Factors associated with unplanned readmissions within 1 day of acute care discharge: a retrospective cohort study

Background: Unplanned hospital readmissions are a quality and safety indicator. In Australian, 8% to 11.1% of unplanned readmissions occur <= 1 day of acute care discharge. The aim of this study was to explore the reasons for unplanned hospital readmissions <= 1 day of acute care discharge, and determine what proportion of such unplanned hospital readmissions were potentially preventable. Methods: A retrospective exploratory cohort design was used to conduct this two phase study. In Phase 1, organisational data from 170 readmissions <= 1 day and 1358 readmissions between 2 and 28 days were compared using the Cochran-Mantel-Haenszel test Binary logistic regression was used to examine factors associated with unplanned readmission <= 1 day. In Phase 2, a medical record audit of 162 Phase 1 readmissions <= 1 day was conducted and descriptive statistics used to summarise the study data. Index discharges occurred between 1 August and 31 December 2015. Results: In Phase 1, unplanned readmissions <= 1 day were more likely in paediatric patients (<0.001); index discharges on weekends (p = 0.006), from short stay unit (SSU) (p < 0.001) or against health professional advice (p = 0.010); or when the readmission was for a Diagnosis Related Group (p < 0.001). The significant predictors of unplanned readmission <= 1 day were index discharge against advice or from SSU, and 1-5 hospital admissions in the 6 months preceding index admission. In Phase 2, 88.3% readmissions were unpreventable and 11.7% were preventable. The median patient age was 57 years and comorbidities were uncommon (3.1%). Most patients (94.4%) lived at home and with others (78.9%). Friday was the most common day of index discharge (17.3%) and Saturday was the most common day of unplanned readmission (19.1%). The majority (94.4%) of readmissions were via the emergency department 58.5% were for a like diagnosis and pain was the most common reason for readmission. Conclusions: Advanced age, significant comorbidities and social isolation did not feature in patients with an unplanned readmission <= 1 day. One quarter of patients were discharged on a Friday or weekend, one quarter of readmissions occurred on a weekend, and pain was the most common reason for readmission raising issues about access to services and weekend discharge planning.