A reader's guide to surgical decision analysis.
BACKGROUND
Studies using decision analysis appear increasingly often in the surgical literature. Because readers and reviewers may be unfamiliar with decision analysis, we review the technique and provide guidance on its interpretation.


METHODS
Review article.


RESULTS
Decision analysis is a systematic approach to structuring a decision, collecting relevant information about the probability and relative value of outcomes, and making quantitative recommendations. Decision analysis includes the following basic components: (1) the decision model, (2) the probabilities of clinical outcomes in the model, (3) the utilities of clinical outcomes, and (4) the analysis and interpretation. To critically interpret the results of a decision analysis, readers must consider the validity of each component. The model should include all relevant clinical strategies and all important clinical outcomes. Probability estimates, whether derived from published studies or based on "clinical consensus," should be in general agreement with the reader's clinical experience. Utilities (values assigned to outcomes) are often expressed in terms of quality-adjusted life expectancy. Methods used to estimate life expectancy and to adjust for quality of life must be scrutinized carefully. Within the analysis, readers should consider the effect of varying uncertain variables in the model (sensitivity analysis) and, thus, the stability of the results. Finally, readers must assess whether the magnitude of expected benefit from the favored clinical strategy is clinically important.


CONCLUSIONS
As decision analysis becomes more frequently used to influence clinical policy in surgery, surgeons must learn to examine the technique more critically.
Birkmeyer
J D
JD
Department of Veterans Affairs Medical Center, White River Junction, Vt 05001, USA.
Welch
H G
HG
D003661:Decision Support Techniques; D013502:General Surgery; D006801:Humans; D008390:Markov Chains; D008962:Models, Theoretical; D019057:Quality-Adjusted Life Years