Relationship between drug burden and physical and cognitive functions in a sample of nursing home patients with dementia

PURPOSE: The Drug Burden Index (DBI) is a tool to quantify the anticholinergic and sedative load of drugs. Establishing functional correlates of the DBI could optimize drug prescribing in patients with dementia. In this cross-sectional study, we determined the relationship between DBI and cognitive and physical functions in a sample of patients with dementia. METHODS: Using performance-based tests, we measured physical and cognitive functions in 140 nursing home patients aged over 70 with all-cause dementia. We also determined anticholinergic DBI (AChDBI) and sedative DBI (SDBI) separately and in combination as total drug burden (TDB). RESULTS: Nearly one half of patients (48%) used at least one DBI-contributing drug. In 33% of the patients, drug burden was moderate (0 < TDB < 1) whereas in 15%, drug burden was high (TDB ≥ 1). Multivariate models yielded no associations between TDB, AChDBI, and SDBI, and physical or cognitive function (all p > 0.05). CONCLUSIONS: A lack of association between drug burden and physical or cognitive function in this sample of patients with dementia could imply that drug prescribing is more optimal for patients with dementia compared with healthy older populations. However, such an interpretation of the data warrants scrutiny as several dementia-related factors may confound the results of the study. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00228-017-2319-y) contains supplementary material, which is available to authorized users.