Case-Mix Adjustment in the Optum Achievements in Clinical Excellence Facility

As part of this effort, called the Achievements in Clinical Excellence (ACE) Facility program, Optum assigns facilities within its network to “tiers” based on their performance on quality measures. Optum offers additional services to facilities in the highest tier and gives those in lower tiers support to improve their performance.

Ensuring that quality measures accurately compare performance can be challenging, because facilities serve populations with different characteristics. To partially account for the differences between facilities, the ACE Facility program uses case-mix adjustment, statistical procedures to control for differences when comparing nonequivalent groups, for key characteristics that vary between facilities, including patient characteristics such as age, sex, diagnosis, and certain aspects of individual patients’ treatment.

Mathematica is reviewing the program’s case-mix adjustment methods. Our team examined program documentation and data, interviewed Optum staff, and reviewed the literature on case-mix adjustment methods. This review revealed that the case-mix adjustment strategy for the ACE program generally follows widely accepted principles that have been applied in medical and behavioral health care A white paper reviews the findings and includes recommendations for refining the methodology.