Discounting and risk characteristics in clinical decision-making.

Time-related aspects have attracted an increasing interest in medical decisions. Health promotion often works toward remote goals, and many clinical judgments and decisions include an exchange of costs today for benefits in the future. The concept of diminishing value over time is positive discounting when the benefits occur so far in the future that they seem of little value relative to the immediate cost. If there is a preference to live for the present rather than save for the future, such a preference might not contribute to good health according to a lower discount rate. As discounting is related to risk an analysis of uncertainty is required being an unavoidable condition in health work. Shared decision-making between doctor and patient has increasingly been emphasized, where risk characteristics and time-related aspects should be taken into account to reach a decision based upon mutual agreement. The framework of time and risk for analysis can perform a useful role in clinical judgments and decisions, where framing of different features of risk might diminish discounting and increase compliance to treatment. A summary of valuation factors in medical decision making is presented: (a) long-term decisions are sensitive to discount rates; (b) discount rates vary by domain, by outcome, by individuals and by level of certainty; (c) probability discounting is used if the risk is perceived as controllable; (d) the doctor uses expected value, the patient is risk aversive; (e) asymmetric discounting for patients and doctors gives poor compliance; (f) discount rates are influenced by framing.