Background: Older persons are often subjected to polypharmacy. There is a large degree of variability in the definitions used, the underlying data sources and the medications included. Our aim was to analyse the influence of different definitions on the prevalence of polypharmacy.
Methods: We used data of the study "Inappropriate Medication in patients with REnal insufficiency in Nursing homes" (IMREN) conducted in nursing homes in Bremen and the surrounding area. Anonymised data were collected by nursing staff. Prescription drugs and over-the-counter drugs as well as scheduled and as-needed medications were assessed.
Results: 852 residents from 21 nursing homes were recruited (mean age: 83.5 years; 76.5% female). Each resident received an average of 8.8 scheduled and as-needed medications, the prevalence of polypharmacy (≥5 medications) was 83.5%. When including scheduled medications only, residents received an average of 6.3 medications (polypharmacy 69.7%). When restricting the analysis to prescription-only medicines, the results were comparable (6.3 medications per resident; polypharmacy 69.1%). However, the two analyses included different drugs. A total of 74.3% received at least one over-the-counter drug as scheduled medication (59.7% on an as-needed basis).
Conclusions: In studies investigating polypharmacy, the methods used should be reported in a transparent manner. This is particularly important when addressing the question of which drugs were included in the study.
Keywords: Arzneimitteltherapie; Health services research; Pflegeheim; Polypharmazie; Querschnittsstudie; Versorgungsforschung; cross-sectional study; nursing home; pharmacotherapy; polypharmacy.
Copyright © 2016. Published by Elsevier GmbH.