Casemix and information systems

Casemix refers to a mix of patients classified in some way. It describes a system which groups patients by predetermined factors into clinically meaningful and resource homogenous groups to describe the hospital or health service product (a measure of output). A number of patient classification (casemix) systems have been developed for various purposes. The casemix system used by Australian acute care hospitals to define their ‘products’ is the Australian National Diagnosis Related Groups (AN-DRGS). Similarly patients may be grouped to represent homogeneity in terms of nursing resource usage. Such classification systems are therefore ‘nursing casemix systems’ and are used to describe the nursing department’s products which are components of the hospital products. Other departments may also use a system to classify their patient services on the basis of resource usage in order to identify other product component costs.