EVAR2.
| Methods |
Study design: Multicentre RCT Method of randomisation: Permuted block randomisation Exclusions post randomisation: EVAR = 18 (died before undergoing repair) Within EVAR randomisation group: 7 died, 8 became ineligible, 1 refused surgery and 2 for unknown reasons Within the no‐intervention group: 70 participants had EVAR Losses to follow up: 1 (no‐intervention group) Intention‐to‐treat analysis: Yes |
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| Participants |
Country: UK Setting: Hospital (33 centres) Recruitment: 1 September 1999 to 31 August 2004 Number: 404 (EVAR = 197; no intervention = 207) Age: Mean (SD) = 76.8 (6.5) years Sex: Male:female = 6:1 Inclusion criteria: Aged ≥ 60 years with AAA ≥ 5.5 cm, assessed by CT scan and deemed unfit for surgery locally by surgeon, radiologist, anaesthetist and cardiologist Exclusion criteria: MI within last 3 months, onset of angina within last 3 months, unstable angina at night or at rest |
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| Interventions |
Treatment: EVAR Control: No intervention |
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| Outcomes |
Primary: All‐cause mortality Secondary: Aneurysm‐related death; HRQoL; postoperative complications; hospital costs |
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| Notes | Results from this trial were published at different stages of recruitment and follow up. Data for outcomes were taken from the most relevant publication and this is reflected in the total number of participants for outcomes | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Randomisation is performed for each trial using a 50:50 ratio randomly permuted block sizes constructed by the STATA package. Randomisation is stratified by centre and is performed centrally by the trial manager only when all necessary baseline data had been received at the trial co‐ordinating centre". |
| Allocation concealment (selection bias) | Low risk | Allocation was done only after all baseline data were recorded |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Blinding of participants and operating surgeons not feasible in such a study |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Information not clear |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Analysis was intention‐to‐treat basis; all participants accounted for |
| Selective reporting (reporting bias) | Low risk | Reported on all predefined outcomes |
| Other bias | Low risk | None identified |