Annual incidence and risk factors for nosocomial bacterial infections in an acute care geriatric unit.

Purpose. - Elderly inpatients are particularly exposed to the risk of nosocomial infections, thus the study of their risk factors and consequences is of interest. Methods. - Among 1,565 subjects referred to a short-term geriatric unit, patients hospitalised for a year for an acute event and unable to move themselves were followed up for the occurrence of nosocomial infections. Results. - Among these 402 immobilised patients (age: 86.3 +/- 7.6 years), 102 nosocomial infections occurred in 91 patients (22.6%), whereas the estimation of the incidence in the total hospitalised population (1,565 subjects, age: 85.1 +/- 6.2 years) was 9.4% (95% confidence interval[CI] 8.3-11.2). Forty-seven point seven percent of nosocomial infections were urinary tract nosocomial infections, 27.5% were lower respiratory nosocomial infections, 9.2% were cutaneous nosocomial infections, 7.3% were septicaemia and 8.2% were of unknown origin. The relative risk (RR) of NI linked to functional dependency for mobility was 5.5 (95% Cl: 3.93-7.7, P < 0.001). Other risk factors were: for all nosocomial infections: cancer diagnosis (RR 1.1, 95% Cl: 1.1-1.2, P = 0.01); and respectively for urinary tract NI: bladder indwelling (RR 4.8, 95% Cl: 2.9-7.7, P < 0.001), pulmonary NI: swallowing disorders (RR 5.4, 95% CI:2.8-10.5, P < 0.001); and septicaemia: venous catheter (RR 5.4, 95% Cl: 1.3-23.3, P = 0.002). NI were associated with an increased length of stay (22.1 +/- 11.7 days in infected patients vs 16.3 9.5 days in immobilised non-infected subjects, P < 0.001). The mean length of stay for the 1,565 subjects was 10.3 +/- 7.6 days. Death was attributed to nosocomial infections in 13 subjects. In conclusion, functional dependency for mobility bladder indwelling, venous catheter, swallowing disorders and diagnosis of cancer were risk factors for nosocomial infections in hospitalised elderly subjects in an acute-care setting. (C) 2001 Editions scientifiques et medicales Elsevier SAS.