A Mobile Executive Functioning Intervention for Momentary Craving in Opioid Use Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Mobile Executive Functioning Intervention for Momentary Craving in Opioid Use Disorders (NCT05086835), a randomized na study. The primary outcome is Modified Craving Scale.

2. Clinical Question

3. Trial Design

NCT05086835, titled “A Mobile Executive Functioning Intervention for Momentary Craving in Opioid Use Disorders,” was registered as a randomized, single-masked, parallel-group study. Its planned conditions were a Working Memory App active intervention and a Visual Search App control condition. The active app was described as a visual-spatial working-memory intervention; the control app was described as an app-based visual-search task. The registry lists the study phase as NA and the study type as other.

The primary outcome was the Modified Craving Scale, with a timeframe of change from pre-task to immediately post-task. The planned endpoint therefore focused on a short interval around task engagement, rather than a longer-term clinical outcome. The registry record describes the measure as a single-item craving measure adapted from the 3-Item Craving Scale.

The study was terminated. The primary outcome record explicitly states that termination occurred before participants were enrolled in either clinical trial arm and that no outcome data were collected. Although the registry lists enrollment of 10, those participants entered Stage 1A, an intervention-development study intended to inform development of the clinical trial. They are not reported as participants in the randomized clinical comparison.

The start date was 2021-10-14 and the primary completion date was 2022-03-01. The sponsor was Mclean Hospital. The registry record does not report the reason for termination, the planned sample size for the clinical comparison, the allocation ratio, or the identity of the person or group masked. These details should not be inferred from the design labels.

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: By design, participants enrolled in the Stage 1A Intervention Development arm were enrolled prior to the primary clinical trial, and no data on primary study outcomes were collected during this initial treatment development phase.

Overall Study

Analysis population for the primary outcome, as defined in the registry: This study was terminated prior to enrolling participants in either of the clinical trial study arms, so no outcome data were collected. Baseline data on the 10 participants who entered the Stage 1A study (designed to help inform the development of the clinical trial) are provided in the Baseline Characteristics section.

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 participants in this phase did not enter into either of the study's intervention arms; by design, these participants provided feedback about the Stage 1B clinical trial design.

6. Primary Endpoint

The registry lists the primary outcome as Modified Craving Scale, measured over Change from pre-task to immediately post-task.

The primary endpoint was the Modified Craving Scale, described as a single-item craving measure adapted from the 3-Item Craving Scale. Its specified timeframe was change from pre-task to immediately post-task. In principle, this endpoint captures a near-term change in reported craving around the time a participant completes an app task. That timing matches the study’s stated interest in delivering a working-memory task when craving occurs in daily life.

A brief, repeated measure can be useful for studying momentary experiences because it focuses on the state of interest close to the activity being evaluated. In general, however, a change score over a short interval addresses a different question from whether an intervention changes longer-term symptoms, functioning, or clinical outcomes. The endpoint as registered was about immediate craving, not return to use or durable improvement.

The registry record does not report the measure’s response options, scoring range, direction of higher scores, or a threshold for a meaningful change. It also contains no observed endpoint values or treatment comparison: the clinical arms did not enroll participants and no outcome data were collected. Consequently, the measure’s performance and any change associated with either task cannot be assessed from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What comparison was planned?

The registry describes a randomized, parallel-group design. In a parallel-group trial, participants are assigned to one study condition and evaluated in that condition rather than crossing through both conditions as part of the main comparison. Randomization is intended, in general, to make the groups comparable on average with respect to measured and unmeasured characteristics. It does not guarantee balance in every realized sample, particularly when samples are small. Here, the planned groups were the Working Memory App active intervention and the Visual Search App control condition.

The registry also labels the study single-masked. Masking is intended to limit the influence of expectations or knowledge of assignment on aspects of conduct or outcome assessment. The record does not identify who was masked, so the label should not be expanded into a claim about participant, investigator, assessor, or analyst masking. Nor does the record report how randomization was implemented or whether allocation was concealed.

What would the primary endpoint describe?

The primary endpoint was change on a single-item modified craving measure from before the app task to immediately after it. A change endpoint focuses on within-person movement over the specified interval. A comparison between randomized groups would then assess whether the average or other prespecified summary of change differed between the app conditions, depending on the analysis plan. The registry record does not report which summary measure or model was planned.

In general, an effect estimate gives a quantitative description of a comparison, while its confidence interval shows a range of values compatible with the data and the chosen statistical procedure. A narrower interval generally indicates greater precision, and a wider interval indicates greater uncertainty. A p-value, when used, quantifies how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and model. It is not the probability that the null hypothesis is true, nor does it measure clinical importance. No estimate, confidence interval, or p-value for the primary endpoint is reported because no clinical-arm outcome data were collected.

Why does the absence of outcome data matter?

Statistical inference requires observed outcomes as well as a design and analysis specification. Since neither clinical arm enrolled participants, there is no randomized sample from which to estimate the treatment contrast. The registry’s Stage 1A enrollment of 10 is not a substitute: those participants entered intervention development, not the clinical comparison. Their enrollment cannot support an estimate of the app-condition contrast on the primary endpoint.

Even if an analysis method had been specified, a method alone could not create an observed effect. The registry record reports zero analyses. It does not report the planned statistical model, covariate adjustment, approach to repeated or missing measurements, or hypothesis-testing procedure. It is therefore not possible to assess whether an analysis followed a prespecified plan or whether any reported result was adjusted for baseline values or other variables.

What can general statistical concepts add?

General statistical explanation can clarify what would ordinarily be considered in a trial of this kind, but it cannot establish what this study planned. For a continuous or ordinal craving score, an analysis might summarize each participant’s change and compare the groups, or use a model that incorporates both pre-task and post-task measurements. Which approach is appropriate depends on the scale, design details, assumptions, and prespecified analysis plan. The registry record does not say which approach was intended, and no approach can be attributed to this trial.

In general, a confidence interval reflects both the variability in the observed data and the amount of information available. A smaller enrolled sample often yields less precise estimates, but precision also depends on outcome variability and design. In this case there is no clinical-arm sample and no observed outcome variation from which to estimate precision. Therefore, there is no trial-based interval to interpret. A planning illustration based on an observed effect would also lack an observed clinical-arm effect to anchor it; any such calculation would not represent observed power or a finding from this trial.

Multiplicity refers to the risk of misleading findings when several outcomes, time points, or comparisons are tested. Statistical plans often specify a primary outcome and methods for controlling or describing multiple testing. The registry identifies the Modified Craving Scale as primary and indicates two outcome measures overall, but does not report a multiplicity strategy. With no clinical outcome analyses, there are no hypothesis tests whose multiplicity adjustment can be evaluated.

Missing-data methods matter when participants enroll but some outcome measurements are unavailable. This study presents a different issue for the clinical comparison: participants were not enrolled in either arm, so there are no clinical-arm outcome measurements to analyze. The registry record does not report a plan for missing endpoint observations, and it would be inappropriate to infer one. Likewise, the analysis population definitions, such as which randomized participants would be included in a primary analysis, are not reported in the registry record.

Finally, sample-size planning and observed evidence are distinct. A planned sample size is a design choice based on assumptions, while an observed estimate comes from actual participant outcomes. The registry does not report the clinical comparison’s sample-size justification. The 10 Stage 1A participants do not supply observed clinical-arm evidence, and no precision or treatment effect for the primary outcome can be calculated from their count alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry names the Modified Craving Scale as the primary outcome and records two outcome measures overall. It does not describe how multiple outcomes, time points, or comparisons would be handled statistically. No multiplicity adjustment or hierarchy of secondary outcomes is reported in the registry record. Because the clinical arms did not enroll and no outcomes were collected, there are no analysis results to assess for selective emphasis or adjustment across tests.

The registry record also does not report a missing-data strategy. In a completed study, such a strategy would explain how unavailable endpoint measurements were handled and what assumptions supported the analysis. Here, the primary issue is that no participants entered either clinical arm, rather than loss of endpoint observations from an enrolled clinical sample. The record does not state what approach would have been used if some pre-task or post-task observations were missing.

Analysis populations are not specified in the registry record. It is not reported whether the intended primary analysis would include all randomized participants, participants who completed tasks, or another defined group. The planned handling of protocol deviations and incomplete task sessions is also not reported. The record lists zero analyses, so there is no population definition or analysis execution to evaluate against an intended plan.

These omissions do not establish that a particular procedure was or was not used; the relevant plans are simply not reported in the registry record. With no clinical-arm enrollment or outcomes, the statistical consequences of multiplicity and missing observations cannot be assessed empirically.

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 adverse-event record lists the Working Memory App and Visual Search App groups with zero participants at risk. Each has zero serious adverse events, zero other adverse events, and zero deaths. These figures should not be read as evidence of safety among participants who received the clinical interventions: the primary outcome record states that neither clinical arm enrolled participants.

For Stage 1A Intervention Development, the registry lists 10 participants at risk, zero serious adverse events, zero other adverse events, and zero deaths. Those descriptive counts refer to the intervention-development group. They are not adverse-event comparisons between randomized clinical arms and do not establish what would have occurred during the planned clinical trial.

In general, an event count needs its corresponding population and observation period to be interpreted. A zero count in a group with no participants at risk is not an observed zero-event experience among treated participants. The registry does not report additional detail about adverse-event monitoring or event definitions beyond the categories and counts recorded.

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

The registry record documents a planned randomized comparison of a visual-spatial working-memory app with an app-based visual-search control for momentary craving in opioid use disorder. The primary endpoint was a modified single-item craving measure assessed from before a task to immediately afterward. The study was terminated before participants were enrolled in either clinical trial arm.

Accordingly, the posted results do not show whether craving increased, decreased, or stayed the same after either task. They do not estimate a difference between the app conditions, and they do not indicate the precision or statistical significance of such a difference. The absence of a clinical-arm estimate is not evidence of no effect, equivalence, or failure of either app. It means the registered clinical question was not answered with trial outcome data.

The enrollment figure of 10 pertains to Stage 1A intervention development. It should not be interpreted as 10 randomized participants or as a clinical trial sample. The registry reports no analyses. It also does not report the reason for termination, the planned sample-size justification, the statistical analysis plan, or the intended analysis populations.

The Stage 1A adverse-event figures describe 10 participants, with zero serious events, zero other events, and zero deaths recorded. The clinical arms have zero participants at risk, so their zero event counts are not safety observations among clinical intervention recipients. These counts cannot support a comparative safety conclusion.

The study’s underlying rationale concerned the possible relevance of working-memory engagement at the moment craving occurs. That rationale explains the question the trial set out to study, but it should not be confused with evidence that the intervention changed craving. The record establishes the trial design and its termination before clinical-arm enrollment; it does not establish the clinical efficacy or safety of either app.

13. Why This Trial Matters Statistically

This study illustrates a basic distinction between a well-defined clinical question and an answerable statistical comparison. The registry identifies two app conditions, a randomized parallel design, and an immediate craving endpoint. Those elements specify the intended comparison in broad terms. But a design cannot yield an effect estimate without enrolled participants and outcome observations in the comparison groups.

The distinction is especially important when a registry contains an overall enrollment count. Here, 10 participants entered Stage 1A intervention development, while the clinical trial arms did not enroll anyone. Keeping those populations separate prevents the development-stage count from being mistaken for evidence from the randomized comparison. It also prevents a misleading interpretation of precision or statistical power.

The record further illustrates why adverse-event counts need denominators and context. The clinical arms show zero participants at risk, while Stage 1A lists 10. A zero event count in the former does not describe observed experience among clinical-arm participants. The same principle applies to efficacy: no observed contrast is not the same as an observed contrast of zero.

From a statistical perspective, the most informative conclusion is therefore about the evidence boundary. The registry makes clear what primary question was intended and that it remained unanswered because clinical enrollment did not occur. It does not support claims about the magnitude or direction of an app effect, its uncertainty, or comparative safety. Recognizing that distinction is essential when interpreting incomplete trial records.

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 most consequential limitation is that the study was terminated before enrollment in either clinical trial arm. No primary outcome data were collected for the randomized comparison, so its effect and precision cannot be estimated. The registry record does not report why the study was terminated.

The total enrollment of 10 refers to Stage 1A intervention development, not the clinical trial arms. The record refers to baseline data for those Stage 1A participants, but the details of those data are not reported in the registry record information available for interpretation. The Stage 1A group cannot stand in for the randomized comparison.

The endpoint is described as a single-item measure adapted from the 3-Item Craving Scale, but the registry does not report its response options, scoring details, or criteria for a meaningful change. The timeframe is immediate, from pre-task to immediately post-task, so the registered endpoint does not itself address persistence of any change or longer-term clinical outcomes.

Important design and analysis details are not reported in the registry record. These include the intended allocation ratio, the identity of the masked party, the clinical trial sample-size justification, the statistical analysis plan, missing-data methods, and analysis populations. The reason for termination is also not reported. These gaps limit assessment of the planned analysis and trial conduct, although the lack of clinical-arm enrollment is sufficient to explain why no treatment comparison is available.

The safety counts require the same population distinction: zero events in clinical arms with zero participants at risk do not provide observed safety data for those interventions. Stage 1A counts are separate and do not establish comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Mobile Executive Functioning Intervention for Momentary Craving in Opioid Use Disorders — NCT05086835.
• Registry record last updated 2022-06-10; status last verified 2022-05.
• Results first posted 2022-06-10.
• 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

NCT05086835 was a randomized, single-masked, parallel-group study sponsored by Mclean Hospital. It planned to compare a visual-spatial working-memory app with an app-based visual-search control for momentary craving in opioid use disorder. The primary outcome was change on a modified single-item craving measure from pre-task to immediately post-task.

The study was terminated. The registry says this occurred before participants enrolled in either clinical trial arm, and no outcome data were collected. The enrollment figure of 10 refers to Stage 1A intervention development. The registry lists zero analyses. The reason for termination and the clinical trial’s statistical plan are not reported in the registry record.