Potentially inappropriate prescribing before and after initiation of medicines for dementia: An Australian population-based study.

AIM: To evaluate the prevalence of potentially inappropriate prescribing (PIP), as defined by the internationally validated Screening Tool of Older Person's Prescriptions (STOPP) criteria, in 12 months before and after initiation of medicines for dementia.

METHODS: A retrospective cohort study was carried out involving people with their first claim for dispensing of medicines for dementia (cholinesterase inhibitor or memantine) between 1 January 2015 and 31 December 2015, aged ≥65 years at 1 January 2016 and alive at the end of 2016. The index date was defined as the date of first supply of medicines for dementia. PIP was identified using the Screening Tool of Older Person's Prescriptions criteria, and PIP prevalence was compared in the 12 months pre- and post-index date. The McNemar's test was used to test differences in the prevalence of PIP between the two time periods.

RESULTS: The cohort included 1176 patients: 60% were women and the median age was 80 years. The overall PIP prevalence was 85% in the 12 months pre-initiation of medicines for dementia compared with 89% in the 12 months post-initiation (P < 0.0001). The median number of Screening Tool of Older Person's Prescriptions criteria was two (interquartile range 1-4) in the 12 months pre-initiation of medicines for dementia, increasing to three (range 2-4) in the 12 months post-initiation.

CONCLUSIONS: PIP was common in people dispensed medicines for dementia, with a significant increase in prevalence post-initiation of medicines for dementia compared with pre-initiation. These results highlight the need for targeted interventions to minimize inappropriate use of medicines in people with dementia. Geriatr Gerontol Int 2019; ••: ••-••.