Coronary Surgery Risk Calculators

The ability to calculate the risk of an operation is valuable in two areas. Firstly, it is vital that surgeons are in a position to explain to their patients the risk of any operation that they and the patient are considering. Secondly, if units or surgeons are to be compared it is vital that differences in patient populations are catered for. This is called risk stratification.

On this page you will find two calculators for estimating the risk of dying during a coronary bypass operation. You will see that they are both quite different and although they are both very accurate for calculating risk in large groups of patients, they frequently give very different answers for individual patients. This highlights the difficulties inherent in accurately predicting operative risk. Although these calculators might give the impression that risk can easily be measured they are, in fact, pretty crude - surgeons base decisions for surgery on much more detailed and often subtle clinical information which is not easy to measure.

The euroSCORE Calculator

The euroSCORE is based on analysis of nearly 15,000 patients from centres around Europe. It has recently been tested on the Society of Thoracic Surgeons Database in the United States and been found to be very accurate. It also works well for predicting risk in the UK. Visit the EuroSCORE website

United Kingdom Bayes Calculator

Enter values for the following variables which have been found to be associated with in-hospital mortality for coronary artery bypass grafting. This calculator is based on more recent analysis of 33,392 patients undergoing coronary surgery in the financial years 1998 and 1999. For definitions and methodology, see the 1996 National Database Preliminary Report . For more detailed discussion see the 1999-2000 report and appendices. You will see that both calculators give different risks because they are based on slightly different variables. This highlights the difficulty of accurately measuring risk.