A decision tree with probabilities and utilities. This sample decision tree outlines strategies of medical versus surgical treatment—below-knee amputation
(BKA) for a particular disease. The decision node (open square) represents the decision itself. All of the possible outcomes for each decision alternative
are listed emanating from an open circle or chance node. The events are governed by chance. The series of events leading to the clinical outcomes is
represented by a series of chance nodes and decision nodes. Terminal nodes (triangles) denote the outcomes. Probabilities and utilities are listed. For
example, if one chooses antibiotics, there is a 10% chance of cure, whereas if one chooses surgery, there is a 95% chance of cure. However, although
surgery has a higher cure rate, one is left with an amputation. Having a BKA has lower utility (eg, 0.75) compared with antibiotic treatment (eg, 0.9). The
Source: Chapter 3. Evidence-Based Endocrinology and Clinical Epidemiology, Greenspan’s Basic & Clinical Endocrinology, 9e
predicted outcome is (0.1 × 0.9) + (0.9 × 0.5) or 0.54 for antibiotics vs (0.95 × 0.74) + (0.05 × 0) or 0.71 for surgery. This indicates that on the average,
Citation:
Gardner DG, Shoback D. Greenspan’s Basic & Clinical Endocrinology, 9e; 2011 Available at: http://mhmedical.com/ Accessed: July 28,
surgery is a better
choice.
2017
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