-
Eur J Cardiothorac Surg 2001 Dec;20(6):1176-82
(Full
text access)
Single centre, single domain validation of the EuroSCORE
on a consecutive sample of primary and repeat CABG.
Sergeant P, de Worm E, Meyns B.
Cardiac Surgery Department, Gasthuisberg University Hospital, 3000, Leuven,
Belgium
Objectives: Intra- and interdepartmental benchmarking require scoring systems
with excellent performance on several properties: discrimination (resolution),
reliability (calibration) and stability over the complete spectrum of peri-procedural
risk. This single centre, single domain study validates the European system for
cardiac operative risk evaluation (EuroSCORE) on an independent sample of
primary and repeat coronary artery bypass grafting (CABG) patients and will
evaluate these different properties. Methods: The study population is a
consecutive series of 2051 isolated primary and repeat CABG patients, inclusive
of patients in cardiogenic shock or resuscitation, operated on in a single
institution from January 1997 to July 2000. The age of the patients was 66+/-9
years, 77% were males and 7% were repeat procedures. The EuroSCORE was 5.0+/-3%,
with a range from 0 to 22. The studied event was in-hospital death, defined as
mortality during hospital stay, which was unlimited in time and included a stay
in a secondary hospital without discharge home. Results: The EuroSCORE predicted
102 deaths versus 81 deaths observed (P=0.14, Fisher exact test). The EuroSCORE
described only 20% of the variance of in-hospital mortality. The EuroSCORE
created an area under the receiver operating characteristic curve of
0.83+/-0.03. The highest discriminative accuracy was obtained with 8% EuroSCORE
risk (only 64% sensitivity and 87% specificity). Further exploration identified
an over score in the EuroSCORE range 0-8 (57%, P<0.0001). There was an equal
score (-2%, P=1) in the range 9-11, but an under score in the range 12-22
(-133%, P=0.003). Conclusions: On the condition that these single centre results
could be extended to any European cardiac surgery centre, it can be concluded
that the overall acceptable performance of the EuroSCORE is the result of an
over score in the lower risk and insufficient correction in the higher risk
spectrum. The EuroSCORE is probably refined enough for improved informed consent
versus aggregated results but should only be used for inter-institutional
benchmarking with great caution, preferably below the 12% risk pivot.
