PIMs and PPO prevalence
At discharge from a geriatric rehabilitation ward, a total of 18,704 medications were prescribed. The most frequently prescribed medications were analgesics (80.9%), cardiovascular medications (72.2%), vitamin D (61.1%) and psychotropics (50.8%) (Appendix I ).
A total of 1856 PIMs and 1368 PPOs (4482 PPOs including vaccines) were identified (Appendix II ). The percentage of patients with at least one PIM was 61.6% on acute admission, 58.8% on admission to geriatric rehabilitation and 54.8% at discharge from geriatric rehabilitation. The percentage of patients with at least one PPO was 91.8% on acute admission, 91.6% on admission to geriatric rehabilitation and 90.8% at discharge from geriatric rehabilitation. However, on excluding vaccine data, patients with at least 1 PPO reduced to 51.9%, 51.4% and 46.3%, respectively. There was a significant change in the prevalence of any PIM use across the care transitions (acute admission, admission to and discharge from geriatric rehabilitation), as was with the use of PPOs but without vaccine data. However, the reduction rate was consistent when the use of any PIMs or PPOs were compared between acute admission and geriatric rehabilitation discharge (Appendix III ).