Associations Between Drug Burden Index and Anticholinergic Risk Scale and the Incidence of Adverse Outcomes in Hospitalized Patients

Objectives:  1. To evaluate the utility of Drug Burden Index (DBI) and Anticholinergic Risk Scale (ARS) scores in measuring the quality of drug therapy. 2. To assess whether higher total DBI and ARS scores were associated with higher incidence of adverse outcomes in hospitalized elderly patients.

Methods:  Retrospective chart review of patients ≥ 65 years of age with initial admission to medical services at our hospital between January 1, 2010 and December 31, 2010. Exclusion criteria included patients with < 4 days of hospital stay and initial admission to surgery, trauma, or ICU service.  Primary outcomes will examine the relationship between drug therapy quality measures (total ARS and DBI scores) and occurrence of fall (F), delirium (D), use of restraint (R), and use of a sitter (S). Secondarily, we will assess the impact of drug therapy quality on length of hospital stay (LOS) and all-cause mortality.

Results:  515 patients were identified for the study. So far, data collected for 54 patients included a mean age of 80 years, 63% women, 26% nursing home residents, and 72% had abnormal baseline cognition. Primary outcomes were D = 10, R = 14, S = 4, D+R = 7, D+S = 4, and D+R+S = 3 patients. Twenty-eight patients had no documented adverse outcomes (mean DBI and ARS were 0.68 and 0.46, respectively) and 26 patients had at least 1 adverse outcome (mean DBI and ARS were 1.66 and 1.46, respectively). Mean LOS was 10 days with 1 all-cause mortality.

Conclusion:  Compared with ARS, the use of DBI seemed to better quantify the amount of medication exposure in our patients. Those patients with at least one or more adverse outcomes were observed to have higher average DBI and ARS scores. The remainder of data collection and analysis is anticipated for completion by the end of March.