Association Between Drug Burden Index and Functional and Cognitive Function in Patients with Multimorbidity

Background: Anticholinergic and sedative drugs are associated with adverse events such as cognitive and functional impairment in elderly. The Drug Burden Index (DBI) is a measure of an individual's total exposure to anticholinergic and sedative drugs. Objetive: The study aimed to evaluate the association between the total DBI and cognitive and functional impairment in patients with multimorbidity. Setting: Patients with multimorbidity enrolled in the IMPACTO project. Methods: Cross-sectional observational study. Main outcome measure: The anticholinergic and sedative exposure was calculated using DBI. The Pfeiffer Test (PT) was used for cognitive status and the Barthel Index (BI) for functional status. Results: 336 patients were included (mean age 77.6 ± 8.7 years, 54.2% men and a mean of 11.5 ± 3.7 prescribed drugs). 180 patients (53.6%) exposed to anticholinergic and/or sedative drugs were identified. The median score obtained in PT was slightly higher in exposed patients (1 (IQR 0-2) and 2 (IQR 0-4), p = 0.082 in "non-exposed" and "exposed", respectively). The bivariate analysis showed an association [0.544 (95% CI 0.044-1.063, p = 0.03)]. The median obtained in the BI analysis was 85.0 (IQR 30.0) and 75.5 (IQR 42.5) p = 0.002, in "nonexposed" and "exposed", respectively. After the adjusted analysis, a relationship was obtained between both the variables [-9,558 (95% CI-15,794; -3,321, p = 0.03)]. Conclusion: Higher DBI is associated with the impairment of functional status and, slightly to the deterioration of cognitive function in patients with multimorbidity. DBI should be considered in patients with multimorbidity to optimize the pharmacological treatment of a group of special interest due to its vulnerability.