[Method to calculate the additional hospital stay in patients with cross infection]. / Estimación de la estancia adicional en pacientes con infección hospitalaria.

OBJECTIVE: To calculate additional hospital stay due to specific cross infection. METHODS: Cases and controls study; matched by age +/- 2 years, sex, specialty in which were taken care, diagnosis, surgical procedure and hospitalization stay, between July 2005-June 2006. ANALYSIS: t test, chi(2) to calculate death risk, Kaplan-Meier analysis to calculate survival, Hosmer-Lemeshow test to know the contribution of cross infection for additional hospital stay due to cross infection (AHSDCI). RESULTS: We identified 851 patients with 1347 cross infection in 16 528 discharges. We could match 677. The cases stayed 25.42 days and the controls 13.29 (p < 0.01). The death risk for the cases was 5.8 (CI 95 % = 3.7-8.6, p < 0.01), four weeks survival 55.3 % for cases and 79.2 % for the controls. The AHSDCI for pneumonia was 10.39 days, urinary-tract-infection 6.28, bacteremia 8.92, vascular-catheter-related infection 3.31, surgical site infections 7.42, and skin and soft-tissue-infection 3.31 (p < 0.05). CONCLUSIONS: We used a multivariate model fitted to patient's gravity and complexity to extract the proportion days of AHSDCI of each cross infection.

[Nosocomial infections in a high specialty hospital. Factors associated to mortality in the infected patient]. / Infecciones nosocomiales en un hospital de alta especialidad. Factores asociados a mortalidad.

INTRODUCTION: Nosocomial infections (NIs) are a quality indicator of health care centers. However, a decrement of NIs occurrence can be the cause of an effective prevention program or it could be the result of a poor NI case research. The patient's characteristics and the complexity of his/her ailment are related to a higher risk of mortality. OBJECTIVE: The study was made to estimate the NIs prevalence, to know the NIs etiology, and to analyze the factors that determine the NI patient's death. MATERIAL AND METHODS: All hospitalized patients from January to December 2003 were included in the study. NI was defined as that which has its origin at the hospital. The risk factors of a patient with NI were analyzed in order to explain the death of the infected patient; we also studied the etiology of NIs. STATISTICAL ANALYSIS: Simple frequencies, Mann and Whitney U, chi2, and the exact Fishertestwere used. Taking the risk factors of the patient with NIs and the kind of NI, a multivariate analysis was made to explain the infected patient's death. RESULTS: During the study time, 4.2 % of 17189 patients acquired one or more nosocomial infection; the prevalence was of 7.02 and the incidence was of 8.4 cases per 1000 days-patient. The main infections found were pneumonia, urinary tract infection, and bloodstream infection. Besides, 359 microorganisms were isolated; Eschrerichia coli (15.88 %), Staphylococcus aureus (15.88 %), and Pseudomonas aeruginosa (11.8 %) were the most common ones. The specialties with higher risk of contracting NIs were Haematology, OR 3.65 (CI 95 % 2.99-4.46); Internal Medicine, OR 2.49 (CI 95 % 2.01-3.1); Neurology, OR 2.49 (CI 95 % 1.96-3.16); and Intensive Care Unit, OR 2.14 (CI 95 % 1.61-2.83). CONCLUSION: Immunosupression, ventilator use, tracheotomy, advanced age, chronic-degenerative disease, pneumonia and bloodstream infection contributed to a fatal outcome in patients with NI.