Impact of acute infections on the loss of functional independence in hospitalized older adults: a multicentre cohort study

BACKGROUND: The association between infections and the functional independence of hospitalized older adults has not been extensively characterized. The objective of the present study was to evaluate the association between the occurrence of acute infections and loss of functional independence (LFI) in hospitalized older adults, taking into account previously identified risk factors. METHODS: This French multicentre, observational, prospective cohort study (NCT02949635) included patients aged ≥75 years hospitalized in an acute geriatric unit (AGU). Information on the presence of community-acquired or nosocomial infections and the infection site was collected. The patients' functional independence (according to the Katz Index) was assessed one month before admission to hospital, on admission to the AGU, and on discharge from the AGU. A logistic regression model was used to determine the factors associated with LFI, after adjustment for morbidity and geriatric syndromes. FINDINGS: Of the 3076 included patients (mean (standard deviation) age: 86.4 years (5.4)), 772 (23.7%) had a community-acquired infection, and 154 (5.1%) had a nosocomial infection. In a multivariate analysis, the presence of a community-acquired infection significantly increased the risk of LFI between admission and discharge (odds ratio (OR (95% confidence interval (CI): 1.34 (1.06-1.69)), after adjustment for conventional geriatric comorbidities such as cognitive impairment, malnutrition, and overall comorbidity burden. Only the need for walking assistance (OR: 1.39 (95% CI: 1.17-1.67)) and the length of hospital stay (1.01 (95% CI: 1.01-1.02)) were significantly associated with the risk of LFI. CONCLUSION: The risk of LFI was significantly higher in hospitalized older adults with an acute infection. Particular attention must be paid to maintaining these patients' functional independence as soon as an infection is identified.