Ambulatory care groupings: when, how, and the impact on managed care

This article explores case-mix adjustment systems in the ambulatory care environment as applied by managed care firms. An overview of ambulatory care groupings or ambulatory case-mix systems is given, and the special case-mix adjustment needs of managed care companies are reviewed. Generally, two types of ambulatory care grouping systems are available: encounter-based and population-based. Case examples of three managed care companies that are currently investigating the use of population-based case-mix systems are used to demonstrate the possible use of such systems in the managed care environment such as physician profiling and capitation rate setting.