Association between polypharmacy and dementia in older people: A population-based case-control study in Taiwan

Aim: The aim of the present study was to investigate whether polypharmacy correlates with the risk of dementia in older people. Methods: From representative claims data established from the National Health Insurance with a population coverage rate of 99% in Taiwan, we identified 7135 newly diagnosed patients with dementia in 2000–2008 and 2 8540 randomly selected controls without dementia, both aged ≥65 years. The daily use of prescribed drugs in the past 2 years was compared between cases and controls, controlling for demographic characters and comorbidities. Results: The incidence of dementia increased with the number of medications used and age. Cases were older than controls, predominant with women and more likely to use five or more drugs daily (44.0% vs 32.0%, P