Purpose: The aims of the present study were to evaluate the use of drugs with anticholinergic properties in elderly patients and to identify risk factors that increase the patient's chance of being given such medications.

Methods: The study was performed on a sample of 1636 patients aged 65 years or older hospitalised during the period between 1 Jan 2008 and 31 Dec 2009 in three municipal hospitals in Slovakia.  To evaluate the factors influencing the use of anticholinergic medications, we compared two groups - users and non-users of such drugs - in terms of sociodemographic and clinical characteristics as well as comorbid conditions.  The most important risk factors were identified using the binary logistic regression model.

Results: Hospitalisation led to a significant increase in the prevalence of anticholinergic medication users, when comparing their occurrence at the time of hospital admission and discharge (10.5% and 14.2%, respectively; p less than 0.001).  A significantly higher total number of prescribed drugs were found in the group of users compared with non-users, at both hospital admission (7.2 +/- 3.5 vs 5.7 +/- 3.1; p less than 0.001) and discharge (8.7 +/- 3.1 vs 7.5 +/- 2.9; p less than 0.001).  Immobilisation, urinary incontinence and retention, constipation, gastroduodenal ulcer disease as well as neurological and psychiatric comorbidities (depression, Parkinson's disease, epilepsy) appeared as the most important risk factors for using anticholinergic medications.

Conclusions: Physicians should be aware of the greater risk of adverse anticholinergic effects of drugs in certain therapeutic classes in the elderly.  In patients with risk factors mentioned previously, special attention should be paid to active identification of anticholinergic effects of medications.