Diagnosis Related Groups

Diagnosis-related group (DRG) is a system to classify hospital cases into one of originally 467 groups, with the last group (coded as 470 through v24, 999 thereafter) being "Ungroupable". This system of classification was developed as a collaborative project by Robert B Fetter, PhD, of the Yale School of Management, and John D. Thompson, MPH, of the Yale School of Public Health. The system is also referred to as "the DRGs", and its intent was to identify the "products" that a hospital provides. One example of a "product" is an appendectomy. The system was developed in anticipation of convincing Congress to use it for reimbursement, to replace "cost based" reimbursement that had been used up to that point. DRGs are assigned by a "grouper" program based on ICD (International Classification of Diseases) diagnoses, procedures, age, sex, discharge status, and the presence of complications or comorbidities. DRGs have been used in the US since 1982 to determine how much Medicare pays the hospital for each "product", since patients within each category are clinically similar and are expected to use the same level of hospital resources. DRGs may be further grouped into Major Diagnostic Categories (MDCs). DRGs are also standard practice for establishing reimbursements for other Medicare related reimbursements such as to home healthcare providers.

The original objective of diagnosis related groups (DRG) was to develop a classification system that identified the "products" that the patient received. Since the introduction of DRGs in the early 1980s, the healthcare industry has evolved and developed an increased demand for a patient classification system that can serve its original objective at a higher level of sophistication and precision. To meet those evolving needs, the objective of the DRG system had to expand in scope. Today, there are several different DRG systems that have been developed in the US. They include:

The system was created in the early 1970s by Robert Barclay Fetter and John D. Thompson at Yale University with the material support of the former Health Care Financing Administration (HCFA), now called the Centers for Medicare & Medicaid Services (CMS).

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