describes a randomized study of two stress-management formats and a treatment-as-usual group, with caregiver depressive symptoms as the primary outcome. That information establishes what the study is designed to investigate. It does not establish whether either program changes CESD scores, whether the programs differ from one another, or how large or precise any group difference may be. The registry record does not report primary-outcome estimates or statistical comparisons.

Even when a trial reports a difference, statistical interpretation needs more than a direction of change. In general, the size of an estimate, its confidence interval, the analysis population, and the comparison being made all shape what can be concluded. A change in an average score is also not automatically equivalent to a change in every participant’s symptoms. The registry’s CESD description identifies a score at or above 16 as reflecting significant depressive symptomatology, but no score distributions or participant-level threshold results are reported.

The study’s expectation about reduced depressive symptoms is not a result. Likewise, the planned enrollment of 538 does not indicate how many caregivers contributed data at each follow-up visit; the record notes that analyzed numbers vary because of withdrawals or missing data. The listed adverse-event counts are recorded separately from the efficacy outcome and cannot substitute for CESD findings.

The appropriate interpretation is therefore bounded by the available record: the trial is randomized and parallel, has three described groups, and plans repeated measurement through 12 months. Its primary outcome and some safety counts are described, but numerical outcome results and details of the analysis are absent. No conclusion about efficacy, absence of effect, or clinical importance can be drawn from these registry entries alone.

13. Why This Trial Matters Statistically

Statistically, this trial raises questions about how to compare several intervention formats over repeated follow-up. PEPRR is described as virtual one-on-one support, while Pep-Pal uses self-directed web-accessible video modules; both are contrasted in the design with treatment as usual. A comparison between program formats would address a different question from comparing either format with control. Clear specification of the primary contrast matters because it determines what an effect estimate means.

The repeated CESD schedule is also important. A single follow-up comparison can miss the broader course of scores, while an overall trajectory can obscure differences at particular visits. General repeated-measures methods can account for the relationship between scores from the same caregiver, but the registry record does not state which method was planned or used. Reporting the model, estimate, uncertainty, and analysis population would help readers understand what the data support.

The caregiver and patient populations represented in the safety entries also underscore that the record tracks more than one person per study group. The primary endpoint, however, is caregiver-reported depressive symptoms. Keeping the outcome population and analysis population clear is essential when interpreting results and missingness.

Finally, the record says that the number analyzed changes across visits because of withdrawals or missing data, while reporting no analyses for the primary endpoint. That makes transparent reporting of follow-up counts, missing-data assumptions, and sensitivity checks especially relevant. At present, the statistical significance of the study lies in its questions and design features, not in an outcome conclusion: the registry record contains no primary-result estimates with which to evaluate the intervention comparisons.

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.

A central limitation of the registry information is that no primary-outcome results are reported. There are no CESD summaries by group or visit, no estimated changes or between-group contrasts, and no measures of statistical uncertainty. The record lists 0 analyses and notes that the outcome has several time points rather than one reduced comparison. This prevents an assessment of the magnitude, direction, precision, or statistical compatibility of any result.

The registry notes attrition and missing data but does not give visit-specific analysis counts or describe how missing observations were handled. It also does not report reasons for withdrawal, a missing-data assumption, imputation, or sensitivity analyses. As a result, it is not possible to judge whether those with observed CESD scores at follow-up differ systematically from those without observed scores.

Important analytic details are also not reported in the registry record: the planned primary contrast, the model for repeated measurements, the treatment of baseline scores, multiplicity procedures, and the statistical analysis plan. The registry’s double-masking label does not specify who was masked. The enrollment figure cannot resolve these omissions or establish the number included in each outcome analysis.

The registry lists safety counts but does not provide event descriptions or additional context about the period of observation and ascertainment. The study is listed as active, not recruiting, with a primary completion date of 2025-09-30; the record does not report final primary-outcome findings. These limitations describe what is unavailable in the registry record and do not determine what may appear in other study materials.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Developing a Virtual Stress Management Intervention for Spousal/Partnered Caregivers of Solid Tumor Cancer Patients. — NCT04739696.
• Registry record last updated 2026-09-11; status last verified 2026-09.
• Results first posted 2026-09-11.
• 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

NCT04739696 is a randomized, double-masked, parallel-group study sponsored by the University of Colorado, Denver. It lists enrollment of 538 and is recorded as active, not recruiting. The study compares treatment as usual with PEPRR, a virtual one-on-one psychoeducation and stress-management intervention, and Pep-Pal, a self-directed web-based video-module program.

The primary endpoint is change in caregiver CESD score from baseline through follow-up at 3 months, 6 months, 9 months, and 12 months. The record describes changing analysis populations because of withdrawals or missing data and lists safety counts for caregivers and patients in each group. It does not report primary-outcome results, a single primary comparison, or detailed statistical methods. The record’s purpose and design are described, but statistical conclusions about caregiver depressive-symptom changes cannot be drawn from the reported information.