Medicare Peer Review Organization preprocedure review criteria. An analysis of criteria for three procedures The Medicare Peer Review Organization (PRO) program includes preprocedure review using explicit criteria to assess the appropriateness of specific procedures. This study evaluates the variability in the PRO preprocedure criteria for the three procedures most frequently reviewed by PROs: carotid endarterectomy, cataract removal, and cardiac pacemaker implants. In August 1989, the PRO review criteria were received from the Health Care Financing Administration. To provide a reference point for reviewing the PRO criteria, national practice guidelines for these three procedures were identified. Wide variability was demonstrated in the PRO procedure-specific carotid endarterectomy and cataract removal review criteria among PROs, and the criteria differed significantly from the identified practice guidelines. The criteria for cardiac pacemaker implants were somewhat less variable, and were based, to varying degrees, on practice guidelines developed by the American College of Cardiology (ACC). Greater attention is needed to improve the development of review criteria, including the use of relevant practice guidelines, to ensure that review criteria are optimal. 