Risk factors for 30-day readmission in general medical patients admitted from the emergency department: a single centre study

Background: Overcrowding in emergency departments (ED) around the world is an increasingly serious problem with an adverse impact on both patient flow and patient outcomes. A significant contributing factor to ED overcrowding is possibly due to readmission. Risk factors for readmission in patients admitted from ED are rarely studied, particularly in Asian countries where the length of stay is reportedly longer. Methods: A retrospective study of patients admitted to general medical wards from the ED of a referral centre in northern Taiwan from November 2009 to April 2010 was conducted. The primary outcome was 30-day hospital readmission and clinical characteristics were analysed for predictors of readmission. Results: Of the recruited 2698 patients, 451 (16.7%) were readmitted within 30 days after discharge. Age, gender, marital status and the activities of daily living (Barthel's score) were not associated with 30-day readmission. Higher Charlson score ((score 24) hazard ratio (HR): 1.42, 95% confidence interval (CI): 1.071.89; (score >4) HR: 1.93, 95% CI: 1.372.73), longer hospital stay ((814 days) HR: 1.51, 95% CI: 1.171.95; (1528 days) HR: 1.64, 95% CI: 1.222.19; (>28 days) HR: 1.97, 95% CI: 1.432.71), and presence of underlying active malignancy (HR: 1.66, 95% CI: 1.272.16) and anaemia (HR: 1.26, 95% CI: 1.021.55) were independently associated with readmission. Conclusion: Medical patients admitted from the ED of a referral centre have a 30-day readmission rate of 16.7%. Post-discharge care should focus on patients with higher Charlson score, longer hospitalisation, anaemia and underlying active malignancy, which are independent predictive factors for 30-day readmission.