Brain Mechanisms of Reducing Polysubstance Use Following a Novel Body-mind Intervention: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Brain Mechanisms of Reducing Polysubstance Use Following a Novel Body-mind Intervention (NCT04261504), a randomized na study. The primary outcome is Brain Changes in Functional Activity.

2. Clinical Question

3. Trial Design

The study is registered as a randomized, triple-masked, parallel-group behavioral trial comparing Integrative Body Mind Training (IBMT) with Relaxation Training (RT). The registry records enrollment of 70 and lists Texas Tech University as sponsor. The study status is completed. The recorded start date is 2019-04-19, and the primary completion date is 2023-02-28. The phase is listed as NA.

IBMT is described as mindfulness, while RT is described as relaxation. The study summary says the proposed research examines brain mechanisms of a brief mindfulness intervention in relation to alcohol, tobacco, and cannabis reduction. The primary outcome description focuses on functional activity in the anterior cingulate cortex, measured in beta weights before and after intervention. It identifies baseline and post-intervention assessment, with the latter specified as 2 weeks.

Random allocation supports a comparison between assigned intervention groups, but the registry does not describe the sequence-generation method, allocation concealment, or the identities of people included in triple masking. The meaning of “triple” for this trial is not reported in the registry record. Details of intervention dose, treatment fidelity, adherence, concurrent care, and participant flow are also not reported. These omissions limit how fully the design and conduct can be evaluated from the registry information alone.

The record identifies one outcome measure and one analysis, but its outcome summary indicates that the primary outcome has several categories or time points and is not reduced to a single comparison. Thus, the design information identifies the intended groups and assessment schedule, but the posted record does not provide a singular outcome estimate that can be interpreted as the primary between-group result.

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

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 Brain Changes in Functional Activity, measured over The outcome measure is assessed at baseline and post-intervention..

The primary endpoint is titled “Brain Changes in Functional Activity.” It measures functional activity in the anterior cingulate cortex, with results expressed as beta weights. The registry identifies the summary measure as a mean and the dispersion measure as a standard deviation. Assessments are described at baseline and post-intervention; the post-intervention assessment is stated to occur at 2 weeks.

In general, a continuous brain-activity measure can describe the level of a signal or a change in that signal across assessments. A mean describes the central value for a group, while a standard deviation describes the spread of individual measurements around that mean. Beta weights are a scale for the modeled functional-activity measure; their interpretation depends on the underlying imaging task and analysis specification. Those details are not reported in the registry record.

The endpoint is relevant to the stated mechanistic aim because it focuses on brain activity rather than directly measuring substance use. A change in this measure would not, by itself, demonstrate a change in alcohol, tobacco, or cannabis use. The registry record does not report numerical endpoint means, standard deviations, changes, or a reduced contrast between IBMT and RT. It therefore does not support an assessment of the direction or size of any brain-activity difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical explanation: the methods below describe how the named design and outcome are commonly interpreted. They do not identify procedures used in this trial unless the registry record explicitly reports them. The record gives only limited information about the analysis itself.

What does randomization contribute?

Randomization assigns participants to intervention groups according to a chance-based procedure. In general, it is used to reduce systematic differences between groups at assignment, supporting an interpretable comparison of outcomes by assigned group. It does not guarantee that every group characteristic will be balanced, particularly in a trial of limited size. The registry calls the study randomized but does not report its sequence-generation procedure, concealment method, or stratification factors. Those details are therefore not reported in the registry record.

The parallel-group designation means the registered design compares groups assigned to different interventions rather than describing a crossover sequence. The record names IBMT and RT as the behavioral interventions. It does not report whether treatment contact, expectations, or other elements were designed to be equivalent. Such factors can influence outcomes in behavioral studies and are relevant when interpreting a group contrast.

How should the continuous endpoint be read?

General statistical explanation: a continuous outcome can take a range of values rather than only event/no-event categories. A group mean describes its average level, and a standard deviation describes variation among measurements. The registered endpoint uses beta weights for anterior cingulate cortex functional activity. The meaning of a particular beta weight depends on the imaging task, preprocessing, and statistical model. Those specifications are not reported in the registry record, so the scale cannot be given a more detailed biological interpretation from the registry description alone.

Measurements at baseline and post-intervention allow researchers to consider both initial level and subsequent measurement. In general, an analysis may compare post-intervention values while accounting for baseline, compare changes from baseline, or model repeated measurements together. These approaches can answer related but not identical questions and may produce different estimates. The registry record does not report which approach was used. The outcome is described as having several categories or time points and is not reduced to one comparison, so the relevant estimate cannot be identified from the posted outcome information.

What would uncertainty measures add?

General statistical explanation: an estimate describes the observed contrast, while its uncertainty measure conveys how precisely that contrast is estimated. A confidence interval gives a range of values compatible with the data and the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, but neither precision nor statistical significance alone establishes clinical or biological importance. The registry record does not report a confidence interval or another uncertainty measure for a singular primary-outcome contrast.

A p-value, when reported, measures how inconsistent the observed data are with a specified null model under the assumptions of the analysis. It does not give the probability that the null hypothesis is true, and it does not measure the size or practical importance of an effect. No p-value for a reduced primary-outcome comparison is reported in the registry record. The statistical model and its assumptions are also not described.

Why does multiplicity matter?

General statistical explanation: testing multiple outcome categories, time points, or contrasts creates multiple opportunities to obtain an apparently unusual result by chance. Statistical plans may address this through a prespecified primary contrast, adjustment procedures, or a clear hierarchy of tests. The registry indicates that the primary outcome includes several categories or time points but does not reduce these to one comparison. It does not report a multiplicity strategy. Without the analysis details, the consequences of selecting among possible comparisons cannot be assessed.

What do the planning assumptions mean?

The registry describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. The specific fractions and numerical planning estimates are not reported in the registry record. Such illustrations are planning quantities, not observed power and not results from the trial. They do not establish that the trial was designed around a particular clinically meaningful difference, because a sample-size justification and the assumptions used by the investigators are not reported in the registry record.

The record does not report an interim-analysis plan or any details about monitoring statistical results during the study. It lists one analysis, but does not describe its model, adjustment variables, analysis population, handling of repeated measurements, or missing-data procedure. The single analysis listing therefore does not establish which statistical method was applied. These omissions prevent a full assessment of whether the analysis matched a prespecified plan or how robust the result would be to alternative reasonable methods.

10. Multiplicity, Missing Data and Analysis Populations

The registry indicates that the primary outcome has several categories or time points and is not reduced to one comparison. It does not describe a prespecified hierarchy among those comparisons or a method for controlling multiplicity. In general, examining multiple time points or outcome components can increase the chance that one result appears notable by chance. A clear primary contrast and analysis plan help readers distinguish planned inference from exploratory comparisons. The relevant plan is not reported in the registry record.

Missing-data handling is not reported in the registry record. The posted description does not state how many outcome observations were available at each assessment, why observations might be missing, or whether the analysis used complete cases, imputation, or a model that could use incomplete repeated measurements. Those choices can affect both the estimate and its uncertainty, particularly if missingness is related to participant characteristics or outcomes.

The analysis population is also not reported in the registry record. It is not stated whether the analysis followed randomized assignment, included only participants who completed intervention, or used another population definition. Details of protocol deviations and adherence are not given. The record lists one analysis, but does not identify its statistical model or whether it was prespecified.

These are reporting limitations, not evidence that the trial necessarily used inappropriate methods. Without the analysis plan and population definitions, readers cannot determine how multiplicity, missing observations, or departures from assigned intervention were handled. The absence of a single reduced comparison further limits interpretation of any one reported result.

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 for each intervention group. For IBMT, the record lists 35 at risk for serious adverse events and 0 affected; it also lists 35 at risk for other adverse events and 0 affected, with 0 deaths. For RT, the corresponding listed figures are 35 at risk for serious adverse events and 0 affected; 35 at risk for other adverse events and 0 affected; and 0 deaths.

These are registry-reported counts. A zero in the affected column means no events were recorded in that category in the posted safety results; it does not prove that no symptoms or events occurred, or that risks are absent. The registry record does not report the collection period, definitions used for event categories, completeness of safety reporting, or procedures for soliciting events. It also does not provide event-level descriptions. The figures should therefore be read as the safety counts recorded in the registry, not as a comprehensive assessment of all possible harms.

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

The record establishes that a randomized, triple-masked, parallel-group study comparing IBMT with RT was completed and that the registered primary outcome concerns anterior cingulate cortex functional activity. It also identifies baseline and post-intervention assessment and specifies beta weights as the measurement unit. Those details describe the research question and design, not the result of the comparison.

The registry does not report one reduced primary-outcome comparison or numerical results for a single comparison. It therefore cannot show from the posted information whether the outcome changed, in which direction it changed, or whether change differed between the intervention groups. No effect estimate or uncertainty interval is reported for such a contrast. The missing result should not be interpreted as either a positive finding or a null finding.

The study summary refers to possible reductions in alcohol, tobacco, and cannabis use, but the primary endpoint described in the record is a brain functional-activity measure. A result on that endpoint would address a mechanistic question, not directly establish a change in substance use. The registry information does not report numerical substance-use outcomes, and it does not establish a causal pathway from intervention through brain activity to substance-use behavior.

General statistical explanation: measured changes can be affected by variability, measurement procedures, missing observations, and the analytic choices used to compare groups. A result is most informative when its estimate, uncertainty, outcome definition, and analysis population are available together. Those elements are not reported sufficiently to interpret a singular treatment contrast in this record. The appropriate conclusion is therefore about the limits of the posted evidence: a trial and endpoint are registered, but the available outcome entry does not quantify what the comparison found.

13. Why This Trial Matters Statistically

This study raises a statistical question that is common in mechanistic behavioral research: how should a continuous brain measure be analyzed when it is assessed at baseline and after an intervention, and when the registered outcome includes multiple categories or time points? The answer depends on a clearly defined contrast, an analysis model, and transparent reporting of the estimate and its uncertainty. Without those elements, a reader cannot distinguish a change over time within a group from a difference in change between groups.

The comparison of mindfulness-oriented IBMT with relaxation-oriented RT also makes the comparator important. In general, an active behavioral comparator can help distinguish intervention-specific effects from changes associated with participation, attention, or a structured activity. The registry identifies RT as the comparator but does not report whether the intervention conditions were matched in contact, expectations, or delivery. That information would help contextualize the estimated contrast.

The mechanistic focus is another reason for careful interpretation. Brain functional activity and substance-use behavior are different outcome domains. A statistical association between them would not by itself establish that changes in brain activity explain changes in substance use. A causal mediation claim would require clearly defined outcomes, timing, and analysis assumptions, none of which are described in sufficient detail in the registry record.

Finally, the record illustrates why outcome completeness matters. A completed study status and a named primary endpoint do not replace a reported result. Readers need a defined analysis population, the actual group estimates or contrast, uncertainty, and information on missing observations and multiplicity. The registry’s outcome entry does not provide one reduced comparison, which prevents a quantitative assessment of the central brain-activity question.

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.

The main trial-specific limitation is that the primary outcome is not reduced to a single comparison. The registry describes several categories or time points but does not provide a numerical result for a clearly identified contrast. Means, standard deviations, changes, and uncertainty measures for that contrast are not reported in the registry record. This prevents assessment of effect direction, magnitude, precision, and compatibility with a range of values.

The outcome description gives the brain region, measure type, unit, and assessment schedule, but not the imaging task or analytic definition that gives beta weights their specific meaning. It also does not report whether the primary comparison was based on post-intervention values, baseline-adjusted values, change scores, or a repeated-measures model. Without this information, the estimand and statistical model cannot be evaluated.

Other limitations include unreported participant characteristics, eligibility criteria, allocation procedures, masking roles, intervention delivery, adherence, and participant flow. The registry record does not describe missing-data methods, the analysis population, multiplicity control, or the investigators’ statistical plan. The available information also does not report a numerical result for substance-use outcomes, despite the study summary’s focus on alcohol, tobacco, and cannabis reduction. These limitations concern what can be assessed from the registry record; they do not establish that the study lacked these procedures or measurements.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Brain Mechanisms of Reducing Polysubstance Use Following a Novel Body-mind Intervention — NCT04261504.
• Registry record last updated 2024-05-29; status last verified 2024-05.
• Results first posted 2024-05-02.
• 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

NCT04261504 is a completed randomized, triple-masked, parallel-group behavioral study sponsored by Texas Tech University. It records enrollment of 70 and compares Integrative Body Mind Training, described as mindfulness, with Relaxation Training, described as relaxation. The registered primary outcome concerns anterior cingulate cortex functional activity in beta weights, assessed at baseline and post-intervention, with the post-intervention assessment stated at 2 weeks.

The registry identifies the outcome as having several categories or time points and does not reduce it to one comparison. A numerical primary-outcome contrast and its precision are not reported in the registry record. Safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each group. The record does not provide enough analysis detail to assess the handling of missing data, multiplicity, or the analysis population.