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 Immediate Management of the Patient With Rupture : Open Versus Endovascular Repair (NCT00746122), a randomized na study. The primary outcome is Mortality.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00746122 |
| Phase | NA |
| Condition | Abdominal Aortic Aneurysm |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 613 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Imperial College London |
| Results posted | Yes |
2. Clinical Question
Population
Patients with suspected ruptured abdominal aortic aneurysm (AAA). The registry record names abdominal aortic aneurysm as the condition and describes suspected rupture as the clinical setting. It does not provide further eligibility criteria or a detailed description of the enrolled population.
Intervention
An endovascular strategy: immediate computed tomography (CT), emergency endovascular aneurysm repair (EVAR) for patients whose anatomy is suitable, and open repair for those anatomically unsuitable for EVAR.
Comparator
Immediate open surgery. This is the comparator arm described in the registry record, rather than a strategy that first assesses suitability for EVAR.
Primary question
Does a strategy of endovascular repair when anatomically suitable, with open repair otherwise, reduce early mortality compared with immediate open repair? The listed primary outcome is mortality assessed at 30 days, 1-year and 3-years from randomisation. The registry record does not report the mortality results or an effect estimate.
3. Trial Design
This was a randomized, parallel-group trial of strategies for managing suspected ruptured abdominal aortic aneurysm. The registry record lists an enrollment of 613, identifies Imperial College London as sponsor, and marks the study as completed. The start is recorded as 2009-09 and primary completion as 2013-08-21. The phase is listed as NA.
The comparison concerns treatment strategies, not simply receipt of EVAR versus receipt of open repair. Participants assigned to the endovascular strategy were to receive immediate CT; those with anatomy suitable for EVAR were to undergo emergency EVAR, while those unsuitable were to receive open repair. The comparator was immediate open surgery. This distinction matters when interpreting any comparison: the endovascular arm includes the pathway of imaging, assessment of anatomical suitability, and different repairs according to that assessment.
Allocation is listed as randomized, with a parallel model and no masking. The registry record does not describe the randomization method, allocation concealment, or procedures for limiting bias in outcome assessment. It also does not report the detailed eligibility criteria, sites, participant flow, or the number assigned to each treatment arm in the trial-design information cited.
The listed secondary outcomes are quality-adjusted life years (QALYs) and hospital costs for cost-effectiveness evaluation. The record lists three outcome measures, but does not provide analyses for them. The registry record does not report a detailed protocol or statistical analysis plan, so further design choices cannot be established from the recorded information.
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: Exclusions: persons younger than 50 years, prior AAA repair
Overall Study
| Stage | Open Repair | Endovascular Strategy |
|---|---|---|
| STARTED | 297 | 316 |
| COMPLETED | 297 | 316 |
| NOT COMPLETED | 0 | 0 |
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 | Open Repair | Endovascular Strategy | Total |
|---|---|---|---|---|
| Participants analysed | 297 | 316 | 613 | |
| Age, Continuous | years | 76.7 (SD 7.8) | 76.7 (SD 7.4) | 76.7 (SD 7.6) |
| Sex: Female, Male: Female | Participants | 63 | 70 | 133 |
| Sex: Female, Male: Male | Participants | 234 | 246 | 480 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: Canada | participants | 6 | 7 | 13 |
| Region of Enrollment: United Kingdom | participants | 291 | 309 | 600 |
6. Primary Endpoint
The registry lists the primary outcome as Mortality, measured over 30 days, 1-year and 3-years from randomisation.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is mortality, recorded as a count of participants, at 30 days, 1-year and 3-years from randomisation. The registry describes these as three prespecified time points. Mortality is a binary outcome for each participant at a given assessment: a participant is either recorded as having died by that time or not. A count alone does not convey the proportion of participants affected, the difference between strategies, or the uncertainty around that difference.
Mortality is used to assess the trial’s stated question about early survival after management of suspected ruptured AAA. The registry’s aim was to assess whether an endovascular strategy, with open repair for those anatomically unsuitable for EVAR, reduces early mortality compared with immediate open repair. The later listed time points extend assessment beyond the earliest period, allowing outcomes to be considered at different points after randomisation.
The registry record does not report the mortality counts by arm, a comparison between arms, or confidence intervals for any of the listed time points. Consequently, the endpoint definition and assessment times are available, but the posted record does not establish the direction, size, or precision of a mortality difference.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a clinically focused randomized comparison: immediate open repair versus a strategy that uses CT to identify patients suitable for emergency EVAR and directs those unsuitable for EVAR to open repair. Its primary outcome is mortality at 30 days, 1-year and 3-years from randomisation. These details establish what was intended to be compared and measured; they do not show the comparative outcome.
Mortality results by treatment group are not reported in the registry record. Nor are an estimated treatment effect, confidence interval, or test result for the primary outcome. Thus, the posted information does not support a conclusion about whether mortality was higher or lower with either strategy, or how precisely any difference was estimated. The trial is marked completed, but completion status is not a substitute for posted outcome results.
The adverse-event information includes serious-event counts and a listed serious-event term, “Not discharged from hospital alive,” with 42.1%. These entries should be read as registry safety fields, not as a replacement for the primary mortality comparison. In particular, the record’s separate “deaths” entries are 297 for Open Repair and 316 for Endovascular Strategy, while the primary mortality outcome results are absent. The record does not explain how those entries relate to the primary outcome or to the adverse-event counts. They cannot be treated as a comparative mortality result without that context.
General statistical interpretation: an effect estimate describes the observed contrast between groups, while a confidence interval describes the range of values compatible with the data and analysis under its assumptions. Neither is available for the primary endpoint in this registry record. A p-value, even if reported, would not by itself describe the magnitude or clinical importance of an effect; no primary-outcome p-value is reported.
The record lists QALYs and hospital costs as secondary outcomes for cost-effectiveness evaluation, but no analyses are listed. The statistical interpretation is therefore limited to the design, endpoint definition, and posted safety fields. It cannot establish treatment benefit, lack of benefit, equivalence, or the comparative safety of the strategies.
9. Statistical Methods Explained
Randomization and the comparison. The registry identifies the allocation as randomized and the model as parallel. In general, randomization is intended to make treatment groups comparable at baseline, on average, with respect to both measured and unmeasured characteristics. It supports an intention-to-treat comparison when participants are analysed according to their randomized strategy, but the registry record does not state which analysis population was used. It also does not report the random sequence method, allocation concealment, or a primary statistical model.
The strategies differ in their decision pathway. The endovascular strategy includes immediate CT and uses EVAR when anatomy is suitable, with open repair for patients unsuitable for EVAR. The comparator is immediate open surgery. A comparison of randomized groups would therefore estimate the effect of assignment to these care strategies, not the isolated effect of EVAR among all participants. This distinction is important because some people assigned to the endovascular strategy are described as receiving open repair.
Binary mortality outcomes. The primary endpoint is mortality, recorded as counts of participants at 30 days, 1-year and 3-years from randomisation. General explanation: a binary outcome records whether each participant experienced the event by a specified assessment. An analysis can express results as event counts and denominators, and can estimate an absolute or relative contrast between groups. Those summaries require the relevant group counts and denominators, and inferential interpretation ordinarily also requires an estimate of uncertainty. The registry record does not report the primary mortality counts, denominators by arm, effect estimates, confidence intervals, or p-values.
The mortality assessments occur at multiple specified times. General explanation: each time point can answer a distinct question about when events occurred or accumulated. Repeated assessment also raises analytic choices, including how to define the event status at each time, how to handle participants whose status is unavailable, and how to address the multiplicity of testing several outcomes or time points. The registry record does not report the model or methods used for these assessments, or whether any adjustment for multiple comparisons was planned or applied.
Masking and outcome assessment. Masking is listed as none. The interventions are different procedures and pathways, and the record does not describe blinding of participants, clinicians, or outcome assessors. General explanation: lack of masking can affect outcomes that depend on subjective judgement or reporting. Mortality is comparatively objective as an outcome, but reliable interpretation still depends on complete ascertainment, clear definitions, and appropriate follow-up. The registry record does not provide details on outcome adjudication or completeness of follow-up.
Planning illustrations. A sample-size illustration based on an observed effect is a planning exercise, not evidence about the trial’s original design and not “observed power.” The stated assumptions for such illustrations are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is specified as a fraction of the observed effect. The registry record does not report its own sample-size justification, the effect size used for its design, or whether the planning illustration corresponds to the trial’s original assumptions. Any displayed planning values should therefore be interpreted only as hypothetical requirements under their stated assumptions, not as participants actually enrolled or evidence that the study could detect a particular effect.
Analysis methods not documented. General explanation: an analysis plan ordinarily defines the primary comparison, treatment of missing outcome data, analysis population, covariate adjustment, and handling of multiple outcomes. These choices influence what an estimate means and how its uncertainty should be interpreted. The registry record does not report the statistical analysis plan or the specific methods used for the primary outcome. It lists zero analyses. Without posted analyses and results, there is no basis for attributing an inferential method or determining whether analyses followed a prespecified plan.
10. Multiplicity, Missing Data and Analysis Populations
The primary mortality outcome is assessed at 30 days, 1-year and 3-years from randomisation. The registry record describes these as three prespecified time points but does not identify a single time point as the sole primary comparison, explain how the time points were prioritized, or report whether multiplicity was addressed. General explanation: testing several outcomes or time points can increase the chance of a nominally positive finding when each is considered separately. A prespecified testing strategy or adjustment can clarify how results should be interpreted, but no such strategy is reported in the registry record.
Missing outcome data can affect both the estimated event frequency and the comparison between randomized groups. General explanation: interpretation depends on how many participants have known outcome status, why data are missing, and what assumptions or sensitivity analyses are used. The registry record does not report missingness, follow-up completeness, reasons for loss to follow-up, or methods for handling missing mortality information.
The record identifies randomized allocation, but it does not state whether the primary analysis included all participants according to assigned strategy, used another analysis population, or accounted for treatment changes. These details are not reported in the registry record. It also does not describe protocol deviations or exclusions from analysis. The number of analyses is listed as zero, so the posted record does not supply an analysis account with which to evaluate these issues.
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 |
|---|---|---|---|
| Open Repair | 125 | 297 | 42.1% |
| Endovascular Strategy | 117 | 316 | 37.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Open Repair | 297 of 297 |
| Endovascular Strategy | 316 of 316 |
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 |
|---|---|
| Open Repair | 3 of 243 |
| Endovascular Strategy | 5 of 259 |
Most frequent serious adverse event terms
| Event term | Organ system | Open Repair | Endovascular Strategy |
|---|---|---|---|
| Not discharged from hospital alive | Vascular disorders | 125 of 297 | 117 of 316 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Open Repair | Endovascular Strategy |
|---|---|---|---|
| Major lower limb amputation after aneurysm repair | Vascular disorders | 3 of 243 | 5 of 259 |
Serious events with the highest arm-level rate: not discharged from hospital alive (42.1%).
The registry lists serious adverse-event fields for Open Repair and Endovascular Strategy. For Open Repair, the serious-event entries are 297 participants at risk and 125 affected; the “other” entries are 243 at risk and 3 affected. For Endovascular Strategy, the corresponding serious-event entries are 316 at risk and 117 affected; the “other” entries are 259 at risk and 5 affected. These are registry counts and should be read according to their labels, without assuming they use the same analysis population as the primary outcome.
The listed top serious-event term is “Not discharged from hospital alive,” at 42.1%. The record does not explain the denominator or further context for this percentage. The “deaths” entries are 297 for Open Repair and 316 for Endovascular Strategy. Because the primary mortality results and an explanation of these fields are not reported in the registry record, these entries should not be interpreted as the trial’s comparative mortality findings. Serious-event counts also do not, by themselves, establish a causal treatment effect or the relative safety of the strategies.
12. What the Result Does, and Does Not, Mean
The registry record describes a randomized comparison of immediate open surgery with a strategy that first uses CT and then selects EVAR or open repair according to anatomical suitability. It identifies mortality at 30 days, 1-year and 3-years from randomisation as the primary outcome. This is enough to understand the trial’s intended question and the basic structure of its comparison.
The posted record does not report the primary mortality results, an effect estimate, confidence interval, or p-value. It therefore does not show the direction or size of any difference, and it does not show how precisely any effect was estimated. The completed status cannot be used to infer a particular outcome. Nor can an absence of posted results be interpreted as evidence that the strategies had the same outcomes.
The record also identifies QALYs and hospital costs as secondary outcomes, but does not list analyses. Its adverse-event fields provide counts and a serious-event term, but not enough explanatory context to resolve how the “deaths” entries relate to the primary endpoint. These fields should not be used to make an unsupported comparative claim.
General explanation: a nonsignificant result, if one were available, would not automatically establish equivalence or absence of a meaningful difference. Equivalence or non-inferiority requires a suitable design, prespecified margins, and analysis. Those details are not reported in the registry record. Likewise, statistical significance alone would not describe the size or practical importance of an effect.
The responsible conclusion is limited: the registry documents the trial question, randomized design, endpoint timing, and some safety entries, but does not report the analyses needed to answer the comparative mortality question. It does not establish that either strategy improves outcomes, has no effect, or is preferable.
13. Why This Trial Matters Statistically
This trial is statistically notable for comparing care strategies rather than treating EVAR as an option available to everyone. The endovascular strategy incorporates immediate CT and directs patients to EVAR or open repair based on anatomical suitability. The randomized comparison is therefore about assignment to a clinical pathway, including its assessment step and the possibility of open repair in that arm.
That distinction affects the estimand, or the effect the trial is designed to assess. General explanation: a strategy-level comparison asks about the consequences of assigning patients to the whole pathway, whereas a procedure-only comparison would ask a different question. Interpreting results as if every person in the endovascular strategy received EVAR would misrepresent the strategy described in the registry.
The specified mortality assessments span 30 days, 1-year and 3-years from randomisation. This makes the endpoint definition and handling of multiple time points important for interpretation. The registry record does not report the analysis plan, multiplicity approach, mortality estimates, or uncertainty, so the statistical evidence for the central question cannot be assessed from the posted results.
The record also illustrates why registration details and outcome reporting serve different purposes. Randomization and the endpoint description clarify the intended design, while outcome estimates are needed to judge what the trial observed. The completed status and enrollment of 613 do not substitute for those results. The listed economic outcomes point to broader evaluation aims, but their analyses are not listed.
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 for interpreting this trial from the registry record is the absence of reported primary mortality results. Mortality is specified at 30 days, 1-year and 3-years from randomisation, but no group counts, comparisons, confidence intervals, or test results are reported. As a result, comparative effectiveness and precision cannot be assessed.
The registry gives limited methodological detail. It identifies randomized allocation, a parallel model, and no masking, but does not report the randomization procedure, allocation concealment, analysis population, statistical model, or handling of missing outcomes. It also does not report participant flow, follow-up completeness, or reasons for missing data. These omissions limit assessment of possible bias and the reliability of any comparison.
The endovascular strategy is conditional on anatomical suitability, with open repair for patients unsuitable for EVAR. The registry record does not report how many participants followed each procedure pathway or provide further details on suitability assessment. The posted information therefore does not permit examination of treatment received within the strategy arm.
The serious adverse-event fields include counts and a listed term, but the record does not explain the denominator for the 42.1% figure or the relationship between its “deaths” entries and the primary endpoint. QALYs and hospital costs are listed as secondary outcomes, but analyses are not reported. Sample-size justification, interim analyses, and a detailed statistical plan are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Immediate Management of the Patient With Rupture : Open Versus Endovascular Repair — NCT00746122.
- Registry record last updated 2019-12-19; status last verified 2019-12.
- Results first posted 2019-12-19.
- 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
NCT00746122 is a completed randomized, parallel-group trial sponsored by Imperial College London, with enrollment of 613. It compares immediate open surgery with an endovascular strategy involving immediate CT, emergency EVAR when anatomy is suitable, and open repair otherwise. Masking is listed as none, and phase as NA.
The primary outcome is mortality at 30 days, 1-year and 3-years from randomisation. QALYs and hospital costs are listed as secondary outcomes. The record includes serious adverse-event fields and lists “Not discharged from hospital alive” at 42.1%. It lists zero analyses; mortality results and the statistical analysis plan are not reported in the registry record.