P438: Is the Drug Burden Index a useful tool for quantifying exposure to anticholinergic and sedative medication? A systematic review

Introduction: Anticholinergic and sedative drugs are likely to increase older people's frailty. The Drug Burden Index (DBI) was developed to quantify total anticholinergic and sedative drug load of patients with polypharmacy. The objective was to systematically review associations between the DBI and clinical outcomes. Methods: A search in PUBMED and MEDLINE databases for publications since the launch of the DBI in 2007 (search term 'drug burden index' [all fields]) resulted in twenty-five publications. Excluding publications that did not report associations between the DBI and clinical outcomes, a publication of which the abstract and results were inconsistent and retrieving a publication from the references of one publication, resulted in 15 eligible publications (Ns 71-3075). Results: A higher DBI was associated with impaired activities of daily living (4 studies), (length of) hospital admission (3 studies), reduced mobility (2 studies), and slower walking speed (5 studies). Associations were equivocal regarding falling (1 positive and 1 negative finding), grip strength (3 positive and 3 negative findings), cognitive function (2 positive and 2 negative findings), and mortality (1 positive and 1 negative finding). Strengths of the studies were the large samples and objective assessment of outcomes. Potential weaknesses were cross sectional design of some studies and DBI measurement error. Conclusions: The associations between the DBI and several negative clinical outcomes support the usefulness of the DBI for quantifying exposure to anticholinergic and sedative medication. However, heterogeneity of findings warrants longitudinal designs, stratified sampling, and refinement of DBI calculation.