Composite Risk Scores

Abstract

The following chapter will discuss the history and clinical utility of several different composite risk models. Composite risk models are used to combine the various known risk factors and translate them into a more easily interpretable risk value. The Framingham Risk Algorithm is among the oldest and most widely used risk scores for cardiovascular disease, and over the years, new cardiovascular disease risk algorithms, such as the Reynolds Risk Score and the Pooled Cohort Equations, have been developed. However, the applicability of these scores to ethnically and socioeconomically diverse populations has been questioned. As well, several lifetime cardiovascular disease models have been developed, but the clinical utility of assessing lifetime cardiovascular risk is still debated. Furthermore, different health organizations have developed several criteria for the metabolic syndrome, yet the clinical utility of the metabolic syndrome is still debated. In recent years, staging systems for obesity and cardiometabolic health have been developed to guide medical treatment, though due to their novelty, there is limited research on their effectiveness. However, for a given risk score, there are still individual differences in actual risk score, termed residual risk. This means that even if a patient achieves target levels of metabolic risk factors, some may still experience a cardiac event even if their predicted risk is low. This residual cardiovascular risk that is not accounted for by the risk models is true for all algorithms but can be reduced by adopting a healthy lifestyle or improving other important factors not accounted for by the algorithm. Finally, risk assessment is only valuable if the patient understands what that risk means, and therefore optimal risk communication between health professional and patient is vital for improving patient care. This review will describe the development and clinical utility of the Framingham Risk Score, the Reynolds Risk Score, the Pooled Cohort Equations, lifetime risk scores, the metabolic syndrome, the Edmonton Obesity Staging System, and the Cardiometabolic Disease Staging System. Residual cardiovascular risk and patient communication will also be discussed.