Alcohol Biosensor Monitoring for Alcoholic Liver Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Alcohol Biosensor Monitoring for Alcoholic Liver Disease (NCT03533660), a randomized na study. The primary outcome is Alcohol Use.

2. Clinical Question

3. Trial Design

The record describes a randomized, parallel-group trial with single masking. It lists two behavioral interventions: Feedback and Enhanced Usual Care. The Feedback arm received brief feedback based on data downloaded from the alcohol biosensor monitoring device, along with information about treatment resources. The Enhanced Usual Care arm received information about remaining abstinent and about treatment resources. The record does not report who was masked, how allocation was generated or concealed, or whether the groups received other study procedures.

The registry lists an enrollment of 33 and reports that data for 27 participants were analyzed for the primary outcome. These figures describe different aspects of the record; the reason for the difference is not reported in the registry record. The primary outcome description states that six participants drank alcohol and that their data are presented, while the remaining 21 had no alcohol use data to present. The record does not explain whether those without alcohol-use data were abstinent throughout, had unavailable device data, or had another reason for not contributing data to this endpoint.

The trial is marked completed. Its listed start date is 2018-09-13 and its primary completion date is 2021-02-28. The phase is listed as NA. The University of Pittsburgh is named as sponsor. These record details provide context, but do not establish the trial’s statistical design choices beyond the randomized, parallel structure and single masking reported in the registry. The planned allocation ratio, target enrollment rationale, masking procedures, and protocol deviations 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: We analyzed data for all 27 participants. Only 6 participants drank alcohol and their data is shown below. The remaining 21 participants had no alcohol use data to present.

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: These 27 participants are those that went through the initial intake assessment and thus are included in the analyses

6. Primary Endpoint

The registry lists the primary outcome as Alcohol Use, measured over continuous for up to 3 months.

The primary endpoint, titled Alcohol Use, is a continuous measure expressed in drinks per episode. It is described as the average number of drinks per drinking episode for each monthly interval of device wear, with observation described as continuous for up to 3 months. The record says the analysis presents a group average per month interval of assessment. This definition matters because the measure concerns drinking episodes, not an overall count of drinks across all days, and because the observation period is tied to device wear.

In general, a mean gives a group-level summary of measured values. It can make an outcome easier to compare between groups or across assessment intervals, but by itself it does not show how values vary among individuals. The registry identifies standard deviation as the measure of dispersion. In general, a standard deviation describes the spread of individual observations around a mean. It is distinct from a confidence interval, which describes uncertainty around an estimated quantity.

The endpoint is relevant to the stated research question because the trial proposes monitoring and feedback about alcohol use patterns. However, the registry record does not report the actual group means, standard deviations, confidence intervals, or a single contrast between the groups. It also does not report enough detail to establish how device wear or intervals with no recorded drinking contributed to the endpoint calculation.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The outcome is described as continuous and summarized using a mean with standard deviation. General explanation: a continuous measure can take values across a numerical scale, rather than belonging only to a set of categories. A mean summarizes the center of observed values. A standard deviation describes how dispersed those values are around the mean. Neither statistic alone explains the full distribution, and neither tells readers how uncertain a group comparison is.

What would a group comparison estimate?

In general, a randomized comparison aims to estimate how the measured outcome differs between assigned groups, under the analysis strategy chosen for the trial. For this endpoint, a comparison might be defined for a particular monthly interval or across multiple intervals, but the registry record does not report a single summary contrast. It also does not report whether the intended comparison was adjusted for baseline characteristics, how repeated observations were handled, or which statistical test or model was used. Those choices affect the interpretation of a reported estimate and its uncertainty.

A confidence interval, in general, presents a range of values compatible with the data and the assumptions of the statistical method. It communicates precision as well as direction and magnitude. A significance test addresses a different question: how compatible the observed data are with a specified null hypothesis under a model. The registry record does not report a confidence interval, test statistic, or p-value for the primary outcome. No inference about statistical significance or precision can therefore be made from the registry description alone.

How should the analysis population be read?

The primary outcome description says data were analyzed for 27 participants. It further states that six participants drank alcohol and their data are shown, while the remaining 21 had no alcohol use data to present. These statements should not be interpreted as proof that the latter participants had missing measurements, nor as proof that they remained abstinent. The reason they had no alcohol-use data to present is not reported in the registry record. The record also does not specify whether all randomized participants were analyzed according to their assigned group, or whether another analysis population was used.

General explanation: a missing-data method is needed when an outcome measurement that would be relevant to the analysis is unavailable. Different methods rely on different assumptions about why data are unavailable. A participant with no recorded drinking and a participant with unavailable monitoring data are not necessarily equivalent for analysis. The registry record does not describe how it distinguished these situations, whether it imputed any values, or whether it conducted sensitivity analyses.

What role do the planning assumptions play?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not a description of the trial’s original design rationale. Any resulting sample-size illustration is not observed power and should not be read as evidence that the completed trial had a particular probability of detecting an effect. The record does not report the trial’s own sample-size justification or whether the planning assumptions matched its protocol.

General explanation: a planning calculation asks how much information a future study might need under specified assumptions. It depends on the target effect, outcome variability, significance level, allocation, and analysis method. If the effect used for planning is estimated from the same study’s results, the calculation is an illustration rather than independent confirmation. The registry record does not give a protocol-based power calculation or an interim-analysis plan.

Why can dispersion matter?

General explanation: when outcomes vary substantially among individuals, a group mean alone may conceal that variation and estimates can be less precise. For count-like measures such as drinks per episode, values can also be unevenly distributed; some participants may have no drinking episodes while others contribute observations. In general, over-dispersion means that observed variability exceeds what a simple statistical model assumes. It can make standard errors and confidence intervals misleading if the model does not account for it. The registry record does not state whether over-dispersion was assessed or whether a model accommodating it was used.

These concepts explain what readers would need to assess a continuous group comparison, but they do not identify the method used in this trial. The specific primary-outcome analysis, model assumptions, adjustment strategy, and uncertainty estimates are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and three analyses. It names secondary outcomes involving readiness for abstinence and initiation of change, self-efficacy to remain abstinent, medical outcomes, and qualitative interviews. The primary outcome is described across multiple assessment intervals, and the registry does not reduce it to a single comparison. When a study examines several outcomes, time points, or analyses, the number of opportunities to observe an apparently notable result can increase. General statistical methods for addressing this include prespecifying a primary comparison, adjusting for multiple testing, or clearly treating other analyses as exploratory.

The registry record does not report whether a multiplicity strategy was prespecified, whether tests were adjusted, or how primary and secondary findings were prioritized. It does not report numerical findings for the listed secondary outcomes. The presence of multiple listed outcomes should therefore not be mistaken for evidence that all were formally tested or that a particular correction was used.

For the primary outcome, the record reports analysis of 27 participants and states that six drank alcohol, with data described for those participants. It says the other 21 had no alcohol use data to present. The reason for that distinction, the completeness of device observations, and the handling of any unavailable measurements are not reported in the registry record. No imputation method, missing-data sensitivity analysis, or analysis population beyond the stated description is reported in the registry record. Consequently, readers cannot determine from the registry whether the outcome summaries represent all randomized participants, only those with usable measurements, or another defined population.

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.

Most frequent non-serious adverse event terms

The registry reports serious adverse events affecting 0 of 14 participants in the Feedback group and 0 of 13 participants in the Enhanced Usual Care group. It reports other adverse events affecting 7 of 14 in Feedback and 7 of 13 in Enhanced Usual Care. The death count is 2 in each group. These are the figures recorded for the listed groups; they should be read as separate reported counts, not combined into a new total. The record does not clarify whether deaths overlap with the adverse-event counts.

The registry does not report serious adverse event terms, and it does not describe the nature, timing, severity, or relatedness of the reported events. It also does not state in the information recorded whether deaths were considered related to an intervention or to the study. The figures alone do not establish a cause or a comparative safety effect. General explanation: adverse-event counts are descriptive unless the reporting and analysis establish a suitable comparison, including how events were defined, collected, and attributed. Further safety details are not reported in the registry record.

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

The registry record establishes that a randomized, parallel-group study compared feedback based on alcohol biosensor data with enhanced usual care. It also describes the primary endpoint as average drinks per drinking episode by monthly interval of device wear, for observation extending up to 3 months. The outcome description makes clear that the displayed drinking data concerned six participants, while the other 21 analyzed participants had no alcohol use data to present.

What the registry does not establish is the numerical outcome in either group or the difference between groups. It reports no single primary comparison, estimate of uncertainty, or test result. Therefore, the record cannot show whether the feedback group had a higher or lower mean, how large any difference might have been, or how precisely it was estimated. A completed-trial status is not a substitute for those results.

In general, a trial’s randomized design can support a fair comparison when allocation, follow-up, outcome measurement, and analysis are appropriately implemented. The registry describes randomization but does not provide enough information to assess allocation procedures, the identity of the masked party, adherence to assigned interventions, or the handling of outcome data. Those details are not reported in the registry record.

The record also lists several secondary outcomes and adverse-event counts, but it does not give numerical results for the secondary measures or detail the adverse events. The counts should not be used to infer the cause of an event or a relationship to the intervention. Taken together, the record describes the trial question, interventions, and some features of outcome reporting, but it does not provide a complete statistical account of the primary result. It does not support a conclusion that either intervention did or did not change alcohol use.

13. Why This Trial Matters Statistically

This trial raises a statistical issue common to studies that use device-based monitoring: the outcome depends on what the device records and on the periods in which a participant wears it. Here, the primary measure is framed around drinks per drinking episode within monthly intervals of device wear. That definition is more specific than a general measure of alcohol consumption, but it also makes interpretation dependent on how drinking episodes, wear intervals, and unavailable observations were handled. Those details are not reported in the registry record.

The description also highlights how the analysis population and the endpoint population can differ in practice. The registry says data were analyzed for 27 participants, but only six drank alcohol and their data are described as presented; the remaining 21 had no alcohol use data to present. This distinction matters because the mean among participants with drinking observations may answer a narrower question than a summary intended to represent the entire randomized population. The record does not explain how the groups’ results were summarized in light of this distinction.

More generally, continuous outcomes measured repeatedly require a clear account of the estimand, time structure, and statistical method. A group mean and standard deviation do not by themselves explain change over time, uncertainty in the comparison, or the influence of participants without observed drinking data. The absence of a single reported contrast makes it especially important not to overread the trial’s design description as a result.

The registry also lists readiness, self-efficacy, medical, and qualitative outcomes. This broader scope may help characterize the questions the investigators intended to study, while making transparent reporting of outcome prioritization and multiplicity important. The record does not report those analysis details or numerical secondary findings. The statistical importance of this study record is therefore chiefly in clarifying what was measured and what information remains necessary for interpreting the comparison.

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 limitation of the registry record for interpreting the primary question is the absence of numerical group results and a summary comparison. Means, standard deviations, uncertainty estimates, and a statistical test are not reported in the registry record. The outcome is described across monthly intervals for up to 3 months, but no single summary contrast is given. As a result, the direction, magnitude, and precision of any observed difference cannot be assessed.

The record states that 27 participants contributed to the primary analysis description, but only six drank alcohol and their data are described as presented. It says the remaining 21 had no alcohol use data to present without clarifying why. The record does not report the number of participants with drinking observations in each arm, the amount of device wear, or how the interval-specific data were handled. These omissions limit assessment of both the endpoint and the comparability of observations between groups.

Further methodological details are not reported in the registry record, including allocation procedures, the identity of the masked party, the analysis model, treatment of repeated measurements, adjustment for baseline values, missing-data methods, and sensitivity analyses. The record also does not report the trial’s sample-size justification or multiplicity strategy. These limitations concern what can be learned from the registry entry; they do not establish that the study protocol lacked those procedures.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Alcohol Biosensor Monitoring for Alcoholic Liver Disease — NCT03533660.
• Registry record last updated 2022-11-07; status last verified 2022-11.
• Results first posted 2022-11-07.
• 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

The registry describes a completed, randomized, parallel-group, single-masked trial sponsored by the University of Pittsburgh. It compared Feedback based on alcohol biosensor data with Enhanced Usual Care, which included information about abstinence and treatment resources. The listed enrollment is 33. The primary outcome is average drinks per drinking episode by monthly interval of device wear, for up to 3 months. The registry says 27 participants were analyzed, six drank alcohol and had data described as presented, and 21 had no alcohol use data to present.

Numerical primary-outcome results and a single group comparison are not reported in the registry record. The record lists secondary outcomes and adverse-event counts, but does not give numerical secondary-outcome results or detailed event descriptions. The reasons for the primary-outcome data pattern, analysis methods, and missing-data procedures are not reported in the registry record.