The nursing home case-mix classification system, Resource Utilization Groups Version III (RUG-III), has been tested and refined for long-term home care clients. The study sample included 804 individuals seeking home care through the Michigan Care Management Program or the Home and Community Based Waiver for the Elderly and Disabled. Clients were classified, and RUG-III models were derived using the Minimum Data Set for Home Care (MDS-HC). A refined home care model, RUG-III/HC, was developed incorporating Instrumental Activities of Daily Living (IADLs) to the nursing home RUG-III classification. The model explained 33.7 per cent of the variance of per diem cost, using cost weighted formal and informal care as the dependent variable. Resource use within groups was relatively homogeneous. The case-mix index (CMI) of weighted formal and informal care time spanned an eight-fold range. Further analysis is suggested regarding the inclusion of informal care as a cost in case-mix classification for long-term home care clients.
