Affiliations: [a] Department of Neurology, Danish Dementia Research Centre (DDRC), Rigshospitalet, University of Copenhagen, Copenhagen Ø, Denmark
| [b] National Centre for Register-based Research, Aarhus University, Aarhus V, Denmark
| [c] CIRRAU-Centre for Integrated Register-based Research, Aarhus University, Aarhus, Denmark
| [d] The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
Correspondence:
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Correspondence to: Rachel Underlien Kristensen, Danish Dementia Research Centre, Department of Neurology, The Neuroscience Centre, Rigshospitalet, section 6911, Blegdamsvej 9, 2100 Copenhagen, Denmark. Tel.: +45 3545 8759; E-mail: rachel.underlien.kristensen.01@regionh.dk.
Abstract: Background:Polypharmacy (use of ≥5 different medications) and potentially inappropriate medication (PIM) are well-known risk factors for numerous negative health outcomes. However, the use of polypharmacy and PIM in people with dementia is not well-described. Objective:To examine the prevalence of polypharmacy and PIM in older people with and without dementia in a nationwide population. Methods:Cross-sectional study of the Danish population aged ≥65 in 2014 (n = 1,032,120) based on register data, including information on diagnoses and dispensed prescriptions. Polypharmacy and PIM use among people with (n = 35,476) and without dementia (n = 994,231) were compared, stratified by living situation and adjusted for age, sex, and comorbidity. The red-yellow-green list from the Danish Institute for Rational Pharmacotherapy and the German PRISCUS list were used to define PIM. Results:People with dementia were more frequently exposed to polypharmacy (dementia: 62.6% versus no-dementia: 35.1%, p < 0.001) and likewise PIM (red-yellow-green: 45.0% versus 29.7%, p < 0.001; PRISCUS: 24.4% versus 13.2%, p < 0.001). After adjustments for age, sex, and comorbidity, the likelihood of polypharmacy and PIM was higher for community-dwelling people with dementia than without dementia (odds ratio (OR); [95% confidence interval (CI)] polypharmacy: 1.50 [1.45–1.55]; red-yellow-green: 1.27 [1.23–1.31]; PRISCUS: 1.25 [1.20–1.30]). In contrast, dementia slightly decreased the odds of polypharmacy and PIM in nursing home residents. Conclusion:Use of polypharmacy and PIM were widespread in the older population and more so in people with dementia. This could have negative implications for patient-safety and demonstrates the need for interventions to improve drug therapy in people with dementia.
Keywords: Dementia, inappropriate prescribing, pharmacoepidemiology, polypharmacy, potentially inappropriate medication list
