Objective: The aims of the present study were to: analyse the prevalence of polypharmacy in a group of older patients; evaluate the influence of hospital stay on the number of drugs taken; assess the most frequently prescribed pharmacological classes; identify risk factors that predisposed the patient to polypharmacy. Setting The study was carried out in the Department of Internal Medicine of a non-university general hospital.
Method: In the retrospective study, 600 patients aged 65 years or more were enrolled. They were hospitalised in the period from 1st December 2003 to 31st March 2005. Each person taking six or more medications per day was considered to be a patient with polypharmacy. Particular sociodemographic and clinical characteristics, as well as comorbid conditions, were evaluated as factors potentially influencing the prevalence of polypharmacy.
Main outcome measure: The number and type of medications taken at the time of hospital admission and discharge were recorded and compared for each patient.
Results: Polypharmacy on admission and at discharge was observed in 362 (60.3%) and 374 (62.3%) patients, respectively. Hospitalisation led to a significant increase in the number of medications. The spectrum of medications used corresponded to the proportions of diagnoses in the evaluated group, in which cardiovascular diseases were most prevalent. According to the multivariate analysis using a logistic regression model, diabetes mellitus (odds ratio (OR) 2.40; 95% confidence interval (CI): 1.64-3.50), heart failure (OR 2.14; 95% CI: 1.46-3.14), dementia (OR 2.12; 95% CI: 1.26-3.57), living alone (OR 2.00; 95% CI: 1.28-3.10), arterial hypertension (OR 1.63; 95% CI: 1.08-2.44) and cerebrovascular disease (OR 1.58; 95% CI: 1.03-2.44) significantly increased the risk of the presence of polypharmacy.
Conclusion: Our study confirmed a relatively high prevalence of polypharmacy in Slovak elderly patients. Polypharmacy risk rose especially with the increased prevalence of diseases of advancing age (diabetes mellitus, heart failure, arterial hypertension, dementia and cerebrovascular diseases). The increasing numbers of medications in inpatients indicate the need for the careful re-evaluation of pharmacotherapy during the stay in hospital.