Twenty-Eight Days Later: Emergency Diagnoses Associated With Increased Risk of Readmission, a Retrospective Observational Study of Older Adults

Aims: To describe diagnostic categories and comorbidities associated with increased risk of readmission within 28 days among older adults. Methods: Retrospective observational study of all hospital admissions following ED attendance by patients aged ≥ 60 years between July 2020 and June 2023. Index and subsequent 28-day readmission were identified using ED data and hospital discharge records. ED diagnosis, Australian Refined Diagnosis-Related Group (AR-DRG) discharge codes, and ICD-10-AM comorbidities were extracted. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations with 28-day readmission. The study and findings have been reported against the STROBE-RECORD guideline. Results: Of the 28,730 initial patient visits, 7.9% re-presented within 28 days. The most common ED diagnoses at initial and readmission were chest pain (5.4% vs. 4.6%), falls (5.2% vs. 4.1%), dyspnoea (3.5% vs. 3.1%), abdominal pain (3.1% vs. 3.3%) and cerebrovascular accident (1.7% vs. 1.7%). The most frequent AR-DRGs were respiratory infections/inflammations, kidney and urinary signs/symptoms, and other digestive system disorders. Key ICD-10-AM codes associated with a higher likelihood of readmission within 28 days were obstructive/reflux uropathy (OR 2.66, 95% CI 1.78–3.96), urinary retention (OR 1.84, 95% CI 1.38–2.46), chronic ischaemic heart disease (OR 1.57, 95% CI 1.10–2.25), delirium (OR 1.35, 95% CI 1.07–1.71) and disorders of fluid, electrolyte, and acid–base balance (OR 1.29, 95% CI 1.09–1.54). Conclusion: Nearly 8% of older adults are readmitted within 28 days. Our described approach offers a potential framework to identify at-risk groups and intervene to reduce avoidable representations and/or admissions. Relevance to Clinical Practice: The results reported here create the opportunity for clinicians to identify areas for improvement in clinical practice, care coordination, and service delivery. Our approach and methodology can be replicated in other health services. Patient or Public Contribution: No patient or public contribution.