Short Info: What are DRGs?

The abbreviation DRG signifies «Diagnosis Related Groups».1 DRG systems are medico-economical patient classification systems. In acute hospitals, they allow for classification of hospital stays into a limited number of clinically defined groups with costs of treatment as similar as possible.

A DRG system consists of a list of individual DRGs which are labelled and codeable case groups. DRGs are defined by grouping criteria in a comprehensive framework of rules. Specific figures and prices can be attributed to each DRG.

To create DRG lists, list of diagnoses have been usually roughly structured and aggregated by groups of physicians. The fine-tuning was then elaborated often based on statistical analyses of cost data. (Because in the early days of the development of DRGs almost no cost data was available, length of stay was used as a proxy for cost.)

The development of DRG systems started in the late 70s in the United States. One of the framework conditions was that only data routinely collected was admissible. At that time, the discharge data set in US hospitals contained the following clinical data: [Table 1]

• principal and secondary medical diagnoses
• surgical and diagnostic procedures
• age and sex of patients

This data – together with the birth weight of newborns, which was later added – has ever since been the backbone of grouping criteria in DRG systems worldwide.

Such information made it possible to define a part of the products rendered by hospitals. While the first DRGs had been originally defined as part of a quality control project, they soon came to reflect the money value of treatments, and were used in price lists. 1983, "Medicare" of United States was the first insurance provider to use DRGs as a basis for reimbursement of hospital stays.