LHCH Heart Surgery Outcomes
The Need for Risk Adjustment
Every patient who has the need for a cardiac surgery procedure has his or her own unique health history.
Liverpool Heart and Chest Hospital uses a published and validated prediction tool to estimate the risk of a cardiac surgery procedure resulting in death. This estimated risk is based on each individual patient’s own history.
This system weights the importance of each health fact (Eg. male/female, the patient’s age, urgent/non-urgent operation etc) based on the experience of many thousands of patients who have undergone the same procedure in recent years. Health facts that are linked to a high chance of death are given much more weight relative to those that are not. These health facts are known as “risk factors”.
The potential risk is different for every individual procedure. Risk factors for cardiac surgery can be put into 3 groups:
- Factors related to the patient – for example age.
- Factors related to other co-existing medical conditions – for example diabetes, kidney problems or problems in other arteries in the body.
- Factors relating to the nature of the cardiac operation procedure itself – for example, operations performed as an emergency to treat a heart attack in progress are more complex than a planned procedure designed to treat a more stable and predictable problem.
By adding up the weights of each of these risk factors, our medical staff can estimate a patient’s individual risk. By summing the risk in all patients operated on at Liverpool Heart & Chest Hospital we can estimate how many patients we predict may die based on their health histories. Lastly, by summing how many patients actually die and comparing this estimate to our predictions, we can derive a measure of how well our organisation or a particular clinician is performing. The result is a “risk adjusted” estimate of performance.
Risk adjusted estimates are essential in order to really make sense of results. If a hospital published unadjusted outcomes, it would be possible to ensure good results simply by denying procedures to those patients at the highest risk.
Liverpool Heart and Chest Hospital has been deriving risk-adjusted estimates of performance since 1997. We seek to provide the best treatment for all patients and have the experience and skills to deal with the most complex and highest risk cases – it is these latter patients who often have most to gain from the intervention. Risk adjustment allows us to compare the performance of doctors in a fair and rational manner and preserves our capability to offer life-saving treatment to those most in need.