Casemix for inpatient care of elderly people: Rehabilitation and post-acute care

Background: defining contracts for the care of elderly people on the basis of the number of episodes is inappropriate as it fails to take account of the wide variation in their physical disability and rehabilitation needs. Resource use on a day-to-day basis can be estimated for patients using the Resource Utilization Groups version III (RUG-III) casemix system. For practical use, RUG-III assessments cannot be made daily and so assessments at different time intervals were evaluated in order to give an indication of resource use for an inpatient stay. This study describes how RUG-III assessments can be used to give an indication of resource use for an inpatient episode. Method and results: RUG-III assessments were completed for all admissions to elderly care rehabilitation wards in two Health Districts over a 10 week period. There were 336 patients and 965 RUG-III assessments. The average time required to make RUG-III assessments fell from 10 to 4 min by the end of the study period. Fortnightly assessment intervals including a discharge assessment correlated well with the average of weekly assessments (R-2 = 0.88-0.91, P < 0.0001). Conclusion: using the results from these assessments we propose a model for use of the RUG-III system in contracts for rehabilitation and post-acute care of elderly people which addresses the difficulty of combining clinical characteristics, rehabilitation, resource use and length of stag into a single useful meaningful casemix system.