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 A Study of Avastin (Bevacizumab) And Fotemustine in Patients With Recurrent Glioblastoma (NCT01474239), a non-randomized phase 2 study. The primary outcome is Percentage of Participants Alive 6 Months After Start of Treatment.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01474239 |
| Phase | Phase 2 |
| Condition | Glioblastoma Multiforme |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 91 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Hoffmann-La Roche |
| Results posted | Yes |
2. Clinical Question
Population
Patients with recurrent glioblastoma, described in the record under the condition Glioblastoma Multiforme. The stated enrollment was 91. The primary endpoint definition identifies an Intent-to-Treat population as all randomized participants who received at least one administration of study drug, although the allocation field labels the study non-randomized.
Intervention
Bevacizumab, also called Avastin in the record, at 10 mg/kg intravenously every 2 weeks. Treatment was anticipated to continue until disease progression or unacceptable toxicity.
Comparator
Fotemustine, designated the calibration arm. The described schedule was 75 mg/m2 on days 1, 8 and 15, followed after a 5 weeks interval by 100 mg/m2 intravenously every 3 weeks. The record says this arm was intended for calibration, not as a formal efficacy comparator.
Primary question
What percentage of participants were alive 6 months after treatment began? The record defines overall survival as time from treatment start to death from any cause and says it was estimated by Kaplan-Meier. No numerical estimate or confidence interval for the six-month result is reported in the registry record, so the endpoint’s observed value cannot be described from this record.
The clinical question is therefore primarily about a six-month survival proportion in the bevacizumab study, with fotemustine included as a calibration arm. The description says no formal efficacy comparison would be made between the treatment arms. That distinction matters: the record does not establish a prespecified head-to-head test, and it does not report a numerical result that would support one.
There is an internal design-description conflict. The official title and brief summary call the study randomized, while the allocation field says non-randomized. The record does not resolve that inconsistency. Consequently, the allocation process should not be inferred from the prose alone, and the fotemustine group should not be treated as a like-for-like randomized control group.
3. Trial Design
This is a phase 2, parallel-arm study listed as completed, with 91 participants enrolled. The sponsor is Hoffmann-La Roche. The record gives a start date of 2011-11 and a primary completion date of 2013-12. It lists bevacizumab and fotemustine as the study drugs and recurrent glioblastoma as the clinical setting.
The design fields describe the study as non-randomized, unmasked, and parallel. However, the official title calls it a randomized non-comparative trial, and the brief summary says participants would be randomized to one of the two regimens. These descriptions do not agree. The record does not explain whether random assignment occurred, so the metadata and narrative cannot be reconciled from the registry record alone.
The two treatment schedules differ. Bevacizumab was described at 10 mg/kg intravenously every 2 weeks. Fotemustine was described as 75 mg/m2 on days 1, 8 and 15, followed after a 5 weeks interval by 100 mg/m2 intravenously every 3 weeks. The anticipated treatment duration was until disease progression or unacceptable toxicity. The arm descriptions themselves are blank in the record.
The study is explicitly described as non-comparative: fotemustine serves as a calibration arm, and no formal efficacy comparison was planned according to the brief summary. This means the existence of two arms should not be mistaken for a conventional comparative trial. The record contains no formal rationale for allocation, no sample-size justification, and no detailed statistical plan for comparing treatment effects. These details 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.
Before assignment: Study included 28-day screening period. Participants were randomized according to a 2:1 ratio to one of the 2 treatment groups. A total of 99 participants were screened, of which 91 were randomized.
Overall Study
| Stage | Bevacizumab | Fotemustine |
|---|---|---|
| STARTED | 59 | 32 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 59 | 32 |
Reasons for not completing this period:
| Reason | Bevacizumab | Fotemustine |
|---|---|---|
| Disease Progression | 37 | 25 |
| Adverse Event | 12 | 3 |
| Withdrawal by Subject | 1 | 2 |
| Death | 1 | 1 |
| Clinical Disease Progression | 7 | 1 |
| Withdrawal for Economic Reason | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT) population included all randomized participants with at least one administration of the study drug.
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.
Population: Safety population included all randomized participants with at least one administration of the study drug and at least one safety assessment.
| Characteristic | Unit | Bevacizumab | Fotemustine | Total |
|---|---|---|---|---|
| Participants analysed | 59 | 32 | 91 | |
| Age, Continuous | years | 56.86 (SD 9.40) | 55.63 (SD 10.64) | 56.43 (SD 9.81) |
| Sex: Female, Male: Female | Participants | 20 | 9 | 29 |
| Sex: Female, Male: Male | Participants | 39 | 23 | 62 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants Alive 6 Months After Start of Treatment, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants alive 6 months after the start of treatment. It represents survival status at a specified time point rather than the full pattern of time to death. The record defines overall survival as the time in months from treatment start to death due to any cause. Participants not known to have died were censored at their last known date alive, determined from the latest of several possible contact or assessment dates. Participants with no information after baseline were censored at Day 1.
The record states that overall survival was estimated using the Kaplan-Meier method. In general, this method uses information from participants with different follow-up durations, including participants whose survival time is censored because death was not observed during their available follow-up. It can therefore estimate survival at a chosen time without requiring every participant to have the same follow-up duration.
A six-month survival percentage can communicate survival at a clinically specified time, while the underlying time-to-event approach accounts for censoring. The confidence interval describes uncertainty around the estimate; it is not a range containing a known individual outcome. The record identifies a 95% confidence interval as the dispersion measure, but gives no numerical six-month estimate or interval. The actual precision and observed survival proportion are therefore not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted registry information identifies the primary outcome and its estimation method, but does not include the numerical six-month survival estimate or its 95% confidence interval. As a result, the observed percentage alive at the primary time point, and the precision of that percentage, are not reported in the registry record. The study’s primary result cannot be reconstructed from the endpoint description alone.
This absence also limits any assessment of the amount of uncertainty. A confidence interval would show which survival proportions are reasonably compatible with the observed data under the analysis assumptions. Without its endpoints, readers cannot judge whether the estimate is precise or wide. A named endpoint and a stated method are not substitutes for the numerical result.
The registry describes fotemustine as a calibration arm and says no formal efficacy comparison would be made. Accordingly, the record should not be read as establishing a treatment difference between bevacizumab and fotemustine. The available description does not provide an effect estimate, a test of a between-arm difference, or a comparative confidence interval. In general, comparisons between arms require an analysis designed for that purpose and an allocation process that supports the intended interpretation.
There is additional uncertainty about allocation because the record’s fields label the study non-randomized, whereas the title and brief summary describe randomization. This internal conflict matters when interpreting groups: randomized assignment can support a different comparison than non-random allocation, particularly when participants may differ before treatment. The registry record does not say how the conflict should be resolved.
The listed enrollment of 91 does not itself indicate how many participants contributed to the primary estimate, how many were alive at the endpoint, or how much follow-up was available. Those outcome details are not reported in the registry record. Nor does the record give the underlying survival curve, numbers at risk over time, or the number of deaths for the primary endpoint. No conclusions about the observed survival pattern or relative performance of the regimens follow from the design description alone.
In general, the Kaplan-Meier estimate depends on the censoring approach and on the assumption that censoring is appropriately handled for the estimand. The record describes how censored times were assigned but does not report diagnostics or sensitivity analyses. Those methods and results are not reported in the registry record. Interpretation should therefore remain limited to what is explicitly documented: a planned six-month survival endpoint, a stated estimation method, and no numerical primary result in the posted record.
9. Statistical Methods Explained
The registry describes a time-to-event outcome summarized as the percentage of participants alive 6 months after treatment began. It defines overall survival as time from treatment start to death from any cause. This definition treats death from any cause as the event, rather than limiting the outcome to a particular cause of death.
What does Kaplan-Meier estimation do?
In general, Kaplan-Meier estimation builds an estimate of the probability of remaining alive over time by using each participant’s observed follow-up. A participant who dies contributes an event time. A participant whose death is not observed contributes follow-up until the last date known alive and is then censored. Censoring means that the participant’s later survival status is unknown for the analysis; it does not mean the participant died at the censoring date.
The registry says the latest among the date of last visit, last laboratory sample, MRI assessment, last treatment, discontinuation, and last available follow-up visit defined the last date known alive. It also says participants with no information after baseline were censored at Day 1. These rules define how the record intended to handle incomplete follow-up for overall survival. The registry does not report additional sensitivity analyses or diagnostics concerning censoring.
How should a confidence interval be read?
In general, a confidence interval communicates uncertainty in an estimated quantity. A narrower interval indicates greater precision than a wider interval, subject to the analysis assumptions. The registry names a 95% confidence interval for the primary endpoint, but does not report its numerical limits or the point estimate. Therefore, no conclusion about precision can be drawn from the stated confidence level alone.
The endpoint is expressed as a percentage alive at a fixed follow-up time, while the method uses time-to-event information and censoring. Those are compatible ways of describing the same survival analysis: the estimate at the specified time is read from the estimated survival function. The registry does not provide the survival function or its values at other times in the information.
What does the analysis population mean?
The primary endpoint description defines the Intent-to-Treat population as all randomized participants who received at least one administration of study drug. The record’s allocation field, however, says non-randomized, while its title and brief summary describe randomization. That inconsistency makes the population definition difficult to reconcile with the design metadata. The registry does not explain how the analysis population was operationalized or report the number included in the primary analysis.
In general, specifying an analysis population is important because it determines which participants contribute to an estimate. Excluding participants after treatment begins can alter the population being described, while including all participants according to their assigned group is often intended to preserve the benefits of random allocation. The record’s stated definition requires randomization and at least one administration, but the allocation conflict prevents a clear interpretation of how that definition was applied.
What can the sample-size illustrations establish?
The study’s sample-size justification is not reported in the registry record. The separate planning illustrations are described as calculations based on an observed effect, rather than the trial’s own design. Their stated assumptions include a two-sided significance level of 0.05, equal allocation, a normal approximation, and detecting a stated fraction of the observed effect. For time-to-event outcomes, the illustrations concern total events; for other outcomes, they concern participants per arm. These are planning assumptions, not evidence that the study was designed to those targets.
In general, power is a property of a planned design under specified assumptions, not a measure of whether a completed study produced a persuasive result. A sample-size illustration based on an observed effect is especially dependent on that effect and should not be called observed power. No numerical illustration values or observed primary effect are reported in the registry information, so no planning count or power statement can be inferred.
The record also lists multiple outcomes, including survival, progression-free survival, response, quality of life, and corticosteroid initiation. The registry does not provide a full account of how analyses across these outcomes were controlled or prioritized. The stated endpoint and analysis method are therefore useful, but they do not amount to a complete statistical analysis plan.
10. Exact Estimates for Each Arm
No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Bevacizumab | 59 | 37 | 62.7% | 49.1% to 75.0% | 50.0% to 73.9% | 49.9% to 73.9% |
| Fotemustine | 32 | 23 | 71.9% | 53.3% to 86.3% | 54.6% to 84.4% | 54.5% to 84.4% |
R code and output
arm <- c("Bevacizumab", "Fotemustine")
n <- c(59, 32)
events <- c(37, 23)
for (i in seq_along(n)) {
ci <- binom.test(events[i], n[i])$conf.int # Clopper-Pearson exact interval
cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i]) # Bayesian, uniform Beta(1,1) prior
wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}
ARM Bevacizumab 59 37 62.7 49.1 75.0 50.0 73.9 49.9 73.9
ARM Fotemustine 32 23 71.9 53.3 86.3 54.6 84.4 54.5 84.411. Multiplicity, Missing Data and Analysis Populations
The record lists 16 outcome measures and identifies the percentage alive 6 months after treatment start as the primary endpoint. The secondary outcomes include survival and progression-free survival at specified follow-up points, overall progression-free survival, response, quality-of-life score changes, and corticosteroid initiation. Examining multiple outcomes can create multiplicity: in general, the more statistical questions tested, the greater the chance that at least one result appears notable by chance. A prespecified strategy can address this, but a multiplicity adjustment or testing hierarchy is not reported in the registry record.
The record states that one analysis entry is present, but does not provide enough detail to determine the full set of analyses, whether other analyses were performed, or how analyses were selected for reporting. Interim analyses and stopping rules are not reported in the registry record. The study’s statistical analysis plan, including any multiplicity procedure, is also not reported.
Missing follow-up is relevant to the primary survival endpoint. The record specifies censoring at the latest of listed dates when a participant was not known to have died, and censoring at Day 1 for participants without information after baseline. This describes the recorded rule, but does not show how many participants were censored, their follow-up duration, or whether missingness could have affected the estimate. Those details are not reported in the registry record.
The endpoint population is described as all randomized participants who received at least one administration. Yet the allocation field says non-randomized, while other record text describes randomization. The actual analysis population and its size are not reported in the registry record. The record also does not provide outcome-specific counts for the primary endpoint, so readers cannot evaluate the relationship between enrollment, available follow-up, and the reported estimate.
12. 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 |
|---|---|---|---|
| Bevacizumab | 17 | 59 | 28.8% |
| Fotemustine | 6 | 32 | 18.8% |
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 |
|---|---|
| Bevacizumab | 35 of 59 |
| Fotemustine | 25 of 32 |
Most frequent serious adverse event terms
| Event term | Organ system | Bevacizumab | Fotemustine |
|---|---|---|---|
| Intestinal perforation | Gastrointestinal disorders | 2 of 59 | 0 of 32 |
| Convulsion | Nervous system disorders | 2 of 59 | 0 of 32 |
| Pneumonitis | Respiratory, thoracic and mediastinal disorders | 2 of 59 | 0 of 32 |
| Leukopenia | Blood and lymphatic system disorders | 0 of 59 | 1 of 32 |
| Pancytopenia | Blood and lymphatic system disorders | 0 of 59 | 1 of 32 |
| Thrombocytopenia | Blood and lymphatic system disorders | 0 of 59 | 1 of 32 |
| Acute myocardial infarction | Cardiac disorders | 1 of 59 | 0 of 32 |
| Abdominal pain | Gastrointestinal disorders | 1 of 59 | 0 of 32 |
| Ascites | Gastrointestinal disorders | 1 of 59 | 0 of 32 |
| Condition aggravated | General disorders | 1 of 59 | 0 of 32 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Bevacizumab | Fotemustine |
|---|---|---|---|
| Asthenia | General disorders | 13 of 59 | 4 of 32 |
| Thrombocytopenia | Blood and lymphatic system disorders | 2 of 59 | 14 of 32 |
| Hypertension | Vascular disorders | 13 of 59 | 1 of 32 |
| Neutropenia | Blood and lymphatic system disorders | 2 of 59 | 8 of 32 |
| Pyrexia | General disorders | 5 of 59 | 3 of 32 |
| Transaminases increased | Investigations | 3 of 59 | 4 of 32 |
| Anaemia | Blood and lymphatic system disorders | 1 of 59 | 5 of 32 |
| Nausea | Gastrointestinal disorders | 2 of 59 | 4 of 32 |
| Convulsion | Nervous system disorders | 4 of 59 | 2 of 32 |
| Headache | Nervous system disorders | 5 of 59 | 1 of 32 |
Serious events with the highest arm-level rate: intestinal perforation (3.4%), convulsion (3.4%), pneumonitis (3.4%), leukopenia (3.1%), pancytopenia (3.1%).
The serious adverse-event entries give participants at risk and affected for each arm: for bevacizumab, 59 were at risk and 17 were affected; for fotemustine, 32 were at risk and 6 were affected. The other adverse-event entries list 59 at risk and 35 affected for bevacizumab, and 32 at risk and 25 affected for fotemustine. These are descriptive counts, not evidence that a drug caused an event or that one regimen is safer than the other.
The registry also lists serious-event terms with percentages: intestinal perforation, convulsion, and pneumonitis each at 3.4%; leukopenia, pancytopenia, and thrombocytopenia each at 3.1%. The record does not describe the denominator or arm attribution for these term-specific percentages in the information. They should not be interpreted as comparative rates or used to infer a treatment difference.
Safety comparisons require attention to exposure, follow-up, event definitions, and the method used to collect and summarize adverse events. The registry information does not supply those details for interpreting between-arm differences. The death counts in the adverse-event entries are not reported in the registry record. These figures describe recorded events and participants; they do not establish causality, and the non-comparative study description cautions against a direct safety ranking.
13. What the Result Does, and Does Not, Mean
The registry record establishes that the study was designed to examine bevacizumab and fotemustine in recurrent glioblastoma and identifies six-month overall survival as the primary endpoint. It also states that overall survival was estimated by Kaplan-Meier and names a 95% confidence interval as the uncertainty measure. These details explain what the primary question was and how it was intended to be analyzed.
They do not reveal the numerical answer. The six-month survival estimate and its interval are not reported in the registry record. There is consequently no basis in this record to state what percentage of participants were alive at that time or how precisely that percentage was estimated. Enrollment alone cannot supply those missing outcome data.
The record does not support a formal efficacy comparison between bevacizumab and fotemustine: it describes fotemustine as a calibration arm and says no formal efficacy comparison would be made. In addition, allocation is labeled non-randomized in the design field, while the title and brief summary use randomized language. The record does not resolve this conflict. Thus the two arms should not be treated as a conventional randomized comparison on the basis of this information.
In general, a clinical study result describes an estimate for a defined population, endpoint, and analysis. It does not by itself establish that a treatment caused an outcome, and a missing estimate cannot be replaced by interpretation of the study title or methods. The posted record also does not give a complete account of missing follow-up, multiplicity handling, or the full statistical analysis plan. These omissions limit conclusions about the reliability and scope of any result.
The most defensible reading is narrow: the registry documents the study question, regimens, planned survival method, and a non-comparative intent, but does not report the primary numerical result. It therefore does not establish the magnitude or precision of six-month survival in this record, nor a between-arm efficacy or safety difference.
14. Why This Trial Matters Statistically
This trial illustrates why design labels and outcome estimates both matter in interpreting clinical research. A study can list two treatment arms and a primary endpoint while still being explicitly non-comparative. The brief summary identifies fotemustine as a calibration arm, not a formal efficacy comparator. Treating the presence of two arms as evidence of a planned head-to-head test would overstate what the registry says.
The record also presents an important design-description inconsistency: its allocation field says non-randomized, while the title and brief summary describe randomization. Random allocation can support particular interpretations of treatment-group comparisons; non-random allocation raises different concerns about whether groups were comparable. When the registry does not reconcile these statements, the design cannot be confidently characterized beyond acknowledging the conflict.
The endpoint description offers a useful example of time-to-event analysis. Overall survival includes censoring for participants not known to have died, and the record gives rules for assigning the last known date alive. Kaplan-Meier estimation is a standard general approach for using such follow-up, but naming the method does not tell readers the estimate, its precision, or how much data supported it. Here, the numerical primary result is not reported in the registry record.
Finally, registry interpretation depends on distinguishing a planned question from a posted result. The study’s phase, regimen descriptions, outcome definitions, and calibration-arm purpose are documented, while several central statistical details are not. The record therefore shows why study design, estimand, analysis population, and numerical results must be considered together—and why the limitations of the record itself should remain visible in any statistical reading.
15. 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 for interpreting efficacy is that the numerical primary endpoint result is not reported in the registry record. Neither the six-month survival percentage nor its 95% confidence interval appears in the information. No primary estimate can therefore be assessed for magnitude or precision.
The design description is internally inconsistent. Allocation is recorded as non-randomized, but the title and brief summary describe randomization. The record does not clarify which description reflects the actual allocation process. This ambiguity is particularly important because fotemustine is called a calibration arm and the study is described as non-comparative; conclusions based on a direct comparison would not match that stated intent.
The record does not report a detailed sample-size justification, full statistical analysis plan, interim-analysis approach, or multiplicity strategy. It lists 16 outcome measures, but does not explain how analyses across outcomes were prioritized or whether adjustment was used. The sample-size illustrations are planning calculations based on an observed effect, not the study’s own design justification, and their numerical values are not described in the record information.
The number of participants contributing to the primary endpoint, the amount of censoring, and the survival follow-up pattern are not reported. Although censoring rules are described, no sensitivity analysis or diagnostic results are provided. The primary population definition also refers to randomized participants who received at least one administration, which is difficult to reconcile with the non-randomized allocation field.
Safety information is limited to the listed counts and term-specific percentages. The record does not supply enough context to interpret the listed term percentages as between-arm rates, and the death counts in the adverse-event entries are not reported. These limitations restrict interpretation to description rather than comparative inference.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: A Study of Avastin (Bevacizumab) And Fotemustine in Patients With Recurrent Glioblastoma — NCT01474239.
- Registry record last updated 2016-03-15; status last verified 2015-09.
- Results first posted 2015-08-07.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
The registry record describes a completed phase 2 study sponsored by Hoffmann-La Roche, with 91 participants enrolled and recurrent glioblastoma as the condition. It lists bevacizumab and fotemustine in parallel arms, with treatment anticipated until progression or unacceptable toxicity. The record identifies percentage alive 6 months after treatment start as the primary endpoint and says overall survival was estimated by Kaplan-Meier.
The study is described as non-comparative, with fotemustine serving as a calibration arm. However, the allocation field says non-randomized while the title and summary describe randomization. The record does not resolve this inconsistency. Most importantly, the numerical six-month survival estimate and its 95% confidence interval are not reported in the registry record. Thus, the registry describes the question and method but does not provide the primary result needed to assess its observed value or precision.