CORONARY ANGIOGRAPHY AND REVASCULARIZATION - DEFINING PROCEDURAL INDICATIONS THROUGH FORMAL GROUP PROCESSES

OBJECTIVES: To summarize the process and extent of interphysician agre ement within two panels convened to derive indications for the appropr iate use of coronary angiography and for coronary revascularization pr ocedures. PARTICIPANTS: Two panels, each with nine practitioners. METH ODS: Panelists rated the appropriateness of intervention for a compreh ensive set of indications for each procedure. Indications were brief p rofiles created by combining and permuting clinical characteristics pe rtinent to case selection for intervention. Ratings were first made at home, with a second round at the panel meeting following open discuss ion. Final rankings of indications as 'appropriate', 'uncertain' or 'i nappropriate' were based on the pattern of panelists' responses on a n ine-point scale, including the median rating and extent of agreement a mong panelists. Agreement was defined as at least seven panelists' rat ings within the three-point region containing the median rating. Panel ists were later mailed a much-reduced list of indications for which th ere was agreement on appropriateness. These were rerated on a necessit y scale. A procedure was rated 'necessary' only if a physician was eth ically obligated to recommend it as the preferred treatment option. RE SULTS: For appropriateness of angiography, agreement occurred in 38.2% of indications in round 1 and 64.4% in round 2 (P<0.0001). For corona ry artery bypass graft (CABG) versus medical therapy, the correspondin g increase was from 43.5 to 54.0% (P<0.0001). Agreement on necessity o f angiography occurred for 44.3% of scenarios. For indications where C ABG alone was appropriate, agreement on necessity was 56%. However, fo r indications where percutaneous transluminal coronary angioplasty (PT CA) could be regarded as the first-line intervention, agreement on nec essity was only 5%. CONCLUSIONS: A two-step panel process permitted co nsiderable convergence of panelists' ratings, highlighting the importa nce of formal panel methods in setting utilization management criteria . However, the extent of continuing disagreement on ratings underscore s the need to avoid a forced consensus; instead, divergent opinions sh ould be taken as indicative of uncertainty about the appropriateness o f intervention. Interpanelist agreement on necessity ratings was modes t, but may help in setting benchmarks to assess possible underprovisio n of invasive cardiac services in Canada.