With increasing pressure on healthcare systems, hospitals frequently face bed shortages, requiring patient admissions outside clinically appropriate wards—so-called overflow beds. While efforts are made to place patients in the most suitable available wards, concerns persist regarding the potential impact of overflow beds on patient safety. Despite these concerns, safety implications are not explicitly considered in clinical decision-making during capacity shortages due to a lack of clear evidence.
This study investigated the extent to which patient exposure to overflow beds influences mortality risk. Adopting a data-analysis and statistical prediction modelling approach, hospital capacity, patient characteristics, and safety data were analysed in three phases: (1) identifying clinically relevant exposure patterns, (2) quantifying and predicting the impact on mortality using predictive models, and (3) evaluating the clinical applicability of findings for decision-making.
These findings highlighted increased mortality risks based on three risk dimensions: general exposure, location, and duration in assessing overflow bed risks. The results revealed a significant association between overflow bed exposure and increased mortality risk. Patients placed in overflow beds had a relative 65% higher odds of mortality than those not exposed. In addition, specific risks were identified for mismatched ward placements, with increased mortality risks for patients placed in overflow bed locations din different types of wards than their intended clinically appropriate ward. Short exposure durations (<34 hours) were also linked to higher odds of mortality.
To translate these insights into clinical practice, risk-based guidelines were developed based on common patient parameters at hospital admission (age, comorbidities, and place of origin). Heat maps visually indicate which patients can be relatively safely placed in overflow beds and which should be avoided, enabling hospital staff to make more informed decisions.
These findings should raise awareness among hospitals and staff of the increased mortality risks when capacity constraints require admissions outside clinically appropriate wards. It is recommended that hospitals initiate discussions across the entire organisation - medical, nursing and support staff - about the identified safety risks, and integrate the implications of the research into future policies and guidelines. This will contribute to a more risk-informed, proactive and explicit consideration of safety in hospital capacity decisions, ultimately leading to a more efficient and, above all, safer approach to managing overflow beds in times of increasing healthcare pressures.