Association between hospital admission either directly or via the emergency department, and readmission rates at 30 days in older adults in two rural hospitals: a retrospective cohort study

Introduction Older patients are frequently re-admitted to the hospital after attending the emergency department (ED). We investigated whether direct admission to the hospital was associated with a lower risk of readmission at 30 days compared to admission via the ED, in patients aged ≥ 75 years. Methods Retrospective multicenter cohort study from 01/01/2018 to 31/12/2019, including patients aged ≥ 75 years from two hospitals. Patients admitted directly were matched 1:1 with patients admitted via the ED for center, age category, sex, major diagnosis category, type of stay (medical/surgical), and severity. We compared readmission at 30 days (primary outcome) and length of stay (secondary outcome) between groups. Results A total of 1486 matched patients with an available outcome measure were included for analysis. We observed no significant difference in 30-day readmission rate between those admitted directly (102/778, 13.1%) and those admitted via the ED (87/708, 12.3%, p = 0.63). There was a significant difference in length of stay between both groups: median 5 days [Q1–Q3: 2–8] vs 6 days [2–11] for direct and ED admissions, respectively (effect size: 0.11, p < 0.001). By multivariate analysis, only moderate to severe denutrition was associated with the risk of readmission at 30 days (Odds Ratio 2.133, 95% Confidence Interval 1.309–3.475). Conclusion The mode of entry to the hospital of patients aged 75 years and older was not associated with the risk of readmission at 30 days. However, those admitted directly had a significantly shorter length of stay than those admitted via the ED.