Background: The drug burden index (DBI) is an evidence-based tool that utilizes pharmacologic principles to calculate an individual's total exposure to anticholinergic and sedative medications. Higher DBI has been associated with functional impairment in observational studies of older people.
Objective: To assess the impact of providing information about DBI to general practitioners (GPs) on prescribing for older people.
Methods: This was a cluster randomized controlled trial with 3 months of follow-up. Participants were volunteers aged ≥70 years, living in self-care retirement villages in Sydney, Australia. The study intervention involved a letter and phone call to GPs, using DBI to prompt them to consider cessation or dose reduction of anticholinergic and sedative medications. The primary study outcome was to assess the impact of information about DBI on prescribing practices of the GPs.
Results: A total of 115 participants were enrolled, 57 in the intervention group (from 6 sites) and 58 in the control group (from 6 sites). At baseline, 19 of 57 participants in the intervention group and 31 of 58 participants in the control group had a DBI >0 (p < 0.05). At follow-up, a DBI change was observed in 16 participants. DBI decreased in 12 participants, 6 (32%) in the intervention group, and 6 (19%) in the control group. GPs identified the following barriers to reducing anticholinergic and sedative drugs: uncomfortable altering prescriptions initiated by specialists; unable to influence patients' attitudes; unaware of patients' medications and strong clinical indication.
Conclusions: The intervention targeting GPs' prescribing practices was less effective than anticipated in reducing anticholinergic and sedative drug exposure, and barriers were identified. Future studies should explore multidisciplinary interventions, engaging patients, specialists, GPs, and pharmacists.