Characteristics and outcomes of emergency interhospital transfers from subacute to acute care for clinical deterioration

Objective: To describe characteristics and outcomes of emergency interhospital transfers from subacute to acute hospital care and develop an internally validated predictive model to identify features associated with high risk of emergency interhospital transfer. Design: Prospective case-time-control study. Setting: Acute and subacute healthcare facilities from five health services in Victoria, Australia. Participants: Cases were patients with an emergency interhospital transfer from subacute to acute hospital care. For every case, two inpatients from the same subacute care ward on the same day of emergency transfer were randomly selected as controls. Admission episode was the unit of measurement and data were collected prospectively. Main outcome measures: Patient and admission characteristics, transfer characteristics and outcomes (cases), serious adverse events and mortality. Results: Data were collected for 603 transfers in 557 patients and 1160 control patients. Cases were significantly more likely to be male, born in a non-English speaking country, have lower functional independence, more frequent vital sign assessments and experience a serious adverse event during first acute care or subacute care admissions. When adjusted for health service, cases had significantly higher inpatient mortality, were more likely to have unplanned intensive care unit admissions and rapid response team calls during their entire hospital admission. Conclusions: Patients who require an emergency interhospital transfer from subacute to acute hospital care have hospital admission rates and in-hospital mortality. Clinical instability during the first acute care admission (serious adverse events or increased surveillance) may prompt reassessment of patient suitability for movement to a separate subacute care hospital.