Impact of polypharmacy on occurrence of delirium in elderly emergency patients.

Objective: To examine associations between polypharmacy and delirium diagnosed in elderly patients hospitalized in geriatric acute care unit after emergency hospital admission.
Methods: Study design was an observational cohort study in the acute geriatric care unit of a university hospital. We included 410 consecutive patients admitted to the acute geriatric ward during 9 months. Within 72 hours of each patient's hospitalization, a clinically trained geriatrician collected the following data: sociodemographic details (age, sex, type of residence), predisposing factors for delirium, main cause of hospitalization, and current medications. Polypharmacy was defined as 6 or more drugs a day. Delirium was assessed by a geriatrician using the Confusion Assessment Method and was diagnosed on the basis of clinical history with an acute change in usual functional status, behavioral observation, and clinical and cognitive assessment.
Results: Nearly 25% of hospitalized patients had delirium. The Confusion Assessment Method was positive in 69% of patients receiving polypharmacy and in 30% of those not receiving polypharmacy, a relative risk of 2.33. The proportion of elderly patients receiving polypharmacy was 58.53%.
Conclusions: In our study, polypharmacy is an independent risk factor for delirium in a population of elderly patients after emergency admission. In the geriatric population, delirium is an underestimated scourge and because of its medicosocial and economic consequences and its impact on morbidity and mortality, we need to give increased attention to the prevention and control of polypharmacy, which is a predisposing factor for delirium.