Longitudinal Analysis of Drug Burden Index

Anticholinergic and sedative drugs are frequently prescribed to older people, despite their negative impact on older people's physical and cognitive function. To estimate the cumulative exposure to anticholinergic and sedative drugs, Hilmer et al. published the Drug Burden Index (DBI) in 2007. The present study aims to complement previous study findings showing higher DBI values to be associated with physical and cognitive impairment. Most previously conducted studies of the DBI were either cross-sectional or were longitudinal but with short follow-ups. Furthermore, it remains unknown whether higher DBI values carry extra risks for patients with dementia. Finally, relatively little is known about the stability of DBI values over time. The current project therefore aims to examine (1) longitudinal relationships between long-term cumulative exposure to anticholinergic and sedative drugs as measured with the DBI and cognitive and physical function, (2) to examine interaction effects between DBI exposure and dementia, and (3) to examine trajectories of DBI exposure, i.e. DBI exposure remaining stable, declining, increasing or fluctuating over time. These project aims will be studied with longitudinal data from eligible participants > 60 years from the LASA study with participants being followed-up during two decades, and the longitudinal data from the InterRAI consortium. Various clinical outcomes regarding cognitive and physical function will be studied. Data will be analysed with generalised linear mixed models and Latent Class Growth Analysis.