The Excess Mortality Risk Associated with Anticholinergic Burden among Older Patients Discharged from Acute Care Hospital with Depressive Symptoms

Background: The relationship between anticholinergic burden and mortality is controversial, and the impact of anticholinergic burden on prognosis may vary in presence of other conditions common in old age. We aimed at investigating the role of depressive symptoms as potential effect modifiers in the association between anticholinergic burden and 1-year mortality in older patients discharged from hospital. Methods: Our series consisted of 576 older patients consecutively admitted to seven geriatric and internal medicine acute care wards in the context of a prospective multicenter observational study. Overall anticholinergic burden was assessed by Anticholinergic Cognitive Burden (ACB) score. Depressive symptoms were assessed by 15-item Geriatric Depression Scale (GDS). The study outcome was all-cause mortality during 12-months follow-up. Statistical analysis was carried out by Cox regression analysis. Results: After adjusting for potential confounders, discharge ACB score = 2 or more was significantly associated with the outcome among patients with GDS > 5 (HR = 3.70; 95%CI = 1.18-11.6), but not among those with GDS <= 5 (HR = 2.32; 95%CI = 0.90-6.24). The association was confirmed among depressed patients after adjusting for ACB score at 3-month follow-up (HR = 3.58; 95%CI = 1.21-10.7), as well as when considering ACB score as a continuous variable (HR = 1.42; 95%CI = 1.10-1.91). The interaction between ACB score at discharge and BADL dependency was statistically significant (p < .005). Conclusions: ACB score at discharge may predict mortality among older patients discharged from acute care hospital carrying high GDS score e. Hospital physician should be aware that prescribing anticholinergic medications in such a vulnerable population may have negative prognostic implications.