Regret graphs, diagnostic uncertainty and Youden's Index.

摘要: Regret is the difference in outcome between action we took and best could, retrospect, have taken. ‘Tent graphs’, representing decision problems under uncertainty terms of expected regret, offer an instructive geometric supplement to standard formulae, allow instant calculations, suggest, as shall illustrate, novel algebraic properties. For instance, problem finding pre-test probability range which it worthwhile doing a diagnostic test becomes trivial, even when costs depend on unknown disease status; take opportunity explore (non-trivial) properties this problem. The graphs also provide simple way illustrate read off value information perfect information. This property used derive clinical interpretation Youden's Index (sensitivity+specificity−1), namely, maximum proportional reduction regret achieved by test. Finally, examine relationship area ROC curve.