This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Alcohol Research Consortium in HIV-Intervention Research Arm (NCT02938377), a non-randomized phase 4 study. The primary outcome is Audit-C Score on a Scale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02938377 |
| Phase | Phase 4 |
| Condition | HIV Positive, Alcohol Use |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 4985 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Alabama at Birmingham |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with HIV and alcohol use. Its registry record describes treatment pathways according to alcohol use disorder (AUD), risky drinking, panic, and depression. The listed categories range from no diagnosis of AUD, panic, or depression to AUD with or without panic or depression. The recorded enrollment is 4985. The registry record does not provide further eligibility criteria or describe the characteristics of participants who contributed data to the primary outcome.
Intervention
The record describes an algorithm-guided approach that varies with the listed clinical category. The least intensive description is a Computerized Brief Intervention (CBI), described as a video about alcohol abuse. For risky drinking without an AUD diagnosis alongside panic or depression, the description adds four sessions of Motivational Enhancement Therapy. For AUD with or without panic or depression, it adds those counseling sessions and a recommendation for alcohol pharmacotherapy. The registry does not report whether each recommended treatment was taken up or completed.
Comparator
Allocation is recorded as non-randomized, with no masking and a parallel model. The record does not identify a randomized control group or a like-for-like comparison between treatment pathways. Because the described pathways depend on clinical category, people in different groups may differ before treatment. The registry record does not report an alternative untreated comparator or a method that would make the groups exchangeable for causal comparison.
Primary question
The primary outcome is the difference in AUDIT-C score before and after intervention, measured over an 18 month window. AUDIT-C is an alcohol-use screening score on a scale from 0-12; higher scores generally indicate a greater likelihood that drinking affects health and safety. The record does not report the observed pre/post differences, group means, confidence intervals, or a statistical test for this endpoint. Thus, the clinical question is described, but the magnitude, direction, and precision of the posted outcome are not reported in the registry record.
3. Trial Design
The registry identifies NCT02938377 as the Alcohol Research Consortium in HIV-Intervention Research Arm, a Phase 4 study sponsored by the University of Alabama at Birmingham. Its status is completed. The recorded study start is 2017-11-06, and primary completion is recorded as 2022-11-01. Enrollment is 4985. These registry descriptors establish the broad setting and conduct status, but they do not by themselves describe how participants were selected, how the treatment algorithm was applied in practice, or how outcome observations were collected.
The design is listed as parallel, non-randomized, and unmasked. Non-randomized allocation means that treatment pathways were not assigned by random allocation according to the registry description. The intervention descriptions link treatment intensity to clinical categories: CBI alone for people without the listed diagnoses, CBI plus counseling for risky drinking with panic or depression and no AUD diagnosis, and CBI plus counseling and a pharmacotherapy recommendation for diagnosed AUD. Since these categories may differ in relevant ways, a comparison across them should not be interpreted as if it arose from randomization.
The study aims include examining alcohol consumption and AUD symptoms, retention in HIV care and HIV-related outcomes, and comorbid conditions. PEth levels are listed as a secondary outcome. The primary endpoint is an AUDIT-C pre/post difference. The registry record does not report detailed allocation procedures, masking procedures beyond the designation of none, follow-up completeness, the statistical analysis plan, or the outcome estimates. It also does not report whether the recommended pharmacotherapy was initiated or maintained. The study's completed status should therefore be distinguished from the availability of interpretable results in this 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
| Stage | Risky Drinking, no dx of AUD, Has Panic or Depression | Dx of AUD With or Without Panic or Depression | No dx of Alcohol Use Disorder, Panic or Depression |
|---|---|---|---|
| STARTED | 115 | 27 | 4843 |
| COMPLETED | 115 | 27 | 4843 |
| NOT COMPLETED | 0 | 0 | 0 |
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.
| Characteristic | Unit | Risky Drinking, no dx of AUD, Has Panic or Depression | Dx of AUD With or Without Panic or Depression | No dx of Alcohol Use Disorder, Panic or Depression | Total |
|---|---|---|---|---|---|
| Participants analysed | 115 | 27 | 4843 | 4985 | |
| Age, Continuous | years | 48 (SD 12) | 45 (SD 11) | 49 (SD 12) | 47 (SD 12) |
| Sex: Female, Male: Female | Participants | 22 | 3 | 969 | 994 |
| Sex: Female, Male: Male | Participants | 93 | 24 | 3874 | 3991 |
| Race/Ethnicity, Customized: Non-Hispanic White | Participants | 45 | 9 | 1839 | 1893 |
| Race/Ethnicity, Customized: Non-Hispanic Black | Participants | 55 | 8 | 2151 | 2214 |
| Race/Ethnicity, Customized: Hispanic | Participants | 11 | 9 | 649 | 669 |
| Race/Ethnicity, Customized: Other | Participants | 4 | 1 | 204 | 209 |
6. Primary Endpoint
The registry lists the primary outcome as Audit-C Score on a Scale, measured over 18 month window.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the difference in AUDIT-C score before and after intervention, within an 18 month window. AUDIT-C is a brief alcohol-use measure scored from 0-12, with 0 reflecting no alcohol use according to the registry description. The record notes thresholds of 4 or more for men and 3 or more for women as positive, and explains that higher scores generally correspond to a greater likelihood that drinking affects health and safety. These thresholds describe screening interpretation; the stated primary outcome is a score difference, not simply whether a threshold is crossed.
A continuous score can retain gradations of change that would be lost if the measure were reduced to a positive/negative classification. In general, a mean summarizes the average score in a group, while a confidence interval communicates uncertainty around an estimated quantity under the analysis assumptions. Neither a mean nor a confidence interval establishes that a change was caused by treatment, particularly in a non-randomized study.
The registry record gives the endpoint definition but does not report baseline or follow-up means, the estimated pre/post difference, a confidence interval for that difference, or the number of participants with usable measurements. It also does not clarify exactly how observations within the 18 month window were selected or handled. The outcome's direction and precision therefore cannot be assessed from the registry record alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a clinically relevant question: whether alcohol-related scores change after algorithm-guided care among people with HIV and alcohol use. It identifies the AUDIT-C pre/post difference as the primary endpoint and gives the measurement window. However, the registry record does not report the result of that endpoint. No observed score change, group estimate, confidence interval, or statistical test is stated. Consequently, the posted registry information does not establish whether scores increased, decreased, or remained similar, nor how precisely any change was estimated.
Non-randomized allocation is important to interpretation. The treatment pathways are linked to recorded clinical categories, rather than assigned at random. The groups may therefore differ in initial alcohol use, comorbidities, care needs, or other characteristics related to outcome. A difference between pathways could reflect those initial differences, treatment exposure, or other influences. The registry record does not report an adjustment strategy or enough information to judge how such differences were addressed. This makes an unadjusted comparison across pathways unsuitable as a straightforward causal estimate.
A pre/post comparison also has limits. A change after intervention describes how a measured outcome differs over time, but alone does not show what would have happened without intervention. Changes in circumstances, care, measurement, or participant follow-up can contribute to observed change. General statistical interpretation treats a confidence interval as a range of values compatible with the estimate under the model and assumptions; it is not a guarantee that the true effect lies within that range, and it does not eliminate bias from study design.
The endpoint is a score, not a direct measure of every aspect of alcohol use or health. Although the registry explains the score scale and screening thresholds, the primary endpoint is defined as a difference in score. A change in an average score would not necessarily mean that every participant changed in the same direction, and a group average would not by itself show the distribution of individual responses. The registry record does not report those distributions or how missing assessments were handled.
Enrollment and completed status describe the study record but do not substitute for outcome reporting. The registry record lists PEth levels as a secondary outcome, but does not report results for it. It also does not report estimates for the aims concerning HIV care, HIV-related outcomes, or comorbid conditions. Interpretation must therefore remain limited to what is recorded: the study's question, design, measures, and safety counts. No conclusion about the direction, size, clinical importance, or causal effect of treatment can be drawn from these registry entries alone.
9. Statistical Methods Explained
What does a mean score describe?
The primary outcome is described as a mean of a continuous measure. In general, a mean represents the arithmetic average of the scores included in an analysis. For a pre/post endpoint, the target may be an average within-person change or a difference between summaries at two time points; the exact analysis definition matters. The registry describes a difference in Audit-C score, pre and post intervention, but does not report the calculation details or its estimate. It is therefore not possible to identify from the registry record whether the reported analysis, if any, used paired observations, a model for repeated measures, or another approach.
A mean is useful because it summarizes the central level of a score, but it can conceal variation. Participants can have different starting scores and different trajectories even when the group average changes little. General interpretation benefits from knowing the spread of observations and the number with paired measurements, in addition to the mean. Those details are not reported in the registry record.
What does a confidence interval add?
The endpoint identifies a 95% Confidence Interval as its dispersion measure. In general, a confidence interval expresses statistical uncertainty around an estimate under the chosen model and assumptions. A narrower interval indicates greater precision in the estimate under those assumptions; a wider interval indicates more uncertainty. It does not show the range of individual participant outcomes, and it does not account automatically for systematic bias, confounding, measurement error, or selective missingness.
The registry record does not state the confidence interval for the primary endpoint, nor does it report the estimate around which such an interval would be formed. Its presence as a planned or designated dispersion format is not a result. Without the estimate and interval, neither magnitude nor precision can be assessed.
Why does non-randomized allocation matter?
In a randomized study, random assignment is intended to balance measured and unmeasured baseline factors on average. This study is recorded as non-randomized. The described pathways are assigned according to alcohol-use and comorbidity categories, so groups can differ by design. In general, statistical adjustment can account for measured characteristics when appropriate data and a defensible model are available, but adjustment cannot guarantee removal of confounding from unmeasured factors or poorly measured variables.
The registry record does not report a statistical adjustment method, covariates, model specification, or whether the primary endpoint was analyzed within pathways or between pathways. Those omissions prevent assessment of the comparability of estimates and the assumptions behind any adjusted result. A before-and-after change within a group also lacks a concurrent untreated counterfactual unless an appropriate comparison and analysis are reported.
What is over-dispersion, and why might it matter?
General statistical explanation: over-dispersion occurs when observed variability is greater than a model assumes. It is most directly relevant to count or binary outcomes analyzed using models with restrictive variance assumptions; it can make standard errors too small if ignored. The primary endpoint is described as a continuous score summarized by a mean, so count-model over-dispersion is not itself the central issue for that endpoint. Variation, skew, repeated observations, and correlation within participants may still matter, depending on the analysis. The registry record does not identify the model used, so its assumptions cannot be evaluated.
The record also lists PEth levels as a secondary outcome, but does not specify their analysis model or results. No methodological conclusion about distributional assumptions for that outcome is possible from the registry record.
How should significance and sample-size planning be understood?
General explanation: a p-value evaluates how unusual data at least as extreme as those observed would be under a specified null model and its assumptions. It is not the probability that a treatment is effective, and statistical significance alone does not establish clinical importance or causality. The registry record does not report a p-value or test for the primary endpoint.
The record describes sample-size planning illustrations as based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. Such illustrations are conditional planning scenarios, not observed power. They do not show the probability that the completed study produced a statistically significant result. The registry record does not state the numerical planning results, the observed effect used in those illustrations, or the trial's own sample-size justification.
The record also does not report interim analyses, stopping rules, or a full statistical plan. These details should not be inferred from the study's phase, completion status, or enrollment. Overall, the statistical methods can be described only at the level of the recorded endpoint and planning assumptions; the specific analysis that generated an outcome estimate is not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The study description names several aims: alcohol consumption and AUD symptoms, retention in HIV care and HIV-related outcomes, and comorbid conditions. It identifies AUDIT-C score change as the primary endpoint and PEth levels as a secondary outcome. When a study considers multiple outcomes, time points, subgroups, or comparisons, the chance of at least one apparently notable result can increase. General approaches to multiplicity include specifying a primary hypothesis in advance, adjusting inference across selected tests, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy, a hierarchy for secondary outcomes, or which analyses were designated confirmatory.
The record does not report a detailed missing-data plan. For a pre/post score, incomplete follow-up can affect which observations contribute to the estimated change. In general, complete-case analysis can be biased if having a recorded follow-up score is related to outcome or participant characteristics. Other methods require assumptions about the missingness process and the data structure. The registry record does not state the amount or pattern of missing primary-outcome data, the method used to handle it, or any sensitivity analysis.
Analysis populations are also not described. The registry record does not specify whether the primary analysis included everyone enrolled, only people who received an intervention, only people with paired measurements, or another defined population. It does not describe adherence, treatment uptake, exclusions, or protocol deviations. Without these details, readers cannot determine precisely who contributed to each endpoint or how the analysis population relates to the enrollment figure.
The registry lists zero analyses in its outcome information. It does not report inferential results for the stated primary and secondary outcomes. Therefore, multiplicity, missing-data handling, and analysis-population choices cannot be evaluated from the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Risky Drinking, no dx of AUD, Has Panic or Depression | 0 | 115 | 0.0% |
| Dx of AUD With or Without Panic or Depression | 0 | 27 | 0.0% |
| No dx of Alcohol Use Disorder, Panic or Depression | 0 | 4843 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Risky Drinking, no dx of AUD, Has Panic or Depression | 0 of 115 |
| Dx of AUD With or Without Panic or Depression | 0 of 27 |
| No dx of Alcohol Use Disorder, Panic or Depression | 0 of 4843 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Risky Drinking, no dx of AUD, Has Panic or Depression | 0 of 115 |
| Dx of AUD With or Without Panic or Depression | 0 of 27 |
| No dx of Alcohol Use Disorder, Panic or Depression | 0 of 4843 |
The registry's serious adverse event information is presented by the listed groups. For “Risky Drinking, no dx of AUD, Has Panic or Depression,” the serious-event count at risk is 115 and the serious-event count affected is 0; deaths are 0. For “Dx of AUD With or Without Panic or Depression,” the corresponding serious-event counts are 27 at risk and 0 affected, with deaths at 0. For “No dx of Alcohol Use Disorder, Panic or Depression,” they are 4843 at risk and 0 affected, with deaths at 0. The registry also records zero affected for other adverse events in each listed group.
These fields should be read as the registry's recorded counts, not as proof that no adverse events of any kind occurred. In particular, the record does not report event-term details, collection procedures, reporting thresholds, duration of safety follow-up, or whether the listed “at risk” counts represent all people exposed to each pathway. No serious adverse event terms are listed. The absence of listed terms does not establish that every possible harm was assessed or that the groups had equivalent safety monitoring.
Because allocation was non-randomized and the record does not describe comparative safety analyses, these counts do not support a causal comparison between pathways. They are descriptive registry entries with limited context. The registry record does not report statistical uncertainty for these safety counts.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the study was a completed Phase 4, non-randomized, parallel investigation of algorithm-guided alcohol treatment for people with HIV and alcohol use. It describes how intervention content varied by alcohol-use and comorbidity category and identifies a pre/post AUDIT-C score difference over an 18 month window as the primary endpoint. These details explain the question and broad design, but they are not evidence of an outcome's direction or magnitude.
The primary endpoint result is not reported in the registry record. Without a pre/post estimate and confidence interval, it is not possible to assess the size, precision, or statistical compatibility of a score change. No conclusion about treatment benefit, lack of benefit, or clinical importance follows from the outcome definition alone. The endpoint's screening thresholds do not replace a reported estimate, and the score itself does not represent every dimension of alcohol use, HIV care, or health.
The non-randomized design further limits causal interpretation. The groups are defined by clinical characteristics and may differ in ways related to their outcomes. A change over time may reflect intervention exposure as well as other influences, and the record does not report a comparison strategy that isolates those contributions. Thus, even if an estimate were available, its causal meaning would depend on the analysis and assumptions, which are not reported in this registry record.
The listed adverse-event counts are descriptive. They do not provide complete information about monitoring or ascertainment and should not be read as a comprehensive assessment of safety. The record also does not report results for PEth levels or for the stated aims related to HIV care, HIV-related outcomes, and comorbid conditions.
In short, this record supports description of study design, intervention pathways, and outcome definitions, but not conclusions about efficacy or the direction of observed changes. Readers need outcome estimates, uncertainty measures, analysis details, and information on missing observations to judge the results and their limitations.
13. Why This Trial Matters Statistically
This study raises a useful statistical question because it links alcohol-related treatment decisions to clinical categories in a population with HIV and alcohol use. It also names outcomes at more than one level: alcohol-use scores, PEth levels, HIV care and HIV-related outcomes, and comorbid conditions. The registry's description therefore illustrates how an intervention strategy can have multiple intended targets and why outcome definitions and analysis priorities matter.
The design is statistically important as well. Treatment allocation is non-randomized and the pathways correspond to different clinical profiles. This creates a central challenge for interpretation: observed differences may reflect baseline differences between groups as well as treatment exposure. A careful analysis would need to define its comparison, describe relevant confounders, and make clear what causal assumptions are being made. The registry record does not report those analytic details, so readers should not mistake a pathway comparison for a randomized treatment contrast.
The primary endpoint focuses on a continuous pre/post score, for which the estimated change and its confidence interval would be essential to understanding both direction and precision. Yet the registry record does not report those quantities. This gap underscores a broader reporting principle: study completion and enrollment are not substitutes for transparent outcome results, analysis populations, missing-data methods, and uncertainty.
The record also provides a setting for distinguishing descriptive safety counts from comparative safety evidence. Counts with no affected events in the registry fields are informative as recorded, but without monitoring and follow-up details they do not resolve broader safety questions. The statistical value of the record lies in clarifying the design and questions while also making clear what information remains unavailable for independent interpretation.
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 registry record does not report the primary endpoint estimate, confidence interval, or test result. This is the most direct limitation for interpreting the study's stated primary question: neither the direction nor magnitude of any AUDIT-C change can be assessed. The record also does not report baseline and follow-up score summaries, the number with paired observations, or how measurements within the 18 month window were selected.
Non-randomized allocation is a design limitation for causal comparisons. The treatment pathways correspond to different AUD, risky-drinking, panic, and depression categories, which may differ in prognostic characteristics. The registry record does not report group comparability, confounder adjustment, or sensitivity analyses. It also does not explain whether comparisons were made between pathways, within pathways over time, or against another reference.
Important operational details are not reported in the registry record, including eligibility criteria, recruitment and retention, intervention uptake, treatment adherence, treatment switching, and the handling of protocol deviations. The analysis population, missing-data methods, outcome-specific participant counts, multiplicity strategy, and statistical model are also not reported. These omissions constrain assessment of bias, precision, and reproducibility.
For safety, the record lists adverse-event counts but does not describe event ascertainment, the safety follow-up period, reporting thresholds, or the meaning of the “at risk” fields. The record identifies PEth levels and several study aims but does not report their results. Enrollment and completed status do not resolve these limitations or provide evidence about outcomes that are absent from the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Alcohol Research Consortium in HIV-Intervention Research Arm — NCT02938377.
- Registry record last updated 2025-03-10; status last verified 2025-02.
- Results first posted 2025-03-10.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT02938377 is recorded as a completed Phase 4, non-randomized, unmasked, parallel study sponsored by the University of Alabama at Birmingham, with enrollment of 4985. The study examines algorithm-guided alcohol treatment among people with HIV and alcohol use. Its intervention descriptions vary by clinical category and include a Computerized Brief Intervention, counseling, and a recommendation for alcohol pharmacotherapy.
The primary outcome is the pre/post difference in AUDIT-C score over an 18 month window. PEth levels are listed as a secondary outcome. The study aims also address alcohol use and AUD symptoms, retention in HIV care, HIV-related outcomes, and comorbid conditions. The registry record does not report the primary outcome estimate, confidence interval, or inferential results for the listed outcomes. It records zero affected serious adverse events and zero deaths in each listed group, without providing further safety-monitoring details.