Delirium in elderly patients hospitalized in internal medicine wards

A prospective observational study was conducted to evaluate the impact of delirium on geriatric inpatients in internal medical wards and to identify predisposing factors for the development of delirium. The study included all patients aged 65 years and older, who were consecutively admitted to the internal medicine wards of two public hospitals in Florence, Italy. On admission, 29 baseline risk factors were examined, cognitive impairment was evaluated by Short Portable Mental Status Questionnaire, and prevalent delirium cases were diagnosed by Confusion Assessment Method (CAM). Enrolled patients were evaluated daily with CAM to detect incident delirium cases. Among the 560 included patients, 19 (3 %) had delirium on admission (prevalent) and 44 (8 %) developed delirium during hospitalization (incident). Prevalent delirium cases were excluded from the statistical analysis. Incident delirium was associated with increased length of hospital stay (p < 0.01) and institutionalization (p < 0.01, OR 3.026). Multivariate analysis found that cognitive impairment on admission (p < 0.0002), diabetes (p < 0.05, OR 1.936), chronic kidney failure (p < 0.05, OR 2.078) and male gender (p < 0.05, OR 2.178) was significantly associated with the development of delirium during hospitalization. Results show that delirium impact is relevant to older patients hospitalized in internal medicine wards. The present study confirms cognitive impairment as a risk factor for incident delirium. The cognitive evaluation proved to be an important instrument to improve identification of patients at high risk for delirium. In this context, our study may contribute to improve application of preventive strategies.