Short-term hospitalisation of older patients in the Emergency Department and early readmission: A case- control study

Background This study sought to identify risk factors associated with early 30-day readmissions in older patients following short-term primary admission discharged from an Emergency Department (ED). Methods This was a case-control study, and the prescription database and hospital records were scrutinised for data on demography, marital status, disability, Charlson comorbidity index (CCI), and systemic prescription drugs. Patients included were aged ≥ 70 years, had a primary hospitalisation of < 48 hours, discharged from the ED, and readmission within 30 days. Exclusion criteria were readmission for specialised treatment and multi-trauma. Data covered a 12-month period at Aalborg University Hospital, Denmark. Results Among 2,343 patients aged ≥ 70 years with short-term hospitalisation, 266 (11.4%) were readmitted within 30 days, and nearly half during the first week and one third with similar diagnosis. Fifty patients were excluded leading to comparison of 216 (9.2%) readmitted and 216 matched controls. Polypharmacy (≥ 8 drugs), CCI, disability and marital status differed markedly between patients with early readmission within 30 days. The odds ratio for early readmission was 4.3 (95%-CI: 1.4–17) for systemic prescription drugs ≥ 8; 2.0 (95%-CI: 1.3-3.0) for CCI ≥ 2; 1.8 (95%-CI: 1.1–2.8) for unwed status; 1.6 (95%-CI: 1.0-2.5) for disability. Conclusion Among older patients discharged from the ED within 48 hours, around 10% had an early readmission. Four factors were associated with the raised risk of early readmission, and one in three had similar diagnosis at discharge and readmission. These findings may guide the attending physician’s focus during primary admission to identify risk factors leading to early readmission.