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 Acetaminophen in aSAH to Inhibit Lipid Peroxidation and Cerebral Vasospasm (NCT00585559), a randomized phase 3 study. The primary outcome is Number of Patients With Vasospasm Based on Magnetic Resonance Angiography (MRA).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00585559 |
| Phase | Phase 3 |
| Condition | Aneurysmal Subarachnoid Hemorrhage, Cerebral Vasospasm |
| Allocation | Randomized |
| Design model | Factorial |
| Masking | Quadruple |
| Enrollment | 44 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Vanderbilt University Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with aneurysmal subarachnoid hemorrhage (aSAH), a condition associated in this trial record with cerebral vasospasm. The record lists an enrollment of 44. It does not provide further eligibility details or a description of the participants whose data contributed to each outcome.
Intervention
The study examined acetaminophen (APAP), N-acetylcysteine (NAC), and their combination. Listed regimens include APAP 1 gm every 6 hours, APAP 1.5 gm every 6 hours, NAC IV infusion at 0.5 gm hourly, and combined APAP and NAC regimens. Placebos were also listed.
Comparator
The listed comparison options include placebo for both drugs, APAP with NAC placebo, NAC with APAP placebo, and combined APAP plus NAC regimens. The trial is described as factorial, but the specific contrasts intended for each analysis are not reported in the registry record.
Primary question
The study aimed to assess whether APAP, NAC, or their combination would inhibit lipid peroxidation, using F2-IsoPs as biomarkers. The registered primary outcome was the number of patients with vasospasm based on magnetic resonance angiography (MRA) at 8 days after the SAH event. No data for that prespecified outcome were analyzed in the registry record.
The clinical question has two related parts in the record: whether the drug regimens affect lipid peroxidation biomarkers, and whether vasospasm is present on MRA. The brief study description emphasizes F2-IsoPs as biomarkers of lipid peroxidation, while the registered primary outcome is MRA-based vasospasm. These are different measures: a biomarker is not itself a direct count of patients with vasospasm. The record does not report analyzed results for the primary outcome or identify a specific regimen as superior on either measure.
3. Trial Design
The registry describes a randomized, quadruple-masked, factorial Phase 3 trial sponsored by Vanderbilt University Medical Center. The study concerns patients with aneurysmal subarachnoid hemorrhage and cerebral vasospasm. Enrollment is listed as 44. The study began in 2007-04, its primary completion date is 2023-10-26, and its status is terminated. The reason for termination is not reported in the registry record.
Five intervention descriptions appear in the record: placebos for both acetaminophen and N-acetylcysteine; APAP 1 gm every 6 hours with NAC placebo; NAC IV infusion at 0.5 gm hourly with APAP placebo; APAP 1 gm every 6 hours with NAC IV infusion at 0.5 gm hourly; and APAP 1.5 gm every 6 hours with NAC IV infusion at 0.5 gm hourly. This range includes single-agent, combined, and placebo regimens. Although the design is labeled factorial, the registry record does not explain the randomization scheme, which comparisons were primary, or how the different APAP doses were to be handled analytically.
The record states that an NIH-approved statistical analysis plan was powered for 34 placebo subjects and 34 NAC subjects to test whether their failure rates were equal, with probability (power) 0.8. The registry also reports an overall enrollment of 44. The relationship between the planned comparison and the full set of listed regimens is not explained. The record does not report whether enrollment targets were revised or how termination affected the planned analyses.
Randomization can help make treatment groups comparable in expectation, while masking can reduce the influence of treatment knowledge on care and outcome assessment. These are general design principles; the registry does not describe who was masked or how masking was maintained. The presence of randomization and masking does not establish that a treatment effect was estimated, and no analyzed primary outcome is reported.
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 | N-acetylcysteine IV Infusion at 0.5 gm Hourly | Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | Acetaminophen Plus N-acetylcysteine Infusion |
|---|---|---|---|
| STARTED | 16 | 17 | 11 |
| COMPLETED | 16 | 17 | 11 |
| NOT COMPLETED | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: No data for the prespecified outcome was analyzed due to the NIH-approved SAP that is powered for 34 placebo subjects and 34 N-acetylcysteine subjects to be able to reject the null hypothesis that the failure rates for placebo and N-acetylcysteine subjects are equal with probability (power) 0.8. Only 44 participants were randomized. As such, no data analysis will be completed for this underpowered study.
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 | N-acetylcysteine IV Infusion at 0.5 gm Hourly | Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | Aacetaminophen and N-acetylcysteine Infusion | Total |
|---|---|---|---|---|---|
| Participants analysed | 16 | 17 | 11 | 44 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | 2 | 3 | 6 |
| Age, Categorical: >=65 years | Participants | 15 | 15 | 8 | 38 |
| Sex: Female, Male: Female | Participants | 12 | 13 | 8 | 33 |
| Sex: Female, Male: Male | Participants | 4 | 4 | 3 | 11 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 1 | 1 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 16 | 16 | 10 | 42 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 | 3 | 1 | 5 |
| Race (NIH/OMB): White | Participants | 15 | 13 | 9 | 37 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 1 | 2 |
| Region of Enrollment: United States | participants | 16 | 17 | 11 | 44 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Patients With Vasospasm Based on Magnetic Resonance Angiography (MRA), measured over 8 Days post subarachnoid hemorrhage (SAH) event.
| 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 the number of patients with vasospasm based on magnetic resonance angiography (MRA), assessed at 8 days after the subarachnoid hemorrhage event. MRA is described as measuring the degree of arterial narrowing. The registry states that a higher MRA score indicates more severe vasospasm and that an MRA score of 84% sensitivity and 72% specificity is indicative of vasospasm.
This outcome is a patient-level classification: it concerns whether vasospasm is present, rather than only a continuous measure of arterial narrowing. The stated sensitivity and specificity describe the diagnostic performance associated with the registry's indicated MRA criterion; they are not trial treatment-effect estimates. The record does not provide an analyzed count of patients with vasospasm, a group comparison, or an uncertainty estimate for this endpoint.
The biomarker focus in the study description is related but distinct. F2-IsoPs are identified as biomarkers for lipid peroxidation, the process the regimen was intended to inhibit. A change in a biomarker and a diagnosis of vasospasm answer different questions, so evidence about one cannot be substituted for a result on the other. The registry record says no data for the prespecified outcome were analyzed. The exact operational threshold, assessment procedures, and handling of missing MRA measurements are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry does not report analyzed data for the prespecified primary outcome. It therefore gives no treatment-group counts for MRA-based vasospasm, no estimated difference between groups, and no confidence interval or p value for that outcome. The absence of these results means the registered primary question cannot be answered from the reported analysis. It is not evidence that the groups had identical outcomes, and it does not establish that the regimens had no effect.
The record states that no prespecified outcome data were analyzed under the NIH-approved statistical analysis plan, which was powered for 34 placebo subjects and 34 NAC subjects to test equality of failure rates with probability (power) 0.8. Overall enrollment is listed as 44. Those entries describe the planned comparison and the recorded enrollment; they do not provide an observed treatment effect or the number of participants included in an endpoint analysis. The reason that the prespecified outcome was not analyzed is not reported in the registry record beyond the statement referring to the plan.
The title and brief description identify lipid peroxidation as the scientific focus and F2-IsoPs as biomarkers, but the registry record does not present analyzed biomarker results in the information reported for this trial. The registered primary endpoint is instead MRA-based vasospasm. Neither the stated scientific objective nor the listed interventions should be read as evidence of a result. A treatment effect requires an analyzed comparison, with information about the estimate and its uncertainty.
Serious adverse-event summaries are reported for three groupings, with counts of participants at risk and affected. These are descriptive safety figures, not evidence of a causal treatment effect. The registry record does not provide enough information to establish whether the groups are directly comparable, how the adverse events were collected, or whether the reported counts cover the same follow-up period. The event counts should therefore be read as registry-reported observations, not as proof that one regimen caused more or fewer events.
The record lists six outcome measures and zero analyses. This indicates that the registry does not display an analysis result for those outcomes. It does not show whether data were collected, whether analyses were performed outside the registry, or whether results were withheld for a particular reason. Those details are not reported in the registry record. Because the primary endpoint is not analyzed, no conclusion about the efficacy of APAP, NAC, or their combination can be drawn from the posted results.
9. Statistical Methods Explained
Randomization and factorial structure. Randomization assigns participants to study regimens by a chance-based process. As a general statistical principle, this can reduce systematic differences in prognostic factors between groups, although randomization does not guarantee balance in every trial. This study is labeled randomized and factorial. A factorial design can evaluate more than one intervention factor within a shared study structure, and may allow investigators to examine both individual factors and combinations. Interpretation depends on the comparisons specified in the analysis plan, including whether interactions between factors are considered. The registry record does not report the full allocation scheme, the planned contrasts, or how the APAP dose levels were incorporated in the analysis.
Masking. The trial is described as quadruple-masked. In general, masking is intended to limit the effects of knowing treatment assignment on participant experience, clinical care, outcome measurement, or analysis. The registry record does not identify which groups of people were masked or describe procedures for maintaining masking. The label alone does not establish whether masking succeeded.
Binary endpoint analysis. The primary endpoint concerns the number of patients classified as having vasospasm on MRA at 8 days after the SAH event. For an endpoint of this kind, a treatment comparison would ordinarily use the number with the outcome and the number assessed in each relevant group to estimate event frequencies and their contrast. The registry record provides neither those endpoint counts nor a result of such a comparison. It is therefore not possible to interpret an estimated difference, its precision, or whether the data are compatible with a range of effects.
A confidence interval is a general statistical tool for expressing uncertainty around an estimated effect. A narrower interval indicates greater precision under the model used; a wider interval indicates less precision. A p value, in general, measures how incompatible the data are with a specified null hypothesis under the assumptions of the test. Neither quantity gives the probability that a treatment works, and neither is reported for the primary outcome in this registry record. Without an estimate and uncertainty interval, the precision of a treatment comparison cannot be assessed.
Planning and power. The registry reports a planned comparison of 34 placebo subjects and 34 NAC subjects, with probability (power) 0.8 for testing whether their failure rates are equal. Power is a planning quantity: under a specified effect and analysis model, it describes the chance of rejecting the null hypothesis if that effect is present. It is not a measure of the probability that a result is correct, and it is not the trial's observed power. The record does not provide an analyzed primary result or enough information about the planned effect and test details to independently assess the planning statement.
Any sample-size calculation based on an observed effect is a planning illustration rather than a finding about the trial. The record's stated calculation assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect defined as a stated fraction of the observed effect. These assumptions describe a calculation framework, not the original study design or an observed outcome. The record does not provide an observed primary effect to interpret alongside such a calculation. In particular, a planning sample size cannot establish that the enrolled sample had adequate power for an effect that was not analyzed.
Multiplicity. When an investigation considers multiple endpoints, treatment arms, doses, or contrasts, the chance of at least one false-positive finding can rise if each test is interpreted separately without adjustment. General approaches include specifying a primary comparison in advance, controlling the familywise error rate, or using a hierarchical testing sequence. Which approach is appropriate depends on the scientific questions and prespecified analysis plan. The registry lists six outcome measures and a factorial set of interventions, but it does not report a multiplicity procedure or the hierarchy of outcome analyses. With zero analyses reported, there are no posted test results to evaluate for multiplicity.
Missingness and analysis sets. Missing outcome data can affect an estimate if the probability of being measured is related to treatment or outcome status. Analysts may describe missingness, define which participants are included, and use methods suited to the assumptions about why data are missing. These are general considerations, not a description of this trial's methods. The registry record does not report the number of participants with evaluable MRA measurements, reasons for missing data, an imputation method, or the analysis population. The reported enrollment cannot be treated as the denominator for the primary endpoint without those details.
Analysis versus description. The record's adverse-event counts and percentages are descriptive summaries. A formal comparative analysis would need to specify the groups, follow-up period, event definitions, and statistical method. The registry record does not report such a comparative safety analysis. Descriptive counts should not be converted into claims about treatment effects or interpreted as a causal contrast without the relevant design and analysis details.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists six outcome measures and zero analyses. It does not report how the outcomes were ordered, which were considered primary or secondary beyond the registered MRA-based primary endpoint, or whether statistical adjustment for multiple outcomes, treatment arms, doses, or contrasts was planned. In general, multiplicity matters because evaluating many hypotheses can increase the chance of at least one false-positive result if each is judged independently. The record does not provide a procedure that would allow that issue to be assessed for this trial.
The registry states that no data for the prespecified outcome were analyzed under the NIH-approved statistical analysis plan. It does not report whether data were missing, whether measurements were unavailable, or whether the absence of analysis followed a decision made before or after data collection. The reason for termination is also not reported in the registry record. These are distinct issues: a terminated study can have collected data, but the record does not establish what data were collected or analyzed.
The analysis populations are not described. The record does not specify whether an intention-to-treat, per-protocol, or other population was used, nor does it give endpoint-specific denominators or a missing-data method. Those details matter because the participants included in an analysis and the handling of missing measurements can affect interpretation. The enrollment of 44 should not be assumed to equal the number analyzed for any endpoint.
Without analysis results and these methodological details, readers cannot assess the impact of missing data, the control of false-positive findings, or the representativeness of any analyzed group. The registry record does not report enough information to resolve these uncertainties.
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 |
|---|---|---|---|
| N-acetylcysteine IV Infusion at 0.5 gm Hourly | 1 | 16 | 6.2% |
| Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | 4 | 17 | 23.5% |
| Acetaminophen Plus N-acetylcysteine IV Infusion | 2 | 11 | 18.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| N-acetylcysteine IV Infusion at 0.5 gm Hourly | 3 of 16 |
| Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | 6 of 17 |
| Acetaminophen Plus N-acetylcysteine IV Infusion | 0 of 11 |
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 |
|---|---|
| N-acetylcysteine IV Infusion at 0.5 gm Hourly | 1 of 16 |
| Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | 1 of 17 |
| Acetaminophen Plus N-acetylcysteine IV Infusion | 1 of 11 |
Most frequent serious adverse event terms
| Event term | Organ system | N-acetylcysteine IV Infusion at 0.5 gm Hourly | Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | Acetaminophen Plus N-acetylcysteine IV Infusion |
|---|---|---|---|---|
| Vasospasm | Nervous system disorders | 0 of 16 | 2 of 17 | 1 of 11 |
| Death | General disorders | 1 of 16 | 2 of 17 | 0 of 11 |
| Pneumonia | Respiratory, thoracic and mediastinal disorders | 0 of 16 | 1 of 17 | 0 of 11 |
| Ischemic Stroke | Nervous system disorders | 0 of 16 | 0 of 17 | 1 of 11 |
Most frequent non-serious adverse event terms
| Event term | Organ system | N-acetylcysteine IV Infusion at 0.5 gm Hourly | Placebo for N-acetylcysteine IV Infusion at 0.5 gm Hourly | Acetaminophen Plus N-acetylcysteine IV Infusion |
|---|---|---|---|---|
| Rash | Skin and subcutaneous tissue disorders | 1 of 16 | 0 of 17 | 0 of 11 |
| Diarrhea | Gastrointestinal disorders | 0 of 16 | 1 of 17 | 0 of 11 |
| Tachycardia | Cardiac disorders | 0 of 16 | 0 of 17 | 1 of 11 |
Serious events with the highest arm-level rate: vasospasm (11.8%), death (11.8%), ischemic stroke (9.1%), pneumonia (5.9%).
The registry's adverse-event summary reports three groupings. For NAC IV infusion at 0.5 gm hourly, 16 participants were at risk for serious adverse events and 1 was affected; 16 were at risk for other adverse events and 1 was affected, and the listed death count is 3. For placebo for NAC IV infusion at 0.5 gm hourly, the corresponding serious-event figures are 17 at risk and 4 affected; other-event figures are 17 at risk and 1 affected, with 6 deaths listed. For acetaminophen plus NAC IV infusion, the figures are 11 at risk and 2 affected for serious events, 11 at risk and 1 affected for other events, and 0 deaths listed.
The registry also lists serious-event terms with percentages: Vasospasm, 11.8%; Death, 11.8%; Ischemic Stroke, 9.1%; and Pneumonia, 5.9%. The denominators and the relationship between these term percentages and the group-level counts are not reported in the registry record. The adverse-event summary includes three groupings; the record does not explain how these relate to every intervention listed for the trial.
These are reported counts, not adjusted comparisons. The registry does not provide the event definitions, complete follow-up information, or a comparative safety analysis. They should not be interpreted as establishing that a regimen caused or prevented an event.
12. What the Result Does, and Does Not, Mean
The posted results establish that the registry records a randomized, quadruple-masked, factorial Phase 3 study of APAP and NAC regimens in aSAH, with enrollment of 44 and terminated status. They also establish that the registered primary outcome was the number of patients with vasospasm based on MRA at 8 days after the SAH event. The record explicitly says that no data for this prespecified outcome were analyzed.
As a result, the registry record does not provide an estimate of whether APAP, NAC, or a combination changed the occurrence of vasospasm. It does not report the size or direction of a primary treatment effect, its precision, or a statistical test for that effect. The study's stated objective of inhibiting lipid peroxidation and its use of F2-IsoPs as biomarkers describe the research question; they are not themselves evidence that lipid peroxidation was inhibited. No analyzed biomarker results are reported in the record information.
The registry's stated planning comparison and power do not fill this gap. Planned power is a design calculation, not an observed treatment result. Likewise, enrollment is not an endpoint result: the number enrolled does not reveal how many participants had usable measurements or what those measurements showed.
Serious adverse-event summaries provide descriptive counts for specified groupings, but do not establish causal differences between regimens. The registry does not report the event definitions, a full comparative analysis, or enough follow-up detail to interpret these counts as relative risks. It also does not report why the study was terminated.
Thus, the record is informative about the study's design, intervention options, registered primary measure, and some adverse-event summaries. It does not support a conclusion that any regimen did or did not affect vasospasm or lipid peroxidation. The missing analysis is an evidentiary limitation, not a finding of no effect.
13. Why This Trial Matters Statistically
This trial is statistically notable because its registered scientific objective and its primary endpoint address related but distinct questions. The brief description focuses on lipid peroxidation and F2-IsoPs, while the primary endpoint is MRA-based vasospasm. Biomarker evidence and a patient-level clinical or imaging outcome are not interchangeable. Clear separation of those estimands is important when interpreting what a study is designed to answer.
The factorial label and multiple listed regimens also make the choice of comparison important. A study can involve several treatment components and combinations, but a reader needs to know which contrasts were prespecified and how each was analyzed. The registry reports a planning comparison of placebo and NAC subjects, yet does not explain how that comparison maps onto all listed arms or whether the APAP doses were evaluated separately. Those omissions limit interpretation of the design's analytic structure.
The registry's statement that no prespecified outcome data were analyzed illustrates the difference between trial planning and trial evidence. A planned power value does not show what the results were, and enrollment alone does not yield a treatment-effect estimate. To assess evidence about an intervention, readers need analyzed outcome data, an explicit comparison, and an indication of uncertainty.
Finally, the adverse-event summaries show why descriptive counts should be distinguished from comparative inference. Counts and event-term percentages can describe what the registry lists, but without clear denominators, follow-up, and a comparative analysis they do not establish differences attributable to treatment. These distinctions are useful in reading any trial record where design information and event summaries are available but the primary efficacy analysis is not.
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 primary limitation is the absence of analyzed data for the prespecified MRA-based vasospasm outcome. No group-specific outcome counts, treatment-effect estimate, confidence interval, or p value are reported in the registry record. The record therefore does not permit an assessment of the direction, magnitude, or precision of the primary comparison.
The available design description does not resolve how the factorial structure was analyzed. Five intervention descriptions include placebo, single-agent, and combined regimens, including two APAP doses. The registry does not report the allocation details, the intended contrasts for each intervention, or how interactions or dose comparisons were to be handled. The planned placebo-versus-NAC comparison is stated, but its relationship to the full regimen set is not explained.
Outcome and analysis details are limited. Although six outcome measures are listed, zero analyses are reported. The record does not provide the endpoint-specific analysis population, missing-data counts or methods, MRA assessment procedures beyond the brief description, or a multiplicity plan. These omissions prevent readers from determining whether any analysis would be vulnerable to missingness or how multiple comparisons were addressed.
The safety information is also incomplete for comparative interpretation. It provides counts for three adverse-event groupings and percentages for selected serious-event terms, but does not report the denominators for the term percentages, event definitions, or complete follow-up details. The registry does not explain how the three groupings relate to all listed interventions. The reason for termination is not reported. Each of these limitations concerns information absent from the registry record; none identifies the unreported reason or outcome.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Acetaminophen in aSAH to Inhibit Lipid Peroxidation and Cerebral Vasospasm — NCT00585559.
- Registry record last updated 2025-04-18; status last verified 2025-03.
- Results first posted 2025-04-18.
- 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 describes NCT00585559, titled “Acetaminophen in aSAH to Inhibit Lipid Peroxidation and Cerebral Vasospasm,” as a randomized, quadruple-masked, factorial Phase 3 study sponsored by Vanderbilt University Medical Center. It lists enrollment of 44, a start date of 2007-04, primary completion on 2023-10-26, and terminated status.
The interventions include placebo, APAP, NAC, and combined regimens. The registered primary endpoint is the number of patients with vasospasm based on MRA at 8 days after the SAH event. The record states that no data for this prespecified outcome were analyzed. It lists six outcome measures and zero analyses.
The record also gives a planned placebo-versus-NAC comparison with 34 subjects in each group and probability (power) 0.8. The reason for termination, primary outcome results, analysis populations, and detailed missing-data and multiplicity methods are not reported in the registry record. Adverse-event counts are listed for three groupings but do not constitute a comparative safety analysis.