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 Pentoxifylline for Acute Alcoholic Hepatitis (AAH) (NCT00205049), a na phase 1 study. The primary outcome is Survival at 28 Days.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00205049 |
| Phase | Phase 1 |
| Condition | Hepatitis, Alcoholic |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | Double |
| Enrollment | 4 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Wisconsin, Madison |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with acute alcoholic hepatitis, listed in the registry under Hepatitis, Alcoholic. The record does not report further eligibility details or describe the characteristics of enrolled participants.
Intervention
The planned intervention was pentoxifylline, described as 400mg orally 3 times daily for 28 days. The record does not establish which participants, if any, received it.
Comparator
Placebo was named as the planned comparator. Although the arm description says participants would be randomized, the allocation field is NA, and the registry characterizes the arms as not a like-for-like control comparison.
Primary question
The stated hypothesis was that pentoxifylline reduces 90-day mortality. The registered primary outcome was survival at 28 days. Because the trial was terminated before any data were gathered or analyzed, neither question has an observed result in the registry record.
The central clinical question was whether pentoxifylline could affect survival in acute alcoholic hepatitis compared with placebo. That question is stated in the study summary, while the listed primary outcome focuses on survival at 28 days and the hypothesis refers to 90-day mortality. These are related but distinct time horizons, and the record does not explain how the primary outcome and the 90-day hypothesis were to be connected in the analysis.
The registry describes a planned intervention and comparator, not a completed randomized comparison. Its allocation field is NA, and its record notes that the arms are not a like-for-like control comparison. The arm description nevertheless says participants would be randomized to pentoxifylline or placebo. Since the trial stopped before data collection, the record cannot resolve this discrepancy through actual assignments or outcomes. It supports describing the question the investigators intended to study, but not estimating a treatment effect.
3. Trial Design
The study was registered as a phase I pilot study of pentoxifylline therapy for acute alcoholic hepatitis, sponsored by the University of Wisconsin, Madison. Its model is listed as single group, its allocation as NA, and its masking as double. The status is terminated. The registry reports enrollment of 4 and gives study dates of 2005-03 for start and 2006-11 for primary completion.
The intervention description names pentoxifylline as a drug. The arm description, titled Pentoxifylline/Placebo, says participants would receive either pentoxifylline 400mg orally or placebo 3 times daily for 28 days, with monthly follow up for 90 days. It also gives planned ranges of 20-40 treated and 1-20 placebo. These are descriptions of the plan; they do not establish the number assigned to either group or the treatment actually received. The registry’s reported enrollment is 4, and it states that the study ended before data were gathered or analyzed.
There is an important design ambiguity. The arm description refers to randomization and a placebo group, but the allocation field is NA, the model is single group, and the registry’s comparison note says the arms are not a like-for-like control comparison. The record does not report how these entries were reconciled. Consequently, the trial should not be presented as a completed randomized controlled comparison.
The record lists one primary outcome, survival at 28 days, and no analyses. It does not report the detailed protocol, eligibility criteria, recruitment process, actual treatment allocation, adherence, or follow-up completeness. Those details cannot be inferred from the planned schedule or the study title.
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 | Pentoxifylline | Placebo |
|---|---|---|
| STARTED | 0 | 0 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Study was terminated before any data was gathered/analyzed.
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 | Pentoxifylline | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 0 | 0 | |
| Age, Categorical: <=18 years | Participants | — | — | — |
| Age, Categorical: Between 18 and 65 years | Participants | — | — | — |
| Age, Categorical: >=65 years | Participants | — | — | — |
| Sex/Gender, Customized: Male | 0 | — | — | — |
| Sex/Gender, Customized: Female | 0 | — | — | — |
6. Primary Endpoint
The registry lists the primary outcome as Survival at 28 Days, measured over 28 days.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The registered primary endpoint is survival at 28 days. In general, a survival endpoint records whether a participant is alive at a specified follow-up time; it can be clinically interpretable because it concerns a direct outcome rather than a laboratory measure or a proposed biological mechanism. Here, however, the registry provides no survival observations. Its outcome description explicitly says the study was terminated before any data were gathered or analyzed.
The study summary identifies 90-day mortality as the main hypothesis, while the primary endpoint is survival at 28 days. The arm description also specifies monthly follow up for 90 days. These details indicate that survival at more than one time point was relevant to the study plan, but the registry does not report a complete endpoint hierarchy, a definition of the analysis time origin, or a method for handling participants whose status might be unknown.
As a general statistical matter, a binary survival status at a fixed time can be compared between groups if the groups and their follow-up are suitable for that comparison. A time-to-event analysis instead uses the timing of events and can account for differing follow-up under appropriate assumptions. The registry does not report an analysis plan that would establish which approach was intended. With no outcome data, neither an event proportion nor a treatment contrast can be estimated from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record contains no efficacy result to interpret. The primary outcome description states that the study was terminated before any data were gathered or analyzed. The record therefore does not report survival at 28 days, 90-day mortality, an estimated treatment effect, a confidence interval, or a significance test. There is no basis for saying that the planned treatment did or did not change survival.
The reported enrollment is 4, but enrollment alone is not an outcome. The registry does not describe the participants’ treatment assignments, outcomes, or follow-up. The planned ranges in the arm description cannot be treated as actual group sizes, and the record’s allocation field and model do not support a straightforward two-arm randomized interpretation. The statements about randomization and placebo should be read as elements of the plan, not evidence that a valid comparison was completed.
The adverse-event entries list 0 at risk and 0 affected for serious and other events in the Pentoxifylline and Placebo groups; deaths are recorded as null. In the context of the explicit statement that no data were gathered or analyzed, these entries should not be interpreted as evidence that no adverse events or deaths occurred among treated participants. They do not supply an observed safety comparison. The record does not report adverse-event definitions, ascertainment, or participant-level exposure.
As a general statistical concept, an effect estimate describes the observed contrast between groups, while a confidence interval conveys the uncertainty around that estimate under the analysis assumptions. Neither is available because the registry reports no analyzed outcomes. A p-value would not repair that absence: without observed data and a defined analysis, it cannot quantify evidence for or against the study hypothesis.
The record includes general assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those are not trial findings and do not constitute the trial’s own statistical plan. The record provides no observed outcome effect from which to interpret such an illustration. The registry does not report a sample-size justification or analysis results.
The most defensible interpretation is therefore descriptive: this was a terminated pilot study with a stated survival question and planned pentoxifylline and placebo regimens, but no posted outcome analysis. The record cannot determine whether the intended comparison was implemented, how precise any effect might have been, or what the results would imply for the underlying clinical question.
9. Statistical Methods Explained
Statistical methods are difficult to assess because the registry record says that the study ended before data were gathered or analyzed. It lists no analyses and does not report an inferential procedure for the primary outcome. The explanations below describe general statistical principles relevant to the registered question; they are not a report of methods used in this trial.
What would a fixed-time survival outcome represent?
Survival at 28 days is a status measured at a specified follow-up point. In a completed study, investigators would need to define how survival status is established for each participant and how missing status is handled. A comparison of survival proportions could then describe the difference between treatment groups, provided the groups were well-defined and the comparison was supported by the design. The registry does not report these data or the analysis choices that would be needed to interpret them.
The study summary’s hypothesis concerns 90-day mortality, whereas the listed primary endpoint is survival at 28 days. These outcomes use different follow-up horizons. A statistical plan would ordinarily clarify which outcome is primary, whether the other is secondary, and how each is analyzed. That hierarchy and the corresponding methods are not reported in the registry record. The follow-up schedule alone does not establish an analysis method.
How would a treatment contrast be estimated?
In a suitable comparative trial, an effect estimate would summarize the observed difference between groups on the chosen outcome. A confidence interval would express the range of values compatible with the observed data under the statistical model and its assumptions. It is useful to consider both the estimated effect and its precision: a point estimate alone does not show how uncertain the result is, and a confidence interval is not proof that every value inside it is equally plausible.
None of these quantities is reported for this study. The registry records no outcome data or analyses, and its design entries do not establish a completed like-for-like comparison. It would therefore be inappropriate to calculate an effect estimate, confidence interval, or test from the enrollment figure or from the planned arm ranges. Those quantities require outcome information and a defensible definition of the groups being compared.
Why does design status matter?
Statistical comparisons rely on the design as well as the outcome measurements. Random allocation, when implemented and preserved, can support a causal comparison by making treatment groups comparable in expectation. Masking can reduce certain forms of bias in treatment delivery or outcome assessment, depending on how it is carried out. But registry labels alone do not show that randomization or masking was implemented. Here, double masking is listed, while allocation is NA and the model is single group; the arm description separately refers to randomization. The registry does not explain this combination, and no participant-level information is available to clarify it.
For that reason, the comparison cannot be treated as a standard randomized estimate simply because the plan mentions randomization and placebo. Nor can a single-group interpretation be substituted without more detail. The registry itself cautions that the arms are not a like-for-like control comparison. This design ambiguity is separate from the absence of outcome data; either issue limits interpretation on its own.
What do the planning assumptions mean?
The registry’s planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. In general, a significance level specifies a threshold used by a testing procedure to assess data against a null hypothesis. Two-sided testing considers departures in either direction. Equal allocation is a design assumption about how participants would be distributed, and a normal approximation is a mathematical method that can simplify calculations when its conditions are suitable.
The record also describes the effect to detect as a stated fraction of the observed effect. Planning illustrations based on an observed effect depend on that effect being available and relevant to the future design. The registry reports that no data were gathered or analyzed, so it gives no trial outcome estimate to serve as an observed effect. These assumptions should not be mistaken for a prespecified protocol, a justification for the actual enrollment, or a statement that the trial had a particular probability of detecting an effect.
Sample-size planning estimates are design illustrations, not observed power. Power is a property of a specified design under an assumed effect and other assumptions; it is not evidence that an outcome was observed or that the treatment had an effect. The record does not report a sample-size justification for the trial. Any planning calculation associated with an assumed effect would need to be understood as conditional on that assumption, not as a result from this terminated study.
What about over-dispersion and other model concerns?
As a general matter, over-dispersion occurs when observed variability is greater than a statistical model expects. It can make standard errors too small if the model fails to account for that extra variability, which can in turn make confidence intervals too narrow and tests too optimistic. This concern can arise in some count or clustered-data settings. The registry does not report a count outcome or a model for which over-dispersion is relevant, so there is no basis for saying it affected this study.
Other important method choices include the analysis population, handling of missing observations, adjustment for baseline variables, and whether any interim analyses were planned. These choices can affect interpretation, but the registry does not report them. Because the study has no posted analysis, there are no model diagnostics or sensitivity analyses to assess. Statistical concepts can explain what would matter in a completed trial, but they cannot supply the missing protocol details or outcomes.
10. Multiplicity, Missing Data and Analysis Populations
The registry does not report a multiplicity plan. It lists survival at 28 days as the primary outcome and the study summary states a hypothesis about 90-day mortality, but it does not describe whether these were treated as separate confirmatory questions, how any additional outcomes were ranked, or whether adjustment for multiple testing was planned. In general, testing multiple outcomes or time points can increase the chance of a false-positive finding if the analysis does not account for the number of questions. That issue cannot be evaluated from a record with no analyses.
Missing-data handling is also not reported. Although the planned follow-up is described as monthly for 90 days, the record provides no observations or account of follow-up completion. It does not explain how unknown survival status, withdrawal, or incomplete follow-up would have been handled. These are general considerations for interpreting fixed-time survival outcomes, not claims about what occurred in this study.
The registry does not identify an intention-to-treat population, a per-protocol population, or another analysis population. It also does not report exclusions after enrollment or define how participants would be classified if they did not receive assigned treatment. Given the ambiguity between the planned randomized description and the single-group model and NA allocation, the record does not establish which groups an analysis would have compared. With no analysis results and no reported analysis-population definitions, neither multiplicity nor missing-data assumptions can be assessed empirically.
11. What the Result Does, and Does Not, Mean
The record establishes that a pilot study of pentoxifylline for acute alcoholic hepatitis was registered, that survival was the central outcome question, and that the study was terminated before data were gathered or analyzed. It does not establish whether pentoxifylline changed survival at 28 days or 90-day mortality. It also does not support a conclusion about adverse events, because the event entries appear alongside an explicit statement that there were no gathered or analyzed data.
The registry’s enrollment figure is not evidence of treatment exposure or of an outcome. The arm regimen and allocation ranges are planned descriptions, not observed assignments. Because the allocation field is NA, the model is single group, and the registry cautions that the arms are not a like-for-like comparison, the record cannot be read as a completed randomized placebo-controlled trial. The randomized wording in the arm description does not resolve that limitation.
As a general statistical distinction, absence of a reported estimate is not evidence of no effect. A null or nonsignificant result would require analyzed data and a reported statistical comparison; neither is present. Conversely, the original hypothesis and planned design cannot be treated as evidence that the intervention had an effect. The record leaves the clinical question unanswered.
The record also does not show why the study was terminated, whether the planned protocol changed, or whether any data existed outside the registry. Those details are not reported in the registry record and cannot be inferred. Interpretation should remain bounded to what the registry states: there is no posted efficacy or safety result to assess, and no precision estimate with which to characterize uncertainty.
12. Why This Trial Matters Statistically
This study matters statistically because it illustrates the difference between a registered question and an analyzed result. A clear hypothesis, named intervention, and planned comparator do not themselves produce evidence about an outcome. For inference, the record would need to establish the comparison actually made and report the measurements and analysis. Here, the registry explicitly states that data were not gathered or analyzed.
It also shows why design fields should be interpreted together rather than in isolation. Double masking is listed, and the arm description refers to randomization, but allocation is NA, the model is single group, and the registry flags that the arms are not a like-for-like control comparison. These entries do not support treating the study as a conventional randomized comparison. No outcome analysis is available to clarify the practical consequences of the design entries.
The record further distinguishes planning assumptions from trial results. A significance level, allocation assumption, or normal approximation can describe a calculation framework, but they do not establish an observed effect, a completed analysis, or an adequate sample-size rationale. The registry does not report a sample-size justification, and the study ended before outcome data were available for an effect estimate.
Finally, empty or zero-valued registry outcome entries require context. When the outcome description says no data were gathered or analyzed, adverse-event entries cannot be interpreted as observed evidence of safety. This is a broader lesson in reading trial records: the status of data collection and the meaning of each field matter as much as the numeric entries themselves.
13. 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 primary limitation is that the registry states the trial was terminated before data were gathered or analyzed. There are no posted survival outcomes, treatment-effect estimates, confidence intervals, or analyses. The registry does not report why the trial was terminated, so the reason cannot be used to interpret the absence of results.
The design is not fully coherent in the registry entries. The study is described as single group with allocation NA, while the arm description says participants would be randomized to pentoxifylline or placebo. The record explicitly says the arms are not a like-for-like control comparison. It does not explain whether the design changed, how the treatment plan related to the enrollment, or whether any planned assignments occurred. Thus, even if outcomes were available, the intended comparison would require clarification.
The record reports enrollment of 4 but gives planned arm ranges of 20-40 treated and 1-20 placebo. The planned ranges cannot be interpreted as actual group sizes, and the registry does not explain their relationship to the reported enrollment. No participant characteristics, exposure, adherence, or follow-up completeness are reported.
Other limitations include the absence of a reported sample-size justification, detailed statistical analysis plan, missing-data approach, analysis population, or multiplicity plan. The study summary refers to 90-day mortality, while the registered primary outcome is survival at 28 days; the record does not explain their hierarchy. Adverse-event values and null death entries are not sufficient to characterize safety in the absence of collected and analyzed data. These limitations arise from the registry record itself and cannot be resolved by statistical recalculation.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Pentoxifylline for Acute Alcoholic Hepatitis (AAH) — NCT00205049.
- Registry record last updated 2014-05-13; status last verified 2014-04.
- Results first posted 2014-05-13.
- 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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17. Record Summary
The registry describes NCT00205049, Pentoxifylline for Acute Alcoholic Hepatitis (AAH), as a phase I pilot study sponsored by the University of Wisconsin, Madison. It lists the condition as Hepatitis, Alcoholic, the model as single group, allocation as NA, masking as double, and status as terminated. The reported enrollment is 4.
The planned regimen was pentoxifylline 400mg orally 3 times daily for 28 days or placebo, with monthly follow up for 90 days. The primary outcome is survival at 28 days; the study summary states a hypothesis concerning 90-day mortality. The registry says the study was terminated before any data were gathered or analyzed and lists no analyses.
Accordingly, the record does not provide an efficacy estimate or an interpretable safety comparison. It also contains unresolved design ambiguity between the single-group and NA allocation entries and the arm description’s reference to randomization. The clinical question remains unanswered by the posted results.