Context Expert panels and decision-analytic techniques are increasingly used to determine the appropriateness of medical interventions, but these 2 approaches use different methods to process evidence. Objective To compare expert panel appropriateness ratings of coronary angiography after myocardial infarction (from the time of hospital discharge to 12 weeks after infarction) with the health gains and cost-effectiveness predicted by a decision-analytic model. Design Comparison of the degree of importance of the clinical variables considered in expert panel appropriateness ratings vs a previously published decision-analytic model. Identification of 36 clinical scenarios from the expert panel that could be simulated by the decision-analytic model. Main Outcome Measures Appropriateness score and appropriateness classification (expert panel) vs gain in quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (derision-analytic model). Results The most important clinical variables were similar in the 2 approaches, with the exercise tolerance test result exerting the greatest leverage on strength of recommendation for angiography. Among the expert panel clinical scenarios considered to be appropriate for coronary angiography that could be simulated in the decision-analysis model, the median (interquartile range) health gain and incremental cost-effectiveness ratio were 0.59 (0.41-0.76) QALYs and $27000 ($23 000-$35 000) per QALY gained, respectively. Among the clinical scenarios that expert panels considered inappropriate, the corresponding medians (interquartile ranges) were 0.24 (0.19-0.34) QALYs and $54 000 ($36 000-$58 000) per QALY gained. The Spearman rank correlation between appropriateness score and QALY gain was 0.58 (P<.001) and between appropriateness score and estimated incremental cost-effectiveness ratios was -0.66 (P<.001). Conclusions For the 36 expert panel scenarios that could be simulated by the decision-analytic model, there was moderate to good agreement between the appropriateness score and both the health gain and the incremental cost-effectiveness ratio of coronary angiography compared with no angiography in the convalescent phase of acute myocardial infarction, but several scenarios judged as inappropriate by the expert panel approach had cost-effectiveness ratios comparable with many generally recommended medical interventions. Formal synthesis of expert judgment and decision modeling is warranted in future efforts at guideline development.