Polypharmacy and potentially inappropriate prescriptions identified by Beers and STOPP criteria in co-morbid older patients at hospital discharge

Rationale, aims and objectives: The objective of this study was to evaluate the prevalence of potentially inappropriate prescriptions (PIP) and the association with polypharmacy (more than six drugs prescribed) in co-morbid older patients in a critical moment of care transition such as hospital discharge by means of two explicit criteria (Beers 2012 and STOPP 2008).

Method: Cross-sectional study carried out in an older patients' population (≥65 years old) discharged from a university hospital in Spain. We recorded patients' information regarding demographics, diagnosis, drugs prescribed and associated pathological conditions and calculated the Charlson co-morbidity index. Data were obtained from the electronic medical records of hospital discharge. Beers (2012) and STOPP criteria (2008) were applied for PIP detection. The strength of association between polypharmacy and the presence of PIP was assessed by calculating the crude and adjusted odds ratio and its 95% confidence interval.

Results: From 1004 patients of a 15% random sample, just 624 that fulfilled the inclusion criteria were included in the study. The number of prescribed drugs was a risk factor for PIP according to both criteria, even after adjusting for confounding variables. PIP frequency was higher in patients who received more than 12 medications (Beers: 34.8%, STOPP: 54.4%). Each additional medication increased the risk of PIP by 14 or 15% (Beers or STOPP).

Conclusions: Our results suggest that the strategies used for PIP reduction in co-morbid older patients should focus on the management of polypharmacy. Medication review at hospital discharge is highly recommended for patients taking more than six drugs.