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 Treating Patients With Aneurysmal SubArachnoid Hemorrhage (SAH) With Epoetin Alfa (NCT00626574), a randomized phase 4 study. The primary outcome is Incidence of Adverse Events After Administering Intravenous Doses of Procrit® Once Daily for Three Consecutive Days to Patients With Aneurysmal SAH Before and After Vascular Clipping.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00626574 |
| Phase | Phase 4 |
| Condition | Subarachnoid Hemorrhage |
| Allocation | Randomized |
| Design model | Single Group |
| Masking | Quadruple |
| Enrollment | 3 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of South Florida |
| Results posted | Yes |
2. Clinical Question
The study asks whether administering intravenous Procrit® around vascular clipping for aneurysmal subarachnoid hemorrhage can be evaluated for safety, with saline as the comparator. The stated primary objective focuses on thrombotic events, hemoglobin and mortality at 6-7 weeks; the posted primary outcome is the number of adverse events during the first 10 days following clipping and at 6 week follow-up.
Population
The planned population was adults aged 30-75 with subarachnoid hemorrhage following cerebral aneurysm rupture, minimal neurological symptoms, hemoglobin less than or equal to 12 g/dL within 24 hours before study entry, and operative aneurysmal clipping. The primary outcome population is described as pilot study, per protocol. The posted arm records contain 2 participants for Procrit and 1 for saline.
Intervention
Procrit® (epoetin alfa) was given intravenously once daily on Study Days 1, 2 and 3. The first dose was intended within 36 hours of the initial hemorrhage or symptoms and immediately before vascular clipping. The arm description states a dose of 40,000U.
Comparator
The comparator was saline given intravenously once daily on Study Days 1, 2 and 3. The registry describes the study as placebo controlled, randomized and quadruple masked.
Primary question
What number of adverse events was recorded for each arm during the stated post-clipping and follow-up period? The study's broader safety objective also names thrombotic events, hemoglobin and 6-7 week mortality, but the posted primary outcome is an adverse-event count.
The brief summary describes an intended total enrollment of twenty, with ten planned for each arm. The registry enrollment field reports 3. The record does not explain the difference between the planned enrollment and the enrollment field. The trial status is terminated.
3. Trial Design
The registry describes a randomized, double-blind, placebo-controlled pilot safety study, with quadruple masking recorded. It is listed as Phase 4. The intervention was intravenous epoetin alfa, identified as Procrit®, and the control was intravenous saline. The stated treatment schedule was once daily for three consecutive study days, with the first Procrit dose immediately before clipping and within 36 hours of the hemorrhage or symptoms.
The brief summary describes a screening phase, a treatment phase and follow-up through discharge and a 6-7 week visit. The primary outcome timeframe is worded separately as the first 10 days following clipping and 6 week follow-up. The registry record does not clarify the relationship between these follow-up descriptions. The primary outcome population is identified as per protocol, but further details about that population are not reported in the registry record.
The brief summary planned twenty participants, with ten assigned to each group. The enrollment field reports 3, and the posted primary results list 2 participants in the Procrit arm and 1 in the saline arm. The record does not explain the relationship between these enrollment figures or provide a reason for termination. A design-model field labels the study as single group, while the record also describes randomization and posts results for Procrit and saline arms. This discrepancy in design description is not explained in the registry record.
The study's stated primary objective was safety assessment, including thrombotic events, hemoglobin and 6-7 week mortality. Secondary objectives address vasospasm, neurological assessment scores and the feasibility of organizing a larger randomized study. The registry lists 4 outcome measures and 3 posted secondary outcomes. The statistical analysis plan, allocation-concealment procedure, and planned methods for evaluating the outcomes 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
| Stage | Procrit | Saline |
|---|---|---|
| STARTED | 2 | 1 |
| COMPLETED | 2 | 1 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Pilot Study- per protocol
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 | Procrit | Saline | Total |
|---|---|---|---|---|
| Participants analysed | 2 | 1 | 3 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 | 1 | 3 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 2 | 1 | 3 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 2 | 1 | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Incidence of Adverse Events After Administering Intravenous Doses of Procrit® Once Daily for Three Consecutive Days to Patients With Aneurysmal SAH Before and After Vascular Clipping, measured over First 10 days following clipping and 6 week F/U.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | adverse events |
| Endpoint classification | not reduced to a single comparison |
The posted primary outcome is the number of adverse events after intravenous Procrit® once daily for three consecutive days before and after vascular clipping. Its timeframe is the first 10 days following clipping and 6 week follow-up. The outcome is presented as a count, rather than as a continuous measurement such as hemoglobin concentration or as a time-to-event outcome. The record identifies the population as pilot study, per protocol.
Adverse-event monitoring is relevant to a safety-focused study because it records unwanted events observed during treatment and follow-up. In general, event counts can describe the observed burden, but interpreting them depends on how events are defined, collected, and attributed, as well as on the number of participants observed. The registry gives the primary outcome description as “Number of adverse events”; details on event definitions, severity grading, attribution rules and the handling of repeated events are not reported in the registry record.
The primary objective in the brief summary separately names the incidence of thrombotic events, hemoglobin and 6-7 week mortality as safety comparisons. Those concepts are not identical to the posted primary outcome of number of adverse events. The registry record does not explain how the posted count relates to those stated objectives. The posted arm values are 1 for Procrit and 2 for saline, with arm sizes of 2 and 1, respectively. These sparse counts should be read as descriptive observations, not as a precise estimate of a comparative safety effect.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome is reported as 1 adverse event for Procrit, with 2 participants in that arm, and 2 adverse events for saline, with 1 participant in that arm. These are the registry's posted per-protocol values. They are event counts, not estimates of event risk, and the available record does not specify whether multiple events could be attributed to one participant. A direct comparison of the counts therefore cannot establish how the participant-level experience differed between groups.
The posted results are extremely limited in scale. The brief summary planned twenty participants, while the enrollment field reports 3 and the posted arm records list 2 for Procrit and 1 for saline. The registry does not explain these differences or state why the study was terminated. With so few observations, the counts provide little precision for characterizing uncommon or variable safety outcomes. No confidence intervals, hypothesis tests, or comparative effect estimates are posted in the registry record.
Related safety fields report serious adverse events for 0 of 2 at risk in the Procrit group and 1 of 1 at risk in the saline group. The other adverse-event fields report 1 of 2 affected in the Procrit group and 1 of 1 in the saline group. These fields should not be assumed to be equivalent to the primary outcome count: the record uses separate serious and other adverse-event entries, and does not explain how these entries map to the primary endpoint or whether event counts and affected-participant counts overlap.
The listed top serious adverse-event term is Severe Headache at 100.0%. Its denominator and relationship to the serious-event entries are not described in the registry record. It should not be interpreted as a comparative rate or as an estimate of risk without that context.
Overall, the posted values describe observations in a very small pilot population. They do not provide a precise estimate of the relative safety of Procrit and saline, and the record does not support a conclusion about the broader safety objectives of thrombotic events, hemoglobin or mortality. The absence of posted statistical analyses also means there is no registry-reported inferential comparison to interpret.
9. Statistical Methods Explained
Statistical interpretation begins with the type of outcome being recorded. The primary endpoint is the number of adverse events, a count outcome. A count records how many events were observed, while a participant-level proportion records how many people experienced at least one event. These are different quantities: one participant may experience more than one event, depending on the endpoint definition. The registry describes the endpoint as a number of adverse events but does not report whether repeat events for one participant were counted separately or how events were assigned to participants.
What does a count comparison describe?
In general, a comparison of counts can be informative when the observation periods and event definitions are clear and comparable. Counts alone do not adjust for differences in the number of people observed or the duration of observation. A rate comparison would require an appropriate exposure-time denominator, and that is not reported in the registry record. The primary outcome gives arm sizes and event counts, but the record does not provide participant-level event histories or exposure times. As a result, a rate-based analysis cannot be reconstructed from the posted summaries.
Counts can also vary more than a simple model expects when events cluster in some participants or when participants have different underlying event rates. In general, over-dispersion means that the observed variation in counts exceeds what a model assumes. Accounting for over-dispersion can make uncertainty estimates more realistic. Whether the study used a count model, assessed over-dispersion, or applied any other model is not reported in the registry record. With sparse observations, model-based estimates would also depend strongly on the assumptions and data available.
What can an uncertainty interval tell a reader?
In general, a confidence interval describes the range of values reasonably compatible with an estimate under a specified statistical method and its assumptions. A narrow interval indicates greater precision than a wide interval; neither interval alone proves that an effect is present or absent. No confidence interval is posted for the primary outcome or for the serious adverse-event fields. The record therefore offers no interval-based description of comparative precision. It also does not report a p-value for the primary outcome.
When an outcome is rare or a study is very small, an estimate may be especially imprecise. A zero observed count in an arm does not establish that the underlying event risk is zero. Conversely, an event observed in a small group does not by itself establish that the event is more common in that group. These are general principles for interpreting sparse safety data. The registry results contain only a small number of posted observations, so the values are best read descriptively rather than as stable estimates of an underlying treatment effect.
Why are the arm counts not a complete comparison?
The primary values are 1 adverse event in the Procrit arm and 2 in the saline arm. The number of participants differs between arms, as reported in the record, and event counts need not correspond one-for-one with participants. Converting those figures to rates or percentages would require calculation and assumptions not justified by the registry summary; no such recalculation is presented. The registry does not report an adjusted analysis, a prespecified contrast, or the statistical test used to compare the arms.
The adverse-event fields add separate information: serious events are listed for participants at risk and participants affected, as are other adverse events. In general, the distinction between the number of events and the number of people affected matters because one person can contribute multiple events. The registry does not define the counting unit for every field or describe how these categories overlap. The serious-event information therefore cannot be combined with the primary event count as though all fields measured the same quantity.
What do planning calculations mean?
In general, a sample-size calculation describes the number of participants a future study might need under specified assumptions about the effect to detect, variability, significance level, allocation and analysis method. It is a planning exercise, not an observation about the results of the trial. The registry's planning assumptions describe a two-sided significance level of 0.05, equal allocation and a normal approximation, with the effect expressed as a fraction of the observed effect. They do not establish the study's original design rationale. No sample-size justification or statistical plan for this trial is reported in the registry record.
Planning illustrations based on an observed effect are particularly uncertain when the underlying trial has sparse data: the observed effect itself may be unstable. Such illustrations should not be described as observed power or treated as a confirmation that a future study would find the same effect. The registry record does not report a sample-size justification, interim analysis plan, or the assumptions used in the trial's original design.
What can be concluded from the available analyses?
The record lists 0 analyses. It posts outcome summaries, but no inferential results that quantify uncertainty or test a between-arm contrast. The posted arm counts can be stated as descriptive results; they cannot support claims about statistical significance or the magnitude and precision of a treatment effect. The registry record does not report the analysis method, treatment of missing observations, adjustment for baseline differences, or a multiplicity procedure.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures and 3 posted secondary outcomes. The secondary objectives concern vasospasm after clipping, neurological assessment scores after hemorrhage and clipping, and the feasibility of organizing a larger randomized study. The primary objective also describes thrombotic events, hemoglobin and 6-7 week mortality, while the posted primary outcome is the number of adverse events. The registry record does not explain how these stated objectives correspond to the posted outcome measures.
When a study examines several outcomes, the chance of at least one apparently unusual result can rise if each is tested separately. In general, a multiplicity plan may specify which outcomes are confirmatory, how comparisons are prioritized, or whether the significance threshold is adjusted. Such a plan is not reported in the registry record. The record lists 0 analyses, so no multiplicity-adjusted or unadjusted inferential results are available to interpret.
The primary outcome population is labeled per protocol. A per-protocol population generally includes participants who met specified conditions for adherence or eligibility, but the exact criteria used in this study are not reported in the registry record. The record does not report an intention-to-treat analysis population or explain how participants were handled when they did not follow the protocol.
Missing-data procedures, reasons for missing outcome information, and the handling of withdrawals are not reported in the registry record. The stated follow-up descriptions include discharge and 6-7 week follow-up in the brief summary, while the primary outcome timeframe says the first 10 days following clipping and 6 week follow-up. The registry does not explain whether outcome information was available for all participants through those time points. These gaps limit assessment of how complete and comparable the outcome ascertainment was across arms.
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 |
|---|---|---|---|
| Procrit | 0 | 2 | 0.0% |
| Saline | 1 | 1 | 100.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Procrit | 1 of 2 |
| Saline | 1 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Procrit | Saline |
|---|---|---|---|
| Severe Headache | Nervous system disorders | 0 of 2 | 1 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Procrit | Saline |
|---|---|---|---|
| Urinary Tract Infection | Renal and urinary disorders | 0 of 2 | 1 of 1 |
| Pseudo aneurysm left groin | Vascular disorders | 1 of 2 | 0 of 1 |
Serious events with the highest arm-level rate: severe headache (100.0%).
The registry's serious adverse-event fields list 0 serious adverse events among 2 at risk in the Procrit group, and 1 among 1 at risk in the saline group. The separate other adverse-event fields list 1 affected among 2 at risk for Procrit and 1 affected among 1 at risk for saline. The record does not state whether these entries count people, event episodes, or both in all fields, nor whether the serious and other categories are mutually exclusive.
The most frequently listed serious-event term is Severe Headache, shown at 100.0%. The registry record does not provide the denominator or clarify whether this percentage describes participants, events, or a subset of serious events. It should therefore be read as a term in the posted safety record, not as a directly comparable arm-specific percentage.
These small counts are descriptive and do not establish comparative safety. In general, zero recorded events in a small group does not show that the underlying risk is absent, while an event in a small group cannot by itself establish a higher underlying risk. No confidence intervals, formal comparison, event attribution method or detailed safety-analysis plan is reported in the registry record. The primary adverse-event count is also presented separately from these serious and other adverse-event fields, and the record does not explain their relationship.
12. What the Result Does, and Does Not, Mean
The posted results establish that the registry contains adverse-event counts for both arms and separate serious and other adverse-event fields. The primary outcome records 1 adverse event for Procrit and 2 for saline, with the listed arm sizes of 2 and 1, respectively. The serious-event fields report 0 affected in the Procrit group and 1 in the saline group. These values describe the observations recorded for this pilot; they do not estimate comparative risk with useful precision.
They do not establish that either regimen has a higher or lower underlying safety risk. Sparse counts are highly sensitive to the experience of each participant, and the registry does not report event-level details, exposure time, uncertainty intervals or inferential comparisons. In general, a treatment effect is best understood through an estimate accompanied by its uncertainty and a clear account of the population, outcome definition and analysis. Those elements are not available in the posted results to the extent needed for a reliable comparative conclusion.
The record also does not provide results for the broader safety objectives as separate comparisons of thrombotic events, hemoglobin and mortality. Although it lists secondary objectives involving vasospasm, neurological assessment and feasibility, it does not post inferential analyses for them. The listed Severe Headache term and its 100.0% value lack a stated denominator, so they cannot resolve these questions.
This trial's posted results should therefore be understood as a limited descriptive record from a small pilot study, not as a definitive test of treatment effect or safety. The terminated status, the difference between planned enrollment and the enrollment field, the single-group model label alongside randomized arms, and the absence of posted analyses further constrain interpretation. The registry record does not explain these issues, and they should not be resolved by assumption.
13. Why This Trial Matters Statistically
This study illustrates why a registry result needs to be read alongside its outcome definition, population, design description and analysis information. The primary outcome is a count of adverse events, while the broader primary objective names several safety measures. Distinguishing these matters: an event count, the number of participants affected, a laboratory measurement and mortality are different outcomes and require different interpretations.
The record also demonstrates the limits of descriptive results from a small pilot. The posted counts are useful as a report of what was entered, but they provide little information about the precision of a comparative estimate. Without a confidence interval, event definitions, or a reported inferential analysis, the reader cannot judge the range of effects compatible with the data using the registry alone.
Comparing the brief summary with the enrollment and results fields raises questions that affect interpretation. The summary describes a planned enrollment of twenty with ten participants in each group, whereas the enrollment field reports 3 and the posted arm sizes are 2 and 1. The study is marked terminated, but the reason is not reported in the registry record. The design-model label says single group even though randomization and two arms are described. These are material differences in record description, not details that can be reconciled from the posted results.
Finally, a safety pilot and a definitive comparative trial have different evidential roles. In general, a pilot can inform the feasibility of further research, but the registry does not report whether its feasibility objective was met or how that judgment was made. These limitations make transparent reporting of the analysis population, outcome definitions, missing observations and analysis plan especially important. Those details are not reported in the registry record.
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 is the small posted population: the primary results list 2 participants for Procrit and 1 for saline. The brief summary planned twenty participants, but the enrollment field reports 3. The registry record does not explain why the completed or analyzed population differs from the plan, nor does it state why the study was terminated. The effect of these differences on the posted outcome values is not described.
The design information is not fully consistent. The study is described as randomized and placebo controlled, with Procrit and saline arms, but its model field is labeled single group. The record does not resolve this discrepancy. It also does not report details of allocation concealment, protocol deviations, adherence, baseline comparability, or the criteria defining the per-protocol population.
The primary endpoint is described as a number of adverse events, but definitions, ascertainment procedures, event attribution and handling of repeat events are not reported in the registry record. The timeframe also differs in wording between the primary outcome and the brief summary. There are no posted confidence intervals or statistical analyses. Missing observations, losses to follow-up, and their handling are not reported.
Safety information is limited by the small counts and by incomplete explanations of the serious and other adverse-event fields. The denominator for the Severe Headache value is not reported in the registry record. The relationship between the primary count and the separate safety entries is also not explained. Together, these limitations prevent a precise comparative interpretation and leave important questions about outcome completeness and analysis unresolved.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Treating Patients With Aneurysmal SubArachnoid Hemorrhage (SAH) With Epoetin Alfa — NCT00626574.
- Registry record last updated 2018-07-31; status last verified 2018-07.
- Results first posted 2012-10-29.
- 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
NCT00626574 is a Phase 4 randomized, quadruple-masked, placebo-controlled pilot study of intravenous epoetin alfa (Procrit®) versus saline for patients with aneurysmal subarachnoid hemorrhage undergoing vascular clipping. The registry lists the study as terminated. The brief summary planned twenty participants; the enrollment field reports 3.
The primary outcome is the number of adverse events during the first 10 days following clipping and at 6 week follow-up, with the population described as pilot study, per protocol. Posted values are 1 for Procrit, with 2 participants, and 2 for saline, with 1 participant. The safety fields separately report serious and other adverse events. The record lists 4 outcome measures, 3 posted secondary outcomes and 0 analyses.
The registry does not explain the enrollment difference, termination, model label or relationship between the stated safety objectives and the posted primary outcome. No inferential comparison or confidence interval is posted. The available values are descriptive observations from a very small study, not a precise estimate of comparative safety.