Potentially Inappropriate Prescribing among People with Dementia in Primary Care: A Retrospective Cross-Sectional Study Using the Enhanced Prescribing Database

Background: Little is known about prescribing appropriateness for community-dwelling people with dementia (PWD). Objective: To estimate potentially inappropriate prescribing (PIP) prevalence among PWD in primary care in Northern Ireland, and to investigate associations between PIP, polypharmacy, age, and gender. Methods: A retrospective cross-sectional study was conducted, using data from the Enhanced Prescribing Database. Patients were eligible if a medicine indicated for dementia management was dispensed to them during 1 January 2013-31 December 2013. Polypharmacy was indicated by use of ≥4 repeat medications from different drug groups. A subset of the Screening Tool of Older Persons Potentially Inappropriate Prescriptions (STOPP) criteria, comprising 36 indicators, was applied to the dataset. Overall prevalence of PIP and the prevalence per each STOPP criterion was calculated as a proportion of all eligible persons in the dataset. Logistic regression was used to investigate associations between PIP, polypharmacy, age, and gender. Results: The study population comprised 6826 patients. Polypharmacy was observed in 81.5 (n=5564) of patients. PIP prevalence during the study period was 64.4 (95 CI 63.2- 65.5; n=4393). The most common instance of PIP was the use of anticholinergic/antimuscarinic medications (25.2; 95 CI 24.2-26.2; n=1718). In multivariable analyses, both polypharmacy and gender (being female) were associated with PIP, with odds ratios of 7.6 (95 CI 6.6-8.7) and 1.3 (95 CI 1.2-1.4), respectively. No association was observed between PIP and age, after adjustments for gender and polypharmacy. Conclusion: This study identified a high prevalence of PIP in community-dwelling PWD. Future interventions may need to focus on certain therapeutic categories and polypharmacy.