THE REPRODUCIBILITY OF A METHOD TO IDENTIFY THE OVERUSE AND UNDERUSE OF MEDICAL PROCEDURES

Background To assess the overuse and underuse of medical procedures, v arious methods have been developed, but their reproducibility has not been evaluated. This study estimates the reproducibility of one common ly used method. Methods We performed a parallel, three-way replication of the RAND-University of California at Los Angeles appropriateness m ethod as applied to two medical procedures, coronary revascularization and hysterectomy. Three nine-member multidisciplinary panels of exper ts were composed for each procedure by stratified random sampling from a list of experts nominated by the relevant specialty societies. Each panel independently rated the same set of clinical scenarios in terms of the appropriateness of the relevant procedure on a risk-benefit sc ale ranging from 1 to 9. Final ratings were used to classify the proce dure in each scenario as necessary or not necessary (to evaluate under use) and inappropriate or not inappropriate (to evaluate overuse). Rep roducibility was measured by overall agreement and by the kappa statis tic. The criteria for underuse and overuse derived from these ratings were then applied to real populations of patients who had undergone co ronary revascularization or hysterectomy. Results The rates of agreeme nt among the three coronary-revascularization panels were 95, 94, and 96 percent for inappropriate-use scenarios and 93, 92, and 92 percent for necessary-use scenarios. Agreement among the three hysterectomy pa nels was 88, 70, and 74 percent for inappropriate-use scenarios. Scena rios involving necessary use of hysterectomy were not assessed. The th ree-way kappa statistic to detect overuse was 0.52 for coronary revasc ularization and 0.51 for hysterectomy. The three-way kappa statistic t o detect underuse of coronary revascularization was 0.83. Application of individual panels' criteria to real populations of patients resulte d in a 100 percent variation in the proportion of cases classified as inappropriate and a 20 percent variation in the proportion of cases cl assified as necessary. Conclusions The appropriateness method is far f rom perfect. Appropriateness criteria may be useful in comparing level s of appropriate procedures among populations but should not by themse lves be used to direct care for individual patients. (N Engl J Med 199 8; 338:1888-95.) (C) 1998, Massachusetts Medical Society.