Adverse drug events in hospitalized elderly in a Geriatric medicine unit: Study of prevalence and risk factors

Introduction. - In the elderly, both the presence of a multiple pathology and multiple medication have been shown to be frequent risk factors for adverse drug events. However, a few studies only have included parameters of standardized geriatric assessment for the purpose of identifying other risk factors. Our study compared the parameters of standard geriatric assessment, in the presence or absence of adverse drug events and evaluated the prevalence of adverse drug events in elderly inpatients, the symptoms, and the drugs involved. Methods. - A total of 823 patients were studied during a two-year period. Two groups of patients were identified, according to the presence or absence of an adverse drug event. Eight fields of geriatric assessment were compared: comorbidities, number of drugs, functional status, nutritional status, mobility, mood, neurosensory disorders, and cognition. For patients who experienced an adverse drug event, we also analyzed the drugs involved and the symptoms of the adverse drug events. Results. - One hundred and twelve patients (13.6%) aged 82 years +/- 7.5 experienced 144 adverse drug events. Significant differences between the two groups were observed in the following: symptoms of depression, problems of mobility, risk of malnutrition (respectively p = 0.001, p = 0.002, p = 0.007), the female sex, number of drugs, number of comorbidities, and the administration of diuretics. Cardiovascular (23.2%), psychotropic (17.9%) and anti-infectious (17%) medicines were the most frequently involved. The symptoms that occurred most frequently were orthostatic hypotension (14.6%), gastrointestinal disorders (12.5%), and neuropsychological (10.4%) disorders. Conclusion. - Elderly patients with multiple pathology and multiple medication are at high risk for adverse drug events. Other lesser known factors, such as depression, problems of mobility, and malnutrition must be researched, as they are evidence of the underlying the frailty of the elderly population. (C) 2009 Published by Elsevier Masson SAS on behalf of the Societe nationale francaise de medecine interne (SNFMI).