In this study, we compared ratings of clinical appropriateness for coronary revascularization between practicing clinicians and members of the AUC Technical Panel. We found there was excellent concordance (94%) between the two groups for clinical indications categorized as appropriate, but only modest concordance (70%) for clinical indications categorized as inappropriate. However, there was wide variation (i.e., non-agreement) in ratings of appropriateness among physicians, with more than 25% of physicians assigning an appropriateness category different from the group as a whole in 2 out of every 3 scenarios. Moreover, there was substantial variation in appropriateness category assignments between individual physicians and the Technical Panel, with some physicians almost never agreeing with the Technical Panel and no physician achieving >80% agreement. Collectively, our findings suggest that, while there is general concordance in ratings of clinical appropriateness between practicing cardiologists and the Technical Panel, there is not uniform agreement between the 2 groups, with markedly different opinions among individual physicians, even after reviewing existing evidence.
An important strength of this study is that the physician ratings were obtained prior to the publication of the ACC’s AUC for Coronary Revascularization in early 2009. This avoided potential contamination of survey results by respondents from the views of the Technical Panel. Importantly, the physician group received similar instructions and access to clinical guidelines for coronary revascularization as the Technical Panel to derive their appropriateness ratings.
Our findings suggest that there was substantial within-group heterogeneity in ratings of appropriateness among the physicians surveyed. More than 1 in 4 physicians rated an indication for coronary revascularization as uncertain or inappropriate for 43% of indications categorized as appropriate by the AUC and rated an indication as uncertain or appropriate for 70% of the inappropriate indications. Notably, physicians’ rates of non-agreement were lower for those indications involving severe CCS Class III-IV angina symptoms and high-risk noninvasive studies for ischemia, where the benefits of coronary revascularization are likely to be greater. Conversely, there was more divergence of opinion in the setting of significant proximal LAD obstruction, suggesting that some clinicians presumably viewed its treatment as life prolonging, while others did not.
The broad range of kappa statistics between individual physicians and the Technical Panel, none of which exceeded 0.76, highlights the variability in current opinions about the roles of coronary revascularization in the care of patients with coronary artery disease. More research and better translation of existing knowledge to clinical practice to clarify the appropriateness of certain clinical indications, especially for those indications where appropriateness was uncertain or where non-agreement existed, is needed. Given this variability in the appropriateness ratings, it is expected that clinicians will vary greatly in their AUC ratings for coronary revascularization. We believe that it will be important to both measure and provide feedback to clinicians about the appropriateness of patients that they treat, while concurrently educating them about the AUC, if more uniform practice is to be achieved.
Our study should be interpreted in the context of the following limitations. Our survey methodology differed somewhat from that of the Technical Panel, as there were not face-to-face meetings to discuss cases for which divergent assessments were made. Second, our survey was conducted among clinical cardiologists from only 10 U.S. institutions, and we did not assess ratings of appropriateness among cardiac surgeons. Third, while our panel was larger and more geographically representative of clinical practices than the Technical Panel, it did not capture all geographical regions of the U.S. Fourth, we did not have sufficient sample size to examine other subgroups of interest nor obtain more detailed data on characteristics of survey respondents.
In conclusion, we found good concordance for ratings of appropriateness for coronary revascularization between a diverse group of cardiologists and the Technical Panel for the AUC for Coronary Revascularization. However, there was substantial variation in ratings of appropriateness between individual physicians and the Technical Panel, as well as non-agreement in appropriateness category assignments among cardiologists for a number of indications. These findings suggest that more research to understand these variations, along with additional education about procedural appropriateness, may help achieve greater uniformity in the appropriate use of coronary revascularization.