[A multicenter prospective cohort study on risk factors for hospital-acquired pneumonia in the elderly]

To investigate the incidence and the risk factors for hospital-acquired pneumonia (HAP) in the elderly in Shanghai.

This was a multicenter prospective clinical cohort study. A total of 5299 patients more than 65 years old, admitted into 31 secondary or tertiary hospitals in Shanghai, were enrolled. Measurements of the demographic and potential risk factors reflecting illness severity, nutrition, drug exposure, surgery and ventilation were performed. Pneumonia was classified by the definition of Chinese Medical Association. Risk factors were analyzed by univariate Pearson Chi-squared test and multivariable logistic regression analysis with backward (Likelihood ratio).

Of the enrolled patients, 2805 male and 2494 female, 255 (4.81%) developed hospital-acquired pneumonia. The incidence was 46.75/1000 hospitalizations. Among them 38 died; and the rough mortality was 14.90%. The incidence of HAP was higher in ICU (21.43%), hematology (12.17%), chest surgery (11.41%), and respiratory medicine (7.92%) departments. The mean of acute physiology and chronic health evaluation (APACHE II) score was 8.3 +/- 3.4 (5 - 31). Multivariable logistic regression analysis with backward (Wald) method found that admission into secondary hospitals, admission into ICU, history of chronic obstructive pulmonary disease > or = 10 years, immunosuppression, administration of antibiotics, insertion of nasogastric tube, mechanical ventilation, administration of H-2 antagonists or antacid and < or = 7 d, central nervous system diseases, depressed level of consciousness, supine position, albumin < 35 g/L were independent risk factors of HAP in the elderly.

Hospital-acquired pneumonia in the elderly was the usual type of nosocomial infections. The risk factors identified from this study may prove useful to target future clinical interventions to prevent HAP in the elderly.