title: Validation of long-term survival prediction for scheduled abdominal aortic aneurysm repair with an independent calculator using only pre-operative variables.
abstract: We observed survival after scheduled repair of abdominal aortic aneurysm in 1096 patients for a median (IQR [range]) of 3.0 (1.5-5.8 [0-15]) years: 943 patients had complete data, 250 of whom died. We compared discrimination and calibration of an external model with the Kaplan-Meier model generated from the study data. Integrated Brier misclassification scores for both models at 1-5 postoperative years were 0.04, 0.08, 0.11, 0.13 and 0.16, respectively. Harrel's concordance index at 1-5 postoperative years was 0.73, 0.71, 0.68, 0.67 and 0.66, respectively. Groups with median 5-year predicted mortality of 40% (n = 251), 18% (n = 414) and 8% (n = 164) had lower observed mortality than 114 patients with 70% predicted mortality, hazard ratio (95% CI): 0.58 (0.37-0.76), p = 0.0031; 0.30 (0.19-0.48), p = 1.7 × 10(-12) and 0.19 (0.13-0.27), p = 1.3 × 10(-10) , respectively, test for trend p = 5.6 × 10(-15) . Survival predicted by the external calculator was similar to the Kaplan-Meier estimate.
authors.affiliation: Department of Anaesthesia, Torbay Hospital, Torquay, UK.
authors.forename: J B
authors.initials: JB
authors.lastname: Carlisle
authors.affiliation: Department of Academic Anaesthesia, James Cook University Hospital, Middlesbrough, UK.
authors.forename: G
authors.initials: G
authors.lastname: Danjoux
authors.affiliation: Department of Anaesthesia, Sheffield Teaching NHS Foundation Trust, Sheffield, UK.
authors.forename: K
authors.initials: K
authors.lastname: Kerr
authors.affiliation: Department of Anaesthesia, Newcastle upon Tyne NHS Foundation Trust, Newcastle, UK.
authors.forename: C
authors.initials: C
authors.lastname: Snowden
authors.affiliation: Department of Anaesthesia, Torbay Hospital, Torquay, UK.
authors.forename: M
authors.initials: M
authors.lastname: Swart
mesh_terms: D000367:Age Factors; D000368:Aged; D000465:Algorithms; D015308:Anaerobic Threshold; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality / Q000601:surgery*; D001835:Body Weight; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D010809:Physical Fitness; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012737:Sex Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures