Non-acute casemix in the Illawarra

Area of Science:

• Rehabilitation Medicine
• Health Economics
• Inpatient Care Management

Background:

• Acute care diagnosis-related groups present challenges for prospective payment in rehabilitation medicine.
• Developing effective casemix systems is crucial for resource allocation in non-acute inpatient settings.

Purpose of the Study:

• To evaluate the Functional Independence Measure (FIM) and Resource Utilization Group (RUG) system's ability to predict staff time costs in Australian inpatient rehabilitation.
• To inform the development of the National Non-Acute Inpatient Casemix Project.

Main Methods:

• A modified costing study was conducted in a rehabilitation and geriatrics ward.
• Data from 51 patients over 3 months were analyzed.
• The study assessed the predictive validity of FIM and RUG (versions 2 and 3) for staff time costs.

Main Results:

• Staff time costs in Australian rehabilitation varied by functional impairment type and carer burden severity.
• The FIM alone was not a significant predictor of rehabilitation costs.
• RUG 2 did not comprehensively predict costs, and RUG 3 weightings were not suitable for Australian costs.
• Combining functional impairment groups with carer burden measures improved cost prediction.

Conclusions:

• Existing FIM and RUG systems require modification for accurate cost prediction in Australian rehabilitation settings.
• An Australian casemix system incorporating functional capacity and carer burden measures could enhance resource allocation.
• Further development is needed to create a tailored system for Australian rehabilitation services.