Testing Brief Personalized Feedback Integrating Lab-based Alcohol Cue Information: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Testing Brief Personalized Feedback Integrating Lab-based Alcohol Cue Information (NCT05873556), a randomized na study. The primary outcome is Daily Drinking Questionnaire.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group study with no masking. Its title describes development and preliminary examination of two brief personalized feedback interventions, while the listed randomized comparison is the Lab-based Cue Reactivity Personalized Feedback Intervention versus assessment-only control. The intervention arm viewed personalized feedback online in the lab after completing the cue-reactivity protocol. The control arm completed assessments and the lab protocol without receiving personalized feedback.

The study description says participants in both groups completed baseline assessment, a lab-based cue-reactivity protocol, a 2-week follow-up, and a 3-month follow-up. The primary outcome timeframe lists baseline, 2-week follow-up, and 3-month follow-up. The outcome measures typical weekly drinking, using a three-month recall period at baseline and 3-month follow-up and a two-week recall period at the 2-week follow-up. Those differences in recall windows matter when interpreting measurements across time.

Enrollment was 93, and the registry status is completed. The record lists the study start as 2023-05-08 and primary completion as 2024-03-25. The randomized groups had 42 participants in the assessment-only control group and 51 in the personalized-feedback group for the posted safety counts. The registry record does not report the allocation sequence generation method, concealment procedures, or a detailed analysis plan. It also does not report why the sample size was chosen.

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

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 Daily Drinking Questionnaire, measured over Baseline, 2 week follow-up, and 3 month follow-up.

The primary endpoint is the Daily Drinking Questionnaire measure of drinks per week. Participants report the number of standard drinks consumed on each day of a typical week. Each day's response uses a scale from 0 (0 drinks) to 25 (25 or more drinks), and the daily values are summed to represent typical weekly consumption. The outcome is summarized as a mean with a standard deviation.

The measure is collected at baseline and at two follow-ups. Baseline and 3-month follow-up ask about the past 3 months, whereas the 2-week follow-up asks about the past two weeks. These differing recall periods mean that the outcome is not based on an identical observation window at every assessment. The record does not report how participants with incomplete daily responses were handled.

In general, a continuous measure such as mean drinks per week can describe the average level of reported drinking in a group and can be used to compare groups or follow-up measurements, provided an analysis specifies the comparison and accounts for the study design. The registry record identifies the endpoint and measurement schedule but does not report a single primary estimate, uncertainty interval, or test for this outcome.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the design establish?

The study is listed as randomized, parallel, and unmasked. In general, random assignment is intended to make treatment groups comparable on average at the point of assignment, including for characteristics that were not measured. A parallel-group design assigns participants to one group and compares their outcomes with those assigned to the other group. These design labels do not reveal how the random sequence was generated, whether assignment was concealed, or how the analysis dealt with follow-up measurements. Those details are not reported in the registry record.

The intervention is behavioral and the comparison is assessment-only control. The registry describes personalized feedback based on participants' responses in a lab-based alcohol cue-reactivity protocol. It also describes additional psycho-educational content about alcohol-related cues and coping with increased desire to drink. The intervention description for the feedback arm is truncated in the record, so its full content and delivery details are not reported there.

How should a mean outcome be understood?

The endpoint is a continuous measure summarized by a mean and standard deviation. In general, the mean represents the average value in a group, while the standard deviation describes the spread of participant values around that average. Neither quantity alone describes the difference between groups or how uncertain that difference is. An analysis would ordinarily need to identify the contrast of interest, such as a group difference at a particular follow-up or a difference in change over time. The registry record does not report a single such contrast or its estimate.

The daily response scale runs from 0 drinks to 25 or more drinks, with daily values summed into a typical weekly total. Because the highest response category is open-ended, the resulting measure is based on the recorded response scale rather than an unrestricted count of drinks. The registry record does not describe any additional handling of that upper category.

Why do repeated measurements need an analysis plan?

Baseline and two follow-ups provide repeated measurements for each participant. In general, measurements from the same person are related; treating them as independent observations can misstate uncertainty. An analysis of repeated measurements can account for within-person association, or an analysis can select one follow-up contrast. Different valid approaches can answer different questions and may yield different estimates. The record does not report the model, covariance assumptions, baseline adjustment, or specific follow-up contrast used.

The recall windows are not the same at all times: baseline and 3-month follow-up refer to the past 3 months, while the 2-week follow-up refers to the past two weeks. In general, outcome timing and recall period should be considered when interpreting change, because values collected over different windows may not represent exactly the same period of behavior. The registry record does not explain how this difference was incorporated into any analysis.

What do uncertainty and significance measures mean?

In general, a confidence interval conveys uncertainty around an estimated quantity, conditional on the statistical model and assumptions. It can help readers assess both the range of effects compatible with the data and the estimate's precision. A p-value, when reported, summarizes how unusual the data would be under a specified null hypothesis and analysis. Neither measure by itself states whether an effect is important in practice. The registry record does not report a confidence interval or p-value for the primary outcome, so these interpretations cannot be applied to a primary-effect estimate.

In general, over-dispersion means that observed variability is greater than expected under a chosen statistical model. It can matter when a model assumes less variability than the data contain, because standard errors and resulting uncertainty may be understated. The primary endpoint is presented as a continuous mean measure, but the registry record does not identify the model or report diagnostics. It is therefore not possible to say whether over-dispersion was assessed or relevant to the sponsor's analysis.

What can planning calculations tell readers?

In general, sample-size planning uses assumptions about a target effect, variability, significance level, allocation, and analysis method to estimate the number of participants needed for a design objective. A planning illustration based on an observed effect is not evidence that the original trial was designed around that effect, and it is not observed power. The registry record does not report the trial's own sample-size justification. It describes planning assumptions for illustrations, including a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects expressed as fractions of an observed effect. No planning count is interpreted as an observed trial result.

Because the registry record does not report an outcome estimate for the primary endpoint, a planning illustration cannot substitute for an observed comparison. A planning count describes a hypothetical design under its assumptions; it does not change the precision of the data collected in this completed study.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint has repeated assessment times, and the registry record notes that it has several categories or time points and is not reduced to one comparison. A study can pose multiple statistical questions across follow-up times, outcomes, or analyses. In general, testing multiple questions can increase the chance of at least one apparently unusual result when all null hypotheses are true. A multiplicity strategy may identify a primary contrast in advance, adjust inference across tests, or clearly label analyses as exploratory. The registry record does not report a multiplicity plan or identify one primary time-point contrast.

The record lists four outcome measures and eight analyses, but does not report a complete statistical analysis plan linking those analyses to a hierarchy of primary and secondary questions. It is therefore not possible to determine from the record how the analyses were selected, whether any adjustment was used, or which result should be treated as confirmatory.

The registry record does not report the extent or pattern of missing outcome data, reasons for missingness, or the methods used to handle incomplete measurements. In general, missingness can affect an estimate if participants with unobserved outcomes differ systematically from those with observed outcomes. Analyses may rely on different assumptions about why values are missing; sensitivity analyses can assess how conclusions change under alternative assumptions. No such assumptions or sensitivity analyses are reported in the registry record.

The record also does not specify the analysis population, such as whether all randomized participants were analyzed according to assigned group or whether another population was used. Without that information and without outcome estimates, readers cannot assess how exclusions or missing follow-up may have affected the posted primary-outcome results.

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 posted safety counts list 42 participants at risk in the assessment-only control group and 51 in the personalized-feedback group. In the control group, serious adverse events were 0, other adverse events were 0, and deaths were 0. In the personalized-feedback group, serious adverse events were 0, other adverse events were 0, and deaths were 0.

These counts describe what was recorded among participants at risk in each group. They do not provide a comparison of the primary outcome, which is weekly drinking, and they do not establish that no adverse event could occur. In general, zero observed events can coexist with uncertainty about the underlying event risk, especially when the number of people observed is limited. The registry record does not provide event definitions, exposure duration for safety monitoring, or further details about how events were collected. No serious adverse event terms are listed.

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

The registry record describes a randomized comparison of personalized feedback based on lab-based alcohol cue reactivity with an assessment-only control. It specifies a primary outcome based on typical weekly drinks and identifies baseline, 2-week, and 3-month assessment times. The record also reports safety counts with no events recorded in either group.

Those details do not establish whether the intervention changed weekly drinking. The registry record does not report group outcome summaries or an effect estimate for the primary endpoint, and it does not identify a single primary comparison across the follow-up times. There is consequently no reported numerical estimate whose direction, magnitude, or precision can be interpreted. The absence of a result in the registry record should not be read as a finding of no difference.

In general, an estimate of a group contrast would describe the observed difference under a specified analysis. Its confidence interval would convey uncertainty, and the study design and analysis assumptions would shape how broadly the result could be interpreted. Even a precise result would need to be understood in relation to the population studied, the intervention as delivered, and the outcome's measurement windows. The registry record does not report enough outcome or analysis detail to make those assessments for the primary endpoint.

The study description is preliminary and focused on developing and examining brief personalized feedback. It does not report evidence about effects outside the studied setting or population. It also does not report long-term outcomes beyond the listed follow-up schedule. No conclusion about clinical benefit, lack of benefit, or broader applicability can be drawn from the registry information alone.

13. Why This Trial Matters Statistically

This trial is statistically notable for combining randomized assignment with repeated self-reported drinking measurements. That structure raises familiar design questions: which follow-up contrast is primary, how repeated observations are handled, and how uncertainty is reported. The registry record identifies the measurements and assessment times but does not report the analysis choices or a single primary comparison. For readers, this distinction is important: a study design can be described even when its outcome evidence is not available for interpretation.

The outcome also uses different recall windows across assessments. Baseline and 3-month follow-up cover the past 3 months, while the 2-week follow-up covers the past two weeks. This means the study's time points do not all summarize the same length of recalled behavior. A clearly specified analysis and careful interpretation are needed to understand how these measurements relate to each other.

Personalized feedback based on lab cue responses is a behavioral intervention, and the control condition is assessment-only. This makes it important to distinguish the intended intervention contrast from the outcome contrast actually estimated. Randomization is a design feature, but the registry record does not provide the effect estimate, precision, missing-data account, or analysis population needed to evaluate the posted outcome evidence.

Finally, the study is listed as completed, while outcome estimates for the primary endpoint are not reported in the registry record. That gap illustrates why a registry description and posted results serve different purposes: design and measurement information clarify what was studied, whereas estimates and uncertainty are needed to judge what the observed data indicate.

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.

Several trial-specific limits affect interpretation of the registry record. The primary endpoint is identified, but no group means, standard deviations, effect estimates, confidence intervals, or p-values are reported for it. The registry record also states that the outcome has several time points and is not reduced to one comparison. As a result, there is no single primary contrast to characterize statistically.

The record lists baseline, 2-week follow-up, and 3-month follow-up, with different recall periods at the 2-week assessment than at baseline and 3-month follow-up. It does not report how this measurement difference was handled analytically. Nor does it describe the method for handling incomplete daily questionnaire responses or missing follow-up data.

The record does not report a detailed statistical analysis plan, the randomization procedure, allocation concealment, analysis population, or sample-size justification. The intervention description for the personalized-feedback arm is incomplete in the registry record. Masking is listed as none, and the record does not specify whether outcome assessment or data analysis was masked.

The enrollment was 93, with safety counts recorded for 42 control participants and 51 intervention participants. Those numbers describe the posted safety denominators, not the number contributing to each primary-outcome analysis; the record does not state outcome-specific analysis counts. The safety counts also lack further information about event definitions and monitoring. These limitations concern what can be learned from the registry record and do not establish the direction or size of any underlying intervention effect.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Testing Brief Personalized Feedback Integrating Lab-based Alcohol Cue Information — NCT05873556.
• Registry record last updated 2025-03-25; status last verified 2025-03.
• Results first posted 2025-03-25.
• 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

NCT05873556 is a completed randomized, parallel-group study titled “Testing Brief Personalized Feedback Integrating Lab-based Alcohol Cue Information.” Its official title describes development and preliminary examination of brief personalized feedback interventions focused on lab-based and EMA alcohol cues. The listed comparison is lab-based cue-reactivity personalized feedback versus assessment-only control, with no masking.

Enrollment was 93. The primary outcome is mean drinks per week on the Daily Drinking Questionnaire, assessed at baseline, 2-week follow-up, and 3-month follow-up. The record describes different recall periods for the 2-week assessment versus baseline and 3-month follow-up. It reports zero serious adverse events, zero other adverse events, and zero deaths in each group. It does not report a single primary-outcome comparison or its statistical estimate.