Risk Factors For Mortality From Infectious Diseases Among Elderly From Long-Term Care Facilities

摘要

Background: The purpose of this study was to analyze risk factors for mortality in elderly residents who had acquired infections in long-term care facilities (LTCF) and were transferred to an acute care hospital.Methods: A retrospective medical record review was conducted in Okinawa Chubu Hospital, a 550-bed community teaching hospital in Okinawa, Japan. Study population included elderly LTCF residents in central Okinawa with signs or symptoms suggestive of infectious diseases or referred with probable infections that were transferred to an acute care hospital from 1995 to 1999. The medical records were reviewed and data were analyzed by stepwise logistic regression.Results: Two hundred patients (median age, 83 years) with diagnosis of infections were evaluated during the 5-year study period. Overall, 23 patients (11.5%) died. Independent predictors of mortality were lower respiratory tract infection, history of hip fracture, systolic blood pressure less than 100 mmHg, and serum creatinine greater than 1.5mg/dl. Conclusions: Our findings could help physicians identify elderly LTCF residents with infectious diseases that pose high risk for mortality and provide prognostic information for patients and caregivers. Strict evaluation for infectious focus is important since lower respiratory tract infection has worse prognosis. Introduction Infectious diseases are important causes of hospitalization and mortality in residents of long-term care facilities [1,2,3]. Previous reports of elderly residents of LTCF focused on incidence and risk factors of general infectious diseases including minor febrile episodes [4,5,6]. Since most patients with those febrile episodes recover rapidly and many needed no specific treatment, special attention should be given to patients with severe diseases who require admissions to acute care hospitals and are therefore potentially high-risk groups for mortality. However, few studies investigating such a specific group of patients have been reported. There is also no report from an Asian country where elderly individuals make up a greater proportion of the population than North America.The aims of this study were to (1) determine the in-hospital mortality rate of hospitalized patients 65 years of age or older who were transferred from long-term care facilities with the admission diagnosis of an infectious disease, and (2) to identify the independent risk factors for mortality. Material and Methods Participants A computerized registration of initial diagnosis was used to identify all patients who had been transferred from long term care facilities for treatment of infectious diseases or presented with a chief complaint of fever or documentation of probable infections in reference letters to Okinawa Chubu Hospital, Okinawa, Japan, a 550-bed community teaching hospital. The division of general internal medicine reviewed the medical records of all identified patients for inclusion in this study. The principal outcome was in-hospital mortality attributed to infectious diseases. The institutional review board of Okinawa Chubu Hospital approved the study. Informed consent for utilizing the individual patient medical record in this study was obtained from the designated surrogate decision makers (i.e., health care agent or next of kin). Data CollectionDetailed baseline demographic and clinical data were obtained at admission for each patient by physicians and nurses in the facilities. Potential risk factors for in-hospital mortality that were evaluated included age, gender, past medical history [7], types of infection [8], dependency of basic Activities of Daily Living (ADL) [9], tube feeding [10], urinary catheterization [11], nasal colonization of methicillin-resistant staphylococcus aureus [12], and the presence of decubitus ulcer. Functional status was assessed using the ADL index of Katz and colleagues [13]. Dependency of basic ADL was defined for the purposes of this study as an ADL score of 4 or 5 (depende