Video Based Mindfulness Based Stress Reduction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Video Based Mindfulness Based Stress Reduction (NCT02705586), a na na study. The primary outcome is Salivary Cortisol Levels (Pre- and Post-) Mindfulness-Based Stress Reduction Program.

2. Clinical Question

The stated aims are to evaluate the feasibility of a video-based mindfulness intervention for stress reduction and to evaluate the cortisol response in persons with Parkinson’s disease and their caregivers. The registry also says the project data will be used for a future grant application of a stress reduction intervention in persons with Parkinson’s disease. These aims describe what the project set out to examine; they do not establish that feasibility or a cortisol change was observed.

Because there is no separate comparator, the central statistical contrast is a before-and-after comparison within the study group. The registry record does not report the cortisol values, the estimated pre–post change, or an analysis of that change.

3. Trial Design

The study is listed as completed and as a single-group, open-label study. Its title is “Video Based Mindfulness Based Stress Reduction,” and the listed sponsor is Oregon Health and Science University. The registry lists enrollment of 13. It records the start as 2016-03 and primary completion as 2016-07. The phase and allocation fields are listed as NA, and masking is listed as NONE.

The sole arm is described as a 2 hour video-based mindfulness-based stress reduction class once a week for 10 weeks. The intervention is categorized as behavioral and named Mindfulness. The registry identifies Parkinson’s disease as the condition and describes an intended population that includes persons with PD and their caregivers. It does not report how enrollment was divided between those groups, nor does it provide participant characteristics.

This design has no randomized allocation and no like-for-like control arm. The intended primary comparison is instead between cortisol measurements before the program and after the intervention. A within-group change can describe what happened over the measurement period among participants with available measurements, but without a separate comparator it cannot isolate the program’s effect from other changes over time or other influences.

The registry record lists one outcome measure and zero analyses. It does not report an analysis plan, a sample-size justification, interim analyses, or the method used to account for repeated measurements. It also does not report how many participants completed the program or contributed both cortisol samples. The status “completed” describes the study status in the record; it does not, by itself, provide outcome findings or establish that every planned measurement was obtained.

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: 13 participants consented for the study. 4 withdrew after screening prior to the intervention due to the amount of travel to the Portland VA in the study.

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.

Population: Baseline visits completed on 13 participants; Parkinson's disease and caregivers. 4 individuals dropped out prior to class week 1 due to difficulty travelling to the VA/too busy to come to the VA weekly. Analysis on 13 (individuals - both Parkinson's disease and caregivers).

6. Primary Endpoint

The registry lists the primary outcome as Salivary Cortisol Levels (Pre- and Post-) Mindfulness-Based Stress Reduction Program, measured over Baseline to 12 weeks.

The primary endpoint is salivary cortisol concentration, measured in ng/mL. The registry describes levels measured by enzyme-linked immunoassay before mindfulness-based stress reduction and compared with samples taken after the intervention. The stated timeframe is baseline to 12 weeks. The outcome is described as a mean with standard deviation, so the intended summary concerns the average concentration and the spread of individual measurements around that average.

Cortisol is included because the project aims to evaluate the cortisol response alongside the feasibility of a stress-reduction intervention. In this setting, the endpoint is a biological measurement collected at two points around the program. A before-and-after comparison can describe whether measured values differ over that period among participants with measurements at both times. It cannot, by itself, show that the intervention caused any difference, because there is no separate control group to help distinguish intervention-related change from other time-related influences.

The registry record does not report the baseline or follow-up means, their standard deviations, the number of paired samples, or an estimated change. It also does not report assay performance details or how samples were handled. Thus, the endpoint’s intended measurement and summary are described, but the magnitude and precision of any observed change are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: salivary cortisol concentration in ng/mL. For a continuous measure, a mean summarizes the center of the observed values, and a standard deviation describes how spread out those values are. The registry specifies these summary types but does not report their numerical values for either measurement time. Without those values, it is not possible to describe the observed central level or variation.

The registry’s stated comparison is between samples collected before the program and samples collected after it. When the same participants provide both measurements, the observations are paired. A paired analysis focuses on each participant’s change between measurement times, then summarizes those changes across participants. This approach accounts for the fact that two measurements from one person are related; treating them as unrelated observations would ignore that relationship. This is general statistical context, not a description of an analysis reported for this study. The registry does not say whether the same participants contributed both samples or how the pre–post comparison was analyzed.

A mean change would describe the average within-person difference, but it would not describe how consistently participants changed. A standard deviation of individual changes could characterize their spread. A confidence interval around the mean change would communicate the range of values reasonably compatible with the data under the chosen method. A narrow interval indicates greater precision than a wide interval, while neither interval width nor statistical significance alone establishes cause. No mean change, standard deviation of changes, or confidence interval is reported in the registry record.

General statistical methods also depend on the distribution and quality of the measurements. If change scores are strongly skewed or affected by extreme values, a mean-based summary and a method relying on approximately normal differences may be sensitive to those features. Repeated measures can also be analyzed with models that account for within-person association. Such models require decisions about the association structure and missing observations. The registry record does not report distributional checks, an analysis model, or assumptions used for the cortisol outcome.

Over-dispersion is a general concern when counts vary more than a chosen model expects; it is not the central issue for this continuous cortisol endpoint. For continuous measurements, the more directly relevant considerations include the shape of the measurement distribution, unusual values, assay variability, and the relation between paired observations. The registry record does not report these diagnostics or assay details. No claim about whether any particular assumption was satisfied can therefore be made.

The record lists one outcome measure and zero analyses. It does not report a prespecified statistical analysis plan, a sample-size justification, or interim analyses. The registry identifies the primary endpoint and its timeframe, but does not state a hypothesis test, a target effect, a confidence level for an interval, or a procedure for handling multiple outcomes. The absence of those details in the record should not be interpreted as proof that no methods were considered outside the registry.

The registry’s planning assumptions describe an illustrative two-arm calculation using a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. These assumptions describe a hypothetical planning exercise, not the actual single-group study design. The observed effect required to interpret such planning calculations is not reported in the registry record. Any resulting sample-size illustration is a planning aid, not observed power, evidence of an effect, or a substitute for the study’s outcome analysis.

Sample size and precision are related but distinct. The enrollment figure alone does not reveal the precision of the cortisol estimate because the number with paired samples and the variability of their changes are not reported. The registry also does not explain how enrollment was determined. No inference about a sample-size justification or the adequacy of enrollment can be drawn from the record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Only One Arm - Open Label Study")
n   <- c(5)
m   <- c(-33.1)
sp  <- c(41.5)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Only One Arm - Open Label Study  5  -33.100  41.500  -84.629  18.429

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity concerns arise when several outcomes, time points, subgroups, or analyses are tested, since repeated testing can increase the chance of a misleading finding. The registry lists one outcome measure, the pre–post salivary cortisol endpoint, and zero analyses. It does not report a statistical analysis plan, a strategy for multiple testing, or whether any additional analyses were conducted outside the registry. The record therefore does not support a judgment about how multiplicity was handled.

Missing data matter for a pre–post endpoint because a participant needs measurements at the relevant times to contribute to a paired change analysis. The registry does not report the number of participants with both samples, the amount or reasons for missing measurements, or any method for handling missing data. It is not possible to determine the primary-outcome analysis population or whether missingness could have affected the estimated change.

The enrollment of 13 is not enough to establish the number analyzed. Nor should the 9 listed at risk in each adverse-event category be treated as the cortisol analysis denominator; the record does not link those counts to outcome completion. The analysis population, including whether all enrolled participants or only participants with paired measurements were to be included, is not reported in the registry record.

No interim analyses or statistical stopping rules are reported. This absence of information does not show what may have been considered outside the registry; it means those methods cannot be assessed from the registry record.

12. 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 5% reporting threshold.

The adverse-event summary lists 9 participants at risk for serious adverse events and 0 affected. It separately lists 9 participants at risk for other adverse events and 0 affected. These are registry counts for the listed categories; they should not be read as outcome results for cortisol or as evidence about the effectiveness of the intervention.

The record lists the group as “Only One Arm - Open Label Study.” It does not explain why the at-risk counts are 9 when enrollment is 13, whether those counts reflect a defined safety population, or whether all participants were monitored for the same duration. The counts therefore should not be treated as a complete accounting of every enrolled participant without additional information.

The deaths field is null, so a death count is not reported in the registry record. No serious-event terms are listed. A zero affected count means no affected participants are recorded in that field; it does not establish that no events of any kind occurred outside the recorded categories or that reporting was complete. The registry information does not provide event narratives, severity details beyond the category, timing, or attribution to the intervention.

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

The record establishes that a completed, single-group study was registered to examine a video-based mindfulness-based stress reduction program and salivary cortisol in persons with Parkinson’s disease and their caregivers. It describes the class schedule, the planned measurement timeframe, and the intended outcome summary. It does not report cortisol findings, feasibility findings, or an analysis. No conclusion about the direction or size of a pre–post change can be drawn from the registry record.

Even if a pre–post change were reported, a single-group comparison would describe change over time among those measured, not isolate the contribution of the program. A control group can help distinguish changes associated with an intervention from other changes occurring over the same period. There is no such group in this study’s registry description. This limitation is about what the design can establish, not a claim that the program did or did not produce change.

The intended use of project data for a future grant application is part of the stated rationale. It does not provide evidence about whether the intervention was feasible, whether participants attended or completed classes, or whether the cortisol endpoint changed. Those results are not reported in the registry record.

The enrollment count does not reveal the number of participants with complete cortisol measurements, and the record does not provide uncertainty estimates for the primary endpoint. Therefore neither precision nor statistical significance can be evaluated. The safety counts likewise describe only the recorded adverse-event fields and do not supply information about the primary outcome.

Statistically, the record is most informative about the study’s question and structure. It is not a report of an estimated treatment effect. Distinguishing a study’s aim, design, and recorded results is essential: the first two are described, while the primary outcome result and analysis are not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a useful statistical question: how should a pre–post biological measurement be interpreted when participants receive an intervention without a separate control group? The design can describe within-group change, but causal interpretation is limited because time, measurement conditions, and other influences are not separated from the intervention. Recognizing that distinction prevents a before-and-after contrast from being mistaken for a controlled treatment effect.

The registry also illustrates why outcome reporting matters. It identifies a continuous endpoint, its unit, its measurement method, and its timeframe, but does not report the values or an analysis. Without an estimate and a measure of uncertainty, readers cannot assess the magnitude or precision of the observed response. A completed status alone cannot fill that gap.

Enrollment and analysis denominators answer different questions. The registry reports enrollment of 13, but the number with complete pre–post cortisol measurements is not reported. The separate adverse-event at-risk counts should not be substituted for an outcome denominator. Clear reporting of who contributed to each analysis is needed to interpret the precision and representativeness of results.

The project is described as intended to evaluate feasibility and cortisol response and to inform a future grant application. Those aims make transparent outcome and feasibility reporting particularly important: the record should allow readers to distinguish the planned purpose from what was observed. In the available registry information, the design and measurement plan are described, while the findings are not reported.

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 most direct limitation is that the registry record does not report the primary outcome results or an analysis. The cortisol means, standard deviations, estimated pre–post change, uncertainty, and p-value are not reported. Consequently, the observed response and its precision cannot be evaluated.

The study is described as single group, with no separate comparator. Any within-group change would not by itself distinguish intervention-related change from other influences over time. The record also does not report how the pre–post measurements were analyzed or whether participants with both measurements were analyzed as paired observations.

Although enrollment is listed as 13, the number of participants who completed the program or contributed cortisol measurements at both time points is not reported. The record does not describe missing data, participant characteristics, the number of persons with Parkinson’s disease versus caregivers, or how the analysis population was defined. These gaps limit interpretation of who the results would represent, even if an outcome estimate were available.

The registry does not report feasibility results, including attendance, completion, or acceptability, despite feasibility being a stated aim. It also does not report assay performance details, a sample-size justification, a statistical analysis plan, or interim analyses. The listed adverse-event counts have an at-risk denominator of 9 in each category, but the record does not explain that denominator or report a death count. These are limitations of the information available in the registry, not evidence that unreported procedures or findings did not exist.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Video Based Mindfulness Based Stress Reduction — NCT02705586.
• Registry record last updated 2019-10-31; status last verified 2019-10.
• Results first posted 2019-10-31.
• 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 registry describes a completed, open-label, single-group behavioral study of video-based mindfulness-based stress reduction in the context of Parkinson’s disease. Enrollment is listed as 13, and the sole arm is described as a 2 hour class once a week for 10 weeks. The intended population includes persons with Parkinson’s disease and their caregivers.

The primary outcome is mean salivary cortisol concentration in ng/mL, measured before the program and after the intervention, with a baseline-to-12-weeks timeframe. The stated aims are to evaluate feasibility and cortisol response. The registry lists one outcome measure and zero analyses, but does not report cortisol results, feasibility findings, or the number with paired measurements.

The adverse-event fields list 0 affected among 9 at risk for serious events and 0 affected among 9 at risk for other events; a death count is not reported in the registry record. The record describes the study question and design, but does not provide an outcome estimate or its precision.