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Comparison of three Bayesian methods to estimate posttest probability in patients undergoing exercise stress testing

1989; Elsevier BV; Volume: 64; Issue: 18 Linguagem: Inglês

10.1016/0002-9149(89)90863-1

1879-1913

Anthony P. Morise, Robert D. Duval,

Reliability and Agreement in Measurement

To determine whether recent refinements in Bayesian methods have ted to improved diagnostic ability, 3 methods using Bayes' theorem and the independence assumption for estimating posttest probability after exercise stress testing were compared. Each method differed in the number of variables considered in the posttest probability estimate (method A = 5, method B = 6 and method C = 15). Method C is better known as CADENZA. There were 436 patients (250 men and 186 women) who underwent stress testing (135 had concurrent thallium scintigraphy) followed within 2 months by coronary arteriography. Coronary artery disease ([CAD], at least 1 vessel with ≥50% diameter narrowing) was seen in 169 (38%). Mean pretest probabilities using each method were not different. However, the mean posttest probabilities for CADENZA were significantly greater than those for method A or B (p < 0.0001). Each decile of posttest probability was compared to the actual prevalence of CAD in that decile. At posttest probabilities ≤20%, there was underestimation of CAD. However, at posttest probabilities ≥60%, there was overestimation of CAD by all methods, especially CADENZA. Comparison of sensitivity and specificity at every fifth percentile of posttest probability revealed that CADENZA was significantly more sensitive and less specific than methods A and B. Therefore, at lower probability thresholds, CADENZA was a better screening method. However, methods A or B still had merit as a means to confirm higher probabilities generated by CADENZA (especially ≥60%). These results may have an impact on how these methods are used in clinical decision making.