Telephone-delivered Mindfulness Intervention for African American Dementia Caregivers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Telephone-delivered Mindfulness Intervention for African American Dementia Caregivers (NCT04058886), a na na study. The primary outcome is Number of Participants Attending at Least 6 Telephone Sessions.

2. Clinical Question

3. Trial Design

This is a completed single-group study of a behavioral intervention, listed as Telephone-delivered Mindfulness. The registry record gives an enrollment of 57 and identifies the sponsor as the University of North Carolina, Chapel Hill. The study start date is 2019-11-15, and primary completion is dated 2022-07-04. Its status is COMPLETED. Phase is listed as NA, allocation as NA, and masking as NONE.

The intervention description calls for 8 weekly telephone mindfulness sessions and one retreat. Respite care for the care recipient is provided for the retreat. The primary outcome concerns attendance at least 6 of the 9 sessions, with attendance assessed by an instructor role call at the beginning of each session. This design is intended to assess feasibility and acceptability in the target population, rather than to compare outcomes with a concurrent control group.

The registry record lists 30 outcome measures and 0 analyses. It names changes in caregiver burden, family satisfaction, intolerance of uncertainty, meaning and purpose, mindfulness, anxiety, and anger among the secondary outcomes. Although the record lists enrollment and outcome measures, it does not report observed primary-outcome results, secondary-outcome estimates, or inferential analyses. The two categories used in the adverse-event record do not change the single-group design or create a control comparison. Further information about implementation, follow-up, and the analysis plan is not reported in the registry record.

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: Primary Caregivers and Care Partners were enrolled as dyads. A total of 28 dyads and 1 additional Primary Caregiver were included in the analysis. One Care Partner was not enrolled as planned after the Primary Caregiver had already been enrolled.

Overall Study

Reasons for not completing this period:

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 Number of Participants Attending at Least 6 Telephone Sessions, measured over 8 weeks.

The primary endpoint is the number of participants attending at least 6 telephone sessions. The registry specifies an 8-week timeframe and describes attendance at 8 class sessions and one retreat. An instructor is to take attendance by role call at the beginning of each session. The registry presents attendance as a proxy for intervention acceptability and states that 85% of participants who start the intervention will complete at least 6 of the 9 sessions. That percentage is a stated target in the outcome description, not a reported observation.

Attendance is useful for describing whether participants engage with a scheduled intervention. It captures a practical feature of feasibility: whether people who begin the program continue to attend. It does not measure the quality of participation, the reasons for missed sessions, or whether participants experienced changes in caregiver burden or other outcomes. The endpoint is phrased as a count, while the stated benchmark is a percentage of those who start. Interpreting the benchmark therefore requires the number of participants who started, as well as the number meeting the attendance threshold. Neither observed count is reported in the registry record. The endpoint results and the method used to handle incomplete attendance information are also not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary outcome count?

The primary endpoint is a participant-level attendance threshold. Each participant can be classified according to whether they attended at least 6 of the 9 intervention sessions; the endpoint then counts participants meeting that condition. The registry’s stated target is expressed as 85% of participants who start the intervention meeting the threshold. These are related but distinct summaries: a count describes how many participants met the rule, while a proportion relates that count to a defined denominator. The record does not give the observed count, the number who started, or an estimated proportion.

As a general statistical point, defining the analysis population and denominator is essential when reporting a proportion. For this attendance measure, using everyone enrolled as the denominator could differ from using only those who started, which is the group specified in the registry’s target statement. The appropriate interpretation depends on the outcome definition and the information available about starts and follow-up. Those observed details are not reported in the registry record.

What can a confidence interval add?

As a general explanation, a confidence interval expresses the statistical uncertainty around an estimate. For a proportion, it can show how compatible the observed data are with a range of underlying values, given the method used. An interval is not a guarantee that the true value lies within its endpoints, and it does not correct weaknesses in study design or missing data. No attendance estimate or confidence interval is reported in the registry record, so the precision of the primary result cannot be assessed from it.

A count alone would also need context. A larger count can reflect a larger group starting the intervention rather than a higher likelihood of meeting the attendance threshold. This is why the registry’s target is framed in relation to participants who start. Reporting both the count and a clearly defined denominator would allow readers to see the scale of participation and the rate of meeting the attendance rule, while an uncertainty interval could communicate estimation precision. These are general reporting considerations, not analyses reported for this study.

What does the single-group design allow?

The registry identifies a single-group, uncontrolled design, with allocation listed as NA. There is no randomized control group in the record. As a general statistical point, a one-group feasibility study can describe attendance and observed measurements within the participants studied. It cannot estimate a randomized between-group contrast. If a measure is collected at baseline and again later, a change over time can be described, but without a comparator that change cannot be attributed uniquely to the intervention.

The registry lists secondary outcomes as changes from baseline, but it does not report the actual values or analyses. The record also lists 30 outcome measures and 0 analyses. Without the results and analysis details, readers cannot determine whether the recorded measures were analyzed, how change was calculated, or how uncertainty was quantified. A planned outcome title should not be mistaken for a finding.

How should planning illustrations be understood?

As a general statistical point, sample-size planning uses assumptions about the outcome, the effect a future study aims to detect, the significance level, allocation, and analysis method. Planning estimates are design illustrations, not observations from participants, and are not observed power. The planning assumptions described for the illustrations use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of an observed effect. The record also distinguishes total events for time-to-event planning from participants per arm for other planning outputs.

Those assumptions do not describe the registered single-group design as a like-for-like two-arm comparison. The registry record does not report an observed effect value, a trial-specific sample-size justification, or the analysis that would connect the planning assumptions to this study’s primary attendance endpoint. No planning output should therefore be read as an observed study result or as evidence that the study had a particular probability of detecting an effect. The registry record does not report the protocol’s sample-size rationale or statistical plan.

What statistical details are not available?

The registry record does not report a specific statistical test, model, adjustment strategy, or method for handling missing values for the primary or secondary outcomes. It does not report interim analyses or define analysis populations. These details matter in general because the analysis choices determine how incomplete records, repeated measures, and multiple outcomes are handled. Without them, readers should not infer a particular method from the outcome names or study design.

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("Primary Caregivers", "Care Partners")
n      <- c(29, 28)
events <- c(27, 23)
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  Primary Caregivers  29  27  93.1  77.2  99.2  78.0  98.1  77.9  97.9
ARM  Care Partners  28  23  82.1  63.1  93.9  64.4  92.1  64.2  92.0

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 30 outcome measures, including secondary measures of change from baseline in caregiver burden, family satisfaction, prospective and inhibitory intolerance of uncertainty, meaning and purpose, mindfulness, anxiety, and anger. It lists 0 analyses. The presence of multiple outcomes raises a general multiplicity issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase if each is considered separately. Approaches such as prespecifying a primary outcome or adjusting for multiple comparisons can address different aspects of this issue, but no multiplicity strategy is reported in the registry record. The listed outcome measures alone do not show which analyses were performed or how any results should be interpreted.

Missing-data methods are not reported in the registry record. In particular, the record does not describe how missing attendance information, missed follow-up assessments, or incomplete questionnaires would be treated. As a general statistical point, missingness can affect both the denominator and the interpretation of change over time; an analysis should make clear which participants contribute to each outcome and what assumptions are made about missing values. No such methods or outcome-specific analysis populations are reported.

The registry record also does not report an analysis population definition, such as whether analyses include all enrolled participants, only intervention starters, or only participants with available follow-up data. The primary target refers to participants who start the intervention, but that wording does not supply an analysis rule for all outcomes. Interim analyses, a statistical analysis plan, and a correction for multiple testing are not reported in the registry record. These omissions limit assessment of how the planned outcomes were handled and how much confidence to place in any outcome claims; the record does not provide analysis results to evaluate.

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.

Most frequent non-serious adverse event terms

The adverse-event record separates Primary Caregivers and Care Partners. For Primary Caregivers, the record lists 0 serious events among 29 at risk, 2 other events among 29 at risk, and 0 deaths. For Care Partners, it lists 0 serious events among 28 at risk, 4 other events among 28 at risk, and 0 deaths. These are the posted counts; they should not be combined into a treatment-versus-control comparison. The study is single-group and uncontrolled, and these categories are not a like-for-like control comparison.

The counts do not establish whether an event was caused by the intervention. The registry record does not report event definitions, the time period used for collection, how events were monitored, or causal assessments. The list of top serious-event terms is empty, so no serious-event terms are reported in the registry record. A zero count in the posted serious-event field means no serious event is recorded for that category in this record; it does not by itself establish the absence of all possible harms. The non-serious event counts are also descriptive and should be interpreted within the limits of the reporting information available.

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

This study addresses a practical question about whether rural African American dementia caregivers and care partners attend a telephone-delivered mindfulness program. Its primary outcome uses attendance at a defined threshold as a proxy for acceptability, and the registry description states an 85% target among participants who start. The record does not report the observed attendance count or whether the target was met. It therefore does not establish the level of acceptability observed in the study.

The record lists outcomes that could describe caregiver burden, family satisfaction, uncertainty, meaning and purpose, mindfulness, anxiety, and anger. It does not report results for these measures. The outcome names do not show whether scores changed, how large any changes were, or whether they were estimated precisely. They also do not demonstrate that a change was caused by the intervention.

As a general statistical point, feasibility evidence and evidence of comparative effectiveness answer different questions. Attendance can provide information about participation in a program, but it is not itself a measure of improvement in caregiver health or wellbeing. A single-group uncontrolled design can document what happened among participants, but it cannot compare their outcomes with what would have happened under a control condition. Even if before-and-after changes were reported, the design would not by itself separate an intervention effect from other changes over time.

The adverse-event record reports no serious events or deaths in either of its categories, and it reports other events in both. These counts do not provide a causal safety assessment, because event definitions, collection details, and attribution are not reported. Overall, the registry record describes the study question, intervention, outcomes, and selected safety counts, but does not provide the primary or secondary outcome results needed to characterize what participants experienced. No conclusion about treatment benefit, lack of benefit, or comparative safety follows from the information reported.

14. Why This Trial Matters Statistically

Feasibility studies can answer operational questions that are important before a larger evaluation: whether a program can be delivered to its intended population and whether participants engage with it. This study focuses on rural African American dementia caregivers and care partners, and uses attendance as an acceptability proxy. The format—weekly telephone sessions plus a retreat—makes attendance a directly relevant process measure for describing participation in the planned program.

The registry record also illustrates why a clearly defined endpoint and its denominator matter. The endpoint counts participants who attend at least 6 sessions, while the stated target is a percentage of participants who start. Enrollment alone does not supply the number who started or the number who met the attendance rule. Reporting those values, along with uncertainty, would help readers distinguish the scale of enrollment from the proportion completing the attendance threshold.

Statistically, the study’s single-group uncontrolled design should guide the kinds of conclusions drawn. Such a design can be informative about implementation and can support descriptive measurement, but it does not produce a randomized comparison. The registry’s secondary outcomes span several domains, so a clear analysis plan and transparent reporting of missing data and multiplicity would also be important for interpreting results. Those methods and results are not reported in the registry record. The study is relevant as a feasibility question, but its record does not establish clinical 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 main limitation for interpreting this record is that it does not report the observed primary attendance result. The enrollment of 57 does not indicate how many participants started the intervention, attended at least 6 sessions, or completed follow-up. The registry describes an 85% target, but does not state whether it was reached or provide an uncertainty estimate. Without these details, the feasibility outcome cannot be evaluated from the record.

The single-group uncontrolled design provides no concurrent comparison. Changes in secondary outcomes, even if available, could not be attributed uniquely to the intervention on the basis of this design alone. The registry does not report the secondary-outcome results, a statistical analysis plan, methods for missing data, analysis populations, or a multiplicity strategy. The record also does not report a trial-specific sample-size justification or interim analyses.

Other details needed for a fuller assessment are not reported in the registry record, including reasons for nonattendance, outcome completion, intervention fidelity, and the timing and completeness of follow-up assessments. The adverse-event record lacks event definitions, collection details, and causal assessments. The target population is described as rural African American caregivers and care partners of people with moderate to severe dementia, with severity defined by the caregiver; the record does not establish how findings would apply to populations beyond that description. These are limitations of what can be concluded from the registry record, not evidence that any particular outcome did or did not occur.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Telephone-delivered Mindfulness Intervention for African American Dementia Caregivers — NCT04058886.
• Registry record last updated 2023-07-19; status last verified 2023-07.
• Results first posted 2023-07-19.
• 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

NCT04058886 is a completed single-group, uncontrolled study sponsored by the University of North Carolina, Chapel Hill. It evaluates telephone-delivered mindfulness training for rural African American dementia caregivers and care partners. The intervention description specifies 8 weekly telephone sessions and one retreat, with respite care provided for the care recipient during the retreat.

The primary outcome is the number of participants attending at least 6 sessions, with an 8-week timeframe; the description states an 85% attendance target among participants who start. Enrollment is listed as 57. The registry record lists 30 outcome measures and 0 analyses, but does not report observed primary or secondary outcome results. Its adverse-event figures list zero serious events and zero deaths in both categories, alongside non-serious events. The record does not report a comparator, statistical analysis plan, missing-data methods, or a causal safety assessment.