Maths Predicts Heart Surgery Risk

How important is it to know the chances of an adverse outcome for heart surgery? Hospital administrators now consider this type of information an important part of hospital operations.

The Risk Stratification Model which has been developed by a Queensland University of Technology Masters student, has enabled Brisbane's Prince Charles Hospital to be able to predict a patient's chance of survival from heart surgery using its own patient base and specialised methodology.

In developing the mathematical model, the research looked at 113 factors including a patient's age and weight, whether they had angina or liver disease or were taking blood pressure tablets, or had undergone previous heart surgery.

Patients who are older, not overweight and have actively managed unstable angina are at minimal risk. For overweight patients, the risk of death is 200 times greater than average. Doctors may still operate on high-risk patients, but they can monitor them more closely.

The model has reinforced ideas doctors already had. In addition, it has given a breakdown of other people who are only a little at risk. For example, doctors have always been careful with female patients who were older and overweight, often waiting until a patient lost weight before operating. With the Risk Stratification Model, doctors are told the predicted risk and how they compared to others with similar characteristics.

The move to evidence-based practice is increasing in Australia and has allowed hospitals to better determine budgets and improve service to patients.