Compassion Meditation for Older Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Compassion Meditation for Older Adults (NCT03964246), a non-randomized na study. The primary outcome is Enrollment Rate.

2. Clinical Question

The study’s stated focus was feasibility of compassion training, rather than a definitive test of clinical benefit. Its rationale was that some older Veterans experiencing distress may under-use mental-health services because of perceived stigma associated with symptom-focused interventions. The registry describes a possible future research direction, not evidence that the intervention improves symptoms or broadens acceptance. Anxiety and depressive symptoms are part of the eligibility context, while social connection, depression and anxiety, satisfaction with life, positive emotions, and inflammatory biomarkers appear among the secondary outcomes. Results for these measures are not reported in the registry record.

3. Trial Design

This was a completed, parallel-group, non-randomized study with no masking. The registry lists an enrollment of 25 participants and identifies the sponsor as the VA Office of Research and Development. The study started on 2019-10-01, had a primary completion date of 2022-04-30, and is marked completed. Its phase is listed as NA.

The two programs were each described as 10-week group interventions. The Compassion Meditation group received compassion meditation training; the psychoeducational healthy-aging group reviewed and discussed videos on healthy-aging topics. The record does not explain how participants were assigned to the groups, whether assignment depended on participant or clinician choice, or whether the groups were recruited or delivered in otherwise comparable circumstances. Those details are not reported in the registry record.

Non-randomized allocation matters for interpretation. Differences between groups could reflect pre-existing differences in participants, care, access, or other factors, as well as any differences associated with the programs. The record itself cautions that the arms are not a like-for-like control comparison. Accordingly, the design can describe feasibility and outcomes observed in the study, but the design information alone does not support a causal comparison between programs.

The primary endpoint is an enrollment-rate measure with a timeframe of 36 months. The registry also lists nine outcome measures, including social connection, inflammatory biomarkers, depression and anxiety, satisfaction with life, and positive emotions. The record does not provide their numerical results, assessment schedules beyond the named baseline-to-post-intervention changes, or a detailed analysis plan. It does not describe an interim-analysis plan or a sample-size justification.

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: 25 participants enrolled (signed the ICF) and were assigned to the CM intervention, but 3 of the 25 withdrew from the study before the first intervention session. Thus 22 participants started the CM intervention (attended at least first intervention session)

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants who were successfully contacted and verbally consented to formal telephone screening

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: Due to unanticipated COVID social distancing restrictions, we had to switch to a telehealth format with which the available videos for the psychoeducational sessions was too dry for a credible attention control. We began identifying more engaging videos from other sources, but with other COVID-related delays we were unable to complete this process during the study period. 25 participants enrolled and were assigned to the CM intervention, but 3 withdrew before the first intervention session.

6. Primary Endpoint

The registry lists the primary outcome as Enrollment Rate, measured over 36 months.

The primary endpoint is titled Enrollment Rate. Its description defines the measure as the proportion of consented subjects among all screened and eligible patients. The population field, however, describes participants who were successfully contacted and verbally consented to formal telephone screening. The endpoint is also assigned the unit Participants and a count-of-participants parameter. These descriptions do not fully clarify the precise numerator and denominator used in the analysis. That operational detail is not reported in the registry record.

Enrollment measures are used in feasibility studies to describe whether eligible people can be contacted and are willing to take part in a study. They address recruitment processes, rather than whether an intervention changes a health outcome. In this study, the stated rationale concerns the acceptability and feasibility of a strengths-based compassion training approach for older Veterans who may be reluctant to use symptom-focused services.

The endpoint has a timeframe of 36 months. The registry record does not report an enrollment-rate estimate, the number screened and eligible, or the number who consented within the endpoint definition. Although total enrollment is listed as 25, that figure does not by itself provide the numerator or denominator needed to evaluate the stated proportion. Therefore, the endpoint’s observed value and its precision cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the question being estimated. Here, the primary endpoint is called Enrollment Rate and is described as a proportion. A proportion requires a clearly specified numerator and denominator. The record’s description refers to consented subjects among screened and eligible patients, while its population field refers to people contacted and verbally consenting to formal telephone screening. The unit and parameter are described as participants and a count of participants. Without further detail, it is not possible to determine exactly how these descriptions were implemented in the analysis.

What does a confidence interval add?

In general, a confidence interval expresses the statistical uncertainty around an estimated quantity. A narrow interval indicates greater precision under the model used; a wide interval indicates less precision. It does not resolve bias from non-randomized allocation, unclear endpoint definitions, or incomplete outcome reporting. No enrollment estimate or confidence interval is reported in the registry record, so precision cannot be assessed for the primary endpoint.

Why does allocation matter?

Random allocation is one way to make comparison groups similar, on average, with respect to factors known and unknown at the time of assignment. This study was non-randomized. As a result, differences between its groups could reflect how participants entered or were assigned to them, as well as differences associated with the programs. Adjustment for measured characteristics can sometimes address some observed imbalance, but it cannot guarantee removal of all confounding. The registry does not report a comparative analysis or adjustment strategy. The record cautions that the groups are not a like-for-like control comparison.

Masking was listed as none. In general, masking can reduce the influence of expectations on certain aspects of treatment delivery, outcome assessment, or reporting. Its absence can be particularly relevant for outcomes based on self-report, such as social connection, mood, satisfaction with life, and positive emotions. That general concern does not establish that any specific bias occurred in this study. The registry does not describe who assessed outcomes or whether outcome assessors were independent of intervention delivery.

How should planning calculations be read?

General sample-size planning calculations ask how much information a future study might need to detect a specified effect under stated assumptions. The planning description associated with this record uses a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It defines the effect for planning as a stated fraction of the observed effect. These are calculation assumptions, not a description of the study’s actual allocation or analysis.

The planning description says that non-time-to-event outputs are expressed as participants per arm and that time-to-event outputs are expressed as a total number of events. These are planning illustrations, not observed sample sizes or observed power. The registry record does not report the observed effect estimate or the resulting planning values, so their numerical implications cannot be assessed. The record also does not report that these assumptions were part of the trial’s own design or sample-size justification.

What does over-dispersion mean in general?

For count outcomes, a simple model may assume that variability follows a particular relationship to the mean. Over-dispersion means the observed variability is greater than that assumption allows. If ignored, uncertainty may be understated and statistical evidence may appear more decisive than warranted. This is a general concept; the registry does not report a count-outcome model, a dispersion estimate, or an over-dispersion assessment for this study.

The record lists nine outcome measures and zero analysis records. It does not report model specifications, handling of repeated measurements, covariate adjustment, missing-data methods, or a statistical analysis plan. The record also does not report interim analyses. These absences limit assessment of how outcomes were estimated, how uncertainty was quantified, and whether analytic decisions were prespecified. The outcome titles and design fields alone are not a substitute for those details.

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("Compassion Meditation (CM) Intervention Group")
n      <- c(33)
events <- c(25)
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  Compassion Meditation (CM) Intervention Group  33  25  75.8  57.7  88.9  59.0  87.2  58.8  87.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists nine outcome measures. The named secondary outcomes include change in social connection, mean and standard deviation of change scores for inflammatory biomarkers, change in depression and anxiety, satisfaction with life, and change in positive emotions. The primary endpoint is enrollment rate. The registry does not report which outcomes were formally tested, how many comparisons were made, or whether any multiplicity adjustment was planned or used. It is therefore not possible to assess how the risk of chance findings across multiple analyses was handled.

There are no analysis records listed. The registry does not report an analysis population, such as whether analyses included all enrolled participants, only participants who completed an intervention, or participants with available measurements at particular visits. It also does not report how withdrawals, missed assessments, or incomplete biomarker measurements were handled. The number of participants with data for each outcome and time point is not reported in the registry record.

Missing-data methods matter because an analysis based only on available observations can be misleading if missingness is related to participants’ outcomes or circumstances. General approaches make different assumptions about why data are missing; no approach can be evaluated without knowing the method and the extent and pattern of missingness. The registry does not provide those details.

The absence of analysis and missing-data information does not demonstrate that no analyses were conducted. It means the registry record does not document them, limiting reproducibility and interpretation of the outcome results.

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 adverse-event record lists the Compassion Meditation group with 22 participants at risk. It records zero serious adverse events, zero other adverse events, and zero deaths for that group. For the psychoeducational healthy-aging group, the record lists zero participants at risk and zero for each of those event counts.

These entries should be read with their denominators. The zero risk count for the psychoeducational group means its event counts cannot be interpreted as evidence of no events among participants who received that program. The registry record does not explain why no participants are listed at risk for that group. The listed zero counts for the Compassion Meditation group describe the recorded events during the registry’s reporting, but do not prove that no harms can occur or that all possible harms were captured.

The record does not provide event definitions, collection procedures, observation duration for safety, or details about whether events were assessed for relationship to an intervention. It also does not list serious adverse-event terms. Therefore, these figures offer only a limited description of the recorded safety data, not a complete comparative safety assessment.

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

The study was designed to examine feasibility of compassion meditation training for older Veterans with anxiety or depressive symptoms. The registry identifies a primary enrollment-rate endpoint and lists a total enrollment of 25. It does not report the endpoint result, so the recorded enrollment figure alone cannot establish the proportion of screened and eligible patients who consented or whether recruitment was feasible by the study’s criteria.

The record also names psychosocial and inflammatory outcomes, but does not report their numerical findings. It therefore cannot establish whether social connection, depression or anxiety, satisfaction with life, positive emotions, or inflammatory biomarkers changed. Outcome names describe what was planned or registered; they are not results. The registry’s completed status does not fill in the missing estimates or analyses.

The non-randomized design further limits causal interpretation. The two groups cannot be assumed to be comparable, and an observed difference, if available elsewhere, would not automatically show that the program caused it. No adjustment strategy or comparative analysis is reported in the registry record.

For these reasons, the record does not show that compassion meditation works or does not work, nor does it establish superiority or equivalence relative to healthy-aging psychoeducation. It also does not provide enough safety information to conclude that either program is risk-free. The defensible interpretation is narrower: the record describes a completed feasibility study, its interventions and registered outcomes, and limited event counts, while leaving the principal outcome estimates and analytic details unreported.

14. Why This Trial Matters Statistically

Feasibility studies address questions that precede a definitive evaluation of clinical effects. In this case, enrollment is especially relevant because the study rationale concerns barriers older Veterans may face in using mental-health services. A clearly reported enrollment measure can help readers understand whether eligible people can be reached and whether they are willing to participate. Here, the endpoint definition is not fully clarified and its result is not reported, so that central feasibility question remains unanswered in the registry record.

The design also illustrates why a comparison group is not automatically a control group. A parallel structure permits programs to be delivered in separate groups, but non-randomized allocation can leave systematic differences between participants. Without a documented allocation process and appropriate analysis, comparisons may be descriptive rather than causal. The record explicitly warns against treating these arms as a like-for-like comparison.

The range of registered outcomes points to a multidimensional research question: feasibility alongside social, emotional, and inflammatory measures. Statistical interpretation requires more than outcome labels. Estimates, uncertainty, analysis populations, missing-data handling, and multiplicity procedures are needed to judge how informative each result is. Those details are not reported in the registry record.

Finally, a completed study can still have an incomplete public statistical record. Clear endpoint definitions and transparent reporting of results would help readers distinguish recruitment performance from clinical outcomes and evaluate the limits of the evidence. In this case, the available record supports understanding the study’s aims and design, but not drawing conclusions about outcome effects.

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 primary endpoint’s wording leaves an operational ambiguity. Its description refers to a proportion of consented subjects among screened and eligible patients, while its population field refers to people who were contacted and verbally consented to formal telephone screening. The unit and parameter are expressed as a participant count. The registry does not explain how these descriptions relate to one another or identify the analyzed numerator and denominator.

The non-randomized allocation and absence of masking limit causal interpretation and may be relevant to outcomes that depend on participant report. The registry cautions that the arms are not a like-for-like control comparison, but does not describe allocation procedures, baseline group characteristics, assessor roles, or adjustment methods. These details are not reported in the registry record.

Although the study is marked completed and lists enrollment of 25, the record does not provide primary or secondary outcome estimates, confidence intervals, p-values, or participant counts by outcome. It lists nine outcome measures but no analysis records. Missing-data handling, analysis populations, multiplicity plans, and a sample-size justification are not reported.

The safety record has a zero risk count for the psychoeducational group, preventing interpretation of its zero event entries as a rate among exposed participants. The registry also does not specify event collection or follow-up procedures. These limitations constrain conclusions about feasibility, comparative outcomes, precision, and safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Compassion Meditation for Older Adults — NCT03964246.
• Registry record last updated 2024-07-05; status last verified 2024-03.
• Results first posted 2024-07-05.
• 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

NCT03964246 is a completed, non-randomized, parallel-group study of compassion meditation and healthy-aging psychoeducation for older Veterans with anxiety or mood disorders. The study lists enrollment of 25, no masking, and a 36-month timeframe for its primary enrollment-rate endpoint. Each intervention is described as a 10-week group program.

The primary endpoint concerns enrollment, while registered secondary outcomes include social connection, inflammatory biomarkers, depression and anxiety, satisfaction with life, and positive emotions. The record lists nine outcome measures and zero analysis records. It does not report outcome estimates, analysis details, or the primary endpoint result. The adverse-event entries list zero events for the Compassion Meditation group among 22 at risk and zero participants at risk in the psychoeducational group. The available record supports a description of study aims and design, but not conclusions about outcome effects or comparative safety.