[Not Available].

Introduction: The increase in health care expenditure threatens the financial sustainability of health systems, and is leading to reforms in hospital use. The length of preoperative stay (POS) depends on the number of interventions and cancellations, but also possibly related to the care process itself (complexity, severity) and the patient (age, sex, comorbidity) with repercussions on the total stay and direct costs. There have been investigations on the length of POS in Spain and its possible relationships with these variables, hospital access (urgent or scheduled) and clinical type (originally medical or surgical).

Materials And Methods: Descriptive and comparative analysis with ANOVA and linear regression of the episodes of the Minimal Data Set 2005 which have resulted in surgery, through variables (relative weight, cost, number of secondary diagnoses and procedures, mortality, stay, age and sex) using SPSS version 15 for Windows, a p<0.05 being established as statistically significant.

Results: The POS averaged 2.92 days, higher in urgent in-patient surgical (5.80) and medical (5.44) procedures, and by age groups and gender was higher in men (7.51) and women (6.31) of 70-74 years with surgical emergencies, but there is a direct link with age in scheduled medical inpatients. There was statistically significant relationship of POS with the length of stay, the relative weight, cost and other variables, all dependent on the severity and complexity.

Conclusions: The POS depends on determining factors such as hospital planning and organization, but also depends on some factors of the process and the patient. Ageing should not cause problems in the emergency surgical in-patient, but must be best managed in the scheduled ones. Adequate management of preoperative studies is essential to reduce the POS, the length of stay and the direct costs of hospitalization.