Measuring improved patient choice

Patient decision support (PDS) tools or decision aids have been developed a s adjuncts to the clinical encounter. Their aim is to support evidence-base d patient choice. Clinical trials of PDS tools have used an array of outcom e measures to determine efficacy, including knowledge, satisfaction, health status and consistency between patient choice and values. This paper propo ses that the correlation between 'subjective expected utility' (SEU) and de cision may be the best primary endpoint for trials. SEU is a measure usuall y used in behavioural decision theory. The paper first describes how decisi on support tools may use decision analysis to structure the presentation of evidence and guide patient decision-making. Uses of expected utility (EU) are suggested for evaluating PDS tools when improving population health sta tus is the objective. SEU is the theoretically better measure when internal consistency of patient choices is the objective.