[What does the average stay say about the diagnosis-related groups?]

The systems for classifying patients into homogeneous groups of resource consumption such as diagnosis related groups (DRG) use mean stay (MS) as the principal predictive variable of this consumer entity. The standard of MS for each DRG is usually defined as the MS of this DRG in one group of hospitals. This method omits the existence of unnecessary days of hospitalization which are added to the standard and may be identified by review of hospitalary use.

A retrospective review of the clinical need for 933 days of hospitalization (190 days of admission plus 743 successive stays for the same) in 190 cases of 167 DRG (appendicectomy without complications or comorbidity in those under the age of 70 years) in 8 public hospitals in Valencia (Spain) was performed by the Appropriateness Use Evaluation Protocol.

Four days of admission (2.1%) and 284 successive stays (38.2%) were considered unnecessary from a clinical point of view. Necessary MS was estimated as 3.4 days for GRD vs the 5.1 days of MS observed.

The common construction of standards of mean stay per disease demonstrates an important proportion of unnecessary use of hospitalization, the correction of which would allow a reduction in the mean costs of the process without a reduction in the quality of care.