European Heart Journal (2003) 24,1 2 - EuroSCORE

1 Letter to the (02)00799-6 The logistic EuroSCOREDear Sir,The European System for CardiacOperative Risk Evaluation ( euro -SCORE) identifies a number of riskfactors which help to predict mor-tality from cardiac pre-dicted mortality (in percent) is calcu-lated by adding the weights assignedto each factor. Since its initial publi-cation in 1999, EuroSCORE has beenwidely used in Europe and elsewhereand has been the subject of severalstudies. Most of these studies com-pared the predictive ability of theEuroSCORE to previously describedsystems2,3or to locally original work used it asa tool in order to assess the intra-institutional benefit in switchingfrom conventional surgery under car-diopulmonary bypass to the off-pumpapproach in coronary , EuroSCORE was found to bean easy tool for inter-institutionalcomparison with good or ,many observers noted a trend to anunderestimation of the operative riskin very high-risk patients.

2 And it hasbeen suggested that full statisticalcomparison to other systems might bedifficult since comprehensive infor-mation on the logistic regressionequation of the score was was initially designedto be a user-friendly system, in thehope of encouraging as many units aspossible to embark on programmes ofrisk-adjusted quality monitoring. Inthis setting, although derived from alogistic regression methodology, onlythe simple additive version of thescore was originally published. Thisscore could be easily calculated atthe bedside4,5and could therefore beused widely in Europe even in hos-pitals with little information tech-nology. Today, European cardi-ologists and cardiac surgeons aredemonstrating a growing interest inquality control and have access toever better information technologyresources.

3 Some may therefore wishto use a more sophisticated riskmodel than the simple additive euro -SCORE. For this reason, we seek tomake public the full details of theEuroSCORE logistic regression equa-tion (Table 1). Using the same riskfactors,thelogisticregressionversion of the score (the logisticEuroSCORE ) can be calculated. For agiven patient, the logistic EuroSCORE which is the predicted mortalityaccording to the logistic regressionequation, can be achieved with thefollowing formula:predicted mortality e( 0 iXi)1 e( 0 iXi)where 0is the constant of the logis-tic regression equation (see Table 1)and iis the coefficient of the vari-ableXiin the logistic regression equa-tion provided in Table acategorical risk factor is present and0 if it is absent.

4 For age,Xi=1ifpatient age <60;Xiincreases by onepoint per year thereafter (ie: age 59or lessXi=1; age 60Xi=2; age 61Xi=3and so on).Cardiologists and cardiac surgeonswill be relieved to note that they donot have to face this complex calcu-lation with every patient; a risk cal-culator (additive and logistic) can beused or downloaded easily from theEuroSCORE website ( ).The additive EuroSCORE is simple,well validated, user-friendly andworks at the bedside without special-ised equipment. Because of its addi-tive properties, it will tend tounderestimate risk in some very highrisk groups. The logistic EuroSCORE ismore suitable for individual risk pre-diction in very high risk patients andwill facilitate further sophisticatedstudy into the field of risk.

5 WithinEurope and elsewhere in the worldthere are hospitals with rudimentary,if any, data collection and others,where data are abundant and thestudy of risk is a specialised area ofadvanced investigation. It can there-fore be argued that there is currentlya place for both simple as well as* Corresponding author. Tel.: +44-1480-364299; fax: 44-1480-364744E-mail (S. Nashef)Table 1 Logistic regression model of EuroSCORE in the 1995 pilot studyVariables CoefficientAge (continuous) creatinine >200 cardiac myocardial 30 50% <30% pulmonary pressure >60 preoperative septal than isolated coronary aortic 0 , left ventricular ejection fraction; full definition of these variables arepublished1and can be seen on-line ( ).

6 European Heart Journal (2003)24,1 20195-668X/03/$ - see front matter 2003 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights risk tools in this rapidlyevolving Nashef SAM, Roques F, Michel P et system for cardiac operativerisk evaluation ( EuroSCORE ).Eur JCardiothorac Surg1999;16(1):9 Geissler HJ, Holzl P, Marohl S et stratification in Heart surgery:comparison of six score JCardiothorac Surg2000;17(4): 400 Kawachi Y, Nakashima A, Toshima Yet al. Risk stratification analysis ofoperative mortality in Heart andthoracic aorta surgery: comparisonbetween Parsonnet and EuroSCORE additive J CardiothoracSurg2001;20(5):961 Pitkanen O, Niskanen M, Rehnberg Set al. Intra-institutional prediction ofoutcome after cardiac surgery: com-parison between a locally derivedmodel and the JCardiothorac Surg2000;18(6):703 Sergeant P, de Worm E, Meyns B et challenge of departmental qualitycontrol in the reengineering J Cardiothorac Surg2001;20(3):538 RoquesCHU Fort-de-FranceMartiniqueFranceP.

7 Michel12 Rue Dubernat33404 Talence NashefPapworth HospitalCambridge CB3 8 REUK2 Letters to the Editor