Set of standard performance measurements developed in 1989, 1993, and 1995 by the National Committee for Quality Assurance. It helps consumers, corporations, employers, and public purchasers of health care compare and determine the quality and value of managed care plans. HEDIS standardizes how health plans examine and report data including: quality of access to care, patient satisfaction, preventive medicine, membership and utilization, finance, and descriptive data on health plan management.