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 An Open Label Trial of Bupropion and Naltrexone for Binge Drinking (NCT02842073), a na phase 2 study. The primary outcome is Number of Participants With Treatment-Associated Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02842073 |
| Phase | Phase 2 |
| Condition | Binge Drinking |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of North Carolina, Chapel Hill |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned binge drinkers. The registry record lists Binge Drinking as the condition and describes the study as a pilot of bupropion and naltrexone for binge drinkers. Further eligibility details, including age criteria and how binge drinking was defined, are not reported in the registry record.
Intervention
Participants received bupropion and naltrexone in an open-label, single-group study. The arm description specifies bupropion-XL at 150 mg/d on Days 1-4, increasing to 300 mg/d for Days 5-84, and describes naltrexone initiation at 25 mg. The description ends before giving the remainder of the naltrexone schedule.
Comparator
There was no separate comparator group in the registered design. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. The registry record therefore does not describe a randomized comparison or a like-for-like control group.
Primary question
The primary endpoint counted participants with treatment-associated adverse events over 12 weeks. In practical terms, the study asked whether adverse events were reported while participants received the combination and how many participants experienced them. The posted safety figures distinguish serious adverse events from other adverse events. They do not establish whether events were caused by treatment. The registry also lists craving and drinks per binge-drinking day as secondary outcomes, but their results are not reported in the registry record.
3. Trial Design
This was an open-label Phase IIa pilot study of bupropion and naltrexone for binge drinkers. The registry lists the study as completed, with an enrollment of 12 participants. Its design is recorded as single-group, with no masking and allocation listed as NA. There is no separate control arm in the registry record, so changes over time cannot be compared with outcomes in a concurrent untreated or alternative-treatment group.
The intervention arm is titled “Naltrexone and Buproprion” in the registry. The description gives a bupropion-XL schedule of 150 mg/d on Days 1-4 followed by 300 mg/d for Days 5-84. It describes naltrexone initiation at 25 mg, but the remainder of that dosing schedule is not reported in the registry record. The brief summary characterizes the study as assessing tolerability and effects on binge drinking.
The primary endpoint was the number of participants with treatment-associated adverse events over 12 weeks. The listed secondary outcomes were final Penn Alcohol Craving Scale (PACS) score and mean number of drinks per binge-drinking day during treatment. The registry lists five outcome measures in total, but results for the secondary outcomes are not reported in the registry record. The record lists no analyses.
The study start date is 2016-11-01 and the primary completion date is 2017-12-13. Those dates describe the registry timeline; they do not add information about the detailed analysis procedures, follow-up completeness, or results beyond the posted counts.
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 | Naltrexone and Buproprion |
|---|---|
| STARTED | 12 |
| COMPLETED | 11 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Naltrexone and Buproprion |
|---|---|
| Withdrawal by Subject | 1 |
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 | Naltrexone and Buproprion |
|---|---|---|
| Participants analysed | 12 | |
| Age, Continuous | years | 33.1 (SD 2.0) |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 |
| Race (NIH/OMB): White | Participants | 9 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 12 |
| Number of Binge Drinking Days in 90 days prior to screening | days | 17.3 (SD 7.8) |
| Intensity of Binge Drinking prior to Study | drinks/binge drinking day | 8.4 (SD 1.0) |
| Craving for Alcohol | units on a scale | 11.25 (SD 7.1) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Treatment-Associated Adverse Events, measured over 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with treatment-associated adverse events during a 12-week timeframe. It is a count of people, not a count of individual events. A participant may experience more than one event, but a participant-level count records whether a person is included as having an event rather than how many events that person had. The registry description says tolerability was assessed by specifically probing for intervention-associated adverse effects.
Adverse-event monitoring is used to characterize tolerability during a study. In an open-label, single-group design, reported events can be described among those enrolled, but the endpoint by itself does not determine whether an event was caused by the intervention. Without a comparator, the registry record cannot show how often similar events might have occurred in the absence of the study intervention or under another condition.
The posted safety figures list 0 participants at risk for serious adverse events as affected, 11 participants at risk for other adverse events as affected, and 0 deaths. These figures describe the reported counts; they do not provide event descriptions for the non-serious events. The registry’s primary endpoint is broader than a serious-event-only measure, so the absence of serious events should not be read as absence of all adverse events.
The registry also names craving and drinks per binge-drinking day as secondary outcomes. Their results are not reported in the registry record, so they cannot be used to describe changes during treatment.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central reported safety finding is that 0 of the 12 participants at risk were reported with a serious adverse event, while 11 of the 12 participants at risk were reported with other adverse events. The record also reports 0 deaths. These are descriptive counts from a small, single-group study. They convey what was recorded among enrolled participants, not a comparison of event rates between treatment groups.
The primary endpoint is participant-based. The distinction matters: the count of participants with an event does not show the total number of events, the number of events per participant, their severity beyond the serious-versus-other categorization, or how long they lasted. The registry record does not list the terms for the other adverse events, and no serious adverse-event terms are listed. Detailed event narratives, timing, and management are not reported in the registry record.
Zero serious events in this study is a descriptive observation, not proof that serious events cannot occur. A small study can provide limited information about uncommon outcomes, and a single-group study cannot estimate a comparative treatment effect. General statistical principle: an observed count is subject to sampling uncertainty, particularly when the number of participants is small. No confidence interval or inferential analysis for the safety counts is reported in the registry record.
The study was open-label and had no comparator. Awareness of the intervention can influence reporting or assessment of subjective symptoms; the extent of any such influence is not reported in the registry record. In addition, the endpoint description says adverse effects were specifically probed, but does not describe the probing instrument or assessment schedule. These details limit interpretation of what was captured.
The registry names final PACS score and mean number of drinks per binge-drinking day during treatment as secondary outcomes, but posts no results for them. Therefore, the record supports no numerical conclusion about craving scores or drinking behavior. The stated study purpose includes effects on binge drinking, but purpose alone is not evidence of a measured change.
Overall, the posted counts describe adverse-event experience in the enrolled group during the stated timeframe. They do not establish causation, comparative safety, or effects on drinking or craving. The record lists no analyses, and the statistical plan, handling of missing observations, and analysis populations are not reported in the registry record.
9. Statistical Methods Explained
The registry identifies a single-group study with no masking and no allocation to comparative arms. This design determines what the counts can answer. A single-group count can describe what was observed among participants receiving the study intervention. It cannot, on its own, separate intervention-related effects from events that might also occur without the intervention. General statistical principle: a control group can provide a reference for comparison, while a single-group study has no concurrent reference group.
What a participant count represents
The primary outcome is defined as the number of participants with treatment-associated adverse events. This is a binary classification at the participant level: each participant is classified as having or not having a recorded event under the endpoint definition. The count is not the number of event episodes. Several events in one participant may still contribute one affected participant to a participant-level count. The registry record does not state how multiple events in one person were handled in any event-level summaries, and it lists no such summaries.
The posted safety figures separate serious adverse events, other adverse events, and deaths. Those categories should be read as distinct reported counts, not added or converted into a rate. The denominator shown for the serious and other adverse-event groups is 12 participants at risk. The record does not provide person-time, event onset dates, or duration, so an event rate over person-time cannot be interpreted from these counts.
Precision and uncertainty
General explanation: a confidence interval describes a range of values compatible with data under a specified statistical method and assumptions. It conveys uncertainty around an estimate; a wider interval generally indicates less precision. The registry record does not report confidence intervals for these counts. It also does not report a hypothesis test or p-value for the primary endpoint. Consequently, the posted safety numbers are descriptive rather than the result of a reported inferential comparison.
When counts are small, a zero observed count remains compatible with uncertainty about the underlying event frequency. General statistical principle: absence of an observed event in a study does not demonstrate that the event is impossible or that its true frequency is zero. The amount of information depends in part on how many participants were observed and how completely events were assessed. The registry reports enrollment and at-risk counts but does not report a detailed account of follow-up completion or missing safety assessments.
Design and causal interpretation
General explanation: random allocation and a concurrent comparator help make groups comparable, although they do not eliminate every source of uncertainty. This study is registered as single-group, with allocation NA and masking NONE. There is therefore no randomized between-group contrast to estimate. Events observed during treatment may be temporally associated with the treatment period, but the registry’s label “treatment-associated” does not by itself establish causation. The record does not report a causal attribution procedure.
Open-label status means the study was not masked. General explanation: knowledge of treatment can affect how subjective experiences are reported or assessed. The registry does not describe whether outcome assessors were separate from participants or investigators, or how adverse effects were elicited beyond noting that they were specifically probed. The consequences of these features cannot be quantified from the record.
Planning illustrations and the trial analysis
The registry record lists no analyses. It does not report a protocol-based sample-size justification or a formal statistical analysis plan. Any sample-size planning illustration based on the observed effect uses two-sided significance level 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those are planning assumptions, not evidence that the trial had two arms. They do not match the registered single-group design, and sample-size illustrations are not observed power. No sample-size justification for this study is reported in the registry record.
The record does not state an interim analysis plan, a model for the primary endpoint, or a method for estimating uncertainty. It also does not report adjustment for covariates or a prespecified rule for handling repeated or recurrent events. These absences mean that the statistical method behind any unposted analysis cannot be reconstructed from the registry entry. The listed outcome and counts can be described, but additional inferential claims would require methods and results that are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures, including the primary adverse-event endpoint and secondary outcomes for final PACS score and mean number of drinks per binge-drinking day during treatment. It reports no analyses. A multiplicity strategy—how to interpret results across several outcomes while accounting for multiple statistical tests—is not reported in the registry record. No multiplicity-adjusted results or unadjusted tests are posted.
Missing-data handling is also not reported in the registry record. The entry does not describe whether any participants missed visits, whether outcome observations were incomplete, how missing values were treated, or whether sensitivity analyses were conducted. The at-risk counts in the safety record do not by themselves establish completeness of all outcome assessments across the study.
The record does not define analysis populations, such as a population based on enrollment, treatment exposure, or completion. It therefore does not specify which participants would have been included in any analysis of drinking or craving outcomes. No interim analyses or statistical analysis plan are reported in the registry record. These omissions limit assessment of the planned analysis and prevent interpretation of unposted secondary-outcome findings.
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 |
|---|---|---|---|
| Naltrexone and Buproprion | 0 | 12 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Naltrexone and Buproprion | 0 of 12 |
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 |
|---|---|
| Naltrexone and Buproprion | 11 of 12 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Naltrexone and Buproprion |
|---|---|---|
| Headache | Nervous system disorders | 5 of 12 |
| Constipation | Gastrointestinal disorders | 3 of 12 |
| Irritability | Nervous system disorders | 3 of 12 |
| Insomnia | Nervous system disorders | 2 of 12 |
| Dizziness | Nervous system disorders | 2 of 12 |
| Low energy | General disorders | 2 of 12 |
| Nausea | Gastrointestinal disorders | 2 of 12 |
| Reduced Appetite | General disorders | 1 of 12 |
| Dry Mouth | General disorders | 1 of 12 |
The safety record lists 0 serious adverse events among 12 participants at risk, 11 participants with other adverse events among 12 at risk, and 0 deaths. These figures indicate that other adverse events were recorded for many participants in the study group, while no serious adverse events or deaths are listed in the posted counts. No serious adverse-event terms are listed.
The endpoint counts participants rather than individual adverse-event episodes. The count of 11 therefore does not establish how many events occurred, whether participants experienced one or several events, or how severe the events were. The specific terms for the other adverse events are not reported in the registry record. The record also does not report event timing or duration.
These are descriptive safety counts from an open-label, single-group study. They do not establish that the intervention caused the events, nor do they provide a comparison with another group. A zero count should be interpreted as no event recorded in this study group, not as proof that the event is impossible or that risk is absent.
12. What the Result Does, and Does Not, Mean
The result supports a limited description of tolerability reporting in the enrolled group: 11 participants were reported with other adverse events, while 0 were reported with serious adverse events and 0 deaths were reported. This account applies to the 12-week primary-endpoint timeframe and the participants at risk listed in the record. It does not describe the nature or burden of the other events in detail.
The result does not show that bupropion and naltrexone caused the reported events. The trial had one group and no comparator, so the counts cannot be contrasted with a concurrent group receiving no intervention or another intervention. Nor do the counts establish that serious events cannot occur; they state only what was recorded in this study.
The study’s stated purpose included examining effects on binge drinking, and its secondary outcomes included craving and drinks per binge-drinking day. However, results for those outcomes are not reported in the registry record. There is consequently no posted numerical evidence in this record for a change in drinking or craving, and no basis for describing a treatment effect on those outcomes.
The registry record also does not report a statistical analysis plan, inferential analyses, confidence intervals, or missing-data procedures. The evidence should therefore be read as a small pilot’s descriptive record, not as a comparative estimate of benefit or harm. The registry’s completed status indicates that the study is listed as completed, but it does not fill in absent outcome analyses or protocol details.
13. Why This Trial Matters Statistically
Statistically, the main feature of this study is the gap between a clinically relevant question and what a single-group pilot can estimate. A pilot can document whether adverse events were reported during treatment and can contribute descriptive information about the enrolled participants. Without a comparison group, it cannot estimate how those observations differ from what would have happened under another condition.
The event counts also illustrate why denominators and outcome definitions matter. The primary endpoint concerns participants with adverse events, whereas event episodes, severity details, timing, and duration are different quantities. The posted counts distinguish serious and other adverse events, but the registry does not describe the individual non-serious events. Reading the counts precisely avoids treating them as a full account of event burden.
The study is labeled Phase IIa and described as a pilot. Its enrollment was 12, and the registry lists no analyses. That context makes it especially important not to interpret a zero serious-event count as proof of no risk, or to infer effectiveness from a stated purpose. The record lists drinking and craving outcomes but does not post their results.
Finally, planning assumptions based on two arms do not describe the actual registered single-group design. General statistical principle: design assumptions need to correspond to the question and comparison being studied. A planning illustration is not a report of observed power and cannot replace the trial’s unreported analysis plan or a comparative result.
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 design and reporting features constrain interpretation. The registered study is open-label and single-group, with no comparator. This prevents a direct comparison of adverse-event counts or changes in drinking with another group and limits causal interpretation. The registry record does not report a procedure for attributing events to treatment beyond describing the endpoint as treatment-associated.
Enrollment was 12 participants. The registry gives participant counts, but no confidence intervals or inferential analyses are reported. The posted safety figures do not give event terms for the other adverse events, event frequency per participant, timing, duration, or individual severity details. No serious adverse-event terms are listed.
Although the registry names final PACS score and mean number of drinks per binge-drinking day during treatment as secondary outcomes, results for them are not reported in the registry record. Eligibility criteria and the operational definition of binge drinking are also not reported. The naltrexone arm description ends after its initiation dose, so the full regimen is not reported in the registry record.
The statistical analysis plan, missing-data approach, analysis populations, interim analyses, and multiplicity handling are not reported. The record lists no analyses. These limitations mean the posted information supports a descriptive account of the safety counts, but not reconstruction of a fuller statistical analysis or interpretation of unposted outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: An Open Label Trial of Bupropion and Naltrexone for Binge Drinking — NCT02842073.
- Registry record last updated 2018-12-26; status last verified 2018-06.
- Results first posted 2018-12-26.
- 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.
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18. Record Summary
The registry record describes a completed, open-label Phase IIa pilot of bupropion and naltrexone for binge drinkers. It lists a single-group design, no masking, enrollment of 12, and a primary endpoint counting participants with treatment-associated adverse events over 12 weeks.
The posted safety counts are 0 participants with serious adverse events, 11 with other adverse events, and 0 deaths. The record lists PACS score and drinks per binge-drinking day as secondary outcomes, but their results are not reported. No analyses are listed. The statistical plan, missing-data procedures, and analysis populations are not reported in the registry record.