Evidence-based medicine integrates clinical experience with patients' values and the best available evidence.1 In the past, clinicians took responsibility not only for being well informed about the benefits and harms of medical options but also for judging their value in the best interests of the patients. More recently, a shared decision making approach has been advocated in which patients are recognised as the best experts for judging values. Evidence-based decision aids are being developed and evaluated to supplement clinicians' counselling regarding values and sensitive options so that patients can understand the probable consequences of options, consider the value they place on the consequences, and participate actively with their clinician in selecting the best option for them. This editorial provides a brief overview of patient decision aids by defining them, identifying situations when they may be needed, describing their efficacy, and discussing practical issues in using them in clinical practice. Decision aids help patients to participate with their practitioners in making deliberative, personalised choices among healthcare options. The key elements of decision aids have been described by the Cochrane Collaboration2 as ### INFORMATION TAILORED TO THE PATIENT'S HEALTH STATUS Information is provided on the condition, disease, or developmental transition stimulating the decision; the healthcare options available; the outcomes of options, including how they affect patient functioning; and the probabilities associated with outcomes. ### VALUES CLASSIFICATION Values clarification exercises are used to explicitly consider and communicate the personal importance of each benefit or harm by using such strategies as balance scales, relevance charts, or trade off techniques. ### EXAMPLES OF OTHER PATIENTS Patients often like to learn from others who have faced the same situation, and aids can give a balanced illustration of how others deliberate about options and arrive at decisions based on their personal situation. ### GUIDANCE OR COACHING IN SHARED DECISION MAKING Skills and confidence in participating in decision making are developed …