An Overview of International Staff Time Measurement Validation Studies of the RUG-III Case-mix System.

The RUG-III case-mix system is a method of grouping patients in long-term and post-acute care settings. RUG-III groups patients by relative resource consumption and may be used as the basis for prospective payment systems to ensure that facility reimbursement is commensurate with patient acuity. Since RUG-III's development in 1994, more than a dozen international staff time measurement studies have been published to evaluate the utility of the case-mix system in a variety of diverse health care environments around the world. This overview of the literature summarizes the results of these RUG-III validation studies and compares the performance of the algorithm across countries, patient populations, and health care environments. Limitations of the RUG-III validation literature are discussed for the benefit of health system administrators who are considering implementing RUG-III and next-generation resource utilization group case-mix systems.