Decision Analysis
User's Guides to the Medical Literature
Evidence-Based Medicine Working Group

Are the Results Valid?
Were all important strategies and outcomes included?
Was an explicit and sensible process used to assemble the evidence into probabilities?
Were the utilities obtained in an explicit and sensible way from credible sources?
Was the impact of uncertainty in evidence explored?

What Are the Results?
Does one strategy yield a clinically important gain for patients? If not, is the result a 'toss-up'?
How strong is the evidence used in the analysis?
Could uncertainty in the evidence change the results?

Will the Results Help Me in My Patient Care?
Do the probabilities fit my patients' clinical features?
Do the utilities reflect my patients' values?

JAMA 1995; 273:1292-1295
JAMA 1995; 273:1610-1613

Decision Analysis:
a systematic, explicit, and quantitative approach to analyzing decisions under conditions of uncertainty the systematic articulation of common sense

A Decision Node (square) depicts a decision between two or more strategies.

A Decision Strategy (line from square) is a sequence of actions that are contingent on each other.

A Chance Node (circle) depicts possible occurrences along a pathway not controlled by the decision maker.

An Outcome Node (rectangle or triangle) depicts the final health state resulting from a pathway.

A Probability is the likelihood of an event's occurrence, expressed in decimals on a scale from 0 (impossible) to 1.0 (certain).

A Utility is a measure of the value of an outcome to the decision maker, expressed on different scales.

The Expected Utility for each chance node is the sum of the products of each probability times its utility.

A Sensitivity Analysis is the systematic exploration of the impact of uncertainty in the evidence used upon the stability of the analytic conclusions.