Case-mix involves patient classification as a tool to improve financial and clinical management in a clinical facility.
The term case-mix refers to the type or mix of patients treated by a hospital or unit. The term is often used to describe the billing system of the hospital or unit, since the "cost per item" of health care is based on the case-mix.

Case-mix measurement is a system that measures hospital performance, aiming to reward initiatives that increase efficiency in hospitals. Case-mix also serves as an information tool that allows policy makers to understand the nature and complexity of health care delivery.
Diagnosis-related groups (DRGs) is the best-known classification system that is used in the case-mix funding model. It classifies acute inpatient episodes into a number of manageable categories based on clinical condition and resource consumption — the DRG is a group of similar clinical conditions that consume similar amount and type of resources.
A single acute episode of inpatient care is allocated to one DRG using coded clinical information derived from the patient’s medical record. This information is coded by health information managers in order to allocate a DRG. Each DRG is allocated a ‘weight,’ which is dependent on the average cost of inputs (e.g., nursing, diagnostic services, procedures) required to achieve the appropriate patient outcome. The facility is reimbursed a predetermined amount for each patient episode.

Uses
• clinical management
• allocation of funds
• planning of services
• monitoring and quality improvement
• comparison of activities between different clinical facilities

This system is increasingly being implemented by many countries worldwide.

Adapted from Wikipedia, the free encyclopedia. Internet. Accessed on January 18, 2016.