[The Gini coefficient. A numerical grading for the degree of standardization of surgical subspecialities]

General hospitals are under pressure especially under payment by DRGs (diagnosis related groups), therefore, a general trend for specialized surgical centers is obvious. For this reason knowledge of the level of standardization is important and allows strategical management of surgical subspecialties.

The Gini coefficient (GC, range: 0-1) is a measurement of the level of standardization when an economical ABC analysis is performed. Low GC values are typical for low levels of standardization. All surgical cases coded by ICD-9-CM in 1 of the 8 central operation rooms in a Swiss general teaching hospital over a period of 30 months were included. The database was analyzed by the ABC method. Due to the ABC analysis the GC for each speciality was specified.

In data period 1 a total of 11,573 and in data period 2 3,449 operations done by 7 specialities were evaluated. The GC for the Pareto distribution was 0.86. Neurosurgery had a value of only 0.34, which means that nearly every operation was unique. The highest level of standardization was reached by vascular surgery with a GC of 0.68. Compared with other industries the degree of standardization in our general hospital is low as measured by the GC.

The GC is a valuable and objective measurement of the different procedures and standardization of surgery of given surgical subspecialties. It can be calculated from the operation room management (ORM) database and allows an objective analysis of the variety of surgical procedures per subspecialty. In this study the GC was implicated in an ORM setting for the first time.