Remote-delivered MBCT for SCAD Survivors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Remote-delivered MBCT for SCAD Survivors (NCT04983680), a na phase 1 study. The primary outcome is Feasibility of Enrollment: Percent of Participants Enrolled.

2. Clinical Question

3. Trial Design

This was a completed phase 1, open pilot trial of remote-delivered MBCT for SCAD survivors. The registry describes a single-group model, no masking, and no allocation to a separate control group. It lists Massachusetts General Hospital as the sponsor. The registry dates the study start to 2021-11-04 and primary completion to 2022-06-04. The enrollment field reports 19 participants.

The intervention was group MBCT, described as an 8-week program with 1.5-hour weekly sessions. The registry summary says participants were to complete self-report surveys and actigraphy before and after the intervention. Those procedures were intended to support assessments of feasibility and acceptability, alongside exploratory assessment of psychological and behavioral variables and their inter-correlations. The intervention description says the program was adapted for SCAD survivors and delivered by group videoconferencing.

The registry summary describes a proposed N=16, while the enrollment field reports 19. These entries describe different aspects of the record; the registry does not explain the difference. The primary-outcome description also says that the number analyzed for the enrollment variable was n=20, because one person who screened eligible refused to enroll, although the trial-start figure is 19. The record does not clarify how that analyzed count was constructed beyond this explanation.

Because this is a single-group pilot without a control arm, it can describe recruitment and outcomes among participants, but it cannot isolate intervention effects from other explanations for change over time. A statistical analysis plan, detailed eligibility criteria, and specific analytic procedures are 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: The number of participants analyzed for this variable (n=20) is higher than the number who started the trial (n=19), because one person who screened eligible refused to enroll.

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 Feasibility of Enrollment: Percent of Participants Enrolled, measured over 7 months.

The primary endpoint is named “Feasibility of Enrollment: Percent of Participants Enrolled.” Its stated purpose is to assess whether more than 70% of eligible patients enroll, over a timeframe of 7 months. Enrollment feasibility is a process outcome: it concerns whether the study can recruit eligible people, rather than whether a clinical or psychological measure improves.

This kind of endpoint is relevant to a pilot because recruitment is necessary for a larger study to be conducted. A prespecified threshold can make the feasibility question concrete, provided the eligible-patient denominator and the enrolled numerator are defined and reported. Here, the registry's outcome description states the threshold but does not give the observed percentage or the underlying count of eligible patients. It also describes the primary measure as a participant count and says n=20 were analyzed, while the enrollment field says 19 participants started the trial. The record explains that one eligible person refused to enroll, but does not report the number of all eligible patients.

As a result, the primary endpoint's criterion can be identified, but its observed value and whether it met the criterion cannot be determined from the registry record. The outcome title and feasibility description also use different forms of measurement—percent enrolled and count of participants—which should be kept in mind when interpreting the entry.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

A single-group study follows participants receiving an intervention without a separate control group. If measurements are taken before and after the intervention, the observed within-person change describes how scores differed across those assessment times. It does not, on its own, identify what would have happened to the same participants without the intervention. Natural change over time, concurrent care or events, expectations, and measurement variability can also contribute to a before-and-after difference. This is a general limitation of single-group comparisons, not a finding about what caused any change in this trial.

The registry identifies this study as single-group, with no masking and allocation listed as not applicable. Thus, it should not be read as a randomized comparison. The registry summary mentions surveys and actigraphy before and after intervention, but the numerical results and analysis methods for such comparisons are not reported in the registry record.

How should feasibility proportions be interpreted?

A recruitment proportion uses an eligible-patient denominator and an enrolled-participant numerator. Both need clear definitions and a consistent observation window to make the estimate interpretable. A feasibility threshold can then be compared with the observed proportion. In this record, the threshold is >70% and the stated timeframe is 7 months. The registry does not report the complete eligible denominator or the observed proportion, so the threshold cannot be evaluated from the posted entry.

The outcome title refers to a percentage, while the measurement description identifies a count of participants. The record also says n=20 were analyzed for the enrollment variable and notes one eligible person refused, while the enrollment field reports 19 participants. These details should not be combined into a percentage without the necessary definitions and counts. The record does not clarify the relationship between the count, the percentage title, and the eligibility denominator.

What would an uncertainty interval mean?

In general, a confidence interval expresses the range of values reasonably compatible with an estimate under a specified statistical model and sampling assumptions. For a proportion, an interval can communicate that the estimate may be imprecise when the available sample is limited. The interval does not establish that the true value has a particular probability of lying within the calculated range, and it does not address bias from the way participants were recruited or measured. No confidence interval for the primary endpoint is reported in the registry record.

Why do analysis methods matter?

For repeated measurements, the statistical method should reflect that observations from the same participant are related. A paired analysis accounts for that within-person relationship; treating repeated observations as if they came from unrelated people would not represent the data structure. For outcomes measured at several time points or across multiple scales, analysis choices also determine which contrasts are estimated and how uncertainty is represented. The record does not report the specific model, test, covariate adjustment, handling of repeated measures, or statistical analysis plan.

For count outcomes, the appropriate model depends on how events are generated and on the distribution of counts. If counts vary more than a simple model expects, over-dispersion can make standard errors too small and confidence intervals too narrow; methods that account for over-dispersion may be needed. This is a general statistical point. It does not establish that this trial had a count outcome with over-dispersion, and the registry record does not report such an analysis.

How should exploratory outcomes be viewed?

The registry lists multiple psychological outcomes and describes exploratory assessment of behavioral variables and inter-correlations. When many outcomes or comparisons are considered, the chance of at least one apparently unusual result can increase if each is interpreted without regard to multiplicity. Some studies address this by defining a primary outcome in advance, adjusting for multiple testing, or treating secondary analyses as exploratory and emphasizing estimation and uncertainty rather than isolated significance tests. The registry record does not report whether any multiplicity approach was planned or used, nor does it provide numerical results for the listed outcomes.

The registry lists 24 outcome measures and 0 analyses. The number of listed measures indicates breadth of registered measurement, not how many outcomes were successfully collected or analyzed. A zero in the analyses field does not substitute for a complete description of the statistical methods and should not be used to infer which calculations were or were not performed outside the registry entry.

What can planning calculations tell readers?

Sample-size planning calculations illustrate how many participants might be needed under specified assumptions to detect an effect of a chosen size with a chosen statistical procedure. They depend on assumptions about the effect, variability, allocation, significance level, and design. Such calculations are planning illustrations, not results from the enrolled participants and not observed power. The assumptions described for the planning illustration include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a fraction of an observed effect. Those assumptions describe a hypothetical planning setup; they do not turn this single-group study into a two-arm comparison or establish that these were the trial's design assumptions. The registry record does not report a trial-specific statistical plan or sample-size justification.

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("Mindfulness-Based Cognitive Therapy")
n      <- c(20)
events <- c(19)
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  Mindfulness-Based Cognitive Therapy  20  19  95.0  75.1  99.9  76.4  99.1  76.2  98.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists several secondary psychological outcomes, including fear of recurrence, cognitive de-centering, distress tolerance, attention regulation, non-judgmental body awareness, interoceptive bias, intolerance of uncertainty, and cardiac anxiety. The study summary describes these and behavioral variables as exploratory outcomes, with inter-correlations also of interest. Considering multiple outcomes creates a multiplicity issue: if many comparisons are tested, some results may appear noteworthy by chance even when there is no corresponding underlying effect. This is a general statistical concern, not a claim that a particular result in this study is false.

The registry record does not report whether analyses were adjusted for multiplicity, how exploratory findings were prioritized, or whether a statistical analysis plan specified a hierarchy of outcomes. It also does not report numerical estimates or uncertainty measures for these outcomes. Consequently, readers cannot assess the size or precision of any exploratory change from the registry entry.

Missing-data methods and analysis populations are also not described. The summary says participants were asked to complete surveys and actigraphy before and after the intervention, but does not report completion, missingness, exclusions, or how incomplete measurements were handled. The primary-outcome description says n=20 were analyzed for the enrollment variable and explains that one eligible person refused to enroll, while the enrollment field reports 19 participants. The registry does not provide a broader account of analysis populations or reconcile these entries. There is not enough information to infer whether all participants contributed to each outcome or how missing values affected analyses.

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 registry's adverse-event entry lists the MBCT group with 19 at risk for serious adverse events and 0 serious events. For other adverse events, it lists 19 at risk and 1 event. Deaths are reported as 0. These are the counts recorded for the categories shown; they are not percentages, and no rate should be inferred without a defined observation period and suitable denominators.

The registry does not list serious-event terms in the top serious terms field. The other event is not described in the adverse-event details included in the record. The entry therefore does not identify its nature, timing, severity, or relationship to the intervention. Nor does it establish that all potential adverse events were captured or that no events occurred outside the reporting definitions.

Safety counts in a pilot with no separate comparison group are descriptive. They cannot show whether events occurred more or less often than they would have in a different group, and the counts should not be treated as proof of absence of risk. The registry record does not report additional safety analyses or a comparison group.

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

This trial record is useful for understanding the design and aims of an open pilot of remote MBCT for SCAD survivors. It identifies enrollment feasibility and acceptability as primary concerns, describes the intervention format, and lists psychological and behavioral outcomes for exploration. It also reports enrollment of 19 participants and provides adverse-event counts for the MBCT group.

The record does not report the observed enrollment percentage, the full number of eligible patients, or numerical results for the primary endpoint. Although the stated criterion is that >70% of eligible patients enroll, the available entry does not establish whether the criterion was met. The distinction matters: a target is not an observed result, and a count of enrolled participants alone does not supply the eligible denominator needed to evaluate that target.

The record also does not report numerical changes in fear of recurrence, sleep, physical activity, or the other listed psychological outcomes. Therefore, it cannot establish the direction, magnitude, or precision of changes in those measures. The intervention's rationale and intended targets are described in the registry summary, but rationale is not evidence of an observed outcome.

Because the study had a single group and no comparator, it cannot provide a randomized estimate of the effect of MBCT relative to an alternative. Even if pre/post changes had been reported, the design would not by itself separate intervention-related change from other influences over time. The registry does not provide enough statistical detail to assess models, uncertainty, missing data, or multiplicity handling.

The appropriate reading is therefore bounded: the registry documents a completed phase 1 pilot and its stated feasibility question, but the posted information is insufficient to determine the primary endpoint result or assess exploratory outcome changes. The adverse-event counts are descriptive and do not establish comparative safety.

14. Why This Trial Matters Statistically

This study is statistically notable as a pilot focused on the feasibility of conducting remote group MBCT with SCAD survivors. Feasibility questions differ from efficacy questions: they concern whether recruitment and study procedures can be carried out, rather than whether an intervention produces a clinical benefit. The stated enrollment threshold makes the recruitment aim explicit, but the registry does not report the eligible denominator or observed enrollment percentage needed to evaluate it.

The single-group design is also important to interpretation. It can support descriptive work and may inform how an intervention and its measurements are implemented, but it does not offer a controlled estimate of what would have happened without the intervention. This matters particularly when outcomes are measured before and after participation, because time and other influences can accompany intervention exposure.

The registry identifies a broad set of psychological and behavioral outcomes, with inter-correlations as an exploratory interest. Such breadth can be informative for planning future research, but it increases the need for transparent outcome definitions, analysis plans, missing-data reporting, and careful interpretation of multiple comparisons. Those details and numerical results are not reported in the registry record.

Finally, the entry illustrates why registry counts and outcome descriptions need to be read together. It reports 19 enrolled participants, describes n=20 analyzed for the enrollment variable, and notes one eligible person refused to enroll. Because the record does not fully explain the denominator or the connection between the count and percentage endpoint, the feasibility result cannot be reconstructed from the entry. Clear reporting of these elements is central to interpreting pilot evidence.

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.

Several limitations specific to this record constrain statistical interpretation. The primary endpoint is described as a percentage of eligible patients who enroll, but the registry does not report the observed percentage or the complete eligible-patient denominator. It also gives a participant count for the measure and states that n=20 were analyzed, while the enrollment field reports 19 participants. The accompanying explanation notes one eligible person refused to enroll, but does not fully reconcile the entries.

The study has a single group and no separate comparator, so any within-group change cannot be interpreted as a controlled intervention effect. The registry summary describes planned pre- and post-intervention surveys and actigraphy, but corresponding numerical results are not reported. Numerical estimates, uncertainty intervals, and analysis methods for the primary and exploratory outcomes are also not reported in the registry record.

The summary proposed N=16, whereas the enrollment field reports 19; the registry does not explain the difference. The record also does not provide detailed eligibility criteria, participant characteristics, adherence information, outcome completion, missing-data handling, or a statistical analysis plan. Although the registry lists 24 outcome measures and 0 analyses, those fields do not provide the substantive analysis details needed to assess outcome selection, model assumptions, or multiplicity.

Finally, the adverse-event entry is descriptive and does not identify the one other event. The registry does not report the event's nature or timing, or comparative safety data. These limitations mean the entry can describe the study's setup and selected counts, but cannot support a detailed assessment of outcome precision or causal effects.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Remote-delivered MBCT for SCAD Survivors — NCT04983680.
• Registry record last updated 2024-09-19; status last verified 2024-08.
• Results first posted 2024-05-16.
• 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

The record describes a completed phase 1, open, single-group pilot of remote-delivered MBCT for SCAD survivors, sponsored by Massachusetts General Hospital. The enrollment field reports 19 participants. The intervention is described as an 8-week group program with 1.5-hour weekly sessions. The primary feasibility question was whether >70% of eligible patients enroll over 7 months.

The registry describes n=20 analyzed for the enrollment variable and notes one eligible person refused to enroll, but does not report the observed enrollment percentage or complete eligible denominator. Numerical results for the primary endpoint and exploratory psychological and behavioral outcomes are not reported in the registry record. The adverse-event entry reports 0 serious events, 1 other event, and 0 deaths, with 19 at risk for each event category.

Because there was no control group, the study does not provide a randomized between-group comparison. The registry record does not report a statistical analysis plan, missing-data methods, or multiplicity handling.