LAUSR

Background The use of potentially inappropriate medications (PIMs) are associated with negative health effects for older adults. The purpose of this study was to apply national register data to investigate the impact of hospitalisation to geriatric wards in Norway on the use of medications and PIMs, and to compare two explicit PIM identification tools. Methods We included 715 patients ≥65 years (mean 82.5, SD = 7.8) admitted to Norwegian geriatric wards in 2013 identified from The Norwegian Patient Registry, and collected their medication use from the Norwegian Prescription Database. Medication use before and after hospitalisation was compared and screened for PIMs applying a subset of the European Union (EU)(7)-PIM list and the Norwegian General Practice – Nursing Home (NORGEP-NH) list part A and B. Results The mean number of medications increased from 6.5 (SD = 3.5) before to 7.5 (SD = 3.5) (CI:1.2–0.8, p  < 0.001) after hospitalisation. The proportion of patients with PIMs increased from before to after hospitalisation according to the EU(7)-PIM list (from 62.4 to 69.2%, p  < 0.001), but not according to The NORGEP-NH list (from 49.9 to 50.6%, p  = 0.73). The EU(7)-PIM list and the NORGEP-NH list had more than 70% agreement on the classification of patients as PIM users. Conclusions Medication use increased after hospitalisation to geriatric wards. We did not find that geriatric hospital care leads to a general improvement in PIM use after hospitalisation. According to a subset of the EU(7)-PIM list, PIM use increased after hospitalisation. This increase was not identified by the NORGEP-NH list part A and B. It is feasible to use health register data to investigate the impact of hospitalisation to geriatric wards on medication use and PIMs.