Diagnostic entropy as a function of therapeutic benefit/risk ratio.

Current clinical practice is based upon 'out stubborn quest for diagnostic certainty' which in turn is considered as one of the major reasons for ever-increasing health costs. We linked a treatment-threshold concept with classic information theory to show that measurable clinical variables, such as benefit and risk of available treatments, can be used to calculate the acceptable levels of diagnostic uncertainties associated with a particular clinical situation. Our analysis shows that practising physicians should aim for diagnostic certainty only when the benefit of treatment is equal to its associated risk. In all other cases, decisions about treatment do not have to rely on maximum diagnostic certainty. Determination of acceptable levels of diagnostic uncertainty according to the concepts outlined here should lead to improvement of clinical practice and decrease healthcare costs.