Analysis of patient-related factors associated with post-discharge adverse events in older patients quickly discharged home after emergency department care with no complementary investigations

Background: To investigate factors associated with post-discharge adverse events in older patients discharged after emergency department (ED) care with no complementary investigations (CI)-blood test (BT), X-ray (XR) or both. Methods: We included patients >= 65 years who attended 52 Spanish EDs and were discharged home in <= 12 hours from 01-07 April 2019. The outcomes assessed were post-discharge combined adverse event (CAE) (all-cause ED revisit, hospitalization or death) occurring within the next 30 days. We analyzed whether age, sex, comorbidity, functional capacity, ability to walk, previous falls, dementia, depression and polypharmacy were associated with outcomes, and whether these outcomes differed compared to discharged patients undergoing CI. Results: We identified 4976 patients (mean time in ED: 1.44 hours, 95% confidence interval (CI): 1.41-1.47) and 1048 (21.4%) presented a CAE, associated with increased comorbidity, decreased functional capacity and polypharmacy but not with age. Compared with patients discharged after CI and spending 3.08 (3.05-3.11) hours in the ED, the CAE of patients without CI did not significantly differ (1208 cases, 22.2%, adjusted Hazard ratio (HR): 1.032, 95% CI: 0.949-1.122). Performing BT and XR increased ED time by 2.07 (1.59-2.15) and 0.35 (0.31-0.40) hours, respectively, while the increase when ordering both investigations was 2.23 (2.17-2.31) hours. Conclusions: ED discharge of older patients without CI does not increase risk of post-discharge events or shorten the time in ED. Age is not related to the risk of post-discharge adverse events, but comorbid and dependent patients with polypharmacy should be cautiously considered for being at increased risk of adverse outcomes.